i am working on the mechanical foundations unit and would like my students to use rack gears and slide rails to modify their structures.
the slide rails are sold out. however, even if they weren’t sold out, i am in ecuador so probably couldn’t get them for another year or so.
so, i am wondering what folks think if i 3d printed the actual slide rails? would there be too much friction for the gears to work on some PLS or ABS slide? if so, how could i modify them? wd-40?
I don’t have a 3D printer of my own (I wish… ), But this seems plausible.
I probably don’t need to remind you… but I will anyway… It will definitely be weaker compared to the steel versions (unless you made your own versions with a rib running the length) 
Thanks! What is a rib? We probably wouldn’t manufacture any slides of steel. I only need four. Anyone want to lend me 4 slides and happens to be in Quito?!
Check this out:
Here is an example of a reinforced slide rail I made last night, It should be 3d-printable (if you have a large enough bed XD)
Linear Rail v8.step (1.4 MB)
Here you can see where I added ribs:
Only the inside dimensions of the rail are left unchanged. This means you will only be able to use the slider that sits inside of the rail.
Also, I only reinforced the rail in this direction:
As you can see, it would take a LOT of reinforcement to get even close to the strength of steel, so this would probably only be a good idea to 3d-print if you aren’t using this for loads greater than 10N (If the load is applied in the same way as the simulation)
Oh, btw, the simulation results I provided is displaying the safety factor of the part. The safety factor of my part isn’t significant, I just needed something to illustrate the difference between the ABS part and original steel part.
Thank you so much for all of the great information!
Now that I have it I need some simple instructions to figure out where I screw in the rack gears. If the rack gears are on top, and the ribs are facing to the bottom, where and how do the trucks go?
