- Joined
- Sep 28, 2013
- Messages
- 4,392
couple of little projects, one intentional and one not 
I need an internal threading tool to thread the chuck backplate I'm making, so I got a piece of scrap (ex-treadmill roller rod) which had a handily sized hole in the end and make this:
the rod was 7/16 or thereabouts and turned down to fit the 3/8 bore of my tool holder. If I need a longer one I'll just make a new tool holder so I can adjust stickout. Hole was filed (poorly) square and a set screw put in the end. Cuts PVC very nicely! I need to get another project done before trying it out on steel..
The unintentional project was the flycutter. I set out to make a copy of my lathe spindle nose to use to check for fit on the backplate I'm making, but cut the blank 1.5thou to small. After sleeping it off, I decided to make it into a flycutter instead, which I've been meaning to make for ages. Lots of different designs, but I liked the look of the dual cutter type, where you have a rougher and a finisher cutter. The rougher having less nose radius is a little higher and (theoretically, I need to check) a little further inboard, so it takes a chunk and then the finisher shaves the final few thou. That's the theory anyway.
finisher shown
rougher shown. Cutting edges are about 1 1/8in apart, give or take
cutting bits are 2 pieces of cut down 1/4in drills that some previous owner ground really weirdly. Drilled undersize with a D drill and then finished with a 1/4 reamer (1st time ever!) after drilling and threading the 8-32 set screws. Bits were a tight sliding fit, so they're not going anywhere.
Finished off by heating and dunking in oil for rust prevention. No effect on hardness as it's mild mystery steel scrap
the results! Took a bit of fiddling with cutting angles to reduce chatter (far left) but I ended up with what is a very good finish (close to) for my drill press pretending to be a mill.
close up. Still a wee bit of chatter (don't forget, drill press+collet chuck+heavily modded HF XY vise!) but it feels smooth and looks waaaay better than any surface finish I've managed before. Once I get the treadmill motor on my drill press I'll play with speeds a bit more - this was ~800rpm and seemed to work fine in alu, but would be way too fast for steel, if I even dare to use this cutter on steel.
now I just need to make that spindle nose copy
I need an internal threading tool to thread the chuck backplate I'm making, so I got a piece of scrap (ex-treadmill roller rod) which had a handily sized hole in the end and make this:
the rod was 7/16 or thereabouts and turned down to fit the 3/8 bore of my tool holder. If I need a longer one I'll just make a new tool holder so I can adjust stickout. Hole was filed (poorly) square and a set screw put in the end. Cuts PVC very nicely! I need to get another project done before trying it out on steel..
The unintentional project was the flycutter. I set out to make a copy of my lathe spindle nose to use to check for fit on the backplate I'm making, but cut the blank 1.5thou to small. After sleeping it off, I decided to make it into a flycutter instead, which I've been meaning to make for ages. Lots of different designs, but I liked the look of the dual cutter type, where you have a rougher and a finisher cutter. The rougher having less nose radius is a little higher and (theoretically, I need to check) a little further inboard, so it takes a chunk and then the finisher shaves the final few thou. That's the theory anyway.
finisher shown
rougher shown. Cutting edges are about 1 1/8in apart, give or take
cutting bits are 2 pieces of cut down 1/4in drills that some previous owner ground really weirdly. Drilled undersize with a D drill and then finished with a 1/4 reamer (1st time ever!) after drilling and threading the 8-32 set screws. Bits were a tight sliding fit, so they're not going anywhere.
Finished off by heating and dunking in oil for rust prevention. No effect on hardness as it's mild mystery steel scrap
the results! Took a bit of fiddling with cutting angles to reduce chatter (far left) but I ended up with what is a very good finish (close to) for my drill press pretending to be a mill.
close up. Still a wee bit of chatter (don't forget, drill press+collet chuck+heavily modded HF XY vise!) but it feels smooth and looks waaaay better than any surface finish I've managed before. Once I get the treadmill motor on my drill press I'll play with speeds a bit more - this was ~800rpm and seemed to work fine in alu, but would be way too fast for steel, if I even dare to use this cutter on steel.
now I just need to make that spindle nose copy
