Cutting 1/4 inch MDF advice

[bjones]

I'm cutting some relatively simple templates out of MDF.. using CMT upcut spiral 1/8 inch carbide bits, the mdf is .22 inches thick.. I'd imagine a spiral bit should go through that like butter but it's breaking bits at 3 inches per second.. anyone have any advice on an alternate bit or optimal cutting method??

[Brady Watson]

It sounds to me like you may be cutting too fast...without seeing the design, I can only generalize.

I would cut in 2 passes @ 1.2 IPS. Adjust speeds accordingly. Jagged cuts or broken bits doesn't get the job done...Those little bits like higher RPM and slower move speeds with reduced step-down.

-B

[paco]

The smaller the bit is (CED), the slower it's cutting edge is rotating... this is not a question of RPM but rather diameter involve.

If you can get a 1/4" or a 3/8" CEL bit, that would help; most 1/8" CED are 1/2" CEL... one have took at the "plastic" tool to get shorter tool bits.

I guess you assume your choice but do you really need 1/8" CED for this project. That's the question when you need productivity.

[wemme]

I've used a 6mm double flute cutter (1/4")at single pass 45mm/s (1 1/2")with no problem

[richards]

I cut almost everything with 3/8-inch cutters and then use smaller diameter cutters for tight radii. The large cutters move right along as fast as the machine can move and the small cutters give me the necessary detail. (However, I've never had much success with CMT. Although I haven't had breakage, they run really loud on my machine, making me think that there is a lot more vibration with that brand than will Whiteside and Onsrud cutters.)

[davidp]

Sorry to come late to this discussion

We cut 100 + sheets of 3mm (1/4 )mdf per month around 77 parts per sheet at 105 mm per sec (4.25 in) at 13,000 rpm, single pass on a PRT Alpha. We have been doing this for almost two years now.

We have tried several bits from spirals to straight bits from numerous manufacturers best quality of cut and best life of a bit are the CarbiTool TSPL 04S a solid carbide single flute bit "O" spiral. 1/8 CED and 1/2 CEL. It produces a cut that requires no sanding.

We tried Onsrud, poor cut quality (but almost unbreakable), CMT even worse cut quality and break easily, and extremely noisy.

Belin as good as the Carbi Tool but harder to get for us.

For everything else we use a CarbiTool TSPL 08S a 1/4 version of the above bit. We cut 16mm melamine MDF in a single pass at 65mm per second (2.5 ips) using this bit however we get better cut quality at two passes at 85mm per second.

My two bobs worth

Regards,

David