Removal of Chuck on Motor shaft

[panofish]

My new benchtop mortiser is pretty nice, but comes with a chuck that is pretty lame. It appears to be attached to the shaft by a taper. I believe I have a matching replacement with a much better quality chuck (pic#2). The chuck is a 1/2" chuck, marked 1.5-13mm. The Taper goes from 14.7mm to 16mm.

Here are my questions.

1. What size taper is this?
2. What is the taper rod that is shown in pic2 and what is it for? It is not a drawbar. It seems to be an extension of some kind, but I can't figure out where I got this and the matching chuck originally?
3. How would you remove the chuck from the motor shaft? I do not want to harm the motor, bearings, or shaft.

 

[Swifty]

It looks like a Jacobs taper, common on drill chucks, would have to look up the size to get the number. The shank appears just to be a straight shank for a drill chuck. To remove chucks I always used a special tapered drift, it was a "U" shape with a shallow taper, if you make one, you will have to use some steel blocks or similar to fill the gap behind the chuck, and use the U drift behind the chuck. Give the drift some sharp whacks with a hammer and the chuck should come off.

Whenever I fitted a new chuck, I wound the jaws out of the way, warmed the taper hole in the chuck lightly with a small gas torch, not too hot, then placed the chuck on the taper and gave it a few blows with a nylon faced hammer. When the chuck cooled down, it gripped even tighter.

I will try to find a picture of the tapered drift.

Paul.

 

[Swifty]

Here a couple of links which show the tapered wedges.


http://www.use-enco.com/1/1/32916-1...e-drill-chuck-keys-drifts-removal-wedges.html
http://www.jacobschuck.com/drill-chuck-removal-guide

Paul.

 

[chucketn]

In the first picture of the mortiser, I see the chuck capacity is listed, 1.5-13mm. Most chicks I have seen also list the taper following the chuck capacity. What is printed there?
Some chucks are threaded on the spindle. Open the chuck's jaws and look inside for a screw head, could be allen, cross point, or even slotted. If you can see a screw head in there, the chuck is (right hand) threaded onto the spindle, and held from unscrewing by a left hand threaded screw into the spindle.
The left hand screw will have some type of thread locker on it and will be difficult, but not impossible, to remove. Most battery driven drills have threaded chucks.

Chuck

 

[panofish]

Wedges won't work because there is no shoulder on the shaft.

I am reasonably sure that the shaft is tapered because I can see a slight taper before the shaft enters the chuck.

When I open the jaws fully... I can see there is only a small 3/32" hole at the bottom of the chuck.

My current plan is enlarge the hole and use a punch with a bearing separator to push through the hole and pull the chuck off the tapered shaft. This should avoid any damage to the motor bearings.

 

[chucketn]

Is there a taper spec stamped on the chuck?

Chuck

 

[tornitore45]

When fitting a chuck to the harbor taper is important that both the arbor and the hole be clean and degreased. I use acetone.

 

[panofish]

When fitting a chuck to the harbor taper is important that both the arbor and the hole be clean and degreased. I use acetone.

Good advice.

The chuck is stamped with only "1.5-13mm B16" and nothing more. My guess is the taper is JT33.

 

[Swifty]

B16 is the taper, see here http://www.pretooling.com.au/media/jacobs/taper-dimensions.pdf

Paul.

 

[chucketn]

Good catch, Paul. I'm familiar with the Jacobs Tapers, but wasn't aware of the metric ones listed in the linked pdf. Thanks for that link. Saved to my reference folder!
Though I spent 8 years in Great Britian, that was before my hobby machinist days. I am most familiar with the Yankee tapers and threaded chucks.

Chuck

 

[panofish]

B16 is the taper, see here http://www.pretooling.com.au/media/jacobs/taper-dimensions.pdf

Paul.

Excellent!.... My replacement chuck is also B16

 

[panofish]

Finally finished my video review of the Rikon Mortiser...

[ame="http://www.youtube.com/watch?v=K3ta3OTK5Wg"]http://www.youtube.com/watch?v=K3ta3OTK5Wg[/ame]

 

[Swifty]

Excellent video, and a very nice wood shop.

Paul.