LMS #1275 Tool post grinder- impressions

[S_J_H]

Take it easy Macona. I like to think a little grit helps to polish and lap the ways.

J/K. Of course it was covered during actual use and it will be thoroughly cleaned before using again.
Luckily a SB9 is very easy to pop off the entire saddle and clean any trapped grit that was caught anywhere.

Steve

[macona]

One other thing. There should be some cardboard/paper blotters that go between the grinding wheel and the flanges on the arbor. The stone will not be happy in the long run without these.

The stones are 20mm ID. Which is almost unheard of here and usually only special order. I know, my Tsugami tool grinder uses 20mm ID wheels.

[S_J_H]

Yes, the flanges are both fitted with what looks to be some sort of fiber washer to protect the stone. They a little smaller diameter than the steel flange so you can't see them in the pics.
LMS carries many different grits in this wheel size. I also have a 120 I'll have to try out.

Steve

[macona]

Have you set up something to dress the stones once you get it on the lathe? I had bought a home made TPG at a garage same once and it came with a little dresser that attached to the ways like a steady and gave a secure method to hold the diamond.

Fine wheels are best for form grinding. You cant take very much off at a time. Look up some stuff on surface grinding. Most of the info will translate to this. But LMS gives no real info on the stone specs so its tough.

[S_J_H]

To dress the wheel, I used a diamond dresser in my 6" 4 jaw and locked the spindle, I removed 1 of the jaws for clearance and used 3 of the jaws to hold the dresser tight. Worked real well.
For my HBM machine I'll make a dedicated dresser holder like you mention.

I figure to use the finer wheels for finishing only. I'm not much up on grinding practice but have a pretty good library of material to consult as needed.
By the way, I would love to have one of those Precise grinders. I borrowed one once. Almost bought one like that off ebay a while back.

Steve

[tattoomike68]

Oh, please, please, please tell me you covered the machine before you started grinding.

A TP grinder is one of the fastest ways to ruin a lathe. You cant be too careful. Ideally use plastic under oiled cloth. Or at least a very fine thread count cloth. Grit is much smaller than you think.

Thats real nice and all till that big ass cloth grabs the chuck and turns into the rotary cleaning brush from hell. You will crap your britches. plus that big chunk of metal under the chuck might get wound into the cloth and realy beat the hell out of the ways.

Sorry but thats scarry. like running a drill presss with a necktie.

I say make a few peices of cardboard/paper that you can fling in the trash when you are done. just tape something up.

[macona]

The spindle is turning about 100 RPM. If there is a problem I can hit the estop with my knee and it will stop instantly at that speed.

[macona]

Bad thing about the precise spindle is the collets are horrendously expensive. The ones for my spindle are something like $225 each. I ended up regrinding some from ER collets. They spindles also need to be run in after they have sat for a while to redistribute the grease in the bearings.

Another thing you have to be careful of with these things is there are several different types of motors. The basic is a universal motor like in a hand drill, then there are two and three phase motors. 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.

Then there are all the different arbor configurations. Some are designed for internal grinding only, some can do both, some have 10 or 20 taper noses, and some are collets like mine.

Also there are different cooling options. Water cooling, flow though, and venturi. Mine is the venturi style that requires you to hook it to an air line and uses a venturi to increase the air flow through the spindle. The only reason I can think of for using this system was to eliminate a fan on the motor to lower vibration. Be careful of water cooled ones. I got one off ebay and the thing was plugged solid with lime. The bearings were shot to so I sent it back. Bearings are insanely expensive.

[J Tiers]

I don't think he DID cover the lathe....

In picture #1 there is a nice little pile of pink dust on the bed right where it would go if he ground the rod that shows grinding marks.

Bad Steve!

[S_J_H]

No it was covered. There was TONS OF GRIT from dressing the wheel which was around .020" out at first. . My ways would have been pure pink had it not been covered. When I removed the rags plenty of it fell onto the lathe. But I planned on popping off the saddle anyhow so I could care less.

Steve