This is probably my most ambitious design to date in terms of tolerances; it is a filament guide for my DIGGRO which uses PTFE tube tails and incorporates the filament sensor switch. Location of the switch against the filament feed and absolute location of the filament exit with regards the inlet on the extruder need to be pretty precise; we'll see how well I did...
Sooo close. I could use it if I wanted to do some filing and shim the switch out with washers; I did in fact do so to figure out how far off I was on the offset. I took a few pics while I was doing the prep work to test & fit.
![](https://www.eevblog.com/forum/chat/3d-printer-yet/?action=dlattach;attach=1141922;image)
"Supports Everywhere" does just that... it puts them everywhere. This one looks like it's going to be a major PITA... long holes can be especially miserable little gawddammitts.
One thing that helps greatly on holes where a screw will thread into the plastic, is to do a CHAMFER-2 DIRECTIONS in the design stage. Small m2-m3 screws like this I'll chamfer 0.1mm in the diameter direction, with a depth direction of 2-3mm. You can see them in the design pic below.
A side benefit of this habit is that supports inside the hole come out much more easily; press against the sides of the support inside the hole and wiggle with a jeweler's screwdriver or dental pick to break them loose and even this 20mm long support just pushes right through.
![ThumbsUp :-+](https://www.eevblog.com/forum/Smileys/default/icon_smile_thumbsup.gif)
![](https://www.eevblog.com/forum/chat/3d-printer-yet/?action=dlattach;attach=1141930;image)
Large flat support structures sandwiched between plates like the bottom of this part can be a real PITA; here a razor scraper is your best friend. Slip it between the part and the support like so; go all the way around the perimeter and repeat at the covalent area on each plate to separate both sides of the support.
![](https://www.eevblog.com/forum/chat/3d-printer-yet/?action=dlattach;attach=1141934;image)
Then force a screwdriver under the support at the back of the slot, and lever outwards; the support will come out in a single piece.
![](https://www.eevblog.com/forum/chat/3d-printer-yet/?action=dlattach;attach=1141938;image)
This one is usable as-is; sometimes you'll have to do a little cleanup scraping inside the slot with with an old paring knife.
![](https://www.eevblog.com/forum/chat/3d-printer-yet/?action=dlattach;attach=1141942;image)
Since I wasn't happy with Rev 1, I am now printing Rev 3; Rev 2 got canned in redesign stage. This is what
Iterative Design is all aboot; a couple hours and 50c worth of filament later and I'll have one that
should fit exactly as desired.
![Grin ;D](https://www.eevblog.com/forum/Smileys/default/grin.gif)
mnem
![](https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=1090558;image)