Brian or Hank, do I use full speed to route with a 3/4" roundover bit in MDF? (1 Viewer)

[Wes Nance]

Hi guys,

I'm going to be rounding some edges with a 1/2" shank 3/4" roundover bit (carbide)

I have a DeWalt 621 router with variable speed.

The cabinet is 3/4" MDF- do I use full speed, or back it down a bit on the router?

Thanks,

Wes

 

[Brian Bunge]

Wes,
I used my PC router full speed with a 3/4" roundover bit before and it had a tendency to burn the MDF. I've since done it with a speed control with the PC router in my table and it works better.
Try adjusting the speed about half way down and see if it works for you.
EDIT: For a bit that size you really should use it in a router table. But I did it hand held, just be careful!
Brian

 

[Patrick Sun]

My buddy has a router table, and he goes full bore on the router speed, and maintains a nice constant speed of the MDF moving through the router bit's way. If you move the MDF too slow, it'll burn the MDF. Experiment on some scrap to find what is comfortable and works for your setup.

 

[Pete Mazz]

I make the larger shapes with multiple passes. It's easier on the bit and the router, and usually leaves a nicer finished edge.

Pete

 

[Hank Frankenberg]

A 3/4" roundover bit is on the edge of needing a slower speed, depending on your router and the depth of cut you take. You can use it full speed IF you take small depth cuts per pass. The 621 is what, 2 horsepower? With that and larger bits, I'd slow it down a bit or take small incremental cuts - try both on some scrap and use the method that produces a clean cut. My table-mounted router is a Freud 3 1/4 horse and I don't slow it down for that bit, but for larger overall diameter bits, I would slow it down. For all routing, take your time and don't try to cut to deep per pass, and listen to your router's motor - it will let you know when you're pushing it too hard.