Jacobs Rubberflex Collet Lathe Chuck Official Instructions

[Cannonmn]

Was having trouble getting subj chuck to work well so looked for a manual. Found it at link below, and quickly discovered the things you need to do aren't at all intuitive, at least not to me. I did search this forum briefly for the instructions and didn't find them but if they are already linked, mods are welcome to delete this thread as redundant.

http://www.neme-s.org/images/Jacobs_...llet_Chuck.pdf

[JoeLee]

I have one for my Clausing, L00 spindle. It's OK for small stuff and light work. Just don't try to take and heavy cuts as the rubber flex collets just don't have the holding power.

JL..............

[ngriff]

Thanks for posting this. I have two of these on a L00 taper. I had no idea you could tap the ring to help align the chuck... today I learned

For those that have one of these and a more traditional collet system like 5C can you take heavier cuts using the other system? I've always wondered this. Similar to Joe I have had work slip in these when it snagged on a heavier cut.

Nathan

[JCHannum]

I have one and it is my go-to collet chuck. I have 5C direct mount as well as a Sjorgen 5C collet chuck. None of the collet chucks is for hogging, but the Jacobs has the major advantage of full length engagement on the part. The 5C cannot accomplish this except for a very narrow deviation from the diameter.

I also think the segmented gripping of the Rubberflex collet is better suited to out of roundness and surface irregularities. Use the collet closest to the part size (Use 3/8" to 1/2" size for 1/2" stock, not 1/2" to 5/8" for example.) and do not be afraid to use multiple impacts to tighten.

[BCRider]

This has the advantage of full length support. But then so do ER collets.

It's interesting what it says about short pieces and the need for some form of filler support at the other end of the collet. It suggests to me that this Jacobs setup and the ER collets with the full length engagement surfaces are best used with longer pieces. And that there's still a place in the shop for 5C or R8 collets for use with shorter work parts along side the ER collets or something like this Jacobs setup.

[Toolguy]

I have used these in several places I worked. If you try to take too big a cut, the steel segments lay over and the work slips. You then have to open the collet, reposition the work and retighten. You can take a heavier cut with a 5C collet, but moderation with either one is better. Each system has it's plus and minus. There is no ultimate workholding device, you have to choose the best one available for the job at hand, then work accordingly.

[JoeLee]

Yes, that's exactly right, the segments will lay over if you take too heavy of a cut as I said in my previous post.
It's also recommended that the part extends through the collet or it will tend to bell mouth open and not provide the max. holding force.

JL...........

[wayne101]

Jacobs Rubber Collet Chuck

Was having trouble getting subj chuck to work well so looked for a manual. Found it at link below, and quickly discovered the things you need to do aren't at all intuitive, at least not to me. I did search this forum briefly for the instructions and didn't find them but if they are already linked, mods are welcome to delete this thread as redundant.

http://www.neme-s.org/images/Jacobs_...llet_Chuck.pdf

Thank you Cannonmn, I have one of these chucks, and i've always had trouble getting it to
work right. I never thought of looking for a manual and and probably never would have got
it to work right.
Thanks for using your head
Wayne

[Forrest Addy]

Thank you. That's handy. I lost track of mine years ago.

Not much to a Jacobs Rubberflex collet chuck but I like to have my stuff documented.

[Mcgyver]

likewise thanks, need it for a new one that was taken apart and couldn't find it on the web

[mudnducs]

Was having trouble getting subj chuck to work well so looked for a manual. Found it at link below, and quickly discovered the things you need to do aren't at all intuitive, at least not to me. I did search this forum briefly for the instructions and didn't find them but if they are already linked, mods are welcome to delete this thread as redundant.

http://www.neme-s.org/images/Jacobs_...llet_Chuck.pdf

Thanks! Thats the chuck that came with my lathe when I bought it. I've already found a couple things I was doing wrong. These have never given me any problem with taking off as big a cut as I wanted. Held fine for me.