[Semus]

Hey guys,

I'm about to do a treadmill motor conversion for my G0704. I already have it converted to belt drive, but the treadmill motor I have doesn't seem like all the other treadmill motors that I've seen around here.

Mine does say that it's rated at 2.75 HP @ 130VDC, but the physical size of it doesn't seem right.

Will I run into any problems using this motor?

I plan on using the KBMM 225 controller board with it, and was just wondering if this will even work. I don't want to do the conversion just to find out I'm using the wrong motor. It seems to be powerful enough for what I want, but the size has me a bit scared.

Any suggestions?

[Azalin]

Bigger isn't always the better Nothing is wrong with your motor.

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[Semus]

Bigger isn't always the better Nothing is wrong with your motor.

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Awesome. Thanks.

I also have the added benefit of having the treadmill electronics. I can just use the electronics that came with the treadmill itself to drive the G0704. This should be an interesting build ;-)

[lcvette]

They are physically small. But the HP rating should be right. However I will warn that they don't tend to last long when pushed much. They arc and the brushes seem to go out quickly.

I would recommend that if you are looking for a better long term solution to go a different route. It will be a little more upfront cost but cheaper in the long run when the treadmill motor fails on you.

I would look at a 3phase AC motor, even a 1.5 HP motor will perform worlds better then that 2.75hp treadmill motor.

If size is an issue, Groschopp motors makes a small frame 1.12hp 3ph AC motor that has an full torque low rpm of 320rpm and full HP to 6400 rpm. Cost is for the motor is ~$200 and a single phase input vector duty VFD from Automation Direct is around $250.. Other odds and ends such as an emi filter, line regulator for input and output side will add about another $150.

However this Motor setup will last the lifetime of your mill and perform rock solid with plenty of power for most jobs.

If you will have a spacer or aren't concerned with a lower drawbar (at least a tradition centered over the spindle type) a larger 1.5hp leeson 3phase metric motor with same drive will give you more power. Don't be fooled by the power rating as a 3phase AC motor will easily outperform the motor you currently have on your machine and will run much cooler with very stable power for cut entries.

Just some something experience from going the same route you are starting on, hopefully it saves you some headaches an money... If not and you want to buy a kbmm225..i will sell you mine cheap..lol and my 3 treadmill motor carcusses from my motor escapades.



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[Semus]

They are physically small. But the HP rating should be right. However I will warn that they don't tend to last long when pushed much. They arc and the brushes seem to go out quickly.

I would recommend that if you are looking for a better long term solution to go a different route. It will be a little more upfront cost but cheaper in the long run when the treadmill motor fails on you.

I would look at a 3phase AC motor, even a 1.5 HP motor will perform worlds better then that 2.75hp treadmill motor.

If size is an issue, Groschopp motors makes a small frame 1.12hp 3ph AC motor that has an full torque low rpm of 320rpm and full HP to 6400 rpm. Cost is for the motor is ~$200 and a single phase input vector duty VFD from Automation Direct is around $250.. Other odds and ends such as an emi filter, line regulator for input and output side will add about another $150.

However this Motor setup will last the lifetime of your mill and perform rock solid with plenty of power for most jobs.

If you will have a spacer or aren't concerned with a lower drawbar (at least a tradition centered over the spindle type) a larger 1.5hp leeson 3phase metric motor with same drive will give you more power. Don't be fooled by the power rating as a 3phase AC motor will easily outperform the motor you currently have on your machine and will run much cooler with very stable power for cut entries.

Just some something experience from going the same route you are starting on, hopefully it saves you some headaches an money... If not and you want to buy a kbmm225..i will sell you mine cheap..lol and my 3 treadmill motor carcusses from my motor escapades.



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I appreciate the info. The only thing I'm concerned about is that I'm not an electronics guru. I have no experience with wiring. I can do simple jobs, but anything complicated is out of my skill level.

I do have experience with wiring up a spindle to a VFD, but that was for my CNC machine, and the instructions were very clear and straightforward.

You mention other odds and ends, but if I'm to go the route you suggest, I will need a complete parts list and links to where I can find them. I know I can just google most of this stuff, and that's fine. However, I don't know what these "odds and ends" are. Care to share them with me? Or better yet, send me a PM, and we can discuss this in further detail.

[lcvette]

Here ya go.. Listed it for anyone after all my headaches to try and help those upgrading from falling into the same pitfalls I had to muddle through.

http://www.cnczone.com/forums/bencht...formation.html

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[Semus]

Here ya go.. Listed it for anyone after all my headaches to try and help those upgrading from falling into the same pitfalls I had to muddle through.

http://www.cnczone.com/forums/bencht...formation.html

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Unfortunately, that thread doesn't list the smaller motor you suggested above. Size is going to be a problem, and I need to have a motor that will fit onto the belt drive conversion kit from benchtop precision. I can definitely drill and tap new holes if I need to, but I want to be able to use the belt drive kit I already have. That will make things much easier.

I don't see the motor you're referring to on the Groschopp website. Do you have a direct link to this motor? I do see the VFD on Automation Direct, and it looks like I'll be going with that. I just need to know what motor you're referring to. I can probably figure things out from there.

[lcvette]

Then you skipped the first post, it lists part numbers.. The groschopp motor link is here.


Groschopp | AC Motors and Gearmotors
You might also contact Groschopp as they also have motor controls specifically matched to their motors.

Re-read the first post in that thread it explains everything..

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[Semus]

Then you skipped the first post, it lists part numbers.. The groschopp motor link is here.

You might also contact Groschopp as they also have motor controls specifically matched to their motors.

Re-read the first post in that thread it explains everything..

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Yes, you're right, I missed it. Although, I don't see the Groschopp motor link. I must be blind...

[lcvette]

No.. I forgot to add.. In there now! Lol

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[Semus]

No.. I forgot to add.. In there now! Lol

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Awesome, thanks. So, I think I'll definitely go with what you suggested. It sounds to me like this will be the better solution.

I really appreciate you taking the time to list all of those products. This will save me a very large headache ;-)

Do you happen to know if I will need anything else if I'm going to use the smaller motor from Groschopp?

[lcvette]

My suggestion is to contact Groschopp, they are excellent at helping to build you list of components, they also have drivers and may be less expensive then the Automation Direct unit I listed. When I spoke to their representative he was extremely helpful.. Let them know that you want a 10:1 constant torque ratio which will give you a very good low end rpm and allow the motor to make peak torque down to 1/10 the rated rpm which would be 321rpm (3210/10=321). If the is going to be a manual mill make sure the speed controller VFD, has a manual entry interface. They build these motors and engineer them so can accommodate minor requests fairly easy. If you want super accurate controlled rotation you will need a feedback loop from motor to VFD. This will allow much better control of the motor speed and give you the absolute best results the combination can attain.

On any VFD it is highly recommended (i believe the power companies require it) you use a line regulator on the input side. It also helps to smooth the feedline side to have one on the outgoing lines to the motor from the VFD, especially on non inverter rated motors, will help it run much cooler at lower rpm. You will want fuse or perhaps circuit breaker protection for the lines going to the VFD, they will need to be sized for the VFD/motor amp load. If you use the Automation Direct VFD they spell it out very clearly what you will want to use, if you go Groschopp drive, they can help specific or even possibly supply what they recommend you use.

The rep at Groschopp was looking into adding a seperately driven fan which would also really allow low rpm without heat concerns.. Would be worthwhile to request information on that as well. The EMI filter as well as an RFI supressor will help keep noise out of your system if it is cnc or if you will run a cnc system on another machine nearby. I would ask them if their drives have any of these built in. If they don't you will need to buy them seperately and the technician should be able to help you properly size them, supply them or give you a specific part number or data with which to purchase from Automation Direct or similar supply company.

It is very straight forward and the wiring diagrams on Automation Direct's website for their GS3 VFD's is very well document and written in proper English for easy understanding with all of these explanations as well.

It should be noted that I don't know of anyone currently using the groschopp motor on a mill. But their very well documented power and torque graphs show them to be excellent motors and they are built here in the USA so support should be very easy to come by if it is needed.

If I were to go with a Groschopp motor I would strongly suggest an towards using a drive they supplied to have a very well matched combination. I never asked for pricing on their drives so I'm of no help there, but if you speak to them, please post your findings in this thread and the one I linked to help out the next person who may be struggling.. The shared information only helps the community more and gives everybody more options and easier avenues for modding their machines!

Hope that helps!!

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[Semus]

My suggestion is to contact Groschopp, they are excellent at helping to build you list of components, they also have drivers and may be less expensive then the Automation Direct unit I listed. When I spoke to their representative he was extremely helpful.. Let them know that you want a 10:1 constant torque ratio which will give you a very good low end rpm and allow the motor to make peak torque down to 1/10 the rated rpm which would be 321rpm (3210/10=321). If the is going to be a manual mill make sure the speed controller VFD, has a manual entry interface. They build these motors and engineer them so can accommodate minor requests fairly easy. If you want super accurate controlled rotation you will need a feedback loop from motor to VFD. This will allow much better control of the motor speed and give you the absolute best results the combination can attain.

On any VFD it is highly recommended (i believe the power companies require it) you use a line regulator on the input side. It also helps to smooth the feedline side to have one on the outgoing lines to the motor from the VFD, especially on non inverter rated motors, will help it run much cooler at lower rpm. You will want fuse or perhaps circuit breaker protection for the lines going to the VFD, they will need to be sized for the VFD/motor amp load. If you use the Automation Direct VFD they spell it out very clearly what you will want to use, if you go Groschopp drive, they can help specific or even possibly supply what they recommend you use.

The rep at Groschopp was looking into adding a seperately driven fan which would also really allow low rpm without heat concerns.. Would be worthwhile to request information on that as well. The EMI filter as well as an RFI supressor will help keep noise out of your system if it is cnc or if you will run a cnc system on another machine nearby. I would ask them if their drives have any of these built in. If they don't you will need to buy them seperately and the technician should be able to help you properly size them, supply them or give you a specific part number or data with which to purchase from Automation Direct or similar supply company.

It is very straight forward and the wiring diagrams on Automation Direct's website for their GS3 VFD's is very well document and written in proper English for easy understanding with all of these explanations as well.

It should be noted that I don't know of anyone currently using the groschopp motor on a mill. But their very well documented power and torque graphs show them to be excellent motors and they are built here in the USA so support should be very easy to come by if it is needed.

If I were to go with a Groschopp motor I would strongly suggest an towards using a drive they supplied to have a very well matched combination. I never asked for pricing on their drives so I'm of no help there, but if you speak to them, please post your findings in this thread and the one I linked to help out the next person who may be struggling.. The shared information only helps the community more and gives everybody more options and easier avenues for modding their machines!

Hope that helps!!

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Absolutely. Whichever drive I happen to go with, I will make sure to document it here. I may not be able to go into specifics, but I will be sure to at least post the combination I used, and post my successes/failures.

I really appreciate all of the info. It's not often you get this sort of help when doing this kind of thing, so again, it's much appreciated.

I do see that the drive you listed on Automation Direct doesn't have a potentiometer attached. However, most drives have an option to add one, which shouldn't be an issue. I use potentiometers in my own product (I own my own business), so I am very familiar with how they work.

The whole reason I am doing this is because the motor (brand new from Grizzly) on my G0704 is overheating to the point where I can barely keep my hand on it for more than about 1 second. That's WAY too hot. It might have something to do with the fact that it's a V3 motor, and my G0704 might be a V1 or V2, not sure. Also, once I converted to belt drive, I lost a great deal amount of torque, and it stalls out very easily. To add insult to injury, the RPM display only reads RPM's about 1 out of every 10 times I use the mill. I'm just sick of all these problems, and I've had enough. It's time to fix this for good.

[lcvette]

No worries... Yah I went through a few stock motors myself. Not the most robust units if you push them and definitely not ideal for CNC.

You will love the AC motor. Smooth quiet and powerful.

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[Al_The_Man]

The T.M. brand of Johnson are a well made DC motor. here is a blurb on the so called HP rating.
Al.
https://www.johnsonfit.com/blog/trea..._of_horsepower
The PWM style of KB drives give superior performance over the SCR bridge types.

[rusmannx]

Absolutely. Whichever drive I happen to go with, I will make sure to document it here. I may not be able to go into specifics, but I will be sure to at least post the combination I used, and post my successes/failures.

I really appreciate all of the info. It's not often you get this sort of help when doing this kind of thing, so again, it's much appreciated.

I do see that the drive you listed on Automation Direct doesn't have a potentiometer attached. However, most drives have an option to add one, which shouldn't be an issue. I use potentiometers in my own product (I own my own business), so I am very familiar with how they work.

The whole reason I am doing this is because the motor (brand new from Grizzly) on my G0704 is overheating to the point where I can barely keep my hand on it for more than about 1 second. That's WAY too hot. It might have something to do with the fact that it's a V3 motor, and my G0704 might be a V1 or V2, not sure. Also, once I converted to belt drive, I lost a great deal amount of torque, and it stalls out very easily. To add insult to injury, the RPM display only reads RPM's about 1 out of every 10 times I use the mill. I'm just sick of all these problems, and I've had enough. It's time to fix this for good.

If your tach isn't reliable, check the bracket that the sensor is mounted to. It is a common issue that the bracket holes are poorly located and your sensor is not as far over the spindle encoder ring as it should be. Mine had this problem and all I had to do was file the hole into a slot (not by much) so the sensor could be slid over a tiny bit. I have no problems now and my spindle gets up to nearly 5kRPM with my treadmill motor.

[Semus]

If your tach isn't reliable, check the bracket that the sensor is mounted to. It is a common issue that the bracket holes are poorly located and your sensor is not as far over the spindle encoder ring as it should be. Mine had this problem and all I had to do was file the hole into a slot (not by much) so the sensor could be slid over a tiny bit. I have no problems now and my spindle gets up to nearly 5kRPM with my treadmill motor.

I checked this, and it's mounted perfectly. There's something wrong with the electronics, and I'm not sure how to fix it. I think at this point it's a lost cause, and once I adapt the new motor and VFD, I'll have a much better solution.

I appreciate the suggestion, though ;-)

[Buontinh]

If the tach displays weird number or 0, it probably is not getting enough power. Check the voltage and if it's too low, replace the 5v regulator - the component that looks like a transistor next to C5. Refer to this picture CNC for Model Engineers: September 2014

[Semus]

If the tach displays weird number or 0, it probably is not getting enough power. Check the voltage and if it's too low, replace the 5v regulator - the component that looks like a transistor next to C5. Refer to this picture CNC for Model Engineers: September 2014

While I do appreciate the info, the entire electrical system is going to be replaced by a new motor + VFD. Again, I do appreciate the info, and if anyone else reads this thread that has the same issue, I'm sure it will be very helpful ;-)

Thanks!