Re: [CAD_CAM_EDM_DRO] Re: Creating long straight edges (and big squares)

cnc_4_me wrote:

> Jon:
>
> Your use of a toolpost grinder to grind to V ways using the tailstock
> ways is very cleaver.

Thanks, but I think I'd heard of this being done before. It was pretty neat,
though. The compound rest came off the lathe and made a perfect height
adjusting axis for this. All I needed to make was an angle plate to mount
the compound so it would travel vertically.

> But how did you get the tool post grinder to the exact angle of the V
> ways.

First, I sighted between the wheel and the ways with a flashlight shining
through the gap, which got me very close. Then, I made a very light touch,
and made minute adjustments until it was cutting across the full width
of the way. Since I had to remove some .013" of material on the front way,
it was no big deal if I made a few little gouges, as all that was going to be
ground down in many more passes.

Also, the EXACT angle is not important. it has to be straight and true
for the full length, but I will fit the carriage to the ways, when they are done.
I will be casting Moglice into the carriage as a low friction way liner
material. This will build the carriage back up to the correct height, too.

> And how did you prevent chatter of the grinder as you moved it
> manually down the ways.

Chatter was not a problem at all. I took very small cuts, about .001" at the
most. I dragged the grinding rig down the ways with a small gearmotor and
picture hanging wire. If the grinding is done such that the wheel will tend to
climb up the 'hill' when it grabs a little, it will not chatter. If the wheel is turning
the opposite way, such that it drives the wheel deeper when it digs in, that
can cause chatter with a flimsy setup, which this certainly was.

Jon