[Jaxian]

Just thought I would throw out a heads up for something I found. Still trying confirm it at all rpms but it looks consistent so far. I discovered this while looking at some full sized mills and their belts systems and rpms.

I have the newest motors on mine at this time, the new ones that drove the cost up. They are 1400 rpm at 50hz. As you know you adjust the little dial by Hz to change speed. If you are like me you make a little chart and stick it next to the dial so you can see the actual rpm.

Knowing the rpm is obviously critical for working out SFPM on both lathe and mill operations, drilling also of course.

So I read the little tag on the motor itself and was looking at the 1400rpm at 50Hz, (not 1500 at 75Hz as the manual says that was the old motors). Then looked at the power 1.1kw or 1.5hp, not 2hp. This cause some emailing back and forth until it was cleared up. Now all their marketing and ads specify the 1.5hp true number. It's not lower than the old 2hp, the new motors are 100% efficient (hence the price bump), whereas the old 2hp where only 75%. Both made the same power, but the Chinese didn't understand the marketing aspect of the change. All fixed now so no big deal.

Anyhow as I was looking at the motor and the drive on the mill I realized that the pulley's where not the same size. So if the motor is turning 1400 rpm the mill won't be the same. Larger pulley on the mill so slower actually. The 1400 rpm is the advertised number so thought I should do some checking.

After measuring the pulleys I came out with a ratio of 1.74:1 for the mill. I then ran the motor at the first few Hz where I could actually watch a large mill end rotate and count the turns. It's was consistent at all the speeds.

For instance at 3Hz which should be 84rpm at the motor (1400/50 = 28rpm per Hz, 3x28=84). So I counted 49 at the actual mill end. 49x1.74=85rpm at the motor, or basically exactly as it should be for the Hz. I don't have a tachometer to test higher speeds. Looking around for one.

So now I need to redo my whole table so I can figure out my SFPM correctly. Also need to take the side off and do the same math for the lathe motor and pulley's and see if they are the same or some other ratio.

Obviously the CNC ramifications as far as threading and such or CNC spindle control could be large although I think the pickups for the signal are on the spindle pulley itself not the motor so might be ok. Haven't actually taken the side off to look.

Might have to have another fix it on the advertised motor speeds. Will drop a line to JT and fill him in at some point but I figure I can't be the only person of the last shipment to figure this out so I assume he is aware of it. Just thought I would throw out a heads up for the new owners.

EDIT: I know this is not specific CNC related but if there is a Shopmaster user forums I don't know where it is. The official one looks like it gets posts about once a year so not really thinking that is very useful.

[tropopv]

I run the lathe most of the time so I have the benefit of the index pulses giving me an RPM reading. I have the VFD set up to control RPM and direction from Mach3 and 125Hz frequency. I get a max of around 2350 RPM at the lathe spindle.

[Timbob]

I put an index pulse pickup on the quill as well, so the lathe and the mill are rpm controlled by mach 3. It works very well, and I would recommend it.

Of course I have to mess with things every once in a while and thereby lose functionality from time to time. The latest I messed with was the debounce and set it too high. Poor motors saw an awful lot of rpm from that

It's probably good to non-destructively fart about with things so you get a feel for how things work and interact. Just remember where everything was when it worked properly!!!

[Jaxian]

Yeah JT had told me when I first brought up the inconsistency between the manual and the actual numbers stamped on the motors that I wouldn't fry any motor control circuitry as the VFD controller was fine to like 120Hz.

My issue was more whether you can run a 1400rpm rated motor faster and at a higher Hz than it is rated for without wrecking it. I mean 120Hz is 3360rpm at the motor. Not sure the machine would like that. But then again that means the mill at least could be spun to near 2500rpm (haven't measured the lathe pulleys to see where it is ratio wise). There are certainly uses for that I could see.

I have not tried tying any more of the Mach3 CNC software to more of the hardware yet. At this point I am still trying to get a really large issue out of the way that will make the machine usable rather than getting to around to messing with the small fun details.

Good feedback on the Mach3 stuff though. I thought it was all tied in together but nothing I do in Mach3 seems to have any effect on the machine so I assume at this point it's not connected inside or something. I had to do a ton of tuning of the SPI settings to get the Test Indicated accurate physical DRO to match with the Mach3 software DRO (although backlash still hoses it up on direction changes). So mostly now I am just using the CNC motors as power feeds.

[Timbob]

You have to hook up the signal wire so mach 3 can see the rpm. It's explained fairly well in the manual, and pretty simple to do.

For the backlash, make sure to adjust the fixed ends of the ballscrews, the end with the crank handles. Also, the gib adjustment makes a big difference. I have my backlash x=.0015, y=.003 and z=.002. Pretty darn good, I think.

Something I am messing with is (drumroll) ....



step pulleys!!! Yes, that is the purpose of a VFD, but power loss at low rpm and motor overspeed at high rpm make step pulleys an attractive option. I have 2 baldor 2HP motors awaiting install and step pulleys I made out of 7075 fitted to them. Fun, fun, fun!!!

[Jaxian]

Timbob you are way in front of me at all this stuff. I am still trying to iron out some basic machine physical layout issues that weren't right front the factory. So barely able to even use the machine much less jump in and attack cool CNC stuff.

I did open the side electrical compartment to check the pulley ratio for non CNC stuff so I could know the actual spindle speed if I wasn't using the computer. It was 1.62:1. So had to make a new chart with both lath and mill rpm vs Hz.

Also unlike other posters here on the forum my motor control wires were not like the manual states all nice and bundled and shrink wrapped like they had pictured. They were folded up and crammed under the lip of the cabinet and loose. I posted a picture in another thread. Ah well.

I sent JT an email asking about motor speed. My motor says 1400rpm on it. With the pulley ratio reduction the max I am able to get is lathe-868rpm and mill-707rpm at 50hz. This is too low for a machine with torque this low and I got the impression some are running their motors at far higher Hz for higher motor rpm. Is this the case? JT mentioned the VFD could run to 120hz no issues but I assumed he meant the controller, not the motor. I mean JT is the last word as he controls the warranty if I fried it but just wondering what others are doing.

[Jaxian]

Got a response from Shopmaster. Here is the cut and paste of my question and his response. Not sure how to interpret this. The old motors where rated 75hz before the very last shipment that arrived early Jan 13. The new ones are rated on the plate on the motor at 50hz. Not sure any of that makes any difference and if it all goes out the window when controlled by the VFD. The answer is short enough to be open to tons of interpretation. Any input would be welcome I really don't want to screw this motor up. Trying for some clarity here.

My email:
JT,
Just talking to a few other Patriot owners who run their VFD's to 75 or even 125hz in one case. I was under the impression that 50hz/1400rpm was the max. I recall you saying it could go to 120hz max without issues. I just assumed you meant the controller itself. Does this apply to the motor? That would be like 3600 rpm at the motor. Can it be run that fast? That would be very useful. Thanks for the information.

Shopmaster response: The factory setting is 75Hz and 120 is the max.

[Timbob]

Yes, you can spin the motors higher than 1400 rpm, 120Hz is doable. Just pay attention to vibrations. Provided the armature is balanced, it shouldn't be a problem. I've had my spindle speed up to 1800, so motor about 2800 rpm, with no problems. I'm not sure about long term use at that speed, but several minutes has been fine. My step pulley project will allow use of the motors at closer to their rated speed and power over a wider range. As with all of my projects, it's gonna take some time.

When I got my machine, the cable had come off the VFD control panel. The wires were tucked away, neat and tidy. Also, the charge pump switch on the G540 was set wrong, so I got a red light. It has certainly been a learning experience, but I enjoy that as much as making chips.

[Timbob]

50Hz/1400 rpm is the motor rating. Factory setting of 75Hz is for the VFD. It can be taken up to 120Hz max. Basically, you are "overclocking" the motor. More Hz = more speed. Running outside of the motor rating can theoretically cause problems, but normally they are "overbuilt" and can handle it no problem. A rating of 50Hz/1400 rpm will give you 3360 rpm at 120Hz. Provided the motor is balanced well enough, this shouldn't be a problem. Vibrations will be your indicator.

The Baldors I am going to install are 60Hz/1740 rpm, 2HP. I'm sure I'll be able to spin them to 3600 rpm quite comfortably.

[Jaxian]

Yeah, I am definitely learning a lot. Don't like experimenting with expensive things that much but seems like it will be fine.

I just went outside and tried to crank it up to 120 like he said as a max. It wouldn't go any farther than 75 using the little knob on the VFD panel. Which is the only way I have been using it so far to learn about the machine and machining in general.

I guess to get it to go higher you must have to change settings within the VFD controller itself. The Nowforever VFD manual is 121 pages long so this might take me a while to figure out how to reset it to go up that high. And hopefully there aren't other things I need to calibrate with it in conjunction to that raised ceiling so that it is outputting the right information to the motor itself.

So stuck at 75 with manual control for now. Trying to figure it out.

[sshroff100]

Yes, you can spin the motors higher than 1400 rpm, 120Hz is doable. Just pay attention to vibrations. Provided the armature is balanced, it shouldn't be a problem. I've had my spindle speed up to 1800, so motor about 2800 rpm, with no problems. I'm not sure about long term use at that speed, but several minutes has been fine. My step pulley project will allow use of the motors at closer to their rated speed and power over a wider range. As with all of my projects, it's gonna take some time.

When I got my machine, the cable had come off the VFD control panel. The wires were tucked away, neat and tidy. Also, the charge pump switch on the G540 was set wrong, so I got a red light. It has certainly been a learning experience, but I enjoy that as much as making chips.

motor is 1hp each not 2 hp each right? my motor is i think 1hp.
can you post where did you make change for 120HZ, can you cut oast photo of menu. I think i can leave with 3000 rpm.
i work on weekend during week day no time.

[Jaxian]

The new motors from the last shipment to arrive around the first of the year are 1.1kw at 50hz and 1400rpm. That's 1.5hp.

It's stamped into a plate on the motors themselves. I originally complained that they weren't the 2hp motors I had paid for (matter of fact they were $500 more expensive) but was told it was a matter of a miscommunication with the Chinese.

The old motors where 2hp but where only 75% efficient. Thereby 1.5hp actual. The new motors are much higher quality and are 100% efficient. Same 1.5hp.

So as far as the Chinese were concerned same exact output but higher quality so better torque curves and balance and all that. They didn't think to take into account US marketing perception and people would be be angry because "2hp is 2hp and you are only giving us 1.5hp" when that just isn't the case.

As soon as I had talked to JT all the advertising and marketing stuff had been changed to reflect the actual numbers on the new motors. The Chinese hadn't bothered to tell him apparently because as far as they were concerned it was the same power in a higher quality motor. Hope that explains some.

[instructor37]

Jaxian,
A couple of tips on posting here- try to make your post titles in such a way as you will encourage people to join in and offer help. Your post " MOTOR RPM INCORRECT" sounds like a complaint rather than a question- try something like " QUESTION ABOUT MOTOR RPM " that will bring more responses from other owners. Also remember that once posted, these thing last for eternity, so someday in the future when all your questions have been answered, new readers will still be wondering if there is something wrong with the Shopmaster motors. Also, as far as pricing goes, don't presume to know that the price increase was only for the motors- I spoke to JT about it, and he told me it was a result of the exchange rate between the Chinese currency and the US dollar. Making it sound like he raised the price just for the motors and then didn't deliver is unfair and untrue.

[Jaxian]

I understand where you are coming from and I guess I could be clearer in how I phrased it.

In my defense if you follow the manual and read the marketing materials you think you have 1400rpm max capable motors. And I guess they are. But they are NOT 1400rpm at the either the spindle or the quill. They are off by ratios of 1.62:1 and 1.74:1 respectively.

Because this affects your ability to compute your SFPM if you do not take into account the pulley ratio and that is mentioned nowhere in any literature or anywhere else all your computations will be incorrect.

That is why I made the post with that title. Upon reflection I guess it should have been more along the line of "Motor RPM and spindle/quill rpm not the same". This was a statement, not a question. I knew they were different, I could see the pulley's and work out the ratios. I wanted to let other people know.

The later stuff where we got kind of off topic on how much you could turn them up and whether it was overclocking and what was allowed and how you could change it all kind of took things in a different direction and probably should have been put under a different post topic in retrospect.

Thank you for pointing out the lack of clarity on my part. I sometimes don't think it through from all perspectives.

As to the price, I was directly told by JT when I wrote the check to make it for $500 more because the new motors were more expensive. They had wanted to raise the price on the previous shipment but since he had already been paid by the customers he told them there was no way to do that.

If there was more to it than that he did not share that information with me. I was passing along only what I was told. I can't know what I wasn't told. Just a case of miscommunication.

[smallblock]

In my defense if you follow the manual and read the marketing materials you think you have 1400rpm max capable motors. And I guess they are. But they are NOT 1400rpm at the either the spindle or the quill. They are off by ratios of 1.62:1 and 1.74:1 respectively.

I'm not sure where you are coming from in all this, but it seems to be a lot of talk about nothing. The motors are 1400 rpm at 50 Hz. You have a variable frequency drive that can run up to as much as 120 Hz, which increases the speed of the motors. You also have different pulley ratios that change the final rpm at the spindle. Did you somehow expect the machine to have a single fixed speed? Mach 3 has a method of calculating your spindle rpm by inputing the motor rpm and the pulley ratio.

[Jaxian]

Again just a miscommunication. When I read the ad copy for a like a Lagun FTV-1 it says 55-4250rpm or a Bridgeport Series 1 60-4200rpm.

Reading the information on the Patriot it just says 1400rpm (actually when I ordered mine it said 1500rpm, old motor, no big deal). I assumed that meant 0 - 1400rpm because it had VFD motors. So far no sweat all good.

So on the first two examples above they are talking about speed at the quill, not the motor. I have no clue what that actual motor speed is on either of those machines and they didn't bother to put in any of the sales or marketing information. Because of course it doesn't matter. As others have said, it's about the speed at the spindle/quill that matters, not the motor.

So please forgive me if I saw the 1400rpm number in the ads, then saw it on the motor housing itself and thought "Oh, same number, that must be what it actually operates at full out".

I mean why would you advertise an arbitrary number in the middle of the motors possible performance range that has nothing to do with the actual working speed of the spindle/quill?

So when I noticed there was a pulley system and the rpm number at the working points was not 0-1400rpm and it isn't mentioned anywhere online or in the manual and that working speed at the tool is so a critical data point I thought other people would want to know so as not to make a mistake working out the SFPM of what they were working on.

I get that if you start on day one with the CNC working and the spindle speed monitored by Mach3 this isn't an issue. But it's not hooked up for a reason. To let new people get used to how it all works.

So you have a beginner trying to learn how his machine cuts at different SFPM in different materials at different feeds and then realize that all their SFPM numbers have been wrong because they didn't know about a ratio change in pulley's that they didn't know about because it isn't referenced anywhere.

So I brought that up because it seemed really important for beginners like me and that it might really help someone else out as they were learning their machines as I was.

Then people started to chip in with extra information about how to overclock the speed past the factory setting and other great information. Even Shopmaster chipped in with some information that I passes along. All good stuff.

How trying to pass along useful information and everyone chipping in their own helpful hints and knowledge turned into a personal attack on my phrasing of the original post title and the subsequent content of the discussion that I couldn't even control I don't know.

Not really sure why any of this is even in here from the attack post until now. It doesn't address any of what I was trying to alert people to in the first place or the excellent information that came later during the discussion. If every post from that one to this one was removed and I retitled the first post this thread would be vastly better. Now it has gone off the rails into pointless for no apparent reason at all.

I apologized for not being clear enough with the original post title. Won't do it again. Should have just stopped right there.

[smallblock]

This is from the Shopmaster website under Specifications

SPINDLE SPEEDS 0-1500 default- adjustable through VFD to 2400
SPINDLE TAPER R-8
TOOL SIZE LIMITS ( END MILLS/DRILL) 1″ recommended
X AXIS TRAVEL 18″ ( 9″ right and left from center)
Y AXIS TRAVEL 10″ ( 5″ forward and back from center)
ELECTRICAL
MOTORS (2) 220/380 VOLT 60 HZ TEFC 1.1 AMPS EACH 4 POLE INVERTER DUTY
HORSEPOWER 1.5 rated at max VFD torque compensation
PHASE THREE
POWER CORDS 1 12 GUAGE
POWER REQUIREMENT 220 VOLT HOUSEHOLD OUTLET 20 AMP CIRCUIT
MOTOR MOUNTING FRAME – DUAL METRIC 425
MOTOR SHAFT SIZE 24 mm ( 15/16″)
MOTOR RPM 1425
INVERTER 220 VOLT SINGLE PHASE INPUT
380 VOLT 3 PHASE OUTPUT

[Jaxian]

Yep, that was the new information put up there. All good and accurate now. I assume since the 2400rpm at the quill requires 120hz to achieve they will probably bump the 75hz cap up on the VFD as delivered. That would make sense. The spindle on the lathe is still max at 2080rpm at 120hz though unless a different set of pulley's is slated for the next shipment.

Mine is the latest batch and the VFD is still capped at 75hz from the factory but as you said it's just a matter of adjusting it. I admit I haven't had a chance to go through the Nowforever manual and find the specific instructions for doing it.

JT didn't imply it was very difficult at all so it's just a matter of getting the time but I have been busy taking care of a few other more important issues with the machine first. Nice to know it's all going to work really well when done. Keep looking at all the stuff the CNC can do and it's very exciting to look forward to.

I even got the dividing table CNC kit although at this point I don't know if that is covered in the Mach3 Turn or Mill manual. So far beyond me it's not really important though. I will have to figure out how to switch the A axis to rotary table control. I would like to do it with a switch rather than physically moving the cables. But that is for another thread.

Thank you for pointing out the information on the web has been all updated Smallblock. That is great to know. As long as people who are beginners remember to take that pulley ratio change into account when they are computing RPM for SFPM. It's easy to forget if you don't make a chart. I made one in excel. One less thing to have to remember. It's easy to look at the VFD and think the rpm there is the rpm at the spindle/quill if not. I put my chart right on the machine above the VFD.

P.S. if someone wants to throw out which chapter in the Nowforever manual covers the changing of the VFD Hz preset that would save me some reading. If not no problem, it's all useful information. Thanks again guys.