Cutting Cogs

[Jonmilligan]

Hi Chuck, I've cut a lot of Bakalite, its what I orignally got a CNC router for nearly 8 years ago! After manufacturing many fishing weights out of carbide router bit shanks, I have finally settled on 3 choices, in no order of preference: 1/8" bit fromTHINKTINK Part No.: RB08-1250-FD-001. 1/8", 3/16", or 1/4" Upcut spiral bits from ONSRUD Pn. 63-710, 63-717, 63-744. and some French Upcut spirals, Evon Belin 1/8", 3/16", and 1/4" (Evon Belin are also ownd by Lietz, same as Onsrud!), Feed is between 1200mm and 1800mm per min depending on cutter Dia. Spindle speed is about 17000/18000 rpm, and depth of cut is 3mm/1/8" on the smaller cutters 5 to 6mm(1/4") on the larger Dia. You have got to work the cutter otherwise the friction from Bakalite wrecks the cutters in notime. I hope that helps.

Regards
John Milligan

http://www.thinktink.com/cgi-bin/carbid ... 0&start=16

[[Edited by Brian to update feedrates following John's correction below]]

[wcarrothers]

I was guessing they came from one of the wood clock book patterns or something (like the one from the scroller mag last month or something) and figured they were perhaps actual size thus was surprised they were scaled.

Since I don't know the assembly sequence and such having the acutal sizes isn't needed.. Although I'm waiting for my scroller mag to come in the mail:)

b/

[Wemme]

Nice work John.
I've tried cutting Tufnol before with a bad stink Thanks for the tips.
Regards
Bart

[CRFultz]

Hi Chuck, I've cut a lot of Bakalite, its what I orignally got a CNC router for nearly 8 years ago! After manufacturing many fishing weights out of carbide router bit shanks, I have finally settled on 3 choices, in no order of preference: 1/8" bit fromTHINKTINK Part No.: RB08-1250-FD-001. 1/8", 3/16", or 1/4" Upcut spiral bits from ONSRUD Pn. 63-710, 63-717, 63-744. and some French Upcut spirals, Evon Belin 1/8", 3/16", and 1/4" (Evon Belin are also ownd by Lietz, same as Onsrud!), Feed is between 1200mm and 1800mm per min depending on cutter Dia. Spindle speed is about 17000/18000 rpm, and depth of cut is 3mm/1/8" on the smaller cutters 5 to 6mm(1/4") on the larger Dia. You have got to work the cutter otherwise the friction from Bakalite wrecks the cutters in notime. I hope that helps.

Regards
John Milligan

http://www.thinktink.com/cgi-bin/carbid ... 0&start=16

Thanks John for the heads up on this....The lowest I can go on my router spindle speed is about 16k.
I'll save the bakelite for the Bridgeport at work.

[Jonmilligan]

Hi,everyone, nobody likes to be stupid, but this time I have to own up! When I posted my message about machining Bakalite, it was 2.00am or so in the morning in Oz, that is my only excuse. the spindle speeds I mentioned, 1700/1800 rpm were almost right apart from the 0's I left off the end of the figures, it should read 17000/18000 rpm. Sorry, I hope nobody has broken any bits!
Regards
John Milligan

[[ I've edited the origianl post above in case people don't read this far - Brian ]]

[Roly]

Hi guys,

Thank you all very much for your help. I can start getting into the cutting now when I get my machine back up and working again. Should be set within the next fortnight.


Roly