Holding a 0.005 tolerance?

[r_jones]

I have a request to bid cutting 50 pieces of teflon holding a 0.005 tolerance. It seems doable as long as I can screw the pieces to my spoilboard but... I am I just assuming here? Also any input on cutting teflon would be helpful:)

Thanks,
Ron

[erik_f]

It depends on how well your machine is set up also. Slow speeds and step down would seem important...the less stress you can put on the machine the more accurate you will be. If you are doing one at a time it would be easier to pull off than if you are cutting many out of a sheet. Doing one at a time you can cut a sample out of something else and them make adjustments to your file to correct for anything out of tolerance.

[blackhawk]

Ron - Are you saying +/- .005" of tolerance or only .005" total. If you have the latter, I would be a little nervous. I don't believe the resolution on the stepper motors would hold to a .005" total tolerance for position.

[richards]

Which machine do you have? My calculations show that my original PRT-Alpha (pre-7.2:1 motor update with 20-tooth gears), moved 0.00314" per step. The 7.2:1 with 1.5" spur gears moves 0.00065" per step. A machine using 1.25" spur gears, Geckodrive stepper drivers and no gearing would move 0.00196" per step. With 3.6:1 gearing, a 1.25" pur gear and Geckodrive stepper drivers, the axis would move 0.000545" per step. Machines without Alpha motors or without the 4g upgrade might move a greater distance per step.

The resolution is there, but my machine, a PRT-Alpha with 7.2:1 motors, can't hold that kind of tolerance due to flexing, at least at speeds over 1-ips. I haven't done any testing at speeds slower than 1-ips.

[r_jones]

Guys I have a PRS Alpha about a year old or so. I would like to cut them out of a sheet but... I believe it's -/+ .005 not a total. Slowing everything down isn't a problem as it would just be a part ot the cost so.

[gene]

what are the parts going to be that a .005 must be kept? :confused: if you can say?

[r_jones]

Ya know Gene I am not really sure, based on the client, my guess is some sort of electronic application.

[cabnet636]

how big are the pieces and sheet size how many to a sheet etc how close is the nesting, i would want strong vacuum to the backup of the screws