[yoopertool]

My work is looking to start making some parts interially. They are small surgical burs made of hardened M2. To be cost competitive we have concluded that due to the diameter tolerances (.0003" total), and straightness tolerances (.001" over 2") that we need to grind these complete after they are hardened. We do alot of stainless steel turning and grinding, but not much with M2. the parts would have to come out of 5/16 barstock and have portions ground to .125". Part length ranges from 4" to 6" with various steps and head configurations. Qtys are up in the 300,000+ range, so it would have to be something quick.

Does anyone have any sugestions as to what style and brand or machine would work best? I do alot of tight tolerance turning and milling, but not much grinding, so any suggestions would be appreciated. Used machines would be preferred. Thanks

[RICHARD ZASTROW]

You might check into CBN plated wheels employed on CNC grinders.

Walter, Hoffman (Huffman?) Haas(Germany) or Star/Sampusili names come to mind. I may have misspelled a few names though.LOL

Dick Z

[yoopertool]

my restraint with a standard CNC grinder is part holding. These parts are very similar to large dremmel tools. If I go with a CNC surface grinder with a rotory, or even a tool grinding machine (rollomatic, huffman, etc.) I would still need to have material to hold onto and steady off of. Being that I want to run high volume, insert a blank, and come out with a ground to size part, I dont know that they would work.

What has been of interest to me is a CNC Centerless grinder. Check out the one in this video:

[ame=http://www.youtube.com/watch?v=lXOcxGcNDU8&feature=related]TOPKING CNC 5 AXIS CENTERLESS GRINDING MACHINE - YouTube[/ame]

I think something like this would be a bit closer to what I would need. Does anyone have any experience with this style of centerless grinder? Thanks

[RICHARD ZASTROW]

I thought you wanted to grind the cutting elements on the burrs as well as the shanks etc. Sorry 'bout that

Dick Z

[yoopertool]

Sorry for the confusion, but we already have a bunch of rollomatics for fluting burs, we just would like to find a way to quickly produce tight tolerance, hardened tool steel blanks. The process of turning, heat treating, grinding, straightening, grinding...... is not cost effective enough. I would like to take a heat treated rod, drop it into a machine and have the finished part come out. If I can make an automated loader for it, that would be even better.

[Delw]

Dick, there was a small company in CA that built cnc grinders 4 and 5 axis ones too. I cant remember the name but they used Fagor controls. my buddy designed and built/wired the electrical cabinats and controls for them.

[yoopertool]

The more research I do, the more I think that a centerless grinder with a form wheel on it would be the machine of choice. I think I will call up some centerless grinder manufacturers to see what their recomendation would be. Thanks for the input!

[RICHARD ZASTROW]

yooper, have you inquired with UNISON? Michigan builder.

Dick Z