Flush trim router bit and 3/4" oak plywood, Will it work well?

[rackoon]

I was praticing on some crappy 3/4" plywood before I cut up my good stuff and had major problems.

I have a very nice jig saw yet in every combination of bit or adjustment (orbital mode and scroll mode) I still have the problem of the blade bending at he bottom of cut.

My cocktail cab has some strange curves to it so I need curves not straight lines. The pieces I am cutting look like a T-shirt sort of. 

What I want to do is make a pattern out of 3/8" plywood, sand it smooth, then clamp it to my 3/4" oak plywood and use a flush trim bit in my router. Will this totally wipe out my plywood? i can just imaging splinters everywhere.

I have seen this done with MDF yet not plywood. Any one already try this or should I just order a bit and see what happens on a test piece.

I have seen some nice bits that have a slanted cut to them to cut down on splintering but they don't mention that one could use them on plywood.

[Brax]

You can.... CNC routers will cut 3/4 plywood but you're asking an awfully lot of your home tools.

I'd say you'd want to use a bad-ass router like a 2 1/4 hp Hitatchi and the very best bits money can buy. Go slow and pray you don't burn the hell out of the edges.

If you smell smoke it's either the wood or your router commiting suicide.

You want a carbide tipped double flute straight bit; the bits with a slight angle are laminate trim bits.

[Maverick]

Those blades bend like that because the get real hot....when metal gets hot it gets soft.
Cut slowly (this may be a prob if it don't have variable speed control) and use a good blade, like Dewalt or Bosch 3 or 4in blade. Black n Decker just wont cut it... no pun intended.

[Xphile]

also, cut your straight sections with a circular saw, cut your round cuts with a jigsaw (at least 1/4" from the line  so your 'saw bend' doesn't encroach on the actual finished piece and your flush-trim bit won't have to cut through more than about half it's own diameter) and finish with your template pinned or clamped to the workpiece and run the flush trim bit around it.

A triple flute , 1/2" shaft, flush-trim bit makes a real nice finished edge real quick if you leave not more than 1/4" to trim off from your other cuts.. if you left more than no biggie, just takes a litttle more time to go around it..:-)

[prOk]

The real trick here is to trim your wood to within 1/4 inch of the line the router is to follow.. so you take of no more than 1/4 inch of wood with the router.. (less is better), take your time and move the router in the right direction and you'll be fine even with a low HP router.

/b

[rackoon]

Awsome this sounds doable. Im going to give it a shot. Ill order a flush trim with bb from mlcswoodworking.com tonight.

Ill post my results with some pics.

[mccoy178]

The real trick here is to trim your wood to within 1/4 inch of the line the router is to follow.. so you take of no more than 1/4 inch of wood with the router.. (less is better), take your time and move the router in the right direction and you'll be fine even with a low HP router.

/b

That is the real trick.  If you can cut with the jig saw as close as possible, the router should tear right through the plywood.  I use 1/2" shank bits and they don't bat an eye at that stuff.  Now, if the width that you are cutting is more then half the width of the router bit, things could get hairy.  That's when you'll see the bits do awful things like kickback, break, and just flat out scare the crap out of you.  This is generally not an issue in 1/2" mdf and very soft woods.  But plywood is a different ballgame.

[rackoon]

Well I cut all my curved lines with a flush trim router bit on 3/4 oak plywood and it worked awesome.

I made a pattern out of some old 1/4 inch plywood and clamped it down to my oak plywood  and went for it. I couldn't be happier. I did like most of you recamended and cut the piece down to within an inch of the cut line first.