# Speeds & Feeds Software



## MontanaAardvark (Apr 15, 2018)

For the last year, I've been using the CNCCookbook G-Wizard speeds and feeds software.   One of the reasons I decided to buy the year's subscription is that after it expires, the SW is still usable.  (It expired a couple of weeks ago and still does what it used to).  It just caps the HP you can analyze at 1HP.  I have a Grizzly that's rated at 1HP - the G0704.  I don't have a way to measure its HP directly.  

During the year I've had the SW, I've noticed it tells me that I can make some cuts that stall my mill when I try them.  Just yesterday, I was cutting some 6010 aluminum with a 3/4" end mill, and the SW said I could cut a 3/4" wide slot, 3/16" deep at 15 IPM and it didn't say it was an aggressive cuts.  The SW said it would take 1/2 HP, so I figured I should be able to do it.   The tool didn't get it's full diameter into the cut before the cut stalled the motor.  I didn't look for the biggest cut I could make without stalling it, but I made the cut in .050 passes, and the program says those cuts are about 1/8HP.  

I'm running my motor wide open here, almost 2200 RPM, and it tells me to do that the majority of the time I set up cuts in Al.  The manual says it's a 750W brushless motor but gives no details on its horsepower curve.  

Is this a software problem in the G-Wizard calculator or am I just doing dumb things?  I thought with the motor torque derated 50% it would work.  I ended up doing the cut at 12.5% of the motor badge.  

If this is a SW problem with the CNCCookbook software, what would you recommend?


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## benmychree (Apr 15, 2018)

Having an amp meter on line would give you an idea of where the "redline" is.


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## Bob Korves (Apr 15, 2018)

750 watts is one HP (actually 746 and change).  But that is your INPUT power.  Output power will be considerably less.  Welcome to Chinese power ratings, sometimes they are even further from the truth than yours...


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## Boswell (Apr 15, 2018)

I also use G-Wizard and have found that I need to slow the feed rate or DOC from what it indicates but I am used to doing that and figure it is just me not understanding some aspect. We to be honest, probably not understanding many aspects.


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## MontanaAardvark (Apr 15, 2018)

Boswell said:


> I also use G-Wizard and have found that I need to slow the feed rate or DOC from what it indicates but I am used to doing that and figure it is just me not understanding some aspect. We to be honest, probably not understanding many aspects.



I didn't say this part because I didn't know if anyone would get it, but you will.  This cut was already done by adjusting the "tortoise/hare" slider from 100% aggressive to about 30%.  It originally had it as a 1 HP cut, feeding at 36 IPM.  I dragged the slide toward the conservative side until it came to about 15 IPM, which sounded reasonable.  

Is that the kind of slowing the cut speed/DOC reduction you do?


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## Boswell (Apr 15, 2018)

I have never tried a 3/4" full slot, but for a 1/4" full slot in 6061 and a DOC of .125 and 2500 rpm. I can go about 8 or 9 IPM. My problem though is not overloading the motor but I will gum up the mill bit. (3 flute) I am using a Fog-Buster coolant system and I am sure I could get more speed if I was using flood coolant. 

To address your question more directly, I almost always am at the turtle setting or 1 to 2 notches to the right. The times that I have had issues have been with cooling and chip removal, not HP.  I hardly ever use my 3/4 end mill and when I do it is usually as a fly cutter substitute. When my End mill would clog up, it would bog the motor down because the bit would quit cutting due to the Aluminum welded to the cutting edges. could that be the issue more than just HP ?


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## MarkDavis (Apr 15, 2018)

I use GWizard feeds and speeds calculator. I have much better luck with the slider in the 20-30% area.
Sometimes the program come up with some numbers that are very hard to swallow.

If there is an error data input, often the box that had the error will auto correct to 0.

But even going back and making sure the tool diameter, or depth and width of cut is not zero, some of the advice on feeds is very generous.


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## MontanaAardvark (Apr 15, 2018)

Boswell said:


> I have never tried a 3/4" full slot, but for a 1/4" full slot in 6061 and a DOC of .125 and 2500 rpm. I can go about 8 or 9 IPM. My problem though is not overloading the motor but I will gum up the mill bit. (3 flute) I am using a Fog-Buster coolant system and I am sure I could get more speed if I was using flood coolant.
> 
> To address your question more directly, I almost always am at the turtle setting or 1 to 2 notches to the right. The times that I have had issues have been with cooling and chip removal, not HP.  I hardly ever use my 3/4 end mill and when I do it is usually as a fly cutter substitute. When my End mill would clog up, it would bog the motor down because the bit would quit cutting due to the Aluminum welded to the cutting edges. could that be the issue more than just HP ?



Thanks, Boswell, and MarkDavis,

I'm also using Fog-Buster, so that's possibly a factor.  I've been trying to come up with a way of going to a flood coolant, but haven't yet.  

I have a surfacing cutter, 1-1/2 cutting diameter but only three carbide inserts - so you don't want to move it too fast.  G-Wizard told me I could take 1/8" cut, but I ended up barely able to take half that, and .050 worked best, then, too.  

It seems it's just best to put the slider where you're talking about - no more than 35%  It makes me wonder what sort of machines are behind the assumptions he wrote into his software.  Do the results work well for anyone?


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## Boswell (Apr 15, 2018)

You might try emailing Bob, He was very responsive via email when I had a question some time back.


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## Doubleeboy (Apr 15, 2018)

I have a friend who is a long time pro CNC machinist, both lathe and mill.  His 15 HP mill he frequently has to run at 20-30% of what Bobs programs says he can do.  He finally gave up on G Wizard.  He has a monster flood coolant set up and even with garden hose type delivery he can not cut as fast as GW says.  I  think you can read endless threads on PM about the inadequacies of the program.  My self, I find it worse than worthless, i would rather go by feel and chip color and surface finish than trust the screwy recommendations that GW gives me.  I have given up caring about what the believers say about it, it does not work for me and countless others.  Twice I have written to Bob, and respectfully questioned why my results are so wacky, no response............


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## Bob Korves (Apr 15, 2018)

Flood coolant performs best, but it is a huge mess, gets stinky after a while, leaves stuff sticky, promotes rust if you do not keep after it, and just is not worth it, IMHO, in a hobby shop.  I use cutting oil or fluid, or mist coolant.  My mist coolant hardware is from China, cost $13.45 delivered, and does not make fog, it makes droplets.  It works great.  For what a Fog Buster costs it should be gold plated.  If it works well, then fine.  
The charts are developed for everything working right at the edge, on big rigid machines, to make a profit.  That is important in competitive business.  In hobby work, we set the pace, are not likely to make a lot of money at it, and so we set our own pace for our own enjoyment.  For me, that means keeping costs down.  I do not want to see how fast I can run an end mill, I want to see how long I can run it before sharpening it, with good results.


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## Boswell (Apr 15, 2018)

Bob Korves said:


> For me, that means keeping costs down. I do not want to see how fast I can run an end mill, I want to see how long I can run it before sharpening it, with good results.



Agreed !


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## Doubleeboy (Apr 15, 2018)

Bob Korves said:


> Flood coolant performs best, but it is a huge mess, gets stinky after a while, leaves stuff sticky, promotes rust if you do not keep after it, and just is not worth it, IMHO, in a hobby shop.  I use cutting oil or fluid, or mist coolant.  My mist coolant hardware is from China, cost $13.45 delivered, and does not make fog, it makes droplets.  It works great.  For what a Fog Buster costs it should be gold plated.  If it works well, then fine.
> The charts are developed for everything working right at the edge, on big rigid machines, to make a profit.  That is important in competitive business.  In hobby work, we set the pace, are not likely to make a lot of money at it, and so we set our own pace for our own enjoyment.  For me, that means keeping costs down.  I do not want to see how fast I can run an end mill, I want to see how long I can run it before sharpening it, with good results.



Hi Bob,  Could you share the source for the mist set up from China that you are happy with?
Thanks
michael


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## Bob Korves (Apr 15, 2018)

Doubleeboy said:


> Hi Bob,  Could you share the source for the mist set up from China that you are happy with?
> Thanks
> michael


It looks like this one.


https://www.aliexpress.com/item/1Pc...57261a5&transAbTest=ae803_1&priceBeautifyAB=0
There are a lot of vendors, and also various sale prices.  Mine cost $13.45 delivered from China.  It works great.  I use 2 liter soda bottles as storage containers for the Kool Mist 77 coolant and water mix I use.  There is zero toxicity.  It is mixed 32:1, one ounce coolant per quart of water.  2 liters of mixed coolant will last me for about 12 hours of continuous use.  I added a brass nut over the tubing between the inlet strainer and the check valve to keep it sunk in the coolant.  Getting the coolant flowing is effortless and the adjustments are not fussy.  There are separate needle valve controls for air and for coolant.  The Loc-Line clone tubing works well, does not droop and fail like much of the import Loc-Line does.  The air and coolant lines simply push into both input fittings, and the blue collars are pushed forward to release them.
Edit:  You supply your own 8mm (5/16") vinyl air tubing to the mixer.


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## spumco (Apr 15, 2018)

MontanaAardvark said:


> If this is a SW problem with the CNCCookbook software, what would you recommend?



I've tried GW, but I find HSM Advisor to have more realistic and consistent F&S recommendations.  Taking your attempted cut for example, and editing the power curve to a 1hp spindle with a max RPM of 4000:

6061 AL
3/4" 2FL HSS end mill
Full slot, .1875" DOC

Recommended SFM - 600
Recommended RPM - 2446
Recommended IPM - 29.35 (0.004 IPT)

This is a .9 HP cut and is 'in the red' on the display.

Dropping the cut depth to 0.100" results in a .66hp cut, which appears manageable with this hypothetical spindle.

Something to pay attention to is how much HP & torque you have at various RPM.  My spindle can get up to about 7500RPM, but I simply can't run a 1/2" end mill that fast as the motor has lost quite a bit of torque.  If I'm trying to max out the material removal I have to set the F&S software to the highest RPM before the torque falls off and then use that to calculate the chipload.  In my case this is about 5500RPM - and at that speed I can take huge chunks with bigger end mills and really plow through aluminum.

I suspect the 750w motor you have may not have all the power on the nameplate, nor does it have that power at all RPM.  Find a torque curve for a similar motor and figure out where the torque tapers off.  Then use that speed in whatever software you choose to use.


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## Groundhog (Apr 16, 2018)

I've used GW for a long time, mostly because I bought it for a year and it has been free ever since. And I have tool libraries set up - which are a pain to set up in any program and I don't want to have to do it again.
I've learned  that I need to set the slider to around 50% when cutting aluminum and 20%-25% for steel. Works good enough for a starting point. But I use it for a lot of the other features, just because they are all in one place. Like screw/bolt data, thread and threading data, geometry, etc.
However, if I was looking for a speeds & feeds program I would probably keep looking.


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## MarkDavis (Apr 16, 2018)

I will keep using G wizard, with the slider set in the 20-30% zone, at this point in my learning curve I can't afford another program
With the use of G wizard, tools have some life, Vs a lot of broken/burned tools with out G wizard's guidance.
My coolant system is kool mist 77/water sprayed with air from tool not bearing the fog buster name.
I only use distilled water, and my coolant tank is a one gallon plastic jug purchased full of distilled water.


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## Bob Korves (Apr 16, 2018)

I have a slide rule type speeds/feeds calculator that I use sometimes. It is free for the asking from Niagara Cutter.  Mostly I do the calculations in my head.:
SFPM x 4 / tool or work (spinning) diameter = cutting speed (rpm)
--------
mild steel, 90 SFPM, 1/2" end mill
90 x 4 / .5 = 720 rpm

2 inch 6061-T6 aluminum, 400 SFPM on the lathe:
400 x 4 / 2 = 800 rpm

These are starting speeds in a hobby shop, adjust as necessary after a test cut...   There are also lots of speeds/feeds calculators free online.   The numbers can be roughly rounded off, and have to be anyway on machines without continuously variable speed.  None of this is rocket science.

When in doubt, start slower.  It is easy to raise the speed up if needed.  It is not so nice to have to lower the speed and also change out the damaged cutter and work.  Machismo is an often poor attribute in a machine shop.


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## MontanaAardvark (Apr 16, 2018)

Bob Korves said:


> Flood coolant performs best, but it is a huge mess, gets stinky after a while, leaves stuff sticky, promotes rust if you do not keep after it, and just is not worth it, IMHO, in a hobby shop.  I use cutting oil or fluid, or mist coolant.  My mist coolant hardware is from China, cost $13.45 delivered, and does not make fog, it makes droplets.  It works great.  For what a Fog Buster costs it should be gold plated.  If it works well, then fine.
> The charts are developed for everything working right at the edge, on big rigid machines, to make a profit.  That is important in competitive business.  In hobby work, we set the pace, are not likely to make a lot of money at it, and so we set our own pace for our own enjoyment.  For me, that means keeping costs down.  I do not want to see how fast I can run an end mill, I want to see how long I can run it before sharpening it, with good results.



Lots here, but first is your last paragraph.  I'm a hobbyist.  I don't want to waste time, I can make more stuff if I don't, but I don't need to be as efficient as a professional and my chances of getting a "big rigid machine" like a $50,000 Haas are zero.  In the big sense, I'm pretty happy with my G0704 and the CNC conversion I did.  I have some nagging little issues I mess with, but it's completely usable.  (I'm tired of hitting my head on the enclosure whenever I bend over to look at something on the table).  

I'm running a fog buster and it does fine in terms of keeping aluminum from self-welding to the cutter.  Not long ago, I cut a deep slot in a piece of 1018 steel, 3/16" end mill diameter and 3/16" deep.  I don't recall the cut specifics, but the cut went fine, the problem was it was too deep to clear chips.  This is where flood cooling might have been better.  The cutter discolored from heating.  I think it was from the heat.  

But thanks to all about keeping the slider down at around 25%, and to Spumco for the tip on HSM Advisor.


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## Doubleeboy (Apr 16, 2018)

Bob Korves said:


> It looks like this one.
> View attachment 265202
> 
> https://www.aliexpress.com/item/1Pc...57261a5&transAbTest=ae803_1&priceBeautifyAB=0
> ...



HI Bob,   Thank you for the link for the mister on aliexpress, I ordered one this morning.  Did you ever do a write up on it in the past?  If you did I missed it, if there is one if you could give me a link I would appreciate it.

Thank you
Michael


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## Groundhog (Apr 16, 2018)

Montana. I built a flood coolant system by making the tank out of a sheet of PVC and PVC angle (like angle iron). All just glued together with a couple of baffles and a screen filter. I use a well sediment filter just before the nozzles and a garden fountain pump. Total cost 6 or 7 years ago was about $150.


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## Bob Korves (Apr 16, 2018)

MontanaAardvark said:


> This is where flood cooling might have been better.


An air blast alone is also a good way to clear chips from a deep slot. and it cools the work.  The only part is misses is the lubrication.


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## Bob Korves (Apr 16, 2018)

Doubleeboy said:


> HI Bob,   Thank you for the link for the mister on aliexpress, I ordered one this morning.  Did you ever do a write up on it in the past?  If you did I missed it, if there is one if you could give me a link I would appreciate it.
> 
> Thank you
> Michael


You're quite welcome, Michael.  I have posted a couple things on the mister, but no more and probably less than you already saw here.  You will need some sort of mounting, like a bracket or magnet or mag base or clamp to bolt to the mister, some sort of reservoir(s) to hold the diluted coolant, and 8mm (5/16") clear vinyl or Tygon tubing for air, and an adapter to your air supply.  No instructions or other paperwork came with the mister.  I mount my coolant about level with the mixer body and it works great.  If mounted above the mixer body, the coolant may continue to siphon after turning off the air if the liquid valve is left open.  If mounted too far below the mixer body you may have trouble with getting the coolant to siphon up the line.  The check valve might help with the low mounted reservoir, once the flow is started.  After use I run water through the system backwards (check valve!) by wrapping my hand around the strainer and the water faucet, followed by doing the same with compressed air.  Keep dirt and grit and stuff out of the system or you will eventually have problems with it clogging up.  Clean coolant, clean air, no contaminated containers or piping.  I only have used mine on my surface grinder so far, but for the cheap price of them it probably makes more sense to buy one for each machine, which also gives you backups.  Still an order of magnitude cheaper than a Fog Buster, which I have no experience with. 
Sorry, getting off topic here...


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