3D printing for accessories? Or other materials?

[Astrosurf]

Has anyone used 3D printing for accessories that take quite a lot of force, e.g. dovetails? I want to make a side-by-side bar. First I thought in wood, then thought about 3D printing. Have you made accessories in wood or other materials or used 3D printing? What have you made and how have they fared?

Alexxx

[Jamie16v]

i printed stepper motor brackets for a diy astro-eq goto system. i haven`t yet installed them but im sure they`ll hold up just fine. i printed in petg with 100% infill. 

bearing in mind i built my D-bot 3d printer with the exact same materials and it works well.

[pete_l]

Yes, I've made wooden dovetail bars. Extremely easy on a table saw (where the angle of the blade can be varied).
They are much lighter than metal ones and have been in use for 3 or 4 years with no problems at all.

[Astrosurf]

17 minutes ago, pete_l said:

Yes, I've made wooden dovetail bars. Extremely easy on a table saw (where the angle of the blade can be varied).
They are much lighter than metal ones and have been in use for 3 or 4 years with no problems at all.

I don't suppose you noted down instructions?!

[pete_l]

1 hour ago, Astrosurf said:

I don't suppose you noted down instructions?!

There aren't many instructions to note down:

• get existing dovetail
• measure angle
• measure width of base
• decide length
• find suitable piece of wood
• cut!

[Astrosurf]

Lol! Thanks.

[moab360]

I've 3d printed quite a few bits and bobs for my scope, including a dovetail to hold a small camera and guide scope.  In practice it worked out okay, but there were a few issues.  

1. I had to re-enforce the wall of the dovetail with a thin piece of metal.  The mount screws would puncture the plastic pretty easily without it
2. Maybe it was the plastic or density I was using, but flexture was an issues in the setup.  

After some use I ended up machining a metal dovetail, which led to better results

[Astrosurf]

Thanks. I did wonder about the hardness of the plastic. Did you do what Jamie said and used PETG with 100% infill?

[Stub Mandrel]

I used PLA at 50% fill. PLA is stiffer than ABS or PETG.

More than 50% fill is probably wasted. If doing again I would provided a socket for the screw. Do not over-tighten.

Dovetailed guidescope holder:

The tube for the focuser barrel (right) is 3D printed too. The original (left) was too long and loose. Most of the knobs are printed. I had to sand the inside of the focuser tube smooth:

Finder bracket:

Scope rings for skip rescue scope:

[Astrosurf]

Thanks Neil! Excellent. What did you use as a template? An existing dovetail?

[Stub Mandrel]

I used a posh protractor (Moore and Wright!)

The Skywatcher & compatible dovetails are 75 degrees.

 

[Gina]

TBH I don't think plastic is good for heavy load bearing items.  It's alright for small brackets and such like but I'm not even using it for my DIY widefield imaging fork mount - I'm using aluminium.  I am using it (ABS) for the micro dome enclosure as that doesn't affect the  imaging system.  I also use 3D printing for gears for remote focussing and for the brackets that hold the stepper motors.  When plastic is put under load it tends to bend and after a while you get creep and that isn't reversible.  So although I make use of 3D printing for a lot of things, I don't use it for items that need to be accurate or very rigid.

[Bagnaj97]

My piggyback tube rings are still fine, with ED80, ST80, QHY163m, filter wheel and dew tapes hanging off now. - https://www.thingiverse.com/thing:2181161 

 

It helps that I massively over-engineered them - the plastic is very thick and the overall weight is probably comparable to a similar conventional system. The primary benefit was cost, a roll of filament is cheap compared to all the rings and dovetails needed, but it was also satisfying making my own.