To Mill or to Route?

[rsecret]

Not sure if a router will have the muscle I need but being new at this I would appreciate some help.

I was considering a mill because of its power but I like to have the option to cut out larger patterns in thiner sheet material like plastics. But from time to time I need to prototype smaller but thicker parts from 1" thick ABS plastic.

Will one of these $2000 hobby like machines I see around do the job or will it just take to many passes to go that deep. Secondly would my #6902 porter cable router be the right choice for this and if yes do I need to control the speed to prevent burning op the the plastic?

Great Site and thanks for your help!!

[ViperTX]

Kinda depends on what sort of finish you want...generally you rough cut and then make subsequent finishing cuts.

[rsecret]

The parts only need to be rough prototypes. We just need to test for strength. They will eventually be injection molded once we get them right.

We have calculated the parts stress requirments and the webbing needed to give it strength. Now we need to prototype a couple and tweak them in the real world. We considered sending them out to cnc shop but if we start getting into multiple parts and changes I am sure it can get expensive. I rather invest the money into a machine of are own.

So for rough parts will a low cost router cut out (not fully through) a webbed pattern in 1" ABS plastic?

Please help?

[ViperTX]

Yes, like a reverse waffle pattern?

[LeeWay]

The router that I have just completed will cut throgh 3/16" lexan in one pass with no burning or bogging down on the 690 PC router. This is with a setting of 60 IPM. You can slow these routers (690) down with a router speed controller if needed, as long as its not the variable speed type router.

I haven't tried it yet due to my dust collection not being complete, but I fully expect this router to mill aluminum as well.

I see no reason these won't be perfect for your needs.

[rsecret]

Yes, I like that....the waffle pattern. Well thanks guys, I think I will start with a router. Now the hard part, which one.

Where on this site or other sites can I find info about mill bits and spindle speeds for plastics? I used the search but nothing specific came back.

Thanks, RJS

[strat]

when i got started on mine i used uhmd plastic instead of ballsrews ect i got a bit for plastic from grizzly tools its a single flute and works great

[mcmmach]

I do a bit of machining in plastics and a good source is at www.onsrud.com. You can request a catalog which contains charts for different materials, sizes and styles of bits.
Most of the time you run your router at 18,000 rpm and change your feed rate to get the surface finish you require.
Most plastics need 150 - 200 ipm feed rates to do a good job, if you can't achieve these feed rates you will have to slow your spindle down.
Dean