- Joined
- Jun 17, 2011
- Messages
- 2,062
This project starts with an old magazine article to be found at: http://www.kinzers.com/don/MachineTools/lathe_projects/taper_attachment/taper4.jpg and other places. It was already posted by Scrapmetal in the General section. Since it was designed for an SB9, it is a perfect fit for the Hercus. Most of the details are as shown in the plans, with a few revisions, which will be pointed out.
I started out by buying a cast iron counter weight at the scrappers to use for the two slides. When I cut off a piece to make my surface gauge, I dulled the 10' blade on my big bandsaw. Always go with your slowest speed on unknown cast. Now I'm afraid to try the new blade on it. The alternative was to choose a different material for the slides. I settled on High Molecular Weight Polyethylene (HMWPE).
The bottom bracket is bolted to a heavy plate attached to the back of the carriage. I milled a notch into both to allow the cross-slide to be removed when necessary without removing the taper attachment or the X-axis DRO.
I used 3/8" plate for the cross-slide connector rather than the suggested 1/8" or 1/4" stock because I wanted it to be as stiff as possible. Any flexing would allow the upper slider to rock, changing the distance from the taper bar. A bit of undercutting at the shoulders allows the cross-slide to move all the way forward when the attachment is not in use.
A bit of milling was necessary to make the underside of the cross-slide parallel to the Y-axis of the carriage.
The V-way clamp was milled from a piece of 1"x2"x4" HRS and angled down toward the position of the lower track.
The plans call for curved slots in both the carrier and the table. I opted for three tapped holes in the table to allow the same range of movement.
The 'complete' attachment - still needs some cosmetic work, plus the degree and taper-per-foot markings.
I haven't tried turning any tapers yet. Watching the DRO displays while moving the carriage shows that it takes about an inch of movement to take up the slack before the Y-axis display starts to advance. I may have to rethink the HMWPE sliders. It's relatively easy to replace parts once the whole attachment is done.
I started out by buying a cast iron counter weight at the scrappers to use for the two slides. When I cut off a piece to make my surface gauge, I dulled the 10' blade on my big bandsaw. Always go with your slowest speed on unknown cast. Now I'm afraid to try the new blade on it. The alternative was to choose a different material for the slides. I settled on High Molecular Weight Polyethylene (HMWPE).
The bottom bracket is bolted to a heavy plate attached to the back of the carriage. I milled a notch into both to allow the cross-slide to be removed when necessary without removing the taper attachment or the X-axis DRO.
I used 3/8" plate for the cross-slide connector rather than the suggested 1/8" or 1/4" stock because I wanted it to be as stiff as possible. Any flexing would allow the upper slider to rock, changing the distance from the taper bar. A bit of undercutting at the shoulders allows the cross-slide to move all the way forward when the attachment is not in use.
A bit of milling was necessary to make the underside of the cross-slide parallel to the Y-axis of the carriage.
The V-way clamp was milled from a piece of 1"x2"x4" HRS and angled down toward the position of the lower track.
The plans call for curved slots in both the carrier and the table. I opted for three tapped holes in the table to allow the same range of movement.
The 'complete' attachment - still needs some cosmetic work, plus the degree and taper-per-foot markings.
I haven't tried turning any tapers yet. Watching the DRO displays while moving the carriage shows that it takes about an inch of movement to take up the slack before the Y-axis display starts to advance. I may have to rethink the HMWPE sliders. It's relatively easy to replace parts once the whole attachment is done.