3D Printing Services?

[Ags]

Inspired by a comment by @vlaiv, I want to print some aperture masks for my Long Perng 90 refractor. I find the color correction fine for visual use, but I am thinking of trimming the aperture slightly for some photographic targets. My only problem is the lack of a 3D printer. I don't want to own one, but surely there must be a website somewhere that can print on demand? Does anyone know of one?

Edited March 16 by Ags

[Ags]

Hmmm, found this one in the Netherlands. No sign of clear pricing, which is usually a bad sign....

3D Printen voor particulier - 3D On Demand (3d-demand.nl)

[bottletopburly]

You could try asking  https://www.astroprinter.co.uk/home formerly Jack the printer .

[vlaiv]

Maybe this will help?

https://all3dp.com/1/best-online-3d-printing-service-3d-print-services/

Most serious online 3d printing services will give you a quote once you upload 3d model and select printing parameters.

@Ags

If you end up not finding any suitable 3d printing service, I'll be happy to print what you need on my printer for you.

[Ags]

Drawing my thing in tinkercad:

[Ags]

Printed via CraftCloud. The object cost EUR 3.50 - and multiple times that for shipping.

[happy-kat]

Thanks for the update to this post. I've moved to using Tinkercad as well.

[Ags]

This is just the 80 mm mask, printed in ABS as a test. I have a few more projects to work on - a 70 mm mask, various focusing aids, a solar finder. If only I could cut the shipping costs... Looks like ordering a 3D print is as cheap as ordering some photo prints!

Only problem with online printing is the need to get the model right first time.

Edited March 16 by Ags

[vlaiv]

1 hour ago, Ags said:

Only problem with online printing is the need to get the model right first time.

Or design in tolerances and features that makes use a bit flexible.

Here is aperture mask I designed for someone once:

It's a bit oversized - by 1 mm or so - just to make sure it will fit and I added 3 pockets for simple nuts so nylon tipped thumbscrews can be added to secure mask in place. They are also designed to be printed without supports with 45 degree overhang.

One could also design holder separately and have just few aperture mask inserts printed along it - no need for several masks. Saves on material use and shipping (I guess this last bit).

[Ags]

I uploaded the design to the Dutch site I initially found, and the price is pretty competitive there, but less choice of materials. 

I see it's possible to print in flexible plastics. I have some ideas for end-caps!

[vlaiv]

1 minute ago, Ags said:

I see it's possible to print in flexible plastics. I have some ideas for end-caps!

I've been both really positively surprised and somewhat disappointed in flexible plastics.

I think that TPU is great material given it's properties. It is very tough, very resistant, somewhat flexible (depending on type), but what I was disappointed about was that it does not have that rubbery feel to enhance grip. I considered it for ergonomic/grip surfaces of some parts.

Then I ran into this:

https://forward-am.com/material-portfolio/ultrafuse-filaments-for-fused-filaments-fabrication-fff/flexible-filaments/ultrafuse-tps-90a/

However, I haven't still had a chance to print with it. It looks like it has been specially designed for hta purpose.

[Ags]

17 minutes ago, vlaiv said:

Or design in tolerances and features that makes use a bit flexible.

Here is aperture mask I designed for someone once:

It's a bit oversized - by 1 mm or so - just to make sure it will fit and I added 3 pockets for simple nuts so nylon tipped thumbscrews can be added to secure mask in place. They are also designed to be printed without supports with 45 degree overhang.

One could also design holder separately and have just few aperture mask inserts printed along it - no need for several masks. Saves on material use and shipping (I guess this last bit).

Yes, I slightly oversized the mask to account for manufacturing tolerances. I will glue on some felt to make the fit snug.

I was considering making the 70 mm mask an insert for the 80 mm, should be doable.

Edited March 16 by Ags

[orly_andico]

IMHO you are better off just buying a 3D printer.  Once you have it, you will find all manner of things to make. I started out ordering 3D prints online as well, but the turn-around time is maddening and you get killed on shipping.

I had an Ender 3 V2 and now an Ender 3 S1 Pro, both were relatively competent but the S1 Pro is far more competent at 300-ish EUR? beats the pants off a made-in-USA Lulzbot Mini ($1200+) that I used to own.

If you want a bit higher on the scale, Bambu Labs and Prusa are the usual suspects.

I'd still go with some variety of Ender 3 for astronomical DIY. They are cheap enough, the better printers are if you want to make a living out of it.

[Ags]

Yes, thinking a lot about buying a printer. Maybe next year after we move house.

[Ags]

My first print arrived today.

It is a counterintuitive aperture mask for a SolarScout 60. One of the criticisms of this scope is that at f15 it is far too fast for its built in Quark. Only the middle 30 mm of the aperture would be on band. But what if Daystar cleverly shifted the SS60 Quark so it's optimised for the light coming in at the f18 angle? Then most of the aperture except for the middle would be on band. This mask tests that theory.

The mask was too small to fit on the scope (of course) but after a little sandpaper it just about fits. 

@vlaiv previously tried to explain why this mask idea wouldn't work, but it seems like an easy experiment to try, so we'll see on the next sunny day 😀

Edited April 4 by Ags

[vlaiv]

4 minutes ago, Ags said:

My first print arrived today.

What material did you choose for that print?

PLA in black color might not be best suited for solar applications - if there is no enough air flow (at least some light breeze) to keep it sufficiently cool.

[Ags]

I looked at the heat characteristics and selected Carbon Fiber FDM Nylon as the cheapest and most heat resistant option.

[vlaiv]

I usually don't like nylon because it creeps a lot, but for this application it will be well suited (one might even say it's a bit overkill - but it will work great).

Looking forward to hearing if this design aperture mask improves contrast.

[Ags]

I also thought nylon might be a better choice as the obstruction is supported by relatively thin vanes.

[vlaiv]

4 minutes ago, Ags said:

I also thought nylon might be a better choice as the obstruction is supported by relatively thin vanes.

It's a pity you did not choose to go with curved spider wanes to avoid diffraction spikes - these come "for free" with 3d printing

[Ags]

I thought about it but decided straight ones should give a little less total diffraction. It's not like I'll be seeing any star spikes  Also, I could have tried 3 vanes instead of 4...

This is 50% linear central obstruction. If this shows any promise I might try 45% or 40% too. I guess there's a balance between contrast loss from the central obstruction and any gain from a more collimated beam.

I am on the verge of buying a printer now - a two week wait for a print is annoying and the delivery costs are painful. And I think some/most designs will need some iterative development.

[Ags]

Maybe this one?

Creality 3D Ender 3 V3 SE - Kenmerken - Tweakers

[vlaiv]

5 minutes ago, Ags said:

Maybe this one?

Creality 3D Ender 3 V3 SE - Kenmerken - Tweakers

What's your budget?

Having started with Ender 3, which was at the time sensible offer, I'm reluctant to recommend it at this time. I've heavily modded mine to get it to print the way I want it. Overall cost of all modifications is higher then much more serious printer.

Now, this is just my opinion on the subject, but I'd recommend getting a printer that will be capable of printing advanced materials like ASA - which means enclosure, good heated bed and all metal hotend. Also, if you want 3d printer for astronomy - then you probably don't want to tinker too much with it.

Such style printer that will be much much better that one would be this:

https://eu.store.bambulab.com/products/a1?variant=47554015691100

On the other hand, if you want to print advanced materials - get this one (it comes with enclosure):

https://eu.store.bambulab.com/products/p1s?variant=47422304289116

Although I haven't personally worked with Bambu labs printers - I recommended one to a friend of mine (P1S model) and he is very happy with it. Two days after receiving it - he was able to print M63/M48 adapter that I designed for him - without any previous knowledge of how 3d printing works (except watching few videos on youtube).

 

[Mr_Cat]

I got given a 3d resin printer two days ago  the resin and wash/cure cab arrived last night so I've been printing a bahtinov mask for my guide scope today

 

 

[Elp]

Also decide what size you want for the print bed. I've got a basic one but if I want to print for my C6 it's usually a multiple assembly job (eg Tri bahtinov mask).

Whatever you choose don't go for an FDM printer which needs custom filament caddies, usually you have to buy them from the manufacturer. Better to get one which accepts any filament and the first job on your list will be to print a filament reel holder so the hotend can autofeed the filament itself.