Eric U
Hot Rolled
- Joined
- Feb 26, 2003
- Location
- Eastern AL
Hi all,
Back when I first got my TL-1, I found that tramming the toolpost was a genuine PITA. Of course back then I crashed my tools a little too frequently, so tramming happened more than I'd care to remember. With my 20+ tool offsets oriented around a trammed toolpost, all I had to do was tram my toolpost and then change my G54 to make my tool 1 offsets zero (actually .0001...the control can't handle zero offsets). When I did that, all the other offsets fall into line. Problem is, jogging an indicator from one side of the dovetail to the other and checking for squareness and trying to adjust is a lesson in futility.
After hours of frustration trying to get that toolpost absolutely square with the x and z axis, I had an idea on how to do this easier. Fast forward a little less than two years and I had just given myself an "opportunity" to test my theory. Rapid one 1/2" cobolt drill into your part and the toolpost will turn a bit.
What is required...turn a large-ish piece of round aluminum stock to a uniform diameter approximately 4" long. I used 1.75" dia. The large diameter piece is stiff enough to have consistent diameter over that 4" turn length without needing to use a tailstock. Mine was about .0001" different at the beginning and end of the cut. You also need a precision turned or ground bar about 8" long. This tooling bar has to be as uniform in diameter as possible. I chose 1" OD and had a tooling buddy of mine grind it out of HSS. Insert that tooling bar into a boring bar holder and mount in the toolpost. This toolholder should hold the bar at very nearly the center height of the lathe. Loosen the top nut on the toolpost and handle or jog the tooling bar that is sticking out alongside the cut you did on the aluminum piece. I then simply held the two bars tightly together with one hand while tightening the toolpost nut with the other. When I measured my tram, my tooling bar was off about .0001" over 4". I then went back and indicated the ground flats on the toolpost and couldn't get a reading on my tenth indicator.
This may be something covered in lathe 101, but I never took that class. A perfectly trammed toolpost was never a necessity on my manual lathe since it didn't remember all my tool offsets.
The two pictures...1st is tooling bar in boring bar holder. 2nd is overhead shot of the tooling bar nearly touching the turned part of the aluminum bar.
Just thought I'd pass this along. I hope it helps someone.
Eric
Back when I first got my TL-1, I found that tramming the toolpost was a genuine PITA. Of course back then I crashed my tools a little too frequently, so tramming happened more than I'd care to remember. With my 20+ tool offsets oriented around a trammed toolpost, all I had to do was tram my toolpost and then change my G54 to make my tool 1 offsets zero (actually .0001...the control can't handle zero offsets). When I did that, all the other offsets fall into line. Problem is, jogging an indicator from one side of the dovetail to the other and checking for squareness and trying to adjust is a lesson in futility.
After hours of frustration trying to get that toolpost absolutely square with the x and z axis, I had an idea on how to do this easier. Fast forward a little less than two years and I had just given myself an "opportunity" to test my theory. Rapid one 1/2" cobolt drill into your part and the toolpost will turn a bit.
What is required...turn a large-ish piece of round aluminum stock to a uniform diameter approximately 4" long. I used 1.75" dia. The large diameter piece is stiff enough to have consistent diameter over that 4" turn length without needing to use a tailstock. Mine was about .0001" different at the beginning and end of the cut. You also need a precision turned or ground bar about 8" long. This tooling bar has to be as uniform in diameter as possible. I chose 1" OD and had a tooling buddy of mine grind it out of HSS. Insert that tooling bar into a boring bar holder and mount in the toolpost. This toolholder should hold the bar at very nearly the center height of the lathe. Loosen the top nut on the toolpost and handle or jog the tooling bar that is sticking out alongside the cut you did on the aluminum piece. I then simply held the two bars tightly together with one hand while tightening the toolpost nut with the other. When I measured my tram, my tooling bar was off about .0001" over 4". I then went back and indicated the ground flats on the toolpost and couldn't get a reading on my tenth indicator.
This may be something covered in lathe 101, but I never took that class. A perfectly trammed toolpost was never a necessity on my manual lathe since it didn't remember all my tool offsets.
The two pictures...1st is tooling bar in boring bar holder. 2nd is overhead shot of the tooling bar nearly touching the turned part of the aluminum bar.
Just thought I'd pass this along. I hope it helps someone.
Eric
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