Rohm Spiro Keyless Chuck bearing verification

tarmo120

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Dec 29, 2012
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Hi guys. I got myself a used and abused Rohm Spiro Keyless chuck with a B12 taper. It is a 0-3/8 or 0-10mm chuck.
It had the old taper broken off so I had to remove it. Damn it was stuck HARD.
I completely took the chuck apart and then was able to press it out.

Now what I did notice when assembling it, that there could be one more bearing ball.
When opening I think I didn't loose any of those balls. I counted 24 pieces.
Can anyone verify the amount of balls in this chuck?
I did try to get info directly fom Rohm, but haven't got any answer so far.
If anyone wants to know how to take it apart let me know.
 
24 is correct with a space open. That is where it looks like an extra ball goes but no it's an empty space. If you had the extra in there the chuck would not work smoothly it would bind.

"Billy G"
 
Let me see if Frank has any papers on them. I'll get back to you tomorrow on this.

"Billy G"
 
I will write an explanation in the evening whem I am near the computer. It is pretty simple though.
 
I saw a pretty good instrucion a few days ago on the Internet. But now I lost it.

Anyhow, first let's explain what part to call what.
The first part I would name is the ''Sleeve''. That is the most outer part with the knurled area and shiny taper.(nose of the chuck=
Then I there is the other knurled part that is located right on top of the taper. That would be called the ''Big Washer''.
Next there is the ''Main Body''. That is where everything mounts to.
Then there is the ''Inner Body''. That would be where the actual arbpr would mount to and what moved the left hand bolt.

Now I did the following.

Took a piece of aluminium and put the chuck upside down in the vice. Grip only the Sleeve. Tightened until it was tight, but the chuck moved freely still.
Then took a pipe wrench and took grip by the main body. A small punch to the wrench and it was free. It is a standard right hand thread.
Now that the sleeve is off, fully open the chuck, and slide out the 3 ''fingers'' that hold the actual tool.
After that you need to hold the chuck by the main body(still upside down) and slowly pry upwards the Big Washer. It is pressed on and this is how I did it.
Once you get it off, don't remove the chuck from the vice. Take a big wrench and open up the washer that you see right under the pressed on washer. That
washer holds the bearing balls. Once removed do not loose those balls.
And you can now pull out the inner body with fingers. I got it all loose and cleaned it and greased it.
Also got the new arbor and now I'm ready to rock'n'roll.

This might sound wrong and incorrect, but I had no info how to do this and also this is the first keyless chuck I have used.
Now I've learned what to look for next time. I only did this this way since the chuck was beat up and I had nothing to lose.
I would not suggest my method with a brand new chuck.

Later.
 
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