Cutting styrene rings?

[Ray Dunakin]

Does anyone have tips on cutting rings from styrene?

I've trying to cut some from .040" thick sheet, with an OD of 1 7/8" and an ID slightly larger than 1.5". So far I'm not real pleased with the results I've been getting.

[Andi Little]

Ray..............

I've cut a lot of rings and I use a version of this Olfa style cutter...........



Mines a bit different the theory is the same, only difference I guess is the fact I use it backwards!!!

Yep, instead of cutting with the blade I reverse it and "score" with the back of the point. Couple or so times round and "snap" it
out as normal. if you're using any other means I can understand why you're struggling if you're using these already I'm at a loss to know why it's foxing you........................Up to a mill' thick has been no problem using this method.

Hope this helps some - apologies if I'm teaching you to suck eggs?

[Frederic Testard]

I use exactly the cutter in Andi's picture. Works very well on thin styrene and reasonably large radii like yours, Ray. A bit more difficult on thicker pieces, but I think 0.04" is still quite easy to cut. I usually plant the point in the center, press the blade and have the sheet turn under the cutter.

[jacq01]

  Ray,

  when cutting you separate and displace the material. When scoring, you remove material at the place you "scrape".
  It is possible to make exact circles and washers the way Andi describes. I do it that way too, not too much pressure and quickly you get a groove and NO distortion.

  Jacq

[Ray Dunakin]

Thanks! No, I haven't been using that tool, never heard of it until now. Just got done ordering one online.

[marklayton]

Ray -

Another suggestion is a jeweler's hole punch set.  Rio Grande sells a 1-7/8" punch and die circle cutter, but it's pretty costly.
http://www.riogrande.com/MemberArea/ProductPage.aspx?assetname=112532&page=GRID&free_text%7c1266974091453=swanstrom&first_answer=61
They have nice set that does 1/8" to 1-1/4" in 1/8" steps.  To make concentric rings, they offer some tapered pins to center a smaller punched hole in a large die.  Check out the demo video on this page:
http://www.riogrande.com/MemberArea/ProductPage.aspx?assetname=112509&page=GRID&free_text%7c1266974091453=swanstrom&first_answer=31
It's designed for non-ferrous metal, but will cut styrene, so I'm told.

Mark

[Ken Hamilton]

Ray, I just noticed this thread so this suggetion might to too late, but here's how I
cut discs for the wheels on the Lumber Carrier:

Score the inner & outer circles with a compass...



Cut close to the line...



Finish the outer edge by chucking the wheel in a Dremel & filing the disc "round"...



Finish cutting out the inner circle; clean up the inneer edge with a file....



Certainly not Hi-Tech, but it worked for me.

[NORCALLOGGER]

Hey Ken,
Now that is milling and machine work I can relate to!!

Love those PMMM's (poor mans milling machines (files)) you can find a large varity at any hardware store and they are inexpensive.  Also there is no large book on how to do the set up and operation 
Later
Rick

[Ken Hamilton]

...that Dremel froze up long ago. 
I chucked in the disc and slid the file back-and-forth real fast.

[finescalerr]

Thanks, Ken, for showing us regular guys how to do better work. -- Russ

[John McGuyer]

On your five axis, dual turret machining center, program the loading robot to place the material......ouch, ouch quit hitting me with that bat!

John