SJ-Astronomy Imaging SIG Meetings, 20 Jul 2021

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From YouTube: SJAA Imaging 7/20/21: 3D Printing for Astrophotography

Description

Glenn Newell, Paolo Barettoni and Jo Herz will each spend 10-minutes giving their perspectives on 3-D printing, perhaps showing off their productions, followed by a general discussion on the topic.

A

So welcome to the uh imaging sig meeting and uh tonight uh we're gonna talk about 3d printing. I wanted to talk about the format a little bit we're going to have three presenters. I've asked them to talk 10 minutes I'll, interrupt them at 15 minutes, but you know shoot for 10 minutes kind of thing and um I'd say we do this without questions have sort of three presentations like that for a half hour to 45 minutes and then we'd have another half hour or so of uh interaction.

A

Where folks can ask questions, make statements do whatever you'd like um and we'll try to end it like in an hour and a quarter hour and a half sort of in the timely way I sort of wanted to give a shot at a fixed time limit for these meetings. So that's my plan, um welcoming everyone.

A

And I guess that's about all I wanted to say so joe you about ready to get started. We got, it seems like we have a quorum now, so our three speakers are uh joe paolo and glenn and uh I assume in that order, so take it away joe.

B

Okay, uh so yeah thanks uh um hi for inviting me and for um for hosting me, that's uh really a new one for me to actually speak in uh california today.

B

So um hi, uh I told told you already it's given us uh a very limited time, so I called this here a futile attempt of an elevator pitch because he's given us about as much time as it takes jeff bezos to go into the stratosphere and then come back down again.

B

So what I want to tell you about 3d, printing first of all is a little bit of an introduction on overview for people who have not used the 3d printer before so. This is basically my setup. It is one of the uh cheapest ones you can have, but also one of the most versatile ones called the ender three uh and what you can see uh here is this: uh that's the 3d printer, that's the printhead in here, a spool with the thermoplastic material.

B

I've got the pi 4 in the back to keep to have a little camera in here to keep an eye on the printing process. I can also record it and that's really all there is to it. So the 3d printer is really not much else, but the clunky inkjet printer.

B

The only difference is that it's not using ink, but it's using thermoplastic material, which you can weld, which is welding together to form a three-dimensional object and both operate on the same principle. The 3d printer also uses stacking software to create a 3d image and that's not unlike what picks inside the deep sky, stacker also doing with individual image frames, but in reverse.

B

So basically, if you've ever used an inkjet printer and if you're using pics inside the keepsky stacker, you already have all um the ingredients in place to productively use the 3d printer as well. So 3d printers are incredibly versatile and I cannot understand really how I could ever live without one. I'm going to give you a little bit of an overview on that, and you can talk about that later. So supporting the astrophotography hobby is really only one small application.

B

3D printers are good for asking more during the discussion session about this, and the best thing also that I don't want to forget to mention is all the basic software. You need to run your 3d printer is open source and it's free, so you're not really really risking a lot. The printer, I showed you costs about 200 and that's all it takes you to get into uh into this hobby and start printing whatever you like, not just escrow here. So this here is an image of one object, for instance the pattern of mask.

B

So this is images created in software called slicer, and that is the software which prepares the data to be sent to the 3d printer. So um pretty much the same thing as what you would have in the print menu- and this here is one one of the things which I've printed is a case for a pi 4. lots of these things. You can actually download directly from the internet, so you don't have to design them themselves.

B

There is a fantastic place called thingiverse and various others. There are all sorts of uh 3d. uh Printable objects are deposited. You just download the files for this this one. Here I have modified, so it actually fits my purposes. I cut in some extra opening and so forth to make it more accessible and to mount it on my rig okay. So this is another object which I'm going to show you shortly. uh This is a frame uh for a asi um 1600. The camera would fit in here.

B

My little guide scope would fit in up there, and here I've got a rail where I can mount my auto focus and I'm going to show you the pictures of those in a second. uh This is what this looks like. um What I just showed. You is another action, so I used uh 3d printed this file, which I designed on the computer using freecad, very simple uh software, not more complicated, really than photoshop.

B

So if any of you can operate photoshop or illustrator, you can also operate 3d printing software- it's not any harder than that, and you clamp. I clamp in here I decided, so I can clamp in my asi 1600.

B

Here's 135 millimeter lens mounted to the asi 1600.

B

I put this gear ring around it, so that I can connect it to my auto focuser here and that is just driven by a small toy analog motor which then is controlled by uh the ecos uh highest already told you probably a lot about ecos and uh the software package entails and a driver called fc usb. So I can autofocus with this here a standard 135 nikkor camera lens, which I got on amazon for fifty dollars uh attached to an asi 1600, and that gives you a a very nice pictures of night sky.

B

So this is what I actually took with this about the year and a half ago, so obviously the orion region with the horse head and that picture was taken with the isi 1600 mm and the 135 millimeter. I think it was a 135 millimeter lens, and uh this manually this uh this auto focuser, which I just uh showed you 3d printed so um all just put together from some really basic pieces. You could also do the same thing with a dslr and a regular dslr lens. So this is and then next step up.

B

I wanted to use that same 3d printed system here, in which I uh again is on auto focuser, but I've now adapted it to a white cat very similar, basically same design as a space cat or a red cat from william optics and, as you know, that's a helical focuser. So I had to clamp this gear ring here around it.

B

I put an extension in so I have a bit of a higher leverage and I used the larger motor which I put onto the rail, because this helical focuser here has more resistance in the small motor, wasn't really cutting it, but this is still an analog motor.

B

The next step up area- and here uh here is this: um the holder for the pi 4, which I printed a holder for the fc usb for a powered usb hub, and all of this here is mounted together and clamped to the leg of my tripod for a cm 25.

B

Then I wanted to get a little bit more sophisticated wanted to get away from the analog motors. For my auto focuses, and so I uh changed that and use basically the same design again but now to mount a stepper motor uh to this. This is uh the setup same. uh The same 25, uh this rail here stepper motor is there drives uh that gear attached to the helical focus of the william optics white cat, okay. So this here is again another piece which has 3d printed the case uh for uh the electronics for the autofocus.

B

So what you're, seeing down there underneath all those wires, is simply a little board with a an arduino on top of it you're seeing this the cpu unity of the arduino right there- and here is the stepper motor driver on the software for this, as well as the design, is also freely available. So the entire setup here, including the thermal thermoprobe, so you get refocusing when the temperature shifts by more than a predetermined amount of degrees, in my case, 2 degrees centigrade.

B

The entire set up here has cost me about 20 25, to put together.

B

This is uh the setup and in action at night, um with everywhere, you can see now everything the 3d printed uh holder for the pi 4 uh for the uh ssd, which is stuck into the sleeve back here.

B

The powered usb hub then a an adapter to put the polar alignment, the polemaster mounted onto the tunnel, the 3d printed autofocus up here and the white cap telescope.

B

So almost all almost everything holding just a rig here together, has been a 3d printer, okay. So now, then next I wanted to adapt that to my um ed 102, explore scientific 102 so that um for that I didn't have an auto focuser. Yet so I printed the new um autofocus or control unit, but now I needed to have a new frame um to drive uh the focus on that 102, and this is a picture which you see now from the bottom of that.

B

So I designed the clamp basically which just uh which I can just screw onto clamp around the base of the telescope between the focuser gears and so there's nothing which is actually screwed onto the telescope. So this is just a pure clamp um construction uh and uh put some gears uh in here. The stepper motor is here driving this little gear, which contrives a large gear which is attached directly to the fine focus knob. So I didn't have to take the fine focus knob off the uh the shaft.

B

This is just stuck on and held in place with three screws which are um threaded through the 3d printed uh gear. Here um now you wonder probably what the spring here is so turns out that the crayford focuser in the ed102 has a tendency for slipping, and that would be the same actually with a commercial focuser as well.

B

So I use this spring here in order to take weight off the filter, wheel and the camera, so the focuser doesn't uh uh slip uh when uh the telescope is pointing straight up, and so the uh the spring really just helps supports uh the bait of uh the filter, wheel and the telescope, and this entire setup here really works very well. So this is a screenshot here from uh ecos control panel. I assume that hai has already told you all about the software package down here.

B

You can see- uh and he actually designed this surface here and down here. Is you see the the recurve of the focuser and the focus which I just showed? You hits the absolute minimum of the v-curve every time you can see here, the yellow spot, so extremely reliable, uh all from self-designed 3d printed pieces. So this uh works really well and now you're wondering probably well and now I'm environmentally conscious. I don't want to waste a lot of plastic and contribute uh to the environmental disaster we're already living in well.

B

I've got some good news for you, so the material which is I'm using it, which is the most popular one, is called pla so that stands for polylactic acid, and that is an organic material. It is fully compostable. So whatever I'm not using goes into my compost, pile here in the backyard and it does take a long time and you have to cut it up, but the material is going to be completely biodegradable, so you don't have any plastic waste okay.

B

So with that, I'm uh I'm through um before high shuts me off cuts me off. I hope I stayed within the 10 minutes and happy to answer any questions to you later.

A

Oh thanks joe, that was incredible. um You met under 15. I'll give you that no no it's fine 15 was the hard limit. 10 was the you know, goal okay! Well, let's move on to. Is it paulo next column?

A

Let's move on to paulo, take it away unmute and present.

C

um Let me share my second screen.

C

C

You can see my screen now, no.

D

E

ah There you go: okay, okay, so.

C

From where to start from the beginning, I have a different kind of uh of in 3d printer, the one that is called delta, because the movement is not x, y cartesian, like the one of joe, but has this 320 degree space at the three motors and and that's helped to move the head.

C

um What I have using as a filament just to sorry joe, but I I don't like the pla, because for my point of view, okay, that saved the planet but is a little too uh soft, especially in terms of of temperature, because uh uh here in the sun in california- and I think also the same in the in texas. Where are you where you are uh the?

C

If you leave the the scope out like I do uh during the day also it covered the pla can bend. If that, if you, if you are under the sun, so normally I'm using or asa, uh I please don't ask me to to read the the the very cryptic chemical name from the acronym is coming or the pet. Gpg is a good compromise that I'm using a lot in this moment, because it's the same plastic.

C

That's used for the soda bottles, and that is very stable and relatively let's say: stiff asa is a very close friends and cousin of abs and is very stable in terms of ultraviolet exposure, so it can can can be left outside without many problems. Okay, what I'm using for designing?

C

I'm not using the the the the the software that joe was mentioning, but I'm using another approach- uh I am a let's say, programmer by trade. So this kind of openscad and other open source is very useful for me because you, you use a sort of c that has many basic, primitive circle cylinder these kind of things, and with that you construct the the things that you are designing, um I'm using ultimate cura for slicing the slice is the process that is a sort of talking about.

C

uh Computer um simulator is like compiling a high high level program, uh take the product of the previous uh program and, uh let's say, translate in order for x y movement of the head that depose the filament.

C

What I am done, okay, you see the the first image previously and now that's the let's say the the realization. That's a a box for an arduino controller, the uh flip flat look-alike.

C

Here there is a flat of a square of led, and this is thick because you need to have a sandwich of various material in order to spread evenly the the the light.

C

That's another example of use of asa for building sort of the dust, but there was just polished, and so uh that's a a classical ring support for a an 80 millimeter. No, actually it was 70. Millimeter was the jerry one, 70 millimeter scope on a eviction.

C

Ducting another, this, I think, is the my my complex so far, design is a a mix, z stage that I plan to use with the otec for setting up a scope, and I need to translate the the laser.

C

And so that's a is a translation in a vertical here in a horizontal here, and that is quite complex because it has um gear inside and slide the dovetail and jib to to to strength and close the dovetail uh play and that's quite complex.

C

Another uh little things was a non-rotating focus, focuser and- and that was a very let's say, challenging and interesting design, because I have no idea how to do it. So I researched in on internet how a lens camera lens are constructed, and I say I reverse and generate the idea and I construct. Those are uh three pieces one pieces here, the second one here and the middle one has the two thread: one clockwise and the other counterclockwise.

C

So when you turn the middle one, the two external piece can, uh let's say, uh be shortened or elongated, and I'm using. I use that on a of axis guide here for focusing the camera without losing the the orientation of the of the camera sensor. Oops, sorry, okay.

C

Next one was a support for a an old tamron category optic for an olympus attachment- and uh I used this for with microfocus control here in order to focus- and that was a manual not a motorized, and I have different bases- uh and I did a lot of uh testing in order to stiffen the the base and avoid fracture with these. uh Let's say ribs that I discover it's definitely better to have these kind of ribs instead of having a thick material like here.

C

Now you see the ribs here, that's the lost monday, um duct tape, another one okay. That was the of course in this moment, uh uh and I uh that's that was the the the batting of mask that uh I printed for the yeah that one that uh high is showing in this moment, and these ones instead are smaller for my geider atsd short tube and that's another use, and that's it and basically I'm using the 3d or beside. Of course, a bunch of cover.

C

Extension boxes for other projects for related projects is useful. Of course. Sometimes you have to plan uh very carefully because the let's say the the 3d printing has a problem to print without the support some pieces. So you have to better, let's say plan for that, but it is very useful and that's it.

A

Well, thanks very much fellow again, unbelievable stuff, you guys are building all right, glenn, take it away, hey.

F

Okay share my screen here apollo needs to stop.

F

Okay: okay, can you see that.

D

F

Okay, great, um so uh I guess I don't have a picture of my uh printers, but there's uh behind me here is the the big one, that's enclosed, uh and that allows me to use um hotter materials that require uh more heat and that's an enclosed printer and keeps the part warm all around, while you're printing, so I'm uh prefer to use nylon carbon fiber.

F

So these parts that are this gray one here and this one that look kind of rough- are this nylon carbon fiber and then uh the ones that are more polished are probably asa, and this uh dust cap here is uh or lens cap is, is uh kind of flexible rubber. It's uh tpu is that that material.

F

uh So I have that printer, which I use for the nylon carbon fiber and also buried back there amongst all the astro junk is uh the same delta printer that that paulo has.

F

So you see here a variety of different things that that I printed uh you know dovetail clamps and various uh ring mounts for lenses and telescopes and and whatnot, and I talked about the the lens cap or dust cover, and then these are uh threaded parts, uh for you know extensions and prototyping things, and also for attaching moonlight focusers to to various uh otas that you know without having to buy a special adapter or the specific moonlight flange for that.

F

So let's go on yeah, so I'm glenn, hi, uh you've probably seen this before, but here's my email or what? If you want to reach out? That's fine, so I'm just going to kind of list a bunch of stuff that that I've done uh so so paulo and I have kind of built up a thread library of of each time. We need a new astro thread, then we add that to our to the library.

F

um So these are. These are the ones that are in there now and I think the most ambitious one here is that the club has this uh vixen 140 and I wanted to remove the stock focuser and use the moonlight focusers that I have so I can autofocus, but this is a petzaval design. So there's a there's a rear. This black piece here that I'm holding is a is a rear lens cell.

F

So there's a lens inside that and it that has to you know, go down inside the focuser, so this adapter had to have three threads on it. You know one for the ota itself, one for the the focuser would be here on the right and then this internal one for the rear lens cell, and you can see here that that was a 55-hour print, because I printed it in solid uh plastic in the in the nylon fiber.

F

So that was a a multi-day print and that's assuming that you didn't have any errors. So I think I think it was maybe four tries before I got through the whole 55 hours, but um okay, so some other things. uh I made a beam splitter for spectroscopy so that I could you know, have a a camera on there for plate solving and then the majority of the light would go through to the to the spectroscopy camera, and then uh it occurred to me.

F

Well, that's pretty much the same as as a on-axis guider that uses a cold mirror instead of a beam splitter. So I did a bunch of experiments, uh semi successfully. I'd say with with the cold mirror and that's where the visible light comes in and hits the mirror and goes up to your imaging camera. But the infrared light goes through the mirror to your guide camera here. So that's an example of what that looks like and that way you get the the full frame guiding of you know.

F

The full frame is available for the guide camera and then also there's a interesting uh side effect, which you can use. There's astigmatism because you're going through at this 45 degree angle, and you can actually use the shape of the stars uh with that astigmatism to build a an autofocuser based on that. So there's a innovations, foresight, onag is the commercial version and and there's software available from him that uh that does that um autofocus real time autofocus as you go through the night, uh some other mechanical stuff is for the planetary.

F

I had a flip mirror that I wanted to automate from from inside the house, and it's maybe a little confusing here what's going on, but the the the flip mirror has a has a knob on the side of it that you would normally turn, and so I was uh gluing that to to this motor here and then I actually use the the pointer uh on the knob. That's part of the the flip mirror to hit these little micro switches here and tell me which position uh it was in.

F

So that's what that was about, and here's a before deciding to switch to the to the moonlight on that vixen. This is the vixen stock focuser and I did some experiments uh trying to automate that focuser. But I wasn't happy with that. But this is a 3d printed clamp here that mounts a inexpensive, stepper motor and you have the the union there to the to the stock focuser.

F

And then this one was a focuser for a mac or an sct where you have the knob sticking out of the back of the the ota and there weren't any screw holes or anything place to mount uh anything on. So I made this ring where the the.

F

Visual back, I guess you would call it. You know, screws down on the ota, so it screwed down over this ring and then held the the mount for the uh the same type of stepper motor here. That would then connect to the to the focusing knob.

F

uh Some other things so uh here's my version of the the camera lens focuser that that we saw uh so the the stepper motor mount on the uh on the small rig here is, is 3d printed and the gears are 3d printed and, and this material here is uh that soft tpu. So it's kind of a little bit like a rubber band. So you stretch it over the over the lens and then it just friction fits and so that's how I was doing that and then uh later this.

F

This huge monstrosity here is is my uh diy rotator, and so it has a lot of 3d printed parts to hold the the big uh massive stepper motor with gears, steady and then you can see here there's a belt, and this is the the gear uh that press fits on the the uh extension for the for the focuser and so the whole the whole uh the focuser- and this is the the commercial on ag uh and here's the bottom of the filter wheel.

F

So this hole uh all everything here rotates around the back of the the back of the telescope and uh the 3d case here for the electronics, it's arduino and the solenoid driver and all that is 3d printed as well and then going back. This is this scope here on the bottom right. This was the the first scope that I had you know it's a department store, kind of for mail order, type scope, it's a matte cavs, actually still good for for planetary uh f13.

F

But uh you know it has this this knob that just refuses to to. I can't figure out how to get that thing off of there and it's uh nestled in amongst this plastic housing to where you can't easily attach anything to it. And if you try to adjust this thing when you're visually observing by hand as soon as you touch that everything wiggles around and you can't tell if you're getting in focus or not so this was my first uh focuser attempt. So this is actually just a dc motor.

F

In this case, and again, the the tpu material forms a rubber band type belt that that friction fits very thinly in the thin gap between this cowling and the knob, and so that worked and then there's three of these rings, two of them to mount the scope and one of them that's flipped around to mount the uh the solenoid or sorry dc motor uh case on. So that was a lot of cluege on that one.

F

So just random other things. This is a newtonian collimation that can also be used for for rc's. So you put a laser in here and and then you have this diagonal surface to make sure the laser goes back in the hole as you line things up.

F

uh Besides all the threaded parts, I've also made non-threaded spacers and washers and things that sometimes are handy for making sure your your camera rotates to a certain place versus.

F

Maybe you don't want it to go further than that uh for for aligning things or, and uh here's an example of a strain relief or wire guide, and it also, I put uh sort of degree markings on it and glued these levels on it. So in this case you know, if the sgp tells me to rotate, you know 60 degrees or something I can go out there and see what I'm doing.

F

What else oh for bruce for his raza, I printed some some transparent storage boxes for the the two inch filters that go in the tray filter system for the raza and then sort of on a completely different note. Here I was trying to experiment with various 3d things, 3d printing being one of them of uh you know showing astrophotos so so this is something called a lithopain and it's designed to to show light through, and so this is.

F

This is my tadpoles image here, and this is what the litho pane looks like, and then I put a transparent image of the the tadpoles behind it to get the get the color and that that's what it that's what it looks like. So it was a okay experiment. I guess um what else? Oh, so that's that's pretty much it for me yeah. So.

F

A

F

Ready for questions yeah.

A

Thank you glenn and thanks everyone all right. Well, let's open it up for questions, please, why don't you just try to go for it and if it gets unruly, we can raise hands. But let's, let's just try. Whoever wants to talk go ahead.

A

I can stop sharing or.

F

A

Can ask the first question, but I'd rather I'd rather get a volunteer from the audience. Nothing burning go ahead. Bj or it isn't pj, it's rob who's uh unneeded. No, you have an unity, I'm sorry I'll shut up.

G

Somebody um question uh all amazing stuff: I don't have a 3d printer, I'm planning on getting one at some point, but for all the materials that you guys are using. What's the cost.

B

Yeah, so the one which I showed you pla, okay, so paulo doesn't like pla that much, but it really is, first of all the simplest uh and probably also the the cheapest material and fully biodegradable. That's why I like it so a five kilogram spool of that uh cost me ninety dollars, okay, so five kilograms! You can print a lot with got it.

C

Yeah normally cost from 20 to 40 50 a kilo. If you go on the exotic like the the carbon fiber, that glenn was mentioning before, but again a kilo and a kilo is a lot of filament.

E

You say how many coulombs have you used in your uh in your career, paulo, oh bad,.

C

I had a bunch of for for the astronomical. I think two three kilos, not more but yeah. That sounds about right.

C

You know a lot you use at the beginning when you throw away a lot of things, because you make mistake and uh learning.

G

C

Learning curves, yes,.

F

Got it, and and some of this you know your prototyping right, so you you might make something and then later replace it with something in metal but for durability. Or what have you, but you know, you're, experimenting and you're trying things so that gives you that capability or, if you're, desperate, to hook this thing to that thing, and you know the stores are closed or whatever right you can. You can build something in an hour or so, or a couple hours.

C

Yeah part of the of the learning curve that help a lot the the junk pile is the fact that normally the the circle or better the cylinder or the hole, the cylindrical hole are different from the nominal size. Because you have to think that, at the end of the story, the um the the the 3d printer head is moving in a rectangular way.

C

So a circle is approximated with a lot of little steps, and so uh that means that and the the the cylinder tend to be smaller, uh sorry, bigger and the unders and the whole tend to be smaller in diameters and that's a create problem, especially if you are printing, I don't know an m48 thread and that's sometimes you have problem and so okay junk and that's create a lot of so.

G

Pla is biodegradable, but the other material can be recycled or what can be recycled. What could potentially be shredded and probably sent to somebody for recycling.

C

I mean the other, the other are all plastic that normally are recyclable, because uh uh the the pad g, for instance, is a as I mentioned before- is a normal plastic solder bottle. So that's that can be uh well.

F

If you're, if you're really hardcore, you can take all your scraps and melt them down and turn them into filament.

C

F

C

Saw the bottle, for instance,.

F

Yeah or you could make a soda ball.

C

No, you can use soda.

F

Oh oh yeah, and make your own filament from the soda bottle.

C

F

C

The problem is that the filament is normally two different to standard in diameter. One is 1.75 millimeter, the other is three millimeters and for the precision of printing and avoid any, um let's say, blockage of the mechanism.

C

You have to have a very precise uh dimension in term of diameter of the filament, and so, if you do by yourself honestly, I don't know if you are able to to reach easily that other things. uh Talking about that. uh I remember that glenn at a certain moment was try. You are trying to join different filament.

C

F

No, I never finished that that project I got distracted by something else. The parts are still sitting here on my desk.

F

uh Yeah that I was going to build a jig yeah, but that that also could get into you know, there's things you can buy if you're trying to do arty stuff, that's different colors, there's different ways to to try to get the different color filaments, either to splice them all together at the appropriate point and have a single print head or to have. You know multiple, multiple extruders, multiple nozzles, doing the different colors, plastics and stuff, and that all involves trying to- uh or some of that involves you know, splicing the material together but yeah.

F

That's why I said if you're hardcore uh you know to do to make your own filament, that's like a whole nother set of machining and stuff to to get that tolerance going.

B

Yeah, but for for most people, actually uh I don't think um uh well, or rather I think that the activation hurdle to overcome uh to get a 3d printer just for astrophotography is a little high okay. So what I would say is you should really take a step back and ask yourself: what can I do with the 3d printer and how much are they costing so the baseline bottom line is a really good one.

B

The one which I showed you, which is an entry model and fully expandable, can be modified to print all sorts of different filaments costs only about 200, okay and uh so you're, not really risking uh a lot of money there, and then you what you can actually do with it or what I found out is not just print things for, as for photography, but uh all those that stuff which breaks around the house all the time.

B

You know you, you can just design your own replacement parts and fix them. uh You don't have to go out drive around. You save a lot of time doing this and you save a lot of money. So I've calculated up the parts which I've printed so far in order to keep things going here in the house pool, uh I have the pool pump going. I have pool light installed because the old one was broken, etc uh pieces for my car.

B

When I add all of this up, I have calculated that I probably saved about four thousand dollars in the meantime in the last two years, simply on uh on parts which I've 3d printed myself. Okay, so that's what I would consider first right this. This thing is just like, as I said in an inkjet printer, it's a very clunky one. It prints one layer, then the printhead moves uh instead of spitting out the paper.

B

Now the printhead simply moves 0.2 millimeters in the c-axis and prints the next layer on top of it and they're just fusing together, that's the entire principle of it. So it's not really a incredibly complex thing, which you have to worry about, it's very easy to get into and you can very quickly actually get the hang of it.

G

Has anyone here use a resin printer, 3d printer.

F

Resin printer, no.

G

I haven't it looks messy. Yes, I have I've been I've been eyeing. I like the resolution, at least from what I've seen online, but yes, there's a whole cleanup process and then you have to cure again with uv afterwards uh just run from the park. But that's I mean that's all I've just seen online. So I I don't have any first time experience.

F

Yeah, my impression is, if you're trying to do small artsy stuff, that's what you want, but for big gross mechanical things that the the other style is preferred. I think.

B

And uh one other question who have you asked grandchildren? Oh hi, okay! Well I mean you can do all sorts of stuff. You know this is uh uh rocket model, five, which um you can just basically download the uh the files for- and I ran that one through my 3d printer.

B

So you can make all sorts of toys for the kids with that. Also, and I've made a bunch of stuff for the kids of friends. They all love me now they all want to be adopted.

B

So out of curiosity, how long does it take to print something like your saturn v that one takes about 24 to 30 hours, cool.

G

And then you glued it together.

B

uh That's actually um four pieces, but uh nothing is clued just stuck together.

C

C

Yeah, the real problem, as I was mentioning before of printing- is that, of course, the the 3d printer had cannot print on air.

C

So, if you have overhang, you have to uh organize for some sort of throwaway support that uh keep the overhang and and and the printer can can work on it, because otherwise, uh you are a traveler, and I understand, for me, is the the biggest limitation of the technology.

C

Actually, there are solutions that are 3d printer with the dual head, that can print special material that can be soluble, so you print virtually you print a complete, solid object and you put in water or in other chemicals, depending on the material that you use for the support and the support to disappear, and you remain with the void that you need for the overhang.

H

I have a different question. uh You guys seem to have pretty large print bits.

H

I I don't so um do you have any like local maker space that I can perhaps go to and find a bigger printer to like do the job for me like locally as uh local to um san jose or maybe santa clara. Something like that.

D

I don't know anything I could be maker nexus in sunnyvale.

D

3D printers, yes,.

H

That's true, that's true! That's true! Oh nexus, yeah I've never been there but uh yeah. Okay,.

D

H

D

About um and glenn and paolo mentioned, the threaded adapters, so is the 3d printer precise enough to print a thread that would then mesh with a with like a thread made on a lathe or do you have to use then tap and die to to chase the thread.

C

No, we print threads, no, no, we print threads, the difficult part uh that was the the the things that glenn mentioned was to uh create a sort of library or better modify the data of an existing library in order to cover all the typical fine thread that are in the astronomical business and right or something involved.

C

The printer has a 0.1 millimeter resolution.

D

Okay yeah because glenn mentioned a thread that was a as small as 0.6 millimeter pitch, so that, basically, you only have a six segments in a full 360 degrees. Right. Yes,.

C

Of course, uh with a lathe, you can have a better thread. There is nothing to that. uh Of course, with uh with metal and elate, you can have a real precise thread, that's a a decent track. I mean I will not attach uh five kilos of of ten thousand dollar camera right, but.

D

I mean, but a filter, for instance, is not heavy, so that should be efficient right.

F

No, but you might you know if you're, maybe you're prototyping, something that you're gonna get a precise parts for or something so you might have your camera and filter wheel and everything hanging. But you know you put some string or something so that if you have a catastrophic failure, it won't, you know, fall off the way to the concrete or something. But you know I've. I've learned uh you know, like I said I was doing things kind of in in solid plastic, but and and paulo's doing the the thick ribs.

F

um You know, I think, we've learned uh you know, there's there's a couple different ways that these parts can fail, and uh you know one is- is making sure that the the finish diameter outside diameter of the threads or inside diameter, depending on male or female is actually correct. Is is one because right if it's slightly too small, then it then it could strip out right and and the other one is just making the whole thing uh strong enough, so that so that it doesn't fail.

F

You know if you have a big 3d printed part and you can squeeze it in here. Hear kind of a crackling noise, you know that's the the infill uh failing right as and so if you've got that, then that's that's a sign that you know it could it could fail, so I've switched to printing and it's a trade-off between print speed and and strength right. But so the parts I'm really worried about. I print in solid uh nylon, fiber, so yeah it might have taken 55 hours.

F

But you know I could just stand on it and it's not gonna. It's not gonna fail and.

C

Also another another, uh let's say trick- is to have an enclosure, because the enclosures create a warm environment and the filament has more time to stick to the previous uh layer, because one other problem is the determination of layer. You have this all this layer and at a certain moment you have a a crack in the middle of the layer, because the layers are not sticking together enough and that's uh the the the enclosure is important. I made, for instance, a it's, a a plastic enclosure.

C

That's this enough to create the let's say: the stable, warm environment, especially when I print with a asa that is like abs or like carbon fiber, needs a high temperature.

G

So that's using temperature when you're printing to help with adhesion of the layers better adhesion of the layers. What about after the fact which material has the least impact on and from temperature? So if you're in a very old environment, does it impact pla different versus abs, different versus usa versus um I mean? Would you get warping in any of these plastics or.

C

Yes, yes, the pla is the one that worked. The most is more sensible to the temperature or better as a what they call a glass point, the point under of the temperature, underneath that the plastic becomes solid over that that point or that temperature. The plastic becomes softer.

C

It's not melting, but you can apply that and for for the pla is relatively soft, see if I remember well, 75 80 degrees celsius uh instead for other uh you are to talking for, for patchy and and abs or asa uh you are, we are talking about 130 150 degree.

G

We're going in the opposite direction,.

C

Getting colder are colder, I don't know honestly in terms of uh resistance in freezing temperatures so below zero if they become brittle or these kind of things. That's your question. I don't know the answer.

F

Oh, we we've thought more about the the um resistance to uv light outside, and so the you know, the the abs and the asa and the carbon fiber are all you know known to to be uh stable outside and those are, but they all have a certain amount of issues that make it harder to print, which is you know the the warping like you mentioned, especially if you don't have a an enclosure um and some are better better than others.

F

You know abs is notorious for being horrible to work with, but you know it produces a real, stable part. That's uv resistant.

G

I guess what I was trying to get get at is: if you have something that's holding your camera and at room temperature everything's aligned. But that's.

H

G

Really cold, would it warp the plastic any such that now it's not aligned is it? Is that substantial enough or or negligible.

C

Not that I know.

F

Yeah I haven't had any issues. um A lot of this has been in the guide on guide scopes, um but you know like in the case of the the vixen. That's the whole. It's holding everything on the on the imaging train, but yeah I haven't noticed any issues.

A

I guess there's a question in the comments from karen who left but I'll ask her a question: um what about like noxious chemicals and things like that? Is there a problem with melting plastic in inside your house? Yes, abs,.

C

That's the reason why is a asa is better than abs because abs, you have to have an enclosure and possibly you have to have ventilation to outside, because uh the the melted plastic is uh smelly. Let's say- and I don't know exactly the chemicals that are in that smell but for sure are not good for your lungs, but for the other, instead pla pla smell of.

C

Caramel roasted sugar, because it's based on sugar, that's the reason. Why is biodegradable the pna?

C

The other plastic, patchy and asa are very, very, very mild, there's mali, and that this, as far as I know, are not considered toxic abs. Yes, I have no experience and glenn with good can can answer about the carbon fiber.

F

Yeah, it doesn't have a doesn't really have a strong odor, but I imagine you want to think about. You know where you put your 3d printer and maybe more for noise than than smell. You know if it's going to be printing overnight, you know you don't want it next to your next to your bed, it it can kind of sound like people having a conversation in another room or something where you just can't quite figure out what they're saying.

F

But it sounds like they're saying something, and so you know all the different noises it makes as it makes the the patterns um yeah.

A

Joe, do you have a point of view? I mean you actually know something about this medicine.

B

A

Medical researcher, in his spare time.

B

uh Well, I mean the pla, I'm just printing inside my office. You know it's actually not really noisy, that uh that ender 3 basic baseline entry model printer is actually pretty fairly quiet, so I can print through the entire day and still work on my computer without being distracted and also as it's a basically polylactic acid toxicity of that is very low if it, if any.

B

And it's actually the cheapest. I mean it's the cheapest uh entry-level material and uh works for most things. uh Yes, I mean if you're gonna expose it to heat. That uh is a perhaps some issue, but it's a it's probably the cheapest material and for prototyping or getting into this and trying out. uh You know what you can actually do.

B

I think that's the perfect material not complicated, very easy to handle, and you know once you want to do some more complex stuff with more structural requirement.

B

Then you know you can change to other other materials. I would look at 3d printing, not you know with this big hurdle, but it's really is going to be a very easy way in into that hobby and.

C

C

For all the boxes, for my little project around the telescope and around the house, and of course, my grandson nine years old is using the pla for old is his project because, uh uh let's say more than a than a a 3d printer mine is a condominium part. Mine and part used by my my grandson for his stuff that he designed with a tinkercad.

A

All right do we have any any more questions.

G

uh For this distance, I I have one question, but that can probably be taken offline uh and that's regarding on the electronics side. um I know some of you guys are using motors and then interfacing them with controller boards and then making them talk with ecos or whichever other software. I guess that I would love to learn more about at a later point, not necessarily right now, but I don't know who to start with.

A

I mean we have, you know we have a little time if somebody wants to address it.

F

You know the arduinos are pretty pretty easy.

F

Yeah um and I guess raspberry pi is probably more involved because you've got you know a whole operating system and everything to deal with, but you know there's like kind of like the 3d printing there's all these people that have gone before and and have posted their their sketches, they're called for the arduino.

F

You know on github or whatever, on different sites instructables, so you might not have to design your own focus, controller, uh sketch and and hardware. It's probably already out there right, and so that's that's the way that I got started with it and.

C

Yeah, for instance, the the the flip flap uh that I using I'm using is has an arduino inside and the servo motor, a normal rc servo motor for moving the the cover and the sketch the program.

C

I started from an existing one, because I was interesting from the fact that that was a and it's a simulation of an existing. The existing flip-flop.

C

Cover and that's that was easy, because at that point I can use the standard driver in ascom or indy and I was able to to work with ecos now, I'm using nina and I'm using that and then without problem, and I modified of course, because uh I want to change the speed of the movement this and the other, but basically uh the the the the interface the api of interface, with the with the driver remained the same, and that was easy.

C

But basically yes, arduino is the way to go for the little motor, and this kind of thing because exists also a bunch of other uh little board that you can use for interfacing. Stepping motor temperature.

G

Yeah, those I'm aware of, I think it was just taking it further right so going beyond just the board and what you're, putting together with the arduino, but now it's taking it further and saying. How do I interface that, with you know, with the ecos protocol or whatever it might be? How do you connect those together right? um I think those are, but you know, conversation related, perhaps.

B

Well from what I, what what I showed the uh the drive of well, the sketch for the arduino, is called my focus of bro, there's and that's freely available, and that is has a driver which is directly uh built into ecos. So uh that really was it's no issue at all. You know you're just in a drop down menu and it works uh basically out of the box.

B

So I the only thing I actually modified in that sketch was the number of steps and it could take in the upper limits. The rest was was already there.

A

Okay sounds like we're uh we're good on questions for the 3d printing. I have one more question. It's only remotely connected, but you see these. You know this house was 3d printed like what does that mean? I mean I don't understand that concept and, like you know, is there some kind of gigantic 3d printer with a hose coming out, shooting plastic or or cement cement?

A

Is that what it means? Well,.

F

I think it can mean different things to different people that are trying to make a point, but yeah I mean so for for rapid construction or or uh you know, constructing things out of moon, regolith or something right. There they're experimenting with the same additive manufacturing, fdm technology, but with different materials like cement or or composited regolith, or what whatever right.

A

Okay, all right yeah in general,.

F

Yeah there are some really big 3d printers room size, all right, yeah.

A

Well, my last question sort of to the group is future meetings like are there topics that I mean? I guess I can start a thread on the uh imaging mailing list, but are there other topics? It seemed like this was an interesting topic for folks. A lot of people at least rsvp'd and many showed up, are there uh think about. If there are other topics feel free to say it now or um we can talk about it on email or where we have panels and discuss things. Yeah.

G

I I know I brought this up to glenn in the past, um uh but you know I'd like to bring it up to the entire panel, um I'm new, getting into astro imaging so from visual to now, starting to dip. My toes a little actually now, I'm knee deep right, then yeah, but uh one of the things that I'm trying to figure out for myself.

G

What kind of workflow do I need to start learning right as I, what are the different softwares? How do people go through their workflow?

G

I don't know if we have any documentation that you know different folks have put their entire workflow down, so someone could learn from oh okay. So let's say paulo. Does this this this this and this all the way from start to end? You know, glenn! Does this joe? Does this? You know- uh and I think that'll be very useful for folks just starting to learn.

F

Yeah, I you know, that's kind of how I started out on my my youtube channel and all that stuff is really aging now, because it's you know, first of all, it was dslr and things have changed so much in the in the meantime, from about 2016 until till now, um but yeah, it's it's almost that there's there's so many choices now right there. You know it used to be. You know, backyard, eos and sgp, and that was about it. uh But now you've got nina and you've got.

F

You know: asi, air and and uh stellar mate and and ecos and voyager, and on and on and on right. So there's lots of choices now so it's hard to.

F

If, if I picked a workflow to to explain, then you know somebody else would say: well, I'm using nina or whatever so it would be. It would be different, but I mean the basic concepts apply across all of them. Right I mean you need to plate solve. You need to come to focus and you need to auto guide and dither, and you know so. Some of that applies but yeah one one challenge would be now. The the plethora of choices, but one one thing I thought I'm trying.

F

I want to change my my program uh for the public. You know I'm tired of giving the same old lecture that I've given for two three years now, every every month um and I'd I'd like to you know, work with with hi on a on a ecos presentation and francesco on a nina presentation, and you know I can do sgp and so that that kind of thing uh sort of pre-produce those or have guest lectures or whatever.

F

Now that we're finally getting somewhat close to to uh having public events again, at least on the imaging side.

A

And francesco did a few lectures there, probably nina recorded. Not I'm not talking about that one though uh no it's insight, pics insight, yeah um francesco recorded, I I'm sure they were reported. I haven't ever. I watched them live, but are they around either glenn or francesco.

F

Some we had some technical challenges at one or more of them. I think it was before the zoom era. You know.

A

um Anyway, so the introduction to uh uh imaging is uh it's a topic of its own right, uh yeah.

F

So so go yeah, so I you know content. That's that's already there right and I had showed my my qr codes and links, but you know the I have a channel. The sjaa has a channel, um so there's a lot of material there, but certainly yeah. We can cover whatever people want to talk about.

G

um If folks are willing, I can maybe try to connect with folks separately and start putting some just at least workflow listings of what people use, and you know that might be a good library but he's collecting what are all the different kinds of things people do and using their workflows. That might be helpful to someone. I know it'll be helpful to me.

F

G

C

Another one other possible things that I I think that is interesting also to the people that start. These kind of things is the choice of the hardware, because there are so many choices in the hardware and everybody each one of us had made mistake and tried to put together all this kind of mistake in let's say troubleshooting or faq, or something- and at least that would be.

C

I think interesting also especially uh hardware respect, let's say the money that you want to spend the respect of the condition that you want to observe or photograph, because many times you end up with something that is good, for uh I mean a border tree uh area, but you you end up having a beautiful piece of hardware, is a piece of optics and used in downtown san jose and that's point: uh you are throwing away money, no something like that.

A

All right: well, I tell you what it's been an hour and a quarter, and I said I was gonna: keep it to an hour and a quarter to an hour and a half. So why don't? We do my first meeting we'll call it a day and uh we'll come back next month with some topic and I'll start a email thread and uh send suggestions or I'll come up with something like the way bruce always did if not and thanks every especially thanks our three presenters, our three panelists. I really thought that was an amazing presentation.

A

Let's give them a hand unmute yourself and get in your hand. In fact, I'll see you guys next month.

F

C

Thank you, bye.

G

Bye bye, everyone. Thank you.

A