I have a lathe but no mill. I'm looking at getting a tabletop 3 axis tramme
l CNC, which I think will be cheaper and more useful for me than a knee mil
l, but I have a project which would require a lot of collet slotting in del
rin, and this machine seems not the best choice. I feel like I've seen a de
dicated machine, but don't remember where. Also, I'm wondering if some sort
of sharpening machine could be adapted.
On further thought, maybe I could mount a small motor fitted with a slotting saw to my lathe carriage or compound, and mount an indexing wheel to the back of the spindle. This seems like it could be done cheaply if I could find the right parts.
ing saw to my lathe carriage or compound, and mount an indexing wheel to th
e back of the spindle. This seems like it could be done cheaply if I could
find the right parts.
Or an arbor in the lathe's chuck with the slotting saw, and an indexing fix
ture mounted on the cross slide or compound. You did not say what type col
let, so hard to help with the fixture, but no extra motor would be needed t
hen. Hex stock makes for an easy indexing fixture if it fits your needs.
Delrin should be easy enough to slot, just don't melt it by going too fast.
I imagine de-burring is going to be tricky, best to avoid burrs in the firs
If I had to do it, I'd use the small Burke #4 horizontal mill that I've got
Yes, that makes sense. From the photo you can see it's a very simple slotti
ng operation. I wouldn't be doing the tapered thread you see there. I haven
't decided on four or six slits, so a hex or square rod would be enough for
indexing. I still can't quite visualize the fixture involved, but perhaps
it could be as simple as a bracket mounted to the compound which holds a sq
uare or hex block center-bored and threaded to accept the threads on the co
llet. That would be cheap enough!!!
Agreed. I've got a Nichols horizontal mill, and that is what I
would use (with an index head, or perhaps a makeshift one for just this
task). But I'm not sure how easy that will be for robobass to get. I
think that he's in Germany? There may be equivalent machines there, but
probably not many by those two names. they are not exactly light for
shipping. My Nichols was something like 1100 LBs (make that about 500
Note that some of the Nichols mills (in particular, the
"toolroom" model) have the choice of a lever feed for the X axis, or a
leadscrew with a half-nut which drops by removing a screw, and allowing
it to hang from a stripper bolt while you put the other bolt back in
place. And yes, I use it in both formats from time to time.
It comes with a three phase motor, and mine at least is 240 VAC,
so I don't know whether that would be a problem as well. But it runs
slow enough so overheating the Delrin would not be a problem.
You probably want support for the Delrin -- plan on an arbor
inside it as well as the grip on the taper. And before you make the
actual runs, run the saw to cut grooves in the arbor (and make sure that
your index system will always use the same arbor positions.
If you were to do it on the lathe, I would suggest a
modification of the usual milling attachment which replaces the
compound. You want at least one axis with lever feed instead of
leadscrew so you don't crank forever on the cuts.