[fragger6662000]

Any thoughts on what to do when the motor and control fails?

[rcazwillis]

Any thoughts on what to do when the motor and control fails?

Seriously?!! That is two machines today. Call Grizzly, get the replacements.

Sent from my DROIDX using Tapatalk

[bjones]

he doesn't have a grizzly g0704 so his title is misleading.
according to his other thread he has an SPG 2217-20lv Milling/Drilling Machine (BF20)
http://www.cnczone.com/forums/bencht...g_machine.html
he should contact them for replacements in the UK.

[fragger6662000]

Yes it is the SPG and i have sent the board back as i was having a arcing issue. As from reading all the posts i always thought the weakest part of the machine was the motor / electronics.

So i am looking beyond the original motor.

Servo, tread mill, ?????????

[paulsv]

Yes it is the SPG and i have sent the board back as i was having a arcing issue. As from reading all the posts i always thought the weakest part of the machine was the motor / electronics.

So i am looking beyond the original motor.

Servo, tread mill, ?????????

Some options:

1. 90 volt treadmill motor off of ebay, with a KBIC-125 or KBMM controller with the proper resistor and fuse from KB Electronics.

2. Small three phase motor such as this:

Surplus Center - 3/4 HP 3400 RPM 230/460 VAC 3 PH MOTOR

with a small vector drive VFD such as this:

Compact Micro AC Drive<BR>1/4 to 3hp, Single or 3 phase <BR>TECO EV Series - wolfautomation.com

3. Buy a replacement motor from Grizzly (about $90) and either the grizzly replacement controller ($63.25) or a KBIC-125. Probably both on back-order.

4. I'm also wondering whether a 90 volt brushed DC servo motor such as one of the first three on this page:

Page Title

could be run without an encoder off of a 90 volt motor controller such as the KBIC-125? When I look at the exploded view of that servo motor here:

http://www.kelinginc.net/KL34-150-90Skewed_Rotor020.jpg

it appears to just be a high rpm 90 volt DC motor. If your mill is already cnc'd, you could, of course, look into a servo motor with a servo drive, controlled by Mach3.

Check out Hoss' "Projects" page for other suggestions:

Projects

In any case, one of these motor swaps looks like it would be a lot easier to do after you have converted to a belt drive system, such as the one Hoss sells excellent plans for. If you are going to use a lower rpm motor, you would need the belt drive or a gear swap to get decent rpm's at the spindle. I plan to finish the belt drive conversion before I try any of the motor swaps.

[fragger6662000]

I have already done the belt drive conversion and it was the removal and remounting the motor cause the issues. I like the servo idea as i can control it directly from mach and don't have to interface it with the a third thing.

[RX-Heven]

I found this link on Hoss's thread and am wondering if this motor is reversible?
Motor, 1 HP, AC/DC - Universal AC-DC Motors - Definite Purpose Motors - Motors : Grainger Industrial Supply

He also lists this an option:
KL-1160_BLM
Page Title
I'm wondering about the complexity of integrating this (electronically speaking) into a manually operated mill. I may convert the mill to CNC down the road as that bug keeps biting but I want to get my mill up and running again first without having to wait for Grizzly to send me my 3rd replacement motor to have it take a poop on me right away.

[fragger6662000]

I think some thing weird is going on. I run the motor and control with the belt drive and it arcs but when i use the original gearbox arrangement with lots of resistance the motor is fine. I am wondering with the belt drive the motor is running away with itself and that is causing my issue.

[paulsv]

I found this link on Hoss's thread and am wondering if this motor is reversible?
Motor, 1 HP, AC/DC - Universal AC-DC Motors - Definite Purpose Motors - Motors : Grainger Industrial Supply

He also lists this an option:
KL-1160_BLM
Page Title
I'm wondering about the complexity of integrating this (electronically speaking) into a manually operated mill. I may convert the mill to CNC down the road as that bug keeps biting but I want to get my mill up and running again first without having to wait for Grizzly to send me my 3rd replacement motor to have it take a poop on me right away.

As to the Dayton Universal motor, it is listed as Counterclockwise. If they are reversible, they are listed as reversible. Also, it's a pretty high RPM motor: range of 10,000 to 20,000 rpm. Since it's a Universal Motor, Speed is controllable, and you may be able to run it with a KB controller with the right resistor, but I don't know if you could slow it down that much and still have any power.

As to the KL-1160 BLM, be sure to read this thread:

http://www.cnczone.com/forums/bencht...ndle_mach3.htm

A number of guys bought them and had torque problems. The manufacturer is working on a fix, but it has been a long wait. The manufacture's rep (named "KungFuPanda" on this board) doesn't speak English extremely well, so it is difficult to understand exactly what the problem or the fix is, or when we can expect it. Keling has been very stand-up about it, but they are at the mercy of the manufacturer too. He currently lists them as out of stock, and has linked the discussion of the problems to his listing on these motors, so I doubt he is currently selling them as a working solution. If they get it sorted out, it will be a great solution for this mill. As I understand it, a properly designed and running brushless motor should keep almost full power down to very low speeds. I don't think it would be too hard to integrate into a manually operated mill- it has its own controller, with a panel for stop, start, reversing and speed, and its own display for rpm, so it would replace all of the current electrical equipment on the mill. except perhaps the safety switch spindle guard, but everyone has removed that anyway.

[paulsv]

I think some thing weird is going on. I run the motor and control with the belt drive and it arcs but when i use the original gearbox arrangement with lots of resistance the motor is fine. I am wondering with the belt drive the motor is running away with itself and that is causing my issue.

Perhaps it could also be a bearing issue, since I assume a belt drive puts more side load on the motor? Does the tightness of the belt affect the way the motor runs? If it's running OK through the gearbox, at least you can run it that way while you work out a permanent motor fix.

[Fastest1]

I spoke with Grizzly today confirming my order for a G0704. They said they do expect a shipment 4/8/2011. They will be doing some quality control when they first arrive (according to the Customer Service Rep) I asked is it in regards to the motor and its failures and she said yes. They are apparently aware of the problem and trying to resolve it.

[RX-Heven]

As to the Dayton Universal motor...

As to the KL-1160 BLM, be sure to read this thread....

Much appreciated info, thank you.

[cjdavis618]

On the Dayton motor above from Grainger. Here is some other info that make it a bit less enticing.

"Full-load speeds can be adjusted 20 to 100%
with proper speed control (sold separately).
Average brush life is about 300 hours. Motors
are series-wound. Gray hammer finish. UL
Recognized."

[Maglin]

An FYI the Brushless Motors offer more power at lower speeds and as you reach it's top speed it drops fairly linearly. Past the max RPM they drop power substantially. That aside a brushless motor would definitely be the ticket. All the heat is produced in the stator instead of the rotor. It's a lot easier to kept cool and their is no brushes to wear out and replace. I think if you look around a VFD and motor can be had for the same price and you wouldn't have to worry about it.

[fragger6662000]

i was thinking off an RC helicopter motor and speed control as the VFD seam to only go up to 3000 rpm on 50hz

[paulsv]

i was thinking off an RC helicopter motor and speed control as the VFD seam to only go up to 3000 rpm on 50hz

Can you get an RC helicopter motor with enough power to run the spindle? I know nothing about them, and when I briefly looked into it, I couldn't find anything in the 3/4 to 1 Hp RANGE, and 5000 rpm. Maybe I was looking in the wrong places. Let us know if you find something.

3000 rpm may be enough if you have a belt drive with high speed pulleys. I think Hoss was getting 6500 spindle rpm on the 5000 rpm motor with his belt drive, which should give you 3900 spindle rpm at 3000 motor rpm. Also, it is my understanding that you may be able to "overspeed" the motor by running it at higher HZ. The Teco EV unit I listed the link to will output up to 200 HZ. The question is whether the bearings and brushes in the motor will withstand more speed. Also I'm not sure if the speed increase is linear with the frequency increase: i.e., if it does 3000 rpm at 50HZ, will it do 5000 rpm at 83.3 HZ? I haven't tried any of this yet- I'm just speaking from what I've read about vfd's and three phase motors. I plan to try it after I've built the belt drive, which I can't do until I've done some set-up work on my lathe, which I can't start til I've finished putting the IGaging scales on the mill, etc. etc. I wish I could work as quickly as Hoss!

[Maglin]

Sorry I mis spoke about 3 phase motors. 3 phase AC motors don't have brushes and are infact brushless motors or so I'm told. DC brushless is the same motor but instead of all three phases being energized at the same time only 2 are which then requires the use of some sort of positioning device on the shaft to know which 2 need to be powered and their polarity. So 3 phase AC motors will still heat the case/stator instead of the shaft/rotor.

Speed is linear to frequency. It's the frequency that actually causes the rotational field speed. So 1500 @ 60hz is 3000 @ 120hz. Most motors can handle 2x rated RPM. It might be a good idea to put some form of temp monitor on the motor for extended 2x rpm uses to ensure you don't overheat the motor. I wouldn't get to fancy with it but should be able to use a thermocouple along with an input on the BOB to monitor temps inside your cnc program and maybe initiate an automatic power reduction if heat gets over a set amount and emergency shut down if over the motors max allowed temp.

[tskguy]

RC brushless motors could have the kw to do the trick but to get a DC power supply will be the hard/expensive part.
2200 series
Check that link out. You can see they have some 5kw motors but keep in mind most RC motors have a bunch of air moving so cooling will also be an issue.
Also they are very expensive! Not to mension the ESC for that size motor. It would be way over a grand. I actually am using a 1kw rc brushless motor for my small desktop router. Im still waiting for it to show up. I hope it works!

[hoss2006]

This thread I have linked to on my site shows an RC motor running a sherline.
http://www.cnczone.com/forums/genera...tors_used.html
A bunch of us bought some 50 amp power supplies on ebay last year for this.
They can be controlled by mach 3 too.
As has been said, adding some cooling fans for these motors is needed.
Hoss

[tskguy]

I followed your link but didnt see what you mentioned. I would love to control my spindle with Mach...How are you doing it with a RC brushless motor?
I briefly looked in to it but didnt find much info.

Thanks
Eric