cnc as a planer

[Clarence Miller]

I was sanding some glued up panels the other day with my drum sander (performax 16-32) and thinking about how nice a 24" wide planer would be for cleaning them up. Then it occurred to me "why not use a 1.25" diameter bit on the cnc to flatten and remove the glue lines then run it through the sander?" I ordered a slot cutter from MLCS with a top mounted bearing to use as a surfacing bit.
Have any of you tried this?

[Jim Underwood]

I've thought seriously several times about flattening panels with our 4 inch flycutter.

If I have a thick enough top, I'll probably do it sometime. In fact I have a bunch of maple lumber I may turn into a bench top...

[Keith Outten]

You Bet!

I use the same 1.25" diameter cutter that I use to machine my spoil board to plane large panels on my CNC Router. For me the size of the cutter isn't a serious consideration when I can machine my 4 foot by 8 foot spoil board in approximately 12 minutes. Panels are quick and easy. Several times I have joined the edges of rough stock and glued them up without ever running the lumber through my planer because I planned to plane the large panel on my CNC router. This works well if your lumber is very flat.
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[james mcgrew]

yesterday i began the carve of a 3" thick piece (will post more on another thread) here is the planing. man do i love this machine!!

[Clarence Miller]

I think 1.25 diameter is about the max I would want to run with my machine. It's a shop made model and the spindle is a makita 2.25hp router so the 1/2" shank puts some limitations on it. But is will still be faster than my drum sander even with 50 grit and I can be doing other things while surfaces.
My router runs at 23000 rpm (another reason 1.25 is about the max I would want to run), what kind of feed rate do you use?

[james mcgrew]

with that high rpm on the router run it as fast as you can and shallow (.3125) heat burns bits

[Mike Package]

Does anybody have tips/techniques for securing material for planing/surfacing when it's not at all flat? I've seen some jigs with clamps coming in from the side, for example. And I've seen others shimming underneath as necessary. But it seems that with a big workpiece and a big cutter, securing the material would be of utmost importance....

[Mick A Martin]

I have used shims and CA glue and place a few screws here and there out the the cutting area, once one side is flat I then turn over the project a machine the other side.

Mick

[Mick A Martin]

yesterday i began the carve of a 3" thick piece (will post more on another thread) here is the planing. man do i love this machine!!

Nice to see you picked a small job Jim

[Bob Schlowsky]

I use the CNC to plane large boards, my jointer is small and handling big stuf just doesn't work.
1. make sure you shim the board before you surface it, if you screw it down tight without shims the curves will be right back when the screws come out.
after it is surfaced join one edge as the top is now parallel to your CNC the edge will be a perfect 90 degrees. I am careful to line up the edge I want to join before I do the surfacing. I use a 1/2 inch bit to join as it eliminates the bit flex issues.
If there is scrap area I screw the plank down with square drive screws that are well countersunk below the surface. If not I clamp the edges with cam clamps after I shim it.
It works well and is pretty quick once you get a system that works on your machine.
If you are using a Shopbot there is a surfacing program on their web forum that makes it really simple. I would guess the other companies have written something similar as well.

[Steve knight]

depending on the size I just screw some stops down to the the spoilboard around the piece and the weight holds it in place. of course shim the high spots.

[Gary Campbell]

We do this often with uneven and sometimes large chunks or glueups that didnt come as flat as we wished. Heres what we do:

Lay on table with any crown down. Slide cedar shims under high spots about 1' on center. Trim off shims flush with blank. Tape around edges with 2" masking tape. Turn on the vac.

We surface with a 2 1/2" Amana bit that has replaceable inserts. RPM 12,500, move speed 6-8ips (360-480 ipm) and depending on the species, .020 to .060 per pass.

We raster in X, with the grain, with 2.25 stepover. We have a custom coded surfacer routine that allow depth and speed changes on the fly. This allows making a last "glamour pass" at half speed and .010 depth that seems to almost polish many oily woods.

This tecnique has been used with Ipe blanks 3.5' by 6'

[Clarence Miller]

my cnc is a side clamp so I just put some sacrificial spacers at the clamps and fence. I only took 0.040 off per pass at 180 ipm but not having glue create burn lines on my sanding drums was enough for me to call it a success. May have to rethink my DC but then again getting a good collection out of a router is a bit challenging.

[Mike Package]

I've planed down individual parts before, but using this thread as inspiration I jointed and planed a 2-pc 8/4 mahogany billet. I used lots of double-sided tape and shims to secure things for the jointing passes. I used a 1.25" bottom-clearing bit taking .02 at a pass with the grain.

Then I flipped the pieces (still unglued at this point) and countersunk two screws in two opposite corners of each piece, putting them parallel on the table but leaving a gap about .4 between them. Planed them down to near final depth. Then I ran a long .5" flat end mill on a path right down the middle between the two, going .25" deep each time. The result was that it jointed the edges of both pieces at the same time.

The end result was a better glue up than I ever got from my usual combination of Ridgid lunchbox planer and Jet 8" benchtop jointer. It was one of those joints that felt like it barely needed glue.

Maybe not as fast but the end result was worth it and I never enjoy the jointer anyway, since the time I somehow got past the safety guard and it nipped my finger...

[Amr Hosni]

This depends on the size of raw material to be removed .This is a link to a German company specializing in the tool an have branches in the countries of the world and I, personally, I deal with them .
http://www.leitz.com.au/catalog/