- Joined
- Oct 20, 2014
- Messages
- 495
Hi All,
After cleaning up my lathe, I got started on making another QCTP. Before anybody starts drooling too much, it's not a wedge or piston type QCTP. It's literally a post mounted on the cross slide that toolholders slip over and are secured with a knob. (or a nut, in this case, until I can cast the brass knob)
The stock Taig toolpost is 1.75" tall, 1" square. The tool slot is 1" from the bottom, and it's secured to the cross slide with a 10x32 SHCS. While it's not a bad design, I hate when the SHCS for removing it gets plugged with chips. The grub screws that secure the cutting tool get full of chips too. Grabbing a T handle hex wrench is quick, but digging out the chips with a pick is a pain in the nether regions.
My design uses 1.25" square stock, around 2" tall, with the slot at the same height as the stock toolpost.
The toolpost itself is a 1/2" stainless steel bolt, which will have two tabs on the bottom to engage the T slot and prevent twisting. It'll be drilled down it's length to clear a 10x32 button head cap screw, and a 10x32 square nut will secure it to the cross slide. The upper end of the bolt is already threaded, and will stand proud of the top of the toolpost high enough for the knob to engage at least 3/8" of threads.
The toolholders will be drilled then bored for a slip fit on the toolpost. One end gets faced, then the drilling and boring (ensures it's perpendicular to the bottom), then it's flipped end-for-end and faced to length.
The second type of toolholder has tabs on it's bottom, to engage the T slots of the cross slide. This lets me position it at a known, repeatable angle to the spindle. Useful for boring and parting operations.
I started by chopping the stock to length with the mitre saw. I use a carbide-tipped Diablo blade on it (brand new), and aside from making a god-awful racket, it cuts quickly, square, and accurately. Stand to one side, wear safety goggles, and beware hot chips. Can you see the QCTP in here? I can.
You can see the longer blank. It's the one that'll have tabs on the bottom.
I then chucked up the piece in the 4 jaw chuck, got it centered, then faced it off. Spotted, drilled, bigger drill, drilled, bigger drill, drill. I actually tried drilling one out to 1/2" as a trial, and while it's usable, it's a bit sloppier on the toolpost than I like. I'll stick to drilling undersize and boring to a slip fit. The shank of the 1/2" bolt is actually very consistent in diameter.
I only had time to get one toolholder mostly finished today, plus my gimp knee was screaming by that point. Way too much walking, standing, and moving.
Definitely beefier than the stock Taig toolpost. I have already cut the head off of the stainless bolt, but haven't machined the tabs or cut it to length yet. That'll wait until the toolholders are finished.
Unfortunately, I won't be doing any shop work this coming weekend (nov 8-9). I *finally* got an appointment for surgery on my knee on Friday the 7th, and it'll be at least a week before I can get back out in the shop. Not a major surgery, thankfully. Just a torn meniscus and probably some torn ligaments. I'm really looking forward to getting it fixed. No more hobbling around or sleepless nights. I might have some free time in the evenings this week, but can't guarantee it. After I get home from work it's dark (Thanks, daylight savings :angry, and my knee is usually screaming. If I do get out there, I'll take more pics. Gotta put that DSLR to use!
After cleaning up my lathe, I got started on making another QCTP. Before anybody starts drooling too much, it's not a wedge or piston type QCTP. It's literally a post mounted on the cross slide that toolholders slip over and are secured with a knob. (or a nut, in this case, until I can cast the brass knob)
The stock Taig toolpost is 1.75" tall, 1" square. The tool slot is 1" from the bottom, and it's secured to the cross slide with a 10x32 SHCS. While it's not a bad design, I hate when the SHCS for removing it gets plugged with chips. The grub screws that secure the cutting tool get full of chips too. Grabbing a T handle hex wrench is quick, but digging out the chips with a pick is a pain in the nether regions.
My design uses 1.25" square stock, around 2" tall, with the slot at the same height as the stock toolpost.
The toolpost itself is a 1/2" stainless steel bolt, which will have two tabs on the bottom to engage the T slot and prevent twisting. It'll be drilled down it's length to clear a 10x32 button head cap screw, and a 10x32 square nut will secure it to the cross slide. The upper end of the bolt is already threaded, and will stand proud of the top of the toolpost high enough for the knob to engage at least 3/8" of threads.
The toolholders will be drilled then bored for a slip fit on the toolpost. One end gets faced, then the drilling and boring (ensures it's perpendicular to the bottom), then it's flipped end-for-end and faced to length.
The second type of toolholder has tabs on it's bottom, to engage the T slots of the cross slide. This lets me position it at a known, repeatable angle to the spindle. Useful for boring and parting operations.
I started by chopping the stock to length with the mitre saw. I use a carbide-tipped Diablo blade on it (brand new), and aside from making a god-awful racket, it cuts quickly, square, and accurately. Stand to one side, wear safety goggles, and beware hot chips. Can you see the QCTP in here? I can.
You can see the longer blank. It's the one that'll have tabs on the bottom.
I then chucked up the piece in the 4 jaw chuck, got it centered, then faced it off. Spotted, drilled, bigger drill, drilled, bigger drill, drill. I actually tried drilling one out to 1/2" as a trial, and while it's usable, it's a bit sloppier on the toolpost than I like. I'll stick to drilling undersize and boring to a slip fit. The shank of the 1/2" bolt is actually very consistent in diameter.
I only had time to get one toolholder mostly finished today, plus my gimp knee was screaming by that point. Way too much walking, standing, and moving.
Definitely beefier than the stock Taig toolpost. I have already cut the head off of the stainless bolt, but haven't machined the tabs or cut it to length yet. That'll wait until the toolholders are finished.
Unfortunately, I won't be doing any shop work this coming weekend (nov 8-9). I *finally* got an appointment for surgery on my knee on Friday the 7th, and it'll be at least a week before I can get back out in the shop. Not a major surgery, thankfully. Just a torn meniscus and probably some torn ligaments. I'm really looking forward to getting it fixed. No more hobbling around or sleepless nights. I might have some free time in the evenings this week, but can't guarantee it. After I get home from work it's dark (Thanks, daylight savings :angry, and my knee is usually screaming. If I do get out there, I'll take more pics. Gotta put that DSLR to use!