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Boucher
12-17-2008, 12:12 PM
I have a Albrecht chuck with jacobs taper on R8 Arbor that came with my first Mill. It probably has a history of abuse at any rate it has come off the jacobs taper several times. I was doing things like Scarfing the end of a 2" pipe with a hole saw. Long story short a big thanks to Forrest for his information on this subject that suggested heating the chuck to 350 and cooling the taper then installing same. This has worked great proving again that brute force is not the solution to most problems. This forum is great because of the knowledge of its members and their willingness to share that with others.

BillH
12-17-2008, 12:35 PM
I havent tried this yet but if you wipe all the oil off and apply some chalk powder and a light whack with a rubber mallet, should be good to go.

torker
12-17-2008, 12:39 PM
Byron...what is exactly going on here? You know better than anyone...you can just weld that sukker on there. Don't forget your roots eh' :D
Russ

Oldbrock
12-18-2008, 09:48 PM
Russ !!!!!!!!

loose nut
12-19-2008, 03:33 PM
Here is an off the wall idea but it might work?????
Once the tapers are deburred if necessary and freed of oil etc. put the arbor in the freezer for a while and then stick it into the chuck and drive it home. When it warms up it should grab onto the arbor.

gzig5
12-19-2008, 04:43 PM
Here is an off the wall idea but it might work?????
Once the tapers are deburred if necessary and freed of oil etc. put the arbor in the freezer for a while and then stick it into the chuck and drive it home. When it warms up it should grab onto the arbor.

I don't remember the source of the information, but I don't think that freezing shrinks a small diameter shaft (under 1" dia) near as much as is generally expected. Steel grows significantly more in dia with heat than it shrinks with cold, unless you are using liquid nitrogen.:D

djc
12-19-2008, 05:11 PM
Steel grows significantly more in dia. with heat than it shrinks with cold, unless you are using liquid nitrogen.

Think a little about what you have just said please.

This implies I could make a 2" bar out of a 1" bar simply by heating it up and cooling it down a few times!

The point with heating is that you can achieve a much larger temperature _difference_ than you can with cooling (using normal domestic appliances).

Say my shed is 15 degrees C. My freezer is perhaps -10 degrees C, hence 25 degrees difference in the 'cold' direction. My cooker goes up to 250 degrees C, hence 235 degrees difference in the 'hot' direction.

macona
12-19-2008, 10:18 PM
I put my chucks on their arbors with the heat method. I stick the chuck in a toaster over set around 250. Let it get hot and drop the chuck on the arbor.

Cooling isnt such a good idea as you will get condensate on the taper and could rust the arbor in place.

gzig5
12-20-2008, 03:32 PM
DJC,
Not quite sure how you inferred making a two inch bar from one. :confused: That is a bit of a stretch.
What I was trying to imply and did so poorly, was that it is much easier for the average person or business to use heat to expand something a given amount, than it is to use cold to shrink it. Unless of course you have access to liquid nitrogen, which most of us don't. Put another way, putting something in the freezer is not going to shrink a part as much as heating with a torch or oven would make it grow. The delta-T is not as great in the freezer.

Bill736
12-21-2008, 10:09 PM
I wonder if there's a locking compound, like Loctite, that might help hold a taper in place ?

Cheeseking
12-21-2008, 11:35 PM
Super-glue:D

Gavin
12-21-2008, 11:54 PM
Loctite 660 will hold the taper permanently.

BillH
12-21-2008, 11:54 PM
I've used loctite before, the tool removal type.

Big Bob
12-22-2008, 09:41 PM
For many years as a shop teacher I showed students how to clean off the oil and use a chalkboard eraser to deposit chalk onto tapers to help them stay together.
Heating the female part seems like a great way to solve difficult cases, but it might be difficult to disassemble later.
I would definately stay away from adhesives because disassembly would be a problem.
Big Bob

skmod
12-22-2008, 10:35 PM
Hello i have found that using a hole saw in that manner it will all most always come off do to side pressure on the chuck and taper use a 5/8 bolt on the hole saw and put in a collet after trying to cut pipe with chuck and making a mess a frierd gave me this tip and no issues since
Ernie