Nice old german keyless chuck question

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yota

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I got this either with my SB9A or my old Delta drill press, can't remember which but it doesn't fit any thing I have. both of the machines mentioned are MT2. really would like to use this on my new PM mill which is R8.

the taper on the chuck is close to MT2 but is just slightly loose in my MT2 holders and of course doesn't have the tab at the top to go in the slot. it also has internal threads. I don't see any way to remove the tapered shaft that's on it. no idea what taper it is or I would look for an adapter. hoping the brain trust here has some ideas. I took the lock ring off and there are no set screws or anything under it. thanks!
PXL_20210915_150130810.jpgPXL_20210915_150138953.jpg
 
oh, and there is no fastener inside where the jaws are, only a dimple like a center drill was used.
 
The tapered shaft is an arbor, and is probably attached to the chuck using another taper fit - most likely Jacobs taper.. The threaded hole is for a drawbar to hold it in the spindle, but as jwmelvin mentioned it will really help you when you try to pull the arbor out.

The visible labels only show the chuck size range (in inches and mm) and the maker - Albrecht is really good stuff! Are there any other markings on the back or elsewhere? If you find something that says "JTx", the x would be the Jacobs taper size that connects the arbor to the chuck itself. You can get R8 to Jacobs taper arbors pretty easily.

It is remotely possible that the arbor is integral with the chuck body, but it sure doesn't look like it.

Figure out the thread in the back of the arbor, and get a matching bolt. Get a piece of pipe that clears the arbor and is just a little longer than the arbor. Drop the pipe over the arbor, put a very heavy washer or scrap of plate, etc, over the end of the pipe, thread the bolt thru the washer and into the arbor, and tighten the bolt gradually to pull the arbor out. If it doesn't pop out when you tighten the bolt try a bit of heat on the outside of the chuck.

By the way, the "not quite MT2" might mean that it is a Brown and Sharpe taper, or maybe even Jarno taper. Brown and Sharpe was used on a lot of old milling machines, which might explain why it has drawbar threads instead of a tang.
 
no other markings on chuck or arbor. I'm hesitant to apply heat as I'm sure there are bearings and grease inside and it works as smooth as glass now. I have a LOT of metric and SAE bolts I've collected over the years and strangely none of them fit. think maybe a trip to ACE Hardware is in order.
 
Perhaps instead of removing the existing arbor it would make sense to try to identify the taper on the arbor. Little Machine Shop has a nice page with taper dimensions: https://littlemachineshop.com/reference/tapers.php

Measure the diameter at both ends as well as the length and try to match it up to something in the table. If you can identify the taper on the existing arbor you can probably buy (or make, if you have a lathe) an adapter from that taper to R8. You said it's close to MT2. Since R8 is quite a bit fatter than MT2 such an adapter would be pretty simple and not add any appreciable length to the chuck.
 
BTW, you may already know this, but Albrecht is still around. Here is the page for the current version of that chuck: https://www.albrecht-germany.com/en/products/1stdrill-chuck/inner-taper/10-13-mm/
It appears to be available with JT3, JT6, or JT33 Jacobs tapers, or a 5/8-16 thread, or "B12" or "B16", which I've never heard of.

There is a service manual (German and English) for the chuck at https://www.albrecht-germany.com/fi...Reparaturanleitung_SBF_-_Stand_06.07.2016.pdf
The service manual contains a cutaway drawing so you know what you are dealing with. It has instructions for disassembly and reassembly if that becomes necessary.
Operating manual here (also German and English): https://www.albrecht-germany.com/fi...itung_Chuck_Manual_Rev_0_20_DE-EN_digital.pdf
 
thanks for taking the time to look that up, that will be very helpful. I thought about the threaded arbor possibility and clamped the arbor in my big vise using copper soft jaws, chucked a large T wrench up in the chuck and tried to see if the chuck would unscrew from the arbor but no luck. also from what I've read online you can't drill thru the Albrecht chucks to the end of the arbor to press them out as they are hardened.
 
yota said:
thanks for taking the time to look that up, that will be very helpful. I thought about the threaded arbor possibility and clamped the arbor in my big vise using copper soft jaws, chucked a large T wrench up in the chuck and tried to see if the chuck would unscrew from the arbor but no luck. also from what I've read online you can't drill thru the Albrecht chucks to the end of the arbor to press them out as they are hardened.
Click to expand...

I despise the drill and punch method of removing arbors.

Get a bolt that fits the threads and pop the arbor using jwmelvin's suggestion. At worst, cut the arbor about 1" from the chuck, drill and tap for a 3/8" x 16 bolt and pull it out that way using jwmelvin's method. I've removed quite a few using this method.
 
jmkasunich said:
Perhaps instead of removing the existing arbor it would make sense to try to identify the taper on the arbor. Little Machine Shop has a nice page with taper dimensions: https://littlemachineshop.com/reference/tapers.php

Measure the diameter at both ends as well as the length and try to match it up to something in the table. If you can identify the taper on the existing arbor you can probably buy (or make, if you have a lathe) an adapter from that taper to R8. You said it's close to MT2. Since R8 is quite a bit fatter than MT2 such an adapter would be pretty simple and not add any appreciable length to the chuck.
Click to expand...

I took some measurements on the arbor.

length of taper - 3.0035 in or 76.29 mm
big end dia - .7096 in or 18.024 mm
small end dia - .5674 in or 14.412 mm

with the arbor stuck in the chuck it was hard to get the micrometer fully on the big end as it was touching the chuck but this is close.

nothing in the charts on the Little Machine Shop website match my measurements. I will do some more googling.

I think if I can find out what taper types have drawbar threading that will narrow things down. and I agree that using an adaptor will be better than trying to remove the arbor. of course the down side with adaptors is that they take up space in the Z axis but my mill has a lot of Z.

thanks.
 
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