[RaptorZ]

Hi,
I recently discovered a FabLab near to where I live, and have been visiting it for the last few weeks to make a project.
However i am not sure of the best cutting speeds for the materials i am using. And as a result it took 2 hours to cut a 2' x 3' piece of 1/2" ply.

I am using a ShopBot, with a 3Kw router. I need to cut the design into 1/2" ply with a 1/4" bit. I have access to a 1/4" 2 flute router bit and a 1/4" Down-Cut Spiral Router Cutter.

currently the cutting settings are:
pass depth - 0.125 (inch) (3mm)
Spindle speed - 12000 (rpm)
Feed rate - 100.0 (inch/min) (60mm/sec)
Plunge rate - 30.0 (inch/min) (20mm/sec)

I am also using a 1"/25mm ramp on all cuts.

Please can you suggest the best router bit to use, and the best settings for the control of the router. Any advice is greatly appreciated.

-Ben

[ger21]

I'd cut it in 3 passes of .166
Ramp at 150ipm, and cut at 300ipm and 16,000-18,000 rpm. The 2 flute downcut should give you the best results.

What kind of plywood is it

[RaptorZ]

I am not exactly sure which plywood it is. It is lightweight, so I would assume that it is Softwood plywood, as its quite lightweight, and splinters quite easily. (it may be spruce, pine, or fir)

Thank you for your recommendations, I will give them a try over the weekend. (it takes the project from an expected 4 hours down to 1 hour 30)

the next question I have is, what plunge rate and RPM would you recommend for a 1/4" and a 1/2" drill in plywood?

[ger21]

If the drill bit will be in the spindle, then spin it as slow as you can and drill as fast as you can. For the 1/4" holes, you'll probably get much cleaner holes by peck drilling with the router bit.

[keebler303]

If the drill bit will be in the spindle, then spin it as slow as you can and drill as fast as you can. For the 1/4" holes, you'll probably get much cleaner holes by peck drilling with the router bit.

And you could interpolate the 1/2" hole so you don't need a tool change. A 1/2" jobbers length drill at 18,000 RPM would scare me.