[SCzEngrgGroup]

Pocketing

Attachment 298336

this was using an un-coated Destiny Viper 3FL rougher, 6000 rpm, .315 deep, .15 width, 36 ipm. This equates to about .003 chip load per tooth. No steps lost.

When running this program with the stock PCNC motor with this tool same cut, the most I could push it while being in the low yellow range of the load meter was 14 IPM @ 3750 rpm which was the sweet spot, any higher and the torque fell off real fast.

The cutting tool manufacturer recommends .005 to .007 ipt so I'm not even beginning to push it. I'm doing a paying job right now, a gang of 8 parts per load so I don't want to experiment to much.

In a couple of weeks I should be able to post some real tests.

jh

That's odd.... The stock machine should have been able to do that cut with relative ease. It's generally good for about 3 cu. in./min MRR, and at least 1.0-1.25 HP. You're only running about 1.6 cu. in./min, and 0.6HP. If you're finding that to be a big improvement over stock, I have to believe there was something wrong with your original motor or VFD.

Regards,
Ray L.

[hanermo]

Excellent thread !

[rowbare]

I wonder what roughing that pocket out with a shear hog at full power would look like...

bob

[wtopace]

That's odd.... The stock machine should have been able to do that cut with relative ease. It's generally good for about 3 cu. in./min MRR, and at least 1.0-1.25 HP. You're only running about 1.6 cu. in./min, and 0.6HP. If you're finding that to be a big improvement over stock, I have to believe there was something wrong with your original motor or VFD.

Regards,
Ray L.

I think he was just tossing out a video of it actually running with the custom motor / VFD configuration, rather than a "pushing it to the limit" video. Definitely gets a thumbs-up from me for great work on the integration!

I'll be excited to see him push it to the limits and see what the machine is capable of with the upgraded motor vs what we can do with our stock motors.

[LeeWay]

I know I put a big A$$ motor on my home made mill with an X2 head and it doubled in performance. It went from a tread mill motor to a larger Iron Horse motor from Automation Direct.
Nice work on the Tormach upgrade.

I helped a guy in Germany install a 327 cu in Chevy motor in a VW bus. No drive shaft. Straight out of the transmission to the new rear end.
Had to put bar bell weights up from to keep the wheels closer to the ground. It was only for the strip though. Quickest VW bus I have ever seen.

[johnh]

That's odd.... The stock machine should have been able to do that cut with relative ease. It's generally good for about 3 cu. in./min MRR, and at least 1.0-1.25 HP. You're only running about 1.6 cu. in./min, and 0.6HP. If you're finding that to be a big improvement over stock, I have to believe there was something wrong with your original motor or VFD.

Regards,
Ray L.

Yeah, maybe so, I've had nothing to compare it to, just what I was experiencing with what I have, the machine is serial #26 or near there. Maybe the newer motors are better?
Cool, now I have a Goal to exceed, more than 3in3 min.

The motor cooling system is really working well. Its an electric 600cfm fan on top of the motor with an intake duct out the top of the enclosure. This way the air is cool and dry to keep the motor and housing clean.
The thermostat sensor is down inside the grease hole for the bearings at the PTO end. This is as buried as it can get away from any external heat influence. Running under load it will slowly climb to 125 F where the fan kicks on, in about 15 minutes the temp is back down to 100 F, so the duct, fan, shroud system is for sure pulling the heat out of the motor.

The fan motor wires shared the same conduit as the motor wires for convenience, But I did discover that when the fan turned on that the 60hz 110v caused the motor to drop 6hz and vary slightly in rpm, since putting the fan wires with the coolant chain the motor runs without a hiccup now.

I also have the load meter hooked up now, with the cutting shown above it is only pulling 2.8 amps.

The spindle bearings are running relatively cool for doing 6400 rpm for a few hours straight. Due to the Kluber grease I'm sure. It's giving me confidence to raise the rpm. Did some more engineering and if I change the gearing to 1:1.5 I can get 9600 spindle rpm without maxing out the motor and the belt and pulley speeds are still well within their limits. Running at 6400 the pulleys stabilize at 125F, the belt is good for 185F

Bumped the feed slider up to 150% on feed rate, so 54 ipm on the same cut, below is the load meter barely registering, was showing 4.8 amps peak on the VFD monitor. VFD is set for 16 amps max output for the motor but the load meter scale is set at 180% right now. Works out to about 2.55 cu in min, getting there. According to Destiny tool this cut should be done at 80 ipm! for almost .007 chip load or 3.78 cu in min

https://youtu.be/IDayTyo90ao

It looks like it will come down to the limits of the steppers torque to push the cutter fast enough to tax the motor and not loose steps. That and get the rpm up higher! That is an easy experiment, I think I'll get the pulleys ordered.



jh

[johnh]

Question,

what MMR rate has anyone actually achieved using a stock a PCNC 1100?

this will be my testing goal below,

Attachment 298444
SGS Tool Company- A Leading Manufacturer of Round, Solid Carbide Cutting Tool Technology.

Viper S&F - Destiny Tool

I'll XYZ 0.0 on the corner of the vise, then use as simple linear cut in 6061-T6 full width 1 Dia in depth, lead in with 50% feed rate and run it for 6" at increasing IPM's until something bad happens. Repeat the process at just below the bad happening for a few passes then check the corner of the vise for XYZ 0 again to check the steppers.

Once this basic max is found I'll design a flower pattern to torment the machine XY axis. I would think that then I can extrapolate this data vs the Destiny recommended numbers for Aluminum and translate that to their mild steel numbers and then create a similar test for mild steel.

Any ideas on testing? I've not done this before so . . .



jh

[johnh]

maybe this is why I was not getting 3 cu in min.

Attachment 298446

as I said before 3750 rpm was the sweet spot, any higher is was easy to bog the motor down, a lot lower it just was slow and rough on the machine and tended to pull the TTS tools out of the spindle. That was my personal experience anyway.

jh

[SCzEngrgGroup]

Question,

what MMR rate has anyone actually achieved using a stock a PCNC 1100?

this will be my testing goal below,

Attachment 298444
SGS Tool Company- A Leading Manufacturer of Round, Solid Carbide Cutting Tool Technology.

Viper S&F - Destiny Tool

I'll XYZ 0.0 on the corner of the vise, then use as simple linear cut in 6061-T6 full width 1 Dia in depth, lead in with 50% feed rate and run it for 6" at increasing IPM's until something bad happens. Repeat the process at just below the bad happening for a few passes then check the corner of the vise for XYZ 0 again to check the steppers.

Once this basic max is found I'll design a flower pattern to torment the machine XY axis. I would think that then I can extrapolate this data vs the Destiny recommended numbers for Aluminum and translate that to their mild steel numbers and then create a similar test for mild steel.

Any ideas on testing? I've not done this before so . . .



jh

Several people here have reported a bit over 3 cu. in./min. My impression (no hard data) is that is getting close to the point where rigidity becomes an issue as well, so it will be interesting to see what you gain with more spindle power. I think the feedrate will likely be your biggest limitation. Next you need to start looking at AC servos! :-)

Actually, more powerful steppers could be a nice improvement without spending too much money. My big Novakon Torus Pro came with steppers, which I've since switched to AC servos. But I ran for about nine months on the steppers, with 250 IPM rapids, and never lost a step. No reason you couldn't do the same with the 1100. The good news is the motors are getting cheaper by the day. The bad news is, you'd almost certainly have to swap out the drivers, unless your machine still has the S1/S2 two-phase steppers. If so, then you would likely be able to just replace the motors, and gain a lot of speed.

Personally, I would never do slotting at 1" deep, even if I could. Using HSM toolpaths will get you the same, or better, MRR with much less stress on the machine. At 1" DOC, you'll have a hard time clearing chips, and you'll need some serious coolant to prevent chip welding.

Regards,
Ray L.

[johnh]

Oh, I meant 1 diameter deep, yes, 1" deep full width on a .375 cutter would be kinda of dumb move! But I do have the serious flood cooling going on!

Yes, I have the series II steppers, my thoughts were the same as yours. Either go to more powerful steppers or use the ClearPath Servos, an all in one package that takes the current step direction signals, stock PCNC is 48v though, they could take 75v.

Brushless DC Servo Motors with Integrated Drive & Controller by Teknic

Some of the sound I'm hearing while cutting is the machine vibrating no doubt.

I'm not sure what the stock series II XY steppers are rated at off hand. I do have my rapids upped to 200 ipm now with out loss of steps, the Z couldn't handle more than 120 before loosing it going up.

Were your steppers NEMA 34's Ray? Which servos are you using now?

So far I'm a super happy camper compared to what my machine would do before.

Seeing what higher rpm can do for relieving stress on the machine and tool holder now really makes me want to drive the spindle as high as I can get it without having to cool it. And if I can get the axis flying around at 500 IPM I'd be stoked!!!! save me from finding a real VMC/tooling etc and relearning a bunch! I've out grown hobby speeds for sure.


jh

[johnh]

Oh, I meant 1 diameter deep, yes, 1" deep full width on a .375 cutter would be kinda of dumb move! But I do have the serious flood cooling going on!

Yes, I have the series II steppers, my thoughts were the same as yours. Either go to more powerful steppers or use the ClearPath Servos, an all in one package that takes the current step direction signals, stock PCNC is 48v though, they could take 75v.

Brushless DC Servo Motors with Integrated Drive & Controller by Teknic

Some of the sound I'm hearing while cutting is the machine vibrating no doubt.

I'm not sure what the stock series II XY steppers are rated at off hand. I do have my rapids upped to 200 ipm now with out loss of steps, the Z couldn't handle more than 120 before loosing it going up.

Were your steppers NEMA 34's Ray? Which servos are you using now?

So far I'm a super happy camper compared to what my machine would do before.

Seeing what higher rpm can do for relieving stress on the machine and tool holder now really makes me want to drive the spindle as high as I can get it without having to cool it. And if I can get the axis flying around at 500 IPM I'd be stoked!!!! save me from finding a real VMC/tooling etc and relearning a bunch! I've out grown hobby speeds for sure.


jh

[SCzEngrgGroup]

Many, probably most, AC servo drives run directly off the 220VAC line, so no power supply required.

My steppers are NEMA43 - BIG suckers. I have no idea what the specs are for those, or the AC servos that replaced them. They're all the stock parts Novakon sells with their machines.

200 IPM is probably all the speed you need, provided they have enough torque for heavy cutting over 100IPM.

Regards,
Ray L.

[popspipes]

Yeah, maybe so, I've had nothing to compare it to, just what I was experiencing with what I have, the machine is serial #26 or near there. Maybe the newer motors are better?
Cool, now I have a Goal to exceed, more than 3in3 min.

The motor cooling system is really working well. Its an electric 600cfm fan on top of the motor with an intake duct out the top of the enclosure. This way the air is cool and dry to keep the motor and housing clean.
The thermostat sensor is down inside the grease hole for the bearings at the PTO end. This is as buried as it can get away from any external heat influence. Running under load it will slowly climb to 125 F where the fan kicks on, in about 15 minutes the temp is back down to 100 F, so the duct, fan, shroud system is for sure pulling the heat out of the motor.

The fan motor wires shared the same conduit as the motor wires for convenience, But I did discover that when the fan turned on that the 60hz 110v caused the motor to drop 6hz and vary slightly in rpm, since putting the fan wires with the coolant chain the motor runs without a hiccup now.

I also have the load meter hooked up now, with the cutting shown above it is only pulling 2.8 amps.

The spindle bearings are running relatively cool for doing 6400 rpm for a few hours straight. Due to the Kluber grease I'm sure. It's giving me confidence to raise the rpm. Did some more engineering and if I change the gearing to 1:1.5 I can get 9600 spindle rpm without maxing out the motor and the belt and pulley speeds are still well within their limits. Running at 6400 the pulleys stabilize at 125F, the belt is good for 185F

Bumped the feed slider up to 150% on feed rate, so 54 ipm on the same cut, below is the load meter barely registering, was showing 4.8 amps peak on the VFD monitor. VFD is set for 16 amps max output for the motor but the load meter scale is set at 180% right now. Works out to about 2.55 cu in min, getting there. According to Destiny tool this cut should be done at 80 ipm! for almost .007 chip load or 3.78 cu in min

https://youtu.be/IDayTyo90ao

It looks like it will come down to the limits of the steppers torque to push the cutter fast enough to tax the motor and not loose steps. That and get the rpm up higher! That is an easy experiment, I think I'll get the pulleys ordered.



jh

Congrats John on the hotrod!


A question I have is how do you make the actual rpm show up in pathpilot? My actual spindle speed is a touch over 5300 rpm on a tach and I would like to have that on the readout if possible?

thanks and good job...........

[hanermo]

Please, please let use know when You can test on mild steel (any steel, really).

I have a scratch built mill and any actual MRR data is very hard to come buy for small machines.
Thats why a comparable test, or data, is tremendously valuable.

I will then know what I need to change, if anything.

When you are doing steel, you will be running much slower on the steppers, so rpms should not be an issue.

Im swapping spindles, atm, from tiny BP to an ISO30 spindle, so no machine atm, but getting there.
Just building the pieces, one by one.

[johnh]

Hats off to your scratch build, that's a huge undertaking. I'll post numbers as I find them out.

Right now I use gates GT2 28 tooth flanged pulleys 1:1 ratio and a Gates GT3 belt. all of that is good for 10k rpm

jh

[hanermo]

Yes, sir.
I spent 15.000 hours of work, and about 100k€ at it, so far.

My comparison is commercial machines, that I worked as a sales manager for, and sold 60+ of.
My stuff is equally (== more) accurate, much cheaper, and much less powerful.
I used a 2.5 kW spindle motor (lathe) vs 25 kW on the commercial ones.
I used similar sized components, ie 35 mm linear guides, and 32 mm ballscrews, as 100k commercial machines.

Hope or expect to end up with a dual-spindle, y-axis lathe with live tooling, and a largish VMC.
Cant do pics until they are buttoned up, too much money invested to spill the beans yet.
No more mention of my stuff, dont want to take away from this excellent thread.

I´m happy if I can use 2 kW on the mill.
Anything over 700 W in usable power is enough for commercial success.
Work envelope 1600x500x300 (-400) mm.
Approximate equivalent to a 1.5 m commercial VMC, like a Haas VF5-40, in work envelope.

Mass is 2000 kg vs 6000 kg on commercial stuff for same work envelope.
(Its rel. easy to make accurate stuff, if you dont care so much about power in cutting, or extreme rapids, or chip-chip times. The servo drives I use are about 5x more powerful than needed already)

Hats off to your scratch build, that's a huge undertaking.
jh

[johnh]

SOME NEWS,

I got up to 6400 rpm - 60ipm, .15 radial and .775 deep which equates to 6.98 cu in min! BUT, the TTS tool kept wanting to pull out

The motor was barely breaking a sweat, I only noticed a draw down in rpm when the tool was trying to cut with the solid shank because of the pull out!

Went back and checked the XY 0 and no lost steps! so it looks like they will handle the load.

Going higher rpm at these settings should alleviate the side loading on the tool and thus the pull out.

It's getting exciting, each time I bumped up the MMR the machine sounded the same or better!

Just Awesome.:cheers:

jh

[hanermo]

Fantastic !
So You have already more than doubled the peak MRR, right ?

[Hirudin]

Right on!

[tmarks11]

Fantastic !
So You have already more than doubled the peak MRR, right ?

Except for those kind of cut rates to be useful, he will have to ditch TTS.

...the TTS tool kept wanting to pull out The motor was barely breaking a sweat, I only noticed a draw down in rpm when the tool was trying to cut with the solid shank because of the pull out!