Knurling anyone?

[nic422]

Hey guys, does anyone here do knurling or know of somewhere I can get a collet holder re-knurled? This one is a bit worn out and sure would be nice to get it refinished.

[namonllor1953]

Can you post a photo of the piece??

[nic422]

Sure, it is posted in the original thread, but you might need to move the image around a bit to see it.

[Bob Tascione]

Hey Nic,
You can try any general machine shop in your area. Most will have knurling tools. The only problem you may have though is that they will need to have a die with the same TPI to pick up and track that straight knurl. If you’re just trying to get something to grip onto and not concerned with appearance then you could have them put a diamond or angled knurl over the straight pattern. Won’t look too purty but will give you something to grab. Might want to check to see if the parts are heat treated first before heading off to the machine shop. If you have a lathe you can always grind up a tool to recut those grooves a little deeper. You can put the tool into the tool post and the part in your chuck or on a simple mandrel and then pick up one groove at a time using a little magnification and then feed the tool along the part by manually feeding the saddle along the goove taking a few thousands off with each pass.
Hope this helps.
Good luck!
Bob

[nic422]

Thanks Bob, thing is I have looked for machine shops near where I live for this task and haven’t had much success. Either the piece is too small for them, or they charge an $80 set up fee with is a little ridiculous for refinishing one of these.

Your advice about making a tool though, to reiterate if I see this clearly, do you mean to manually cut the groove by hand, using the tool post to hold the tool, chucking the collet holder in the lathe, and then scraping it along the already present notches?

[nic422]

Oh, I also have another question about a collet holder like this. When setting it into the tailstock, how do you true it into position, and how do you get it to stick in the tapered recess so that it will stick and won’t turn, like for purposes of threading stems and such?

[Bob Tascione]

Hi Nic,

do you mean to manually cut the groove by hand, using the tool post to hold the tool, chucking the collet holder in the lathe, and then scraping it along the already present notches?

Yes that’s correct. You may need to mount it on some type of mandrel or between centers if possible if there’s no place to chuck it. You would then place the cutter in the tool holder as you mention and traverse along the original groove. The idea is to ‘shear’ a tiny amount of metal on each pass much like a graver does when engraving metal rather than to scrape it off. It would be best to use a center in the tailstock to prevent the part from flexing away from the cutter. If you have no way to lock your headstock the additional pressure from a tailstock center should help prevent rotation of the headstock spindle.

When setting it into the tailstock, how do you true it into position, and how do you get it to stick in the tapered recess so that it will stick and won’t turn, like for purposes of threading stems and such?

If the taper matches the taper in your solid tailstock spindle the holder will be self centering and end pressure will keep it from spinning. The tapers must match for these conditions to take place.

Hope this helps Nic,
Bob

[nic422]

Thanks Bob

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