need help cutting intricate shapes in 5/8" maple

[nitsuj25]

I'd like recommendations for bits, speeds and feeds, # of passes etc... for cutting intricate shapes in 5/8" thick maple. I also need the smoothest finish possible which may be a problem as I need 1/4" (or smaller) bits to achieve the tight radius cuts but i've learned that the best finishes come from 3/8"+ bits. Any thoughts on this would be greatly appreciated. Also I've read of people using one bit to "rough" cut it then stepping it in with a finish bit to polish the whole edge in one final pass. Anyone have experience with that? I'm cutting US state shapes mostly that are 3-4" big

I also plan on cutting a lot of 5/8" to 3/4" cherry and walnut. Some are intricate shapes and some not. I have a t slot table(no vac) and plan on using transfer tape with spray adhesive to hold pieces in place while cutting. A bit tedious I know but could I just use double sided tape to my sacrificial? Any thoughts on how to set up table?

I know of the bit maker onsrud and they are helpful in bit selection but don't have the real world experience you guys do. Which "series" of bits might you recommend. Would I even need to hold the piece in place with tape if I use a down spiral bit? I don't necessarily mind a little post production work on the edge sander if necessary and I will round over and sand the top and bottom edge anyways.

Hope there's no rule against going on too many tangents!? A lot of questions here but any and all opinions are welcome. Thank you in advance, Justin

[scottp55]

Justin, a bit under the weather here, so hoped somebody else would kick in, but hate to see a first post unanswered. Grainasalt please.
First thought is to use the same 1/4" Downcut using a machine allowance on the profile cut of about .015", and the copying the toolpath and setting 0 allowance and setting pass depth for a full depth pass.
Sometimes you can simply set "last pass" depth to something silly like .0001" and last path only lets the bit get away from any cutting forces and will clean up pass cuts. Experiment!
Might recommend using a "backer board" dimensioned to an exact height and then using a "transfer/masking tape---Carpet tape--and the transfer/masking tape again" to make a sandwich that cleans up easily. Can't find the "triple tape" link from Brady and Russell:(
1/4" down Onsrud OR Centurion 1/4" down fem work great for the three woods you mentioned, Spiral ramp seems to leave the least cleanup.
Make sure you make the tabs thin enough for the bearing to clean up totally and not have bearing hit tab at ALL for the radius finish.
Play with it a bit. Small, fast, light(1/2 diameter) passes seem to give the least sanding finishes. Haven't done comparable cuts in 6 months so listen to other opinions please.
Sorry I hadn't taken more relevant pics.
Hope it helped.
scott

[dmidkiff]

I would start with 1-1.5IPS at about 10,000 RPM and adjust up or down from there with a 1/4" down cut bit. Use carpet tape and tabs for hold down. You may need to add screws or nails to go faster. Use climb cut and shallow passes and leave .001 or .002 and then make a full depth pass using conventional cut for the clean up. This should give a good finish. Then as Scott said if your tab is small enough it will be removed by the round over bit.

[knight_toolworks]

I pretty much cut all solid wood tips 10k and 1/4" per pass. downcut is best or a goods harp straight cut. I only use tabs with the grain so if they break it will not tarot but double sided tape is the best choice. I use some coroplast as a base and stick it in a vac bag to make sure ti s well stuck.

[nitsuj25]

ok, thank you guys very much for the info and I apologize for the late reply on my part. I am getting my cnc machine at the end of this week so I'll play with it a bit based on your recommendations, see what happens, and be back in touch. Thanks again!