Last year I bought an albrecht chuck off the bay for a deal that was too good to be true. 1/4" chuck in great condition for $30, ships free. Hmm. It was my bad, the seller showed the taper hole and I noticed that it said D1. Must have been a misprint, there is no D1. Must be a J1 like its supposed to be for a 1/4" chuck. NOPE. It is a "dental taper" (I don't like dentist). Didn't know that such an animal existed. Very little info out there but I found out that a dental taper is .250" over 12" with the major diameter being .375, if anybody cares.
I have been watching the bay for a beater or "parts only" unit I could steal the body off of, but even the worst of the units were selling for $50 or better. I finally decided that I would take a stab at turning the taper between centers on my own. I purchased one of those tailstock taper chinese things with an MT4 for $150 to the door. I didn't mind doing this because I don't have a taper attachment for the lathe and didn't want to pull the tailstock off center. Put a dog driver on the spindle, made a 2 minute dog out of a piece of scrap and pinned up a piece of 9/16" cold rolled between the centers.
Not trusting the hash marks etched in the attachment and too lazy to do the math if I did trust them, I put a travel indicator on the backside of the attachment to adjust from. Worked great. I did the math out to .0001 to give myself every hope of succeeding. The offset for the dental taper on a 4" piece of stock was .0416 for a 1" long taper. Easily set with the indicator.
All light cuts because I turned the end I was going to taper down to .390 before I started. Only taking .040 off the minor end, where most material was to be removed. Used 700 rpm and carbide to make the 5 light passes, checking the progress after the 3rd pass.
When I was done, I set it in the chuck gently to see if had any play and it did not. Tapped the chuck on and spun it in the mill.
.0005 give or take of runout. Better than I expected but great when using small bits.
I like the taper attachment, but it took some creativity when working with short material. I had to rotate the tool post to reach back far enough to touch the live center. Also put a small spirit level on top of the attachment when I put it in the tailstock to make sure my offset travel was true. It can be set very accurately tho. Wouldn't recommend it for heavy work.
Since I can't build anything just right, there is a shallow groove in the shank. While turning the shank down to .500 I bumped the cross slide on the last pass while trying to shake hands with a Clydesdale.
I have been watching the bay for a beater or "parts only" unit I could steal the body off of, but even the worst of the units were selling for $50 or better. I finally decided that I would take a stab at turning the taper between centers on my own. I purchased one of those tailstock taper chinese things with an MT4 for $150 to the door. I didn't mind doing this because I don't have a taper attachment for the lathe and didn't want to pull the tailstock off center. Put a dog driver on the spindle, made a 2 minute dog out of a piece of scrap and pinned up a piece of 9/16" cold rolled between the centers.
Not trusting the hash marks etched in the attachment and too lazy to do the math if I did trust them, I put a travel indicator on the backside of the attachment to adjust from. Worked great. I did the math out to .0001 to give myself every hope of succeeding. The offset for the dental taper on a 4" piece of stock was .0416 for a 1" long taper. Easily set with the indicator.All light cuts because I turned the end I was going to taper down to .390 before I started. Only taking .040 off the minor end, where most material was to be removed. Used 700 rpm and carbide to make the 5 light passes, checking the progress after the 3rd pass.
When I was done, I set it in the chuck gently to see if had any play and it did not. Tapped the chuck on and spun it in the mill.
.0005 give or take of runout. Better than I expected but great when using small bits.
I like the taper attachment, but it took some creativity when working with short material. I had to rotate the tool post to reach back far enough to touch the live center. Also put a small spirit level on top of the attachment when I put it in the tailstock to make sure my offset travel was true. It can be set very accurately tho. Wouldn't recommend it for heavy work.
Since I can't build anything just right, there is a shallow groove in the shank. While turning the shank down to .500 I bumped the cross slide on the last pass while trying to shake hands with a Clydesdale.
