High speed cutting on new shop bot
Will the new shop bot handle cutting 3/4" oak with a 5/16 inch bit at 1 1/2" per second? I am thinking of purchasing a shopbot and am wondering about the strength and construction of the newer version and if it would handle the demands of higher speed cutting.
Member
If you are going in one pass I'd definitely drop that to about .8 in/sec (max). You can also probably get away with a 1/2" bit.
I did a really big job on 3/4" marine ply which I cut at this speed in one pass with a 3/8" bit. Broke a few bits so I'd go with 1/2" but no more since that increases the cutting loads.
You might also want to consider a roughing bit. Surface finish isn't quite as good but it cuts easier/faster. Still don't think you'll want to go faster than 1 in/s though.
Joa
Joa, are the limitations due to the bit, router motor or ShopBot? I get the impression that the ShopBot has enough power for the job (with a 60-80lb cutting force), but that the router and bits are strained the most.
Cutting speed should not be the only consideration. Smoothness of cut, depth of cut and hardness of material comes into consideration in the making of a product on ShopBot. Are you pushing the ShopBot for just the reason of seeing what speed it will cut and at the cost of spending more time sanding the cut edges? Shop efficiency means to minimize time overall to get to the final quality product with all processes considered. Cost of tooling also comes into consideration. Once these items are optimized record of the final determination should be logged so that it can be referred to on future projects.
Senior Member
So now I understand that I shoudn't cut to fast with a 5/16 inch bit, my next question is
All my cutting is with a 5/16 bit and this is the only bit that will be in the shopbot. Do I need to have a real heavy router 3 1/4 hp or will the new bosh 12 amp 1617 be all that is needed. I never plan to use my shopbot for anything else but for this one job.
Kevin, If you already have the Bosch unit use it however,the additional cost of a 3 1/4 hp router over any unit less powerful is minimal when considering the performance and future possibilities for new products that may require that additional power. Bottom line, always assure yourself of more than enough power in the cutter.
That equates to longer life for the router and more satisfaction for you in your work.
Also, with the higher powered router you could look to using 3 or 4 flute spiral end mills as cutters. That means smoother cuts.
I seem to recall that there was a post earlier on this forum which told of a noise advantage when using smaller Bosch routers for lighter work.
Member
Oh man, I feel strong on this one. Get the 3 1/4
Porter Cable. Gotta love that power plus the speed control IS A MUST HAVE. It's a little loud but that's what doors are for (neighbors) and good quality earmuffs (I use shooter's muffs.)
To answer the earlier question I am usually limited on thick sections by how hard I'm pushing the bit. Sure the r&p SB will push hard but the bit will only clean so fast. That and if I'm doing patterns with lots of quick turns then I'll slow it down because at high speeds and hard cuts they really jar the SB.
Keep in mind that the SB really wasn't made for a lot of the cutting we are asking it to do!
Oh, for what its worth I've been cutting 1/4" ply between 1.5 and 2.0 ips and it just rips along nicely!
Joa
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