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View Full Version : Is this Arbor too far gone? (image attached)



davefr
07-12-2012, 11:52 AM
I wonder if this JT33 to MT2 arbor is too far gone. There's scoring on the JT33 big end. It does run true but I'm trying to understand how perfect they need to be.

https://dl.dropbox.com/u/59847735/arbor%20001.JPG

lakeside53
07-12-2012, 11:58 AM
Looks fine. You might want to stone of the high spots around dings.

dian
07-12-2012, 12:38 PM
how "true" does it run? (what else would you expect from the thing except to run true?)

davefr
07-12-2012, 12:50 PM
(what else would you expect from the thing except to run true?)

I "expect" it to reliably seat to the chuck/quill AND run true.

If it wasn't true I'd simply toss it.

LKeithR
07-12-2012, 01:04 PM
I think you have to use your own judgement in this case. The first requirement of any tool is that it "work" correctly; appearance is of secondary importance. Having said that, if either the Jacobs or MT ends of the arbor are damaged enough that they're going to mark either the drill chuck or a spindle they're going to be used in I would toss them. Arbors are cheap and it's not worth the risk of damaging the spindle taper on your lathe, milling machine or drill press. The Jacobs taper end is less problematic since in most cases once an arbor is installed on a drill chuck it's never removed...

JRouche
07-12-2012, 01:09 PM
I wonder if this JT33 to MT2 arbor is too far gone. There's scoring on the JT33 big end. It does run true but I'm trying to understand how perfect they need to be.




Looks ok. Id make sure the chuck is not going too far up the taper and "bottoming" out on the shoulder (running out of taper)... JR

Arthur.Marks
07-12-2012, 02:41 PM
I wonder if someone did just as JRouche mentions by using a B16 taper chuck instead of a JT33 one. It has fooled me before :( The reason I believe it was bottomed out is that the transition between the tapers looks a little mushroomed. See how the very end of the MT2 bulges a little? (or is that a visual illusion?) Might not matter, though, since the Morse Taper extends some from the spindle when seated.

davefr
07-12-2012, 04:30 PM
I wonder if someone did just as JRouche mentions by using a B16 taper chuck instead of a JT33 one. It has fooled me before :( The reason I believe it was bottomed out is that the transition between the tapers looks a little mushroomed. See how the very end of the MT2 bulges a little? (or is that a visual illusion?) Might not matter, though, since the Morse Taper extends some from the spindle when seated.

It's stamped JT33 but I'm going to replace it anyway. When it's seated into the drill chuck there is no clearance (or wedge slot) between the back of the chuck and the start of the MT2 taper. That means the only way to remove the arbor is by totally disassembling the chuck (Albrecht Keyless) and punching it out which is a PIA.

I don't plan to swap chuck arbors often but I want to preserve that option if possible.

Thanks for the responses.

philbur
07-12-2012, 05:15 PM
Cross drilling the arbor close to the back of the chuck, insert a rod and then use a brass two finger wedge to drive it out. No disassembly required.

Phil:)


That means the only way to remove the arbor is by totally disassembling the chuck (Albrecht Keyless) and punching it out which is a PIA.

Rich Carlstedt
07-12-2012, 09:15 PM
Here is a technique for recovering lightly damaged arbors.
Get some common "wet or dry" abrasive paper in 400 or 600 grit
Cut it to fit ( conical) inside a good (!!!!)chuck taper, with the abrasive on the inside to finish the OD of the arbor.
DO NOT overlap the W & D paper, and infact, try to leave a open space ( .040 ie- like a "seam") in the female taper, make it long enough on two side so the extra abrasive paper is on the flat bottom of the chuck and can be gripped with your fingers.
Insert the arbor and gently rotate the arbor while holding the paper stationary.
Any high spots will be quickly seen.
Continue the action ( with new paper) until the high spots are removed.
Oil can sometimes help.
You can ( smooth now !) apply a thin cost of rubber adhesive to help the paper from moving inside the chuck.
Mark the arbor with a felt tip and check for fit.
If it is clean on both the small end of the taper and the large end as well, you will have a good seat. If it has cleaned up on only the top or bottom, you are out of luck.

By the way fellows, I use this technique on MT #2 when guys give me old arbors.
They usually are dinged, and I file the ding out and then check it with the above method.

Rich

dp
07-12-2012, 10:19 PM
If the tapers can be cleaned up you can drill a cross hole in the MT2 side to hold a drift to separate the chuck from the arbor.

goose
07-12-2012, 10:21 PM
Arbors like that pictured are inexpensive, standard catalog items, so I would not waste time or risk damaging other equipment over a $7 - $15 piece.

Over the years I've wasted too much time, sweat, and blood resurrecting (trying to) crapped out Jacobs chucks, broken drill bits, dull end mills, and used shop towels.

Rosco-P
07-13-2012, 09:01 AM
Arbors like that pictured are inexpensive, standard catalog items, so I would not waste time or risk damaging other equipment over a $7 - $15 piece.

Over the years I've wasted too much time, sweat, and blood resurrecting (trying to) crapped out Jacobs chucks, broken drill bits, dull end mills, and used shop towels.

Agreed. It's a common small arbor. Re-use the arbor, possibly score a spindle taper, ruin a workpiece if it slips out of the spindle, etc..

Penny wise, Pound foolish.

sasquatch
07-13-2012, 09:08 AM
Agreed, i too have spent many hours trying to reserect something, when i should have binned it.
It can be a real learning experience though if one enjoys puttering at it, but not good if you ruin something like the tailstock.

Right now i have two old adjustable wrenches, (One Gray Canada, the other Cresent,) soaking, they finally freed up yesterday, now to get them apart and clean them up.):D

AND........... Do i really need another couple? NOPE!:D

uncle pete
07-13-2012, 04:12 PM
Everybody has and are more than entitled to their own opinions, but I'm in agreement with just tossing it. Good MT's are ground and have proper finish designations for both the male and female tapers because there retained by a very fine wedge action. To operate and resist the twisting forces, both the male and female tapers have to match very closely. Maybe with the capability of using a draw bar I'd chance it, but without one? Accurate and highly finished concentric ground female tapers are more than a bit expensive to recondition in comparison to just replacing that male taper. Why take the chance?

Pete