MFS + 1400 EQ as circle cutter?

[MarkV]

I need to cut a bunch of pairs of 5" diameter circular ventilation holes (about 20 total holes) in two large pieces of 3/4" plywood.

I am half way to making a plywood template - it could be a little closer to a perfect circle, but since the holes will not really be visible, it would likely suffice. 

It looks like the mfs 400 can support a circle of that size (30mm minimum from what I could find).  Would it be more or less awkward than the plywood template?  What about in terms of time usage?  I'm 100% sure it will be more accurate

What size bit should I be using?  I've been using a 1/2" straight bit for the template, but it has to take off a ton of material and I'm taking 3 passes.

 

[Administrator_JSVN]

Mark,

Check out Brice Burrell's very extensive and well written (with LOTS of photos) user's guide on the MFS.  Start on page 44 regarding circle cutting.

http://www.festoolusa.com/media/pdf/mfs-users-guide-brice-burrell.pdf

Hopefully some of our members will offer their advice, opinions, etc.

Shane

 

[Rob-GB]

My rule of thumb is that I take 1/3rd of the diameter of the bit as a maximum depth of cut for each pass, it reduces stress on the router, the cutter and on how hard I have to work to control the process. Someone once wrote "Routers don't need to scream to work", they scream when the cutter is under a huge load (friction = noise) both router and cutter last longer when it is not screaming.

As for method either will do. Template or MFS set up. Which do you find easier and faster to set up to accomplish this job?

Rob.

 

[bonesbr549]

How about just getting a 5" hole saw and cut through till the pilot bit breaks through and then reverse the other side and you should not have any blow-out.