The Craftmans Shop > PowerSports
1954 Ford 850 Tractor w/blown Head Gasket (at the very least)
awemawson:
I'd run at about 100 rpm for a first starting point until I were sure things were safe and balanced, and maybe wind up the revs a bit if that went ok. HSS wound be fine for cast iron and much simpler to mount as well as tolerating intermittent cuts better.
I'd find a broken centre drill or end mill of about 6 or 8 mm diameter, drill a hole and pop it in secured with a radial hex socket screw bearing on a ground flat from the outer edge. Grind a cutting edge and off you go.
vtsteam:
Thanks Andrew. HSS would look like 50 rpm, which I can't do -- I think 110 is the lowest speed on the mill drill..
Thoughts on the shank:
I placed a 7/8 end mill I made earlier on the blank to see what a shank would look like. Just looks weak to me, and undersized for the purpose. There's a 7/8" R-8 collet nearby.
So I rummaged around my tools and found the R8 four tool flycutter that usually ships with these Chinese mills. I've never used it and often read that they don't work well. But I was more interested in the R-8 shank that comes with it -- they are removable, so I took it apart:
So I'm thinking of boring the blank 1.063" to take the R8 shank stub end, and actually welding it in place. I can plug weld the end, and also weld around the flange on the top side. Then the R8 shank fly cutter can't shift, as a 7/8" collet mount plain shank could. The draw bolt locks it in place and all dimensions are a lot better -- plus there's a flange to transfer the stresses better. This will be a permanent tool, and probably see more use than the 4 cutter one did anyway.
awemawson:
Years ago (actually 1979 !!!) my first mill was a 'Mill Drill' with a 3 MT spindle and came with one of those cutters. It actually didn't do too badly, but how many of the tips were actually cutting was open to debate. Excellent for hogging out.
Can you not just bore a hole for it rather than weld it? Welding seems rather - well - permanent :clap:
For a one off job though I'd weld a shank in the size of your biggest collet and get on with it - easy to over think and over engineer these things - I should know - I'm as guilty as the rest :ddb:
Also ok 50 rpm is optimum for hss at that radius, but with light cuts you'll get away with your 110 rpm if you don't push the feed too fast
mattinker:
7/8 is much stronger than you think, think about small car drive shafts, around that size,you haven't got that much power going through to your fly cutter! I agree with Andrew about the HSS cutter, slower than carbide and much easier to mount!
Regards, Matthew.
vtsteam:
Thanks for the sound suggestions gents! I'm sticking to the R8 arbor, but will look tomorrow to see if I can't preserve the mounting method. As I remember it there are a retaining bolt in the end and two keys that slot into the older fly cutting head to keep it from rotating on the arbor. If it isn't too big a task, I'll do the same with the new fly-cutter blank. Otherwise I'll weld it.
If welded and I ever do want to use the older cutter as a hogging tool, I only have to make another arbor. Simple, since it doesn't have to be R8, it could be, ahem, 7/8" rod right? :poke:
Matt mounting the insert is just as easy as mounting a HSS tool -- just mill a vertical slot in the periphery and drill and tap a retaining hole for the screw -- I've done it before -- see the first of the three pics above and look on the right side to see an end mill/fly cutter I made the same way, using the same insert. It was used to clean up my iron sand castings last summer and worked a treat!
But, guys, not to ignore your good and helpful advice, I'll also make a mount in this fly cutter for a HSS tool, so I can do either. There's about 20 inches of periphery and plenty of room to make additional tool holders. It will always be used as a single point cutter, but with a choice of tools. Best of both worlds?
Now back to my dumber antics, the first step, no matter what, was to mount the blank on the lathe to clean it up and get a pilot hole started. You'd think I could manage that easily, having added shelving, rearranged tools, built benches and cleaned and organized my shop last fall.
But no. I can't find things any more! Where was that stupid shim I needed for my non standard 4 jaw chuck mount to prevent it from hitting the Craftsman gear shift knob? Nowhere I could remember. I know where it used to be -- right next to the 4 jaw on the board I put across the end of the ways. But that's all gone now the lathe is moved to the other end of the shop.
I haven't done any machine work since I rearranged everything 4 months ago. Everything is too damn organized and out of sight! What was I thinking?
Well that shim was a makeshift solution anyway. I really should turn down the back of the 4 jaw chuck and leave a boss to get clearance at the periphery to accomodate the gear shift knob. So that's what I did this afternoon instead of make the fly cutter to cut the head to replace the head gasket to fix the engine to use the tractor to run the backhoe to dig out my pond where it filled in from the flood from that hurricane Irene. Phew!
And I did. The 4 jaw now mounts properly, and it has the fly cutter blank clamped up for turning tomorrow.
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