Calling all Porper B Owners

I came up with a spindle collet idea that Porper B owners may be interested. The collets are an alternative to the three jaw chuck and compression spiders.

I'm looking for a show of hands of those who might be interested in purchasing them so I an idea who how many to make. The original collet set was 3d printed, but I want to look into injection molding out a stronger such as nylon or LCP.

I have no definitive price at this time. I'm still in the research phase of this project.

I also need everyone to measure the outer spindle diameter. Mine is 45mm and want to ensure that measurement is common to everyone.

The collets can be viewed in this thread.

Porper b thread

Have a good day,
Corey

Internal collet diameters

The collet sizes I am using now are 14mm, 17.5mm, 21.6mm. 27.5mm, 30.5mm, and 33.5mm.

They can shrink at least 3mm smaller, but cannot expand past their nominal size.

What other sizes does everyone prefer?

Thanks,
Corey

So my Q is, did you have to bore them after making them, or would they hold .003 or less TIR right out of the printer?

The holder is a little tight on the spindle on the first and was able to get less than .003 by slight tapping the holder when screwing down the locking bolts.

Also, which plastic did you use?

PLA+ on the plastic.

Price for the set and what is included??

I don't have a price yet. I am researching injection molding
or 3d printing as a possible way to have them made quantities. Six collets, a holder, a nut, and rack make the set.

Also what is the material that you used for system?

Delrin---LBM----?????

I looking for something stonger than PLA+ such as nylon or LCP

thanks

mike 'acedonkeyace' kennedy

PS. I did see you posting on my POST, so I am answering here.[/QUOTE]

Does this mean that after you dialed in the holder, every collet repeated? or does it mean that you have to dial the holder in whenever a new collet is inserted, or the one in place is rotated 90° or 180°?

Further research last night demonstrated there is definitely error in the collets and holder. While I can get a shaft dialed in at <.005", repeatability is not consistent. I am seeing runout of .012" when just swapping shaft wood.

I think the problem may lie in the accuracy of the printer and how the slicing software rendering the print file.

The PLA+ plastic melts easy and I believe it will take a sharp hss bit and water to cut it. I want to try Nylon next.

the original files were drawn in TinkerCad, but I have upgraded to Fusion 360 and redrew the lot. I want to see if the F360 will be any different than what was created in Tinker.

I am also looking into machining the holder. I would do it myself, but unfortunately, I don't have the gears to cut metric threads on my SB lathe.

I think there is potential here, but more R&D is needed and couple daily Porper lathe users to test before I can say its a repeatable solution for the masses. I don't want to get folks hopes up the collet set is something ready to be delivered.

I'm also looking into injection molds and silicon molds. If those options work, then it's just a matter of machining a master holder and buying a set of steel ER collets and use them to create the molds.




I'm not trying to nit pick - just curious how far to pursue my own interests, using the library printer. Though I'm guessing if every collet has more than .003" inherent run-out, it still might be possible to bring them closer by boring each in a "perfectly" centered collet chuck. I just don't know what the limits of possibility are with plastic.