Drill chuck won’t stay on arbor

[vincent52100]

Good evening. I have a couple new drill chucks and arbors where th chuck won’t stay attached to the arbor. Both Chinese, one came with my g0704. Grizzly did replace that one. The other I ordered for my lathe. I’ve attached photos of the one from Grizzly where I showed them it was contacting a small part of the arbor. I tried matching by grinding with valve grinding paste but it still came loose. I thought about matching a small section off the bottom to see if it would set a little deeper but I don’t think it would make a difference. Any ideas?
(Sorry for the poor quality of the one photo. It shows the contact after very lightly rotating to show the first contact point)

 

[mikey]

Please take my comments as being in your best interests, okay?

If you buy a cheap import arbor and put it into a cheap import chuck then this kind of thing can happen. In contrast, if you put a quality arbor - Albrecht, Jacobs (UK-made) or Rohm - into a quality chuck - Albrecht, Rohm, etc - then the tapers will be the proper interference fit and you won't have issues.

You also have to be dead certain that the tapers you have actually match.

On insertion, the male and female tapers must be completely clean and free of any oil residue.

 

[cathead]

You might try some layout fluid to see where the surfaces mate to determine the contact area. Any galling needs to be
removed from both surfaces before doing this. I like to use a flat 2 inch by 6 inch diamond hone on the outside surface.
Once you establish good area contact using the Dykem, it needs to be press fitted together or at a minimum, a good
solid whack with a hammer. It's a good idea to measure to determine that the arbor is not bottoming out as it will not
seat if such is the case.

 

[benmychree]

I bought a used chuck with 30 taper adaptor on EB for a good price, when I got it, I found out why they sold it; the chuck kept coming off --- I investigated and found the cause to be that the arbor was bottoming out in the chuck, I shortened the arbor a bit and solved the problem.

 

[pacifica]

When you press it on you may try freezing the arbor and slightly heating up the chuck to give you an edge. .0000072 expansion coefficent. so a 200 degree difference between the arbor and chuck should give a movement of .0014 ".

 

[markba633csi]

You might want to go balls to the wall and just loctite or epoxy them together- if you have enough parts to dedicate them to specific chuck/ arbor combos
Kind of a brute force strategy but hey, if it works why not. Then save up for better stuff next time

 

[SLK001]

If the taper won't hold, then loctite or epoxy won't either. benmychree may have found your problem - the adapter is bottoming out in your chuck. A couple of quick measurements can check this. Are you sure that the two tapers are the same?

 

[Mini Cooper S]

Old school trick that I have used with great results in the past. This does assume that the tapers match well. Take a piece of chalk and draw about 6 to 8 lines along the length of the taper ( clean and de-grease first), clean the chuck, twist them together and drive the arbor home.
I have had difficulty separating arbors and chucks assembled in this manor.
Richard

 

[vincent52100]

Please take my comments as being in your best interests, okay?

If you buy a cheap import arbor and put it into a cheap import chuck then this kind of thing can happen. In contrast, if you put a quality arbor - Albrecht, Jacobs (UK-made) or Rohm - into a quality chuck - Albrecht, Rohm, etc - then the tapers will be the proper interference fit and you won't have issues.

You also have to be dead certain that the tapers you have actually match.

On insertion, the male and female tapers must be completely clean and free of any oil residue.

Thanks for the reply. The one chuck came with the g0704. The replacement they sent works fine. When able I will get two good chucks, one for the mill and one for the lathe. I know I would like keyless chucks.

 

[vincent52100]

When you press it on you may try freezing the arbor and slightly heating up the chuck to give you an edge. .0000072 expansion coefficent. so a 200 degree difference between the arbor and chuck should give a movement of .0014 ".

I’ve used heat and cold on bearings, bushings and shafts, never thought about using it in this case. I’ll make sure that it’s not bottoming, clean it and try it.