How do I get this Albrecht sensitive (0-1.5mm) chuck off of the shaft?

[CompositesGuy]

I need to detach this tiny (and crazy expensive) chuck from the shaft. The chuck was in good condition (Albrecht 0-1.5mm), but the hand feed needed some work. From some Google research it seems there is a JT0 taper between the shaft and the chuck, but I can't break it loose. I tried holding the shaft in a collet and hitting the backside of the chuck with a tiny home-made slide hammer. I also tried spinning the knurled part at the back side of the chuck, but that just spins on the chuck body.

 

[Bakafish]

My smallest Albrecht is 0-3mm, that's pretty cute. Depends if you want to preserve the arbor shank or not. Wedges (designed for the purpose) are the only effective way I've found of removing these, since there doesn't appear to be any shoulder you will need to weld a nut, cross drill or possibly clamp some kind of secure shoulder for the wedges to act against. Amazon sells the Jacob's brand drill arbor wedges pretty cheaply in the US, make sure you pay attention to the sizes.

 

[CompositesGuy]

I was kinda hoping to save the shaft, so that I could reassemble the sensitive hand feed that it is a part of. Does anyone have a non-destructive solution?

 

[Bakafish]

Also, tiny arbors like this are not common or particularly cheap, why are you trying to remove it in the first place?

 

[CompositesGuy]

The sensitive feed has return spring that runs down the center of the shaft. This extension spring keeps the chuck up off the workpiece until you hand-feed it down. When I removed the hand-feed bits (to replace a drop-damaged bearing) I had to unhook that spring. Sadly, when I unhooked one end, both ends of the spring came loose. I need to pull the shaft from the chuck just to reset the spring hook on the chuck end. It seems like a lousy design that the spring can come unhooked so easily.

 

[CompositesGuy]

Here's a photo of what I just described. The spring and the hook at each end is shown. The left end is simply a brass cap with a loop on it. The right end came dropping out of the shaft (from the chuck end) as soon as the spring tension was removed. I have no idea how it seats on that chuck end, but it sure came out easy. I see no way of resetting the spring without getting the chuck off the shaft.

 

[CompositesGuy]

Found this pic on Ebay. Mine looked just like this before I started disassembling. There's a ball bearing pressed into that aluminum hand-feed-wheel. Mine was trashed.

 

[Bakafish]

Well those tapers are insanely strong, the wedges are the only way I've found to do it. Hammering, heat/cold and gear pullers are useless. Since Alberich's have no through hole, a press isn't typically useful. If you don't want to damage the shaft you will need to make a clamping bushing, don't skimp on the length, for the wedges to push against.

 

[Bakafish]

Also, it would surprise me if they had some sort of fastener in the taper section. I still wonder if this needs to be removed. Would be nice if you documented the parts and how you believe they are arranged a little bit better.

 

[Bakafish]

looking at your pictures, I'm assuming the shank is hollow with a single slot on one side? And the spring fits inside the shank? Seems like the little wire fastener piece runs in that slot, running through the spring end. You need to look for witness marks and see if you can understand where it has been all its life. It doesn't feel like there would be room for it in the taper section, and how would you even machine that area to create a space for it? How did it come out of that theoretical space? Take a step back and rethink this.

 

[CompositesGuy]

Yea... I didn't take pictures along the way because I didn't plan on finding difficulty ;-) The shank is hollow, with the spring inside. That slot is an anti-rotation feature that has a key which I didn't show in the picture. The slot also acts to limit the linear travel of the chuck. I didn't want to get into the details of all that because I hadn't taken good pictures.

As it turns out. I loosely hooked that little black squigly bit (shown in my picture above) on one end of the spring and pushed both down the center hole of the shaft a few dozen times... and magicially the spring rehooked itself down near the chuck. My hunch is that squigly bit just turns sideways on the end of shaft (inside the chuck taper) to hold spring tension. So... I didn't have to take the chuck off after all. Feel like I got a bit lucky with that.

I'm pretty happy now though. I think I paid $20 for this at an estate sale 10 years ago... and now I have a nice little sensitive chuck all in one piece. My only beef is that the replacement ball bearing that I purchase from Zoro said origin = USA on the website but the bearing I recieved says China. Oh, well... I'm not taking it apart again.