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tejano4life72
02-17-2009, 11:09 AM
Hello,

I was ask to put together a form on the material requirements for our swiss lathe machines. To send to our vendors. All I know is how to program them and set them up but now I am stuck with this. I also know if we use centerless ground stock we eliminate a lot of the problems we are having now. Where I use to work we use 12ft long +/-.0005 dia. and must meet print ASTM. This all started when we receive 3/4" bar stock that mic .7595. I was looking at there certs and we didnt have any specifications on the material certs. So now i am stuck putting some kind of form together. We are going to get our material sent out to get centerless ground from now on. If some one has a form I can reference on what specifications I should be looking for Please send it to my email address -tejano4life72@yahoo.com. I just need to look at something to help me get started and make my own.

Thank you,
Tejano

izhammer
02-17-2009, 11:25 AM
hi,

i would suggest you look into automatic guide bushes this could save you a lot of cash in the future that way you dont need to purchase ground stock for its consisitant dia

regards
izhammer

tejano4life72
02-17-2009, 11:44 AM
izhammer,

Thanks for the suggestion, but this company wants to go with centerless ground material. I tried already.

citizencnc
02-17-2009, 04:36 PM
I would suggest +/-.0003 with 32 micro finish. Also a chamfer on one end of the bar would help.(chamfer= 25% of stock dia).

tejano4life72
02-17-2009, 06:01 PM
citizencnc,

Thank you for the suggestion and the chamfer idea.

dasmoose
02-17-2009, 11:33 PM
In the early days I would buy ground stock for our Swiss Machines but have been able to eliminate that by getting the material from Schmolz & Bickenbach(formerly Ugine). I routinely mic the bars and get less than .0005 variation end to end. Another upside is they chamfer both ends of the bars.