Anyone have a surface grinder?

[wv109323]

Does any of the machinists on the forum have a surface grinder? I recently bought a mold from Mi-hec and the sprue plate was not straight. Two of the cavities had .004" clearance between the mold and the sprue plate while the other two were tight. He sent me a new sprue plate that cured the problem. So I have the old one. I would like to have it ground and use it as a spare. Anyone have a grinder?

[kbstenberg]

Just my 2 cents
DO NOT USE ANY POWER TOOLS TO FLATTEN THE PLATE. You can take too much off to quickly. Get a piece of 1/4" glass attach a 400 grit or finner piece of emery paper to the glass. An slowly rub the sprue plate on the paper to flatten it. You also have to use some form of lubricant to ease the flattening.
A question. How is the sprueplate bowed? Is the center higher than the ends? Kevin

[dkf]

A surface grinder will take the bow out of the plate no problem done by an experienced machinist. The plate may need some shimming so the magnet does not pull it flat. Though the sprue plate is probably thick enough to prevent much distortion.

[wv109323]

The sprue plate is tight to the mold near the pivot bolt ( on the two cavities closest the sprue pivot) and then curves out to .004 clearance at the end of the four cavities. My estimation is that the sprue plate is straight for about half it's length then is "bent" to allow for the clearance over the other two cavities.

[Catshooter]

A surface grinder is the right tool for the job.

They don't pull off too much. You can easily set it to remove one ten thousandth of an inch at a time.

It's not a Dremel. :)


Cat

[bwgdog]

Eric hollow point-Has done a few for me-great work and turnaround.