LMS #1275 Tool post grinder- impressions

[lazlo]

The two phase ones were ran off a motor generator unit that created the two phase power they required. The three phase one run at something like 146v 3 phase 900hz. I have a VFD that will do 600, but 900 is pretty rare.

Jerry, I found a relatively common industrial VFD that generates up to 1,000 Hz. I'm using one to drive the high-speed (80,000 RPM) air spindle I bought on Ebay. Send me a PM and I'll tell you about it.

[Timewarp]

Steve, can you take pictures when you "pop off the saddle"? Just got a southbend and would appreciate the play by play.

Thanks, Paul

[Liger Zero]

Ok this seems like a good time to ask the obvious question:

Why grind? All of my lathe-training centers around cutting bits of various and sundry configurations. What situations would arise that would require the use of a grinder?

Also, I can forsee many questions on the horizon about wheel-direction and lathe direction.

Since I've got some "free time" can ya'll kick me in the right direction?

[S_J_H]

Paul, no problem, here you go, just finished cleaning and lubing her up.. There are just 4 bolts to remove and the lock. The 2 slotted screws up front, the 2 rear plate bolts and the lock. It is literally a 2 minute job to remove. So cleaning is nice and simple after grinding. I suppose some lathes might be a big ordeal but not a SB9.





Liger, situations when grinding is used,
Hardened alloys, when a very fine finish is needed, working to tenths, very small diameter work such as making a small tapered needle valve. etc etc. It just opens up a few more capabilities if you don't mind the hassle of covering the lathe and being real anal about the grit.
Steve

[pcarpenter]

A TPG is an alternative to actually owning a centerless grinder which most of us home shop types never will. Forrest has made the case that they are not worth it for most of us (because of the issues of having to cover the lathe very carefully and then (as evidenced here) perhaps still do a very surgical cleanup due to the propensity of grit to go everywhere.

Where they are useful as already stated is in working to very precise tolerances, in producing a very fine finish, or in dealing with very hard materials that will not cut. If a guy were making a shaft that had to pass through a seal (or worse yet, move back and forth without chewing the seal), you need both a great finish and tight tolerances so that the seal will not have to expand and contract to deal with varying diameters.

Another thing they are used for is in "truing" chuck jaws by grinding on their working face while in place in the chuck. There's lots to consider when doing that, but they have to be held "out" under some tension while ground true, usually with a spacer ring at the back of the jaws or by turning fast enough to cause enough centripetal force to keep them in place.

Paul

[Liger Zero]

At home I work mostly plastic and aluminum. Pipe-fittings and filter bodies, the occasional "robot part" for the various robot-construction leagues and school-activities in the area.

At work-work, I'm working mostly steel, brass and bronze... secondary operations on screw machine parts.

Not very likely that I'll ever have a use for one then.

[carlquib]

Has the quality of the wheels that LMS has for this little grinder improved? I got one a while ago and a bunch of different wheels. Most of them had fairly large run out, both thickness and concentricity. It made a huge mess to true up the wheels. I looked for a different source for wheels but didn't turn anything up that had the right o.d. and i.d. Anyone found another source for these grinding wheels?

-brian

[lazlo]

Has the quality of the wheels that LMS has for this little grinder improved? I got one a while ago and a bunch of different wheels. Most of them had fairly large run out, both thickness and concentricity. It made a huge mess to true up the wheels.

That's the same problem I'm having with my Harbor Freight carbide grinder: it's got a ton of runout. With a thick AO wheel you can true most of that out, but when I mounted a diamond wheel on it, it wobbles a lot, even after I trued the wheel mounting plates.

A bunch of guys have have taken the whole thing apart and trued up the motor shaft and the plate spigots -- it's on my tuit list...

[S_J_H]

Brian, I would say no they have not improved. I had to do quite a bit of dressing to the wheel. Made a huge mess like you said. I'll probably buy a decent 4" wheel and make a new spindle shaft. But I would not say the 80mm LMS wheels are a deal buster. Just a bit of a mess to true them up.The 120 grit wheel I bought extra seems a little nicer though than the 80 grit that came with it.
Steve

[Timewarp]

Wow Steve, that looks easy! Mine probably needs a good cleaning.