Chuck slips on taper

Personally, I would tell them the tapers do not fit. You can send them a pic of the Prussian Blue mismatch and that should be enough to prove that the tapers do not match. The seller should replace them or even better, refund your money so you can buy a decent chuck and arbor.

If I could suggest a new chuck to you, I would look at a Rohm Surpa. This is a keyless chuck you can get on Amazon for a fair price. It isn't an Albrecht but it is much cheaper and nearly as good. I can attest to the quality of this chuck. The Rohm Spiro is better but cost as much as an Albrecht. You can also buy a good used Albrecht on ebay.

This is a Surpa-I for a ridiculous price. It is a very good chuck and all the wear components are hardened steel. In the Surpa line, this is their best chuck. It has a 33 jacobs taper. This one has a 6 jacobs taper but costs more.

Look for a good arbor. Jacobs, Rohm, Albrecht all make good ones if you can find them.
 
Is the Surpa suitable for a mini lathe? Is it hard to tighten? My only experience with keyless chucks are on an old Craftsman drill. That chuck is only fair.

I'll look around for a decent arbor. They don't seem to be all that expensive. I have to say, I've wasted a lot of time on this @%#! chuck.
 
It's a 1/2" chuck. They do sell a 3/8" version as well. I bought this one for a friend's Sherline but you will need to look for one with a jacobs taper.

Important: Rohm makes these Surpa's in several grades. You want the I-Supra, or type 136.
 
It's not a horrible price for the chuck, especially if it's a good one. I'd like to stay with a 1/2" chuck for now. One thing that concerns me is the reports of excess runout. Spec claims up to 0.12mm, that's 4.7 thousandths. But I take a lot of the reviews with a grain of salt, especially on Amazon.

I think my mini-lathe uses a shortened MT2. Can I chop off the MT2 if it's too long? Or does this restrict me to use one of theirs?
Gee, MT2s have a tang ending and a drawbar ending, more variations than I expected.
 
You have to be very careful about believing an Amazon reviewer who talks about run out. Most guys who are not machinists evaluate run out by chucking up a drill or blank and watching their DI needle bounce around under power and then assume its the chuck at fault. It is more likely their poor understanding of how concentricity is evaluated. I have used a Rohm keyless chuck for over 25 years on my Sherline lathe and mill and find they are more than adequate for my use.

You can cut an MT arbor. Just make sure you have enough length for the arbor to be ejected when you wind back the hand wheel.
 
Thanks for your help. Yes, I'd probably duplicate the length of the ones that I have. Who needs more problems, not me.
 
mikey said:
You can cut an MT arbor. Just make sure you have enough length for the arbor to be ejected when you wind back the hand wheel.
Click to expand...

To be clear, you may need an abrasive cut-off tool (angle grinder or abrasive chop saw) to do it, depending on hardness.
I recently cut the tang off two big B&S #11 endmill holders and a file wouldn't touch the "skin", once cut however I could drill and tap the end for a draw-bar. The hardness was not very deep.

-brino
 
@mikey Gee that Rohm chuck you recommended is really nice. I just received it. Shame that my friends at Amazon can't be bothered to package it very well. It has a tiny rust spot on the body and a part of the edge are banged. Wouldn't be surprised that it was dropped at some time while in the box. (Might want to measure runout on this soon.) I say this because cardboard from the wrapper and box seems to be embedded in a few of the knurl diamonds. Nothing that would stop it from being used, just minor cosmetics. Even so, it's really smooth. Nice knurling as well. The internal taper is well machined, with no blemishes. Compared to what I had, it's real high end. The rust spot looks worse in the photo than in real life. Thanks for the recommendation! I also have a Jacobs taper coming, but it's hasn't arrived yet. I might have to cut off the end of the new "old stock" Jacobs taper.
IMG_20200121_143327.jpg
Looking at the construction of this Rohm chuck, how would one remove the taper from this chuck? There appears to be a plug of some sort that blocks you from knocking it out from the grip side. Pardon my ignorance on this - it's just nothing that I've experienced yet. Do you have to disassemble it to take out the taper?

I did clean up the old chuck and inspected the internal taper. The internal taper does have some places that are gouged out. I blued it a second time and found it really only contacts at the front edge. I did whack in the arbor with a hammer and a block of wood. It's pretty stuck in there. Actually, I don't know how to remove the arbor now without damaging it. I think I can see the arbor from the grip side. Is it safe to knock out the taper that way? Use a 1/2" aluminum rod and maybe hit the back side of the chuck via a wood block? Maybe put a towel over it to keep it from flying very far?
 
Looks like the box the chuck came in took a hit at some point and the chuck rusted while sitting on the shelf. Not a disaster. I would use a brass brush and get the rust off, then oil it and it should be fine.

You cannot access the inside surface of the arbor from the jaw side of the chuck. You to use wedges or a pry bar like the Albrecht arbor removal tool or a bearing remover or some other method.

For chuck that have access the the inner end of the arbor that you can see from the jaw side, the best way is to use a hydraulic press to get it out. You can also use the methods above that work with keyless chucks. If you have a junk chuck with a junk arbor, I would throw it out so you aren't tempted to use it.
 
I actually don't know that the arbor is junk. It might be. The old chuck, yeah, no plans to use it, except as a paper weight. The Rohm is so much nicer.
 
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