43 replies to this topic

[rfiol]

Just finished printing and assembling version 2 of my 3D-printed 6" (153mm) f/5 Newtonian.  I decided to use carbon fiber truss tubes for this version (small scope so not too expensive), and I'm really happy I did.  It's very light and quite strong.  

 

Design and build video:

https://youtu.be/rt04QXj3ZTo

 

 

 

 

 

 

 

 

 

 

[JohnnyMac]

Wow! That's awesome!

[bmcclana]

What build volume is your printer and how many hours of printing.

That looks very impressive.

[coinboy1]

Wow! Care to share design? I have a 6” F/5 telescope that would be awesome to convert to your design!!!

[petert913]

I love the design !!

[ArizonaScott]

Nicely done, that's a work of art!

[philipdehazya]

A great project and a great video showing the steps! Bravo!

[Mike G.]

Nice!  what's the weight with optics?

[rfiol]

What build volume is your printer and how many hours of printing.

That looks very impressive.

Build volume is 300 x 250 x 200 mm.  Not sure of the total print time.  The longest print was the mirror box, which was 35 hours.  The alt bearings were the next longest -- each part (3 parts each side) was about 7-8 hours.  My guess for everything is about 200 hours.

Edited by rfiol, 03 December 2020 - 11:52 AM.

[rfiol]

Wow! Care to share design? I have a 6” F/5 telescope that would be awesome to convert to your design!!!

Absolutely.  I will post the files (including the exported Fusion 360 project file) on my website.  Give me a couple of days.  I should have it up this weekend.  I'll reply here

[rfiol]

Nice!  what's the weight with optics?

I actually do not have a working scale.     I will take it to a buddy's place to get it weighed and report back.

[rfiol]

I've posted the project online for anyone who wishes to download and print.  I included both the STL files and a Fusion 360 project file.  Please let me know if you print one -- I'd live to hear about it!

 

https://www.bigbigsp...ton-to-see-here

[rfiol]

Printed a simple travel-sized / table-top Dobsonian mount designed for this telescope. The azimuth plate is not shown.

 

https://www.youtube....h?v=HcKJAFJUkfE

 

 

 

 

[cucubits]

Thanks for all the work you've put into documenting and designing this. Also sharing the source files is absolutely awesome on your part.

 

I'm going to start working on a quite heavily modified version of this. I love Fusion 360 so I'm not expecting any problems there. I've already ordered a mirror set and will start making the part changes. It's going to be an 8 inch F5 (1000mm). It's possible I won't stick to the classic truss option as I plan to have it mountable on an equatorial ...mount.

 

If it turns out ok, I will gladly share the new part files and details.

Edited by cucubits, 04 January 2021 - 11:46 PM.

[rfiol]

@Cucubits - This is exciting news!  I am happy you are working on a 8" f/5 version of the scope.  I can't wait to see the results.  I hope you'll consider allowing me to post the finished files on BigBigSpace.com along with my 6" f/5.

[cucubits]

@Cucubits - This is exciting news!  I am happy you are working on a 8" f/5 version of the scope.  I can't wait to see the results.  I hope you'll consider allowing me to post the finished files on BigBigSpace.com along with my 6" f/5.

Of course, I'll gladly provide all the files and details I end up with. The mirror arrives tomorrow and I'll start working on the parts.

 

The Fusion360 files from the website are the latest ones or have you made any recent changes/updates?

[dan_h]

Looks awesome! 

 

So.... for us who are not in the loop and know actually nothing about 3D printing, ( that's me for sure), what do the materials cost to print the parts this 6" scope?  Is it cost effective or does one have to acknowledge that the technology is still fairly new and therefore more expensive than other methods?   One cannot argue with the results. 

 

dan

[rfiol]

 

So.... for us who are not in the loop and know actually nothing about 3D printing, ( that's me for sure), what do the materials cost to print the parts this 6" scope?  Is it cost effective or does one have to acknowledge that the technology is still fairly new and therefore more expensive than other methods?   One cannot argue with the results. 

Hello Dan,

 

That material (PLA filament) is actually inexpensive.  A 1kg spool is about $25 USD and I probably used 1.5 - 2 spools.  I just bought a spool of the CarbonX (PLA + carbon fiber) that is more expensive -- about $50 USD per 1kg spool.  I plan to use that for *some* parts of a 12" f/5 I'm designing now.  So materials are cheap, but a good printer is not.  In order to print carbon fiber and other materials, and to have a large print bed, required an investment.  I spent $2.5K on my newest printer.  There are less expensive options, but this is my third printer and I've been slowly talking myself up into the prosumer space.

[rfiol]

The Fusion360 files from the website are the latest ones or have you made any recent changes/updates?

Yes, I've kept the files online up-to-date with latest changes.

[cucubits]

Yes, I've kept the files online up-to-date with latest changes.

Thank you!

 

I have one more question if I may. How are you securing the truss tubes in the mirror box? Are they press fit, glued in or just held in place by the fixed angles? If it's the latter, is it secure enough?

[rfiol]

How are you securing the truss tubes in the mirror box?

They are just held in place by the tension from the fixed angles.  To be honest, I didn't plan for that.  I had fully expected to need a solution to keep them in place.  But after I did a test fit, I was surprised to find that they were very secure.   I hate to admit that they are probably held securely in place because my angle measurements may be off slightly -- just enough to create the tension needed.  I'll pretend I planned that.

[cucubits]

They are just held in place by the tension from the fixed angles.  To be honest, I didn't plan for that.  I had fully expected to need a solution to keep them in place.  But after I did a test fit, I was surprised to find that they were very secure.   I hate to admit that they are probably held securely in place because my angle measurements may be off slightly -- just enough to create the tension needed.  I'll pretend I planned that.

Thank you! I'll probably end up making some changes to the box section as I'll have different angles for the truss tubes and will make something to secure them.

 

Currently working on the primary mirror cell. So far I'm happy to say that to fit the 8 inch mirror properly, all I need to do is scale it up to a factor of 1.30 in Fusion and it's perfect. Even the PLOP numbers end up where they need to go for my mirror so no changes there either. Same for all the side and colimation bolts.

 

I do need to split it in 3 parts to fit my print bed but that's fine. I'm doing "puzzle" cuts and will glue the parts properly.

Edited by cucubits, 08 January 2021 - 04:46 PM.

[cucubits]

Quick tip for anyone having a go at this build.

 

In the spirit of DIY, I'm trying to make as many parts myself as it's possible. Having said that, the mirrors from Agena mostly will come without center marks. I've been sitting on this for a while but I think I found a great way to precisely cut little donuts: 45 and 22 caliber casings make the perfect hole punches

 

[rfiol]

 I've been sitting on this for a while but I think I found a great way to precisely cut little donuts: 45 and 22 caliber casings make the perfect hole punches

 

 

Clever.  Make sure they are empty before banging with that mallet. 

[orlyandico]

I'm curious as to your printer model.. $2.5K sounds like a Taz-6?

 

I'm looking to upgrade to a large volume printer that's dead reliable. I've had lots of success with my Lulzbot Mini v1 but the build volume is tiny. I bought a Creality Ender 3 Pro on a whim (it is cheap) and while the build volume is large and the print quality decent, it's very slow and not very reliable (the last big print I made, a dangling wire got stuck and ruined the print). I wouldn't dream of trying a 35-hour or even an 8-hour print on the Creality without a lot of modifications.