Tips/Techniques Show your shop related 3DP

[Janger]

I made a similar slide plate for my TCG but its a bit of a rigmarole to set up the compound angles. I wanted to see what I could get away with with 3DP assembly & my bench grinder. The drill is held in a 5C collet block, advance into the wheel along fence up to the finger stop. Flip 180-deg & repeat. This ensure left = right. Increment infeed the fence with the mini lead screw. I was quite shocked, actually not too shabby geometry wise. Its the wrong wheel for the job & the grind striations look worse than in real life because I blackened the drill with felt marker & stroked the facet with a stone in an attempt to photo the dual angle. Yes I know, my facets don't quite meet up perfect because the whole setup is just tacked in place. The big issue I already knew from the TCG is few of these hardware store grade 'practice' drills are very coaxial or equal flute. Well, not exactly machine shop quality but it was a fun little project.

More details please! What is holding down the collet block? And how does that lead screw work inside? Maybe some section views?

 

[pdentrem]

QUOTE="PeterT, post: 199809, member: 22"]
This is an example of something I've been doing more as of late. When you want to fit something with some degree of snugness but the printer tolerance and/or part tolerance can vary a bit so it becomes a trial & error repetition. Sometimes its easier to make the cavity match the actual part dimension, but add some kind of flexure slot so there is some give in the surrounding material.
[/QUOTE]


I was actually pleasantly surprised when I was actually able to seat the carbon fiber plate in the printed slots. I was hoping that the 3 mm plate would not need to be worked to fit the designed .125” slots. I was naturally expecting to sand or file the plate to fit. Well it was a slight snug fit! Bonus! Not every print will be like this, and dried filament is going to be closer to size than wetter stuff. Every machine is also a little different when sizing is more critical.
Pierre

 

[PeterT]

More details please! What is holding down the collet block? And how does that lead screw work inside? Maybe some section views?

The collet block is not held down. You gently push it inward to the fence for contact & slide it down until it grinds a bit off & reaches the foot stop. It is admittedly primitive but this allows you to flip the block & grind the other side to the exact same compound angle repeat

For each grind increment I loosen the lock knob (residing in the slot) & advance the 'leadscrew' knob. It is acting on an embedded hex nut glued into the end. Not in model but I have a spring in between the end of the green fence & the blue swivel table.
The fence runs in a dovetail which actually runs pretty smooth with just minor cosmetic sanding to get the fit.

All the knobs are identical, just use M4 threaded rod to various length

This is the cheesy angle adjuster stop (and is actually needed to support the weight of steel collet block). It has a dome top because the swivel plate above it contacts it tangentially. The idea was to grind a facet, say the primary (both sides of course doing the flip-flop), then screw this adjuster down & grind the secondary with drill/collet remaining in exact same position. This makes a straight band facet. But because of the table swiveling geometry, now the extended drill is a different distance to the wheel. So you adjust the fence stop down the dovetail so the drill end just kisses the wheel & infeed from there. Its this last secondary facet which is pushing the limits of a rather dubious 3DP contraption. Because the facet might only be a 0.010-0.015" wide band depending on the drill size.