Speed and Feed Tools

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Speed and Feed Tools

Postby pringuette » Thu May 31, 2018 2:18 am


Is there a good, free, tool that you wiz kids use to help set your speeds and feeds?

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Re: Speed and Feed Tools

Postby cbr_speedster » Thu May 31, 2018 1:19 pm

And in two years when you have all these charts figured out throw them away and use what works for you and your machine,,, remember, you can't cut what you can't hold... Machine rigidity, Depth of cut, Clamping vs. tape, Bit length, Bit style, Diameter, 1 flute, 2 flute, 4 flute, roughing, finishing, full width cut, step over cuts, plunge cuts, knotty wood, wood grain.... It's rocket science... hahaha

Re: Speed and Feed Tools

Postby SCW » Sat Jun 02, 2018 5:29 am

I gave up trying to calculate speed & feed rates and chip loading and all that nonsense after the first few hours of running my machine... ;-)

Depending on the type of bit, I'll feed somewhere between 0.75-1.5 in/sec on my machine. So far, I tend to run all of my bits between 18,000-15,000 rpm. I'll set my pass depth upto 1/2 of the bit diameter, but typically no more than 1/8" deep per pass. I'm even using the super cheap bits from Amazon (up-cut and 2-flutes) with good results.

But if I'm running a new bit or on a new species of wood, I'll set the run speed on my handheld controller down to 50% run speed. If I quickly see that the bit and wood can handle those settings, then I'll cancel the program. Then I'll rerun the same program but with the handheld controller's run speed at 75% (or even 100% if I'm confidant I'm not going to snap a bit or chew up the wood). Then I'll go back into Aspire's tool database and tweak the default speed and feeds for what I find that works for my bits.

I agree with CBR_speedster - I've found that typically, one of two things happens when you push your bits too hard:
1) the wood shifts in your clamps, or
2) your router will have insufficient torque to follow the calculated toolpath and so your router is no longer where the controller thinks it is.

Bottom line... start off with a slower feed & speed and then increase the rates every time you run the bit. You'll quickly learn where the sweet spot is.
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Re: Speed and Feed Tools

Postby NY Sculptor » Mon Feb 04, 2019 8:39 pm

gkas - thank you!
I was considering the G-Wizard calculator, which costs about $260. Have you tried it? Maybe it is worth it to stop struggling with loading my tool database correctly. That part of Vcarve pro is killing me!
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Re: Speed and Feed Tools

Postby gkas » Mon Feb 04, 2019 8:51 pm

NY Sculptor wrote:gkas - thank you!
I was considering the G-Wizard calculator, which costs about $260. Have you tried it? Maybe it is worth it to stop struggling with loading my tool database correctly. That part of Vcarve pro is killing me!

But, you have to learn to get a feel for the feeds and speeds. The chip calculators will get you in a pretty good ballpark. If you're not sure, start on the slow side and work up. You know you're too fast when you break the bit... :oops: A little trial and error is good. You need to know how YOUR machine performs.

P.S. I think the G-Wizard is WAYYY overpriced for what you get.
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Re: Speed and Feed Tools

Postby Adrian » Mon Feb 04, 2019 9:33 pm

It is just one of those things that you need to learn. Chip load charts should be good enough to get you in the general area and then go from there. There are just so many variables it's impossible for one person to say that their settings will definitely be the optimal for you even if you're using the same machines.

The same type of router bit from two different manufacturers can have very different rates for the best cuts. Wood can vary from batch to batch and piece to piece plus, of course, bits wear so what they can do when they're new might not be the same as a 100ft of cutting later.

In my experience of helping people with their machines in person one of the most misunderstood factors is that a machine cannot accelerate and decelerate from higher speeds in short distances. So the speeds you can use to cut a 2ft cabinet door wouldn't be physically possible on a 6" intricate letter so the rpm needs to be lowered to cater for that. Some going the other way. You might think your machine is incredible because it's just cut a 6" letter using a programmed 600ipm feed rate but it wouldn't have got anywhere near that speed. Try it on the cabinet door and it may get a lot closer with disastrous consequences for the bit etc.

Whenever I start with new material (to me) and or a new bit (to me) I cut a test board to work out the optimum feed rates. It doesn't take long to develop an ear for when a bit is struggling or not and the edge quality speaks volumes. It's really easy with spiral bits to tell if you're going to slow or running the rpms too high for the feed rate, they squeal like crazy.
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Re: Speed and Feed Tools

Postby LittleGreyMan » Mon Feb 04, 2019 9:35 pm


NY Sculptor wrote:That part of Vcarve pro is killing me!

Cutting parameters have nothing (or nearly nothing) to do with the software. They depend on your tool, the material you cut, your machine and the type of job (cutting a slot does not theoretically requires the same parameters as a lateral cut).

Amateur machines often can't reach the required speed values, their rigidity do not allow the theoretical depth of cut and if you use a router or a spindle which doesn't allow low rpm, the spindle speed may be too high.

And you will generally get parameters values for metal metal cutting, rarely for other materials.

AFAIK, last versions of G-Wizard are able to take into account compromises required by these machines. I did not test it so I don't have any comparison with other methods, but it may be worth a try.
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