Mounting Router to Table

[Matt Reeves]

I recently built a heavy-duty router table for use in my workshop. I also purchased a Makita 3612C Router and Phenolic insert plate. Drilling the appropriate holes and mounting the router was not an issue. However, the Makita utilizes 4 - #6 x 1/2" - 32tpi flat head machine screws. I purchased replacement screws to accommodate the extra thickness of the insert plate.

I am concerned that the 4 small screws may be insufficient to provide the necessary strength to secure the router when it is under periods high torque from using large router bits. Of course, the screws were probably only designed to secure the original router plate, which would have little or no torque from handheld use.

Has anyone had experience (or problems) associated with mounting this router to a table in this manner?

Regards,
Matt Reeves

[Jake Helmboldt]

I've got the exact same setup. No problems at all. I wouldn't worry about it, and I've been using big panel raising bits as well.

It has a soft-start feature so the torque is not that significant.

JH

[Steve Beadle]

Matt, I also have a Makita 3612 in my router table, mounted to a 3/8" acrylic base plate. I bought the longer metric screws to accomodate the extra thickness and have had no problems. I really don't think it would be necessary for you to tap out larger diameter mounting holes, if that's what you're thinking of doing. Just make sure your holes in the base plate are not sloppy or oversize.
I don't often use large bits, such as a panel raiser, however. I do use some larger roundovers quite often, though.
Steve

[Rod Sheridan]

Hi, assuming 10,000 RPM, the torque per horsepower is only .52 pound-feet. (at 20,000 RPM it's half that)

If you have a 3 HP motor, that is 1.56 pound feet of torque at maximum feed rate.

If your screws are 6" from spindle center line, you would have a maximum shear load of 3.2 pounds, spread over the screws.

If we assume that you could generate 10 times this force accidently, it's still only 32 pounds, spread over the screws.

I wouldn't worry about shearing the 6-32 machine screws.

Regards, Rod.

[Bill White]

OK Rod. How in h^&l did you come up with those numbers? My head hurts.
Bill

[John Lucas]

I am surprised that Makita uses Imperial sizes. My Hitachi M12Vs all use M11 but as to your question, if all the screws are snugged and holes accurate, you wont have any problems.

[Matt Reeves]

Thanks, to everyone for the good advice - especially the engineering assessment. :) Thanks, also for bringing up the imperial/metric question. After reviewing the parts manual, the Makita does use M4x10 machine screws. I probably would have tried forcing a #6 screw in the router. :eek:

Regards,
Matt Reeves

BTW - As a newbie here, my experience with my first two posts have been most helpful and informative. Hopefully, I will be able to provide assistance, advice or at least share real life experiences (goof ups) in return.