Correct Bit Selection with best Results

[nick]

I'm doing a raised panel for a customer. He wants a raised image on the top of the raised panel and clear the rest to give it the raised look.

The depth is .375. The clearing area is 24" x 24" with the model slightly smaller in the center.

Material is red oak.

I want to use a 1/2" endmill but need one with superior surface finish.

And recommendations?

And cost is a factor also.

[srwtlc]

You could try doing an inlay for the raised image. A 3D file that has say 0.125" base on it that sits in a pocket.

Just did one that way on a large veneered panel.


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[Gary Campbell]

Nick...
I have done this a few times... I used a 3/8 mortise compression to clear the area. Raster cut. Plaque is about 14 by 30,wood is Cherry. Here's an overall pic:

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And a detail of the logo and raised beads (the beads were cut .015 deeper than the surface for a cleaner look)

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Gary

[cnc_works]

Gary, how in the world did you clear that material without leaving tool marks? Or did you have to sand tool marks away?

Nice, clean work!

Donn

[Gary Campbell]

Donn...
It only took a few minutes...

To convince my son to sand it for 6 hours!


Actually the tool marks wern't so bad over the large area. The detail around the logo took the time. Including the in between coats sanding, close to 10 hrs. Sanding to a near perfect finish IS what separates the men from the boys.
Gary

[nick]

Nice work Gary...what was the total time of machining/

[Gary Campbell]

Nick...
Some of this is from memory....
Back Side:
Cut outside profile of rectangle to allow indexing 5 min + bit change
Cut 4 hanging slots for stainless sidewalk bolts: 3 min + bit change
Cut .5 deep slots for gauge index .125 EM + bit change
Inside profile .5 deep for gauge recess .375 MC 4 min + bit change

Front Side:
Clear Inside logo with .125 EM 10 min + bit change
Clear Inside logo with .0625 EM 8 min + bit change
On Vector cut logo with 3/16 pointed roundover 10 min
On vector cut inside and outside of logo, gauge and perimeter beads with 3/16 pointed roundover 20 min + bit change
Cut inside profile of Gauge holes 3 min + bit change
Clear outside logo, inside perimeter with .375 MC 25 min
Cut outside profile 2 pass offset, final pass full depth 10 min.

I was cutting 2 of these (one after the other)so until one split... times were double. All in all about 2 1/2 hrs on the machine.
Gary

[jhicks]

Given the two options presented which are both masterfully executed and your COST comment, I would have to lean towards Scott's applique technique.
Of course its all about the design so if grain match is an issue or concern,the applique and pocket would not be as successful but its definately the quickest alternative in terms of machine time.
On the other hand, an area clear of a 24" square panel isn't that much to be concerned with. Its the finishing that will add up time.
I'm not sure this would work with solid stock but when we cut Color Core area clear sections, we gently remove the sharp end mill corners with a sharpening stone to a tiny radius. This sharp corner removel minimizes mill marks between step overs. Might be worth a try.

[Gary Campbell]

Jerry..
I agree wholeheartedly with you. We were extremely fortunate to have a customer that was willing to pay almost $2k for a knick-knack. These types of jobs are very rare, especially in todays economy.

One note on the toolmarks... if you take the time to tune up your vertical axis to truly perpendicular to the table it substantially reduces toolmarks. Folks that were at our camp saw our table surfaced with a 2.5" bit to a velvet smooth surface. Bits with smaller diameters very seldom show marks, with the exception of some plastics where heat becomes an issue.
Gary