The Home Machinist!

BTW an angle grinder works fine for roughing out a parting tool. No need to remove all that material with the pedestal grinder. I do all the roughing from one side so that when I start the finish work on the pedestal grinder the other side is still flat and square.

BadDog writes:
I have ground the side clearance into a blade, but of course that presents it's own problems for general use (different depths).

The taper doesn't need to continue all the way back: just far enough to make the tip the widest point.

Russ Hanscom wrote: ↑Wed Apr 15, 2020 9:37 am The obvious answer is that there are no specs, if it can be loaded on the boat without failing then it is good to go.

I'm sure they run an analysis in Autocad and it tells them they have a 1.2 safety factor assuming a vertical static load.

I have a neighbor who has a side business working on "big wheel trucks", off-the-road trucks, and similar. He has a legit 2T engine hoist. It looks like it could lift any of my tractors.

Parting without tears I give my parting blades both side and back relief. I grind them so that all of the tool that will ever be in a cut tapers slightly from top to bottom so that the upper face is widest. This reduces the risk of chips getting wedged in. I also add a slight front to back taper so ...

Have you considered altering the design? If the quill has nearly enough travel you could shorten one of the bearings slightly.

> John, the aforementioned lathe has a warped bed and cuts a taper of about .001 in three inches
> — again not bad for a 40-year-old Atlas lathe. OK for most work but this part needs better.

Surprising. My much older Logan holds a tenth over 3 inches (I did shim it).

Harold writes: Have you given any thought to mounting the piece in your mill, taking great care to get the two ends in good alignment, then taking a tiny pass with a boring bar? By using a reasonably large bar (for rigidity) and a tool with a small radius, honed well, you should be able to size the ...

liveaboard wrote: ↑Mon Apr 13, 2020 6:04 pm What I would do...
I'd cut a wooden dowel, and wrap emery cloth around it to use as a hone. I do that all the time. Works for me.

However, someone with more experience will likely have a better idea.

That works but it tends to make the bore very slightly bellmouthed

Your problem is most likely rigidity.

Lots of different ways, since you have all the accessories. I would have used it this afternoon if I had it.

I would have thought that you would have felt such roughness when you were first exploring the problem. In my experience with tapered roller bearings in vehicles and farm machinery well lubricated ones in good condition feel draggy but smooth when overtight (they will overheat, of course). Those wer...