Thread: Cast Iron Lapping Plate

This is a cast iron lapping plate inherited from my great-grandfather. I would put its age at ~70 years. Unfortunately the pictures aren't very good today because it is: 1) late, 2) in a fluorescent lit shop, 3) taken with a 7 year old digicam with an electronic viewfinder that doesn't match up with the shot being taken! Anyway, the lapping plate is 6x10" and uses fine valve grinding compound to do the cutting. As you can see, there is a wide spaced and narrow spaced side. I tend to use the wide spacing on hones. When you're all finished, you wash the grit off in the sink and get honing!

I like it. Thanks for posting the pics. Very cool that it has that family history as well.

Chris L

It actually lapped the surface plate it is sitting on which came from the same source. The surface plate was purchased surplus from Allison transmissions if I were to guess where he got it and the lapping plate was probably there to flatten chucks and mounting plates for lathes (which I still use it for to this day). It is great to use something he used and to have it work so well. I know not many people here will get real excited about a lapping system, but I would LOVE to see how this compares to using a 325 DLP and a Shapton DGLP. I'm in the Indianapolis area, so I imagine Lynn would be the closest member with access to these systems. I'll have to think about having some sort of super nerdy hone flattening get together here in the future .

Originally Posted by shotwell1234

I know not many people here will get real excited about a lapping system, but I would LOVE to see how this compares to using a 325 DLP and a Shapton DGLP. I'm in the Indianapolis area, so I imagine Lynn would be the closest member with access to these systems. I'll have to think about having some sort of super nerdy hone flattening get together here in the future .

Always nice to see some of the good old gear! I would think your lapping plate would compare quite nicely to the newfangled stuff. I am, however, quite envious of that granite surface plate you eluded to. I haven't seen one that large for quite some time but thats mostly cuz I'm out of the business.

Christian

Sorry to disappoint, but the granite is in a different shop. This is actually a solid steel surface plate and only about 1/4 of it shows. I'll have to get a large picture of it sometime for you. Probably should be referred to as a layout plate??? Anyway, I would have to run a DTI across it to remember how flat it is after the lapping, but needless to say, its flat.

Steel.....<shudder>, you could have at least sprung for a cast iron one. Not so prone to raise burrs. Still, nice size layout table for sure.... I'm still envious!!!!

Christian

Haha, you've got me dead to rights. I'm not going to lie, I thought cast iron, meant cast iron, and could have sworn I typed cast iron. As a matter of fact, I went back and looked at the post three time to make sure I typed steel. What can I say, sometimes the brain doesn't agree with the facts .

To show I'm not crazy! First picture is the plate, second is the plate with the straight-edge used for scale, and the third is a shot of the casting. Enjoy my delicious sanity!

URGLE..........