[orion63]

Hello everybody:

After a long hiatus, I am able to work again on my CNC project!
I Bought the Gecko G540 with 3 steppers kit from CNC Router Parts, but now I want to change my design to use two steppers in the X axis. Buying another identical stepper from CNC Router Parts could take much time and be more expensive than I can afford right now (I live in Peru, shipping + taxes can be expensive). But I found a couple of steppers from old copy machines and believe I could use one of them for the Z axis because (please correct me if I am wrong) it doesn't need as much torque as X or Y.
The problem is I am not able to find the torque specifications of these steppers. I hope somebody can recognize them or tell me if it could be ok to go with one of them.
Any advice will be greatly appreciated.
Thanks,

Gonzalo

[mlabruyere]

I wasn't able to find the exact match but there is some info here:

Active Robots - 2 Phase Unipolar Stepper Motors - Sanyo Denki H Series - UK

[orion63]

I wasn't able to find the exact match but there is some info here:

Active Robots - 2 Phase Unipolar Stepper Motors - Sanyo Denki H Series - UK

Thanks! I also found that page. Those are simmilar steppers, but different Amps, and I believe that may mean different torque. By analogy, I believe mine should be in the 1.6 2.0 Nm range, but don't know if it could be ok for an Z axis.

Thanks again

[ahren]

Those appear to be 6 wire motors, which means they are unipolar, and unfortunately will not work with the G540 (requires bipolar steppers). Keep looking -- a 4 or 8 wire motor could be made to work.

Best regards,

Ahren
CNCRouterParts

[hub]

I think using 2 steppers for one axis is a bad idea. Just my personal opinion. If one would loose steps or not to mention stalling, it would twist the machine..
I'm going for using one stepper connected with a timing belt to 2 ballscrews. It's better in my opinion. But sure, there is still a risk that one pulley would "slip" if applying too much force. But it's remote and not likely if the belt is tensioned properly.

[JD68]

Hello everybody:

After a long hiatus, I am able to work again on my CNC project!
I Bought the Gecko G540 with 3 steppers kit from CNC Router Parts, but now I want to change my design to use two steppers in the X axis. Buying another identical stepper from CNC Router Parts could take much time and be more expensive than I can afford right now (I live in Peru, shipping + taxes can be expensive). But I found a couple of steppers from old copy machines and believe I could use one of them for the Z axis because (please correct me if I am wrong) it doesn't need as much torque as X or Y.
The problem is I am not able to find the torque specifications of these steppers. I hope somebody can recognize them or tell me if it could be ok to go with one of them.
Any advice will be greatly appreciated.
Thanks,

Gonzalo

Have you considered the drives Gecko sell? Looks like a quality product made specifically for Gecko.

JD

[orion63]

Those appear to be 6 wire motors, which means they are unipolar, and unfortunately will not work with the G540 (requires bipolar steppers). Keep looking -- a 4 or 8 wire motor could be made to work.

Best regards,

Ahren
CNCRouterParts

Yes, both are 6 wire motors. But the Step-Syn can work as a bipolar (still haven't try with the other). I identified the center taps and wired the others as if it were a bipolar in a DB9 with a 2.4 K ohm resistor. It worked perfectly with the Gecko!

Still don't know the torque of the motor, but I tried to rotate it with my hands against the holding torque and it was impossible.

[orion63]

I think using 2 steppers for one axis is a bad idea. Just my personal opinion. If one would loose steps or not to mention stalling, it would twist the machine..
I'm going for using one stepper connected with a timing belt to 2 ballscrews. It's better in my opinion. But sure, there is still a risk that one pulley would "slip" if applying too much force. But it's remote and not likely if the belt is tensioned properly.

I also had my share of doubts at using two motors and two screws, but with a big bed of 95*150 cms, I believe I can run into power and twist problems with just one motor. It also simplifies the design and I can put the machine on top of my workbench.

Thank for the advice, I just hope the steppers are strong enough to prevent loose steps and stalling.

[orion63]

Have you considered the drives Gecko sell? Looks like a quality product made specifically for Gecko.

JD

Hi, JD:
If I were to buy another stepper, I would go with CNC Router parts. The kit they sent me was just great. The thing is I would like to be able to use the steppers I found here. I can get used steppers like those at aprox US$7 each!

[ger21]

I just hope the steppers are strong enough to prevent lost steps and stalling.

If you lose steps, or the machine stalls, then it's YOUR fault, not the steppers.
You can stall any size steppers, by setting the acceleration of velocity higher than the motors are capable of.

[orion63]

If you lose steps, or the machine stalls, then it's YOUR fault, not the steppers.
You can stall any size steppers, by setting the acceleration of velocity higher than the motors are capable of.

Thanks for the advice, Gerry!
This is going to be my first experience with CNC and I pretend to go very slow as I understand how these machines work and what their limits are.

[louieatienza]

Hello everybody:

After a long hiatus, I am able to work again on my CNC project!
I Bought the Gecko G540 with 3 steppers kit from CNC Router Parts, but now I want to change my design to use two steppers in the X axis. Buying another identical stepper from CNC Router Parts could take much time and be more expensive than I can afford right now (I live in Peru, shipping + taxes can be expensive). But I found a couple of steppers from old copy machines and believe I could use one of them for the Z axis because (please correct me if I am wrong) it doesn't need as much torque as X or Y.
The problem is I am not able to find the torque specifications of these steppers. I hope somebody can recognize them or tell me if it could be ok to go with one of them.
Any advice will be greatly appreciated.
Thanks,


Gonzalo

These are good steppers.... you probably have around 220in oz torque... the 71 denotes 2.2 inch size, which is a little smaller than nema23. You can go to sanyodenki.com and download the specs for the entire step-syn series... I believev this series also has a max rpm of 2000 as well!

[orion63]

Thanks for the advice, Gerry!
This is going to be my first experience with CNC and I pretend to go very slow as I understand how these machines work and what their limits are.

I mean, "...as I BEGIN to understand..."

[orion63]

These are good steppers.... you probably have around 220in oz torque... the 71 denotes 2.2 inch size, which is a little smaller than nema23. You can go to sanyodenki.com and download the specs for the entire step-syn series... I believev this series also has a max rpm of 2000 as well!

Thanks louie!
I am not able to find the exact model. However, all the 103H7126 series steppers I found have 1.27 N-m (179.8 oz-in) of holding torque. So I think it's safe to assume this same figure for my Step-Syn. I also found in some place that in bipolar mode this motors provide 1.6 N-m of torque. Don't know if this is true.
Now, the question is: a holding torque of 1.27-1.6 N-m is reasonable for a Z-axis stepper?

[mlabruyere]

I think using 2 steppers for one axis is a bad idea. Just my personal opinion. If one would loose steps or not to mention stalling, it would twist the machine..
I'm going for using one stepper connected with a timing belt to 2 ballscrews. It's better in my opinion. But sure, there is still a risk that one pulley would "slip" if applying too much force. But it's remote and not likely if the belt is tensioned properly.

My 4x4 (a little more in one axis and a little less in the other) has 2 screws and 2 steppers on the X-Axis. I've run it like this for more than a year. If you setup your machine, use good steppers, screws, and drivers and keep your rates within the limits of your machine you won't lose steps.

I had planned to link the 2 screws with pullys and a belt but didn't add all the extra complexity.

In the future I may still do this and run one large stepper for the X and use the A axis for a true 4th.

[hub]

I also had my share of doubts at using two motors and two screws, but with a big bed of 95*150 cms, I believe I can run into power and twist problems with just one motor. It also simplifies the design and I can put the machine on top of my workbench.

Thank for the advice, I just hope the steppers are strong enough to prevent loose steps and stalling.

Almost exactly the same size as mine which is about 1m x 1.5m.
Using 2 screws for X with one motor is my plan, if the belt doesn't slip there is no twist problems. As for it being strong enough, the Y axis has the same motor (3Nm). That way both X & Y have the same power. And additionally, which also affected my decision, is that some day I will add a 4th axis I hope

Hub

[orion63]

My 4x4 (a little more in one axis and a little less in the other) has 2 screws and 2 steppers on the X-Axis. I've run it like this for more than a year. If you setup your machine, use good steppers, screws, and drivers and keep your rates within the limits of your machine you won't lose steps.

I had planned to link the 2 screws with pullys and a belt but didn't add all the extra complexity.

In the future I may still do this and run one large stepper for the X and use the A axis for a true 4th.

Almost exactly the same size as mine which is about 1m x 1.5m.
Using 2 screws for X with one motor is my plan, if the belt doesn't slip there is no twist problems. As for it being strong enough, the Y axis has the same motor (3Nm). That way both X & Y have the same power. And additionally, which also affected my decision, is that some day I will add a 4th axis I hope

Hub

Good to know that this setup works fine for these dimensions!
Using a belt and just one motor is tempting, but finding the necessary parts could be really difficult for me.
However, the 4th axis is not really an issue for me at this time and the near future.
Thanks!

[hub]

I can maybe help you finding the parts you need since I have done a lot of searches, I know many stores etc.. But I have tried to focus on suppliers in Europe (because I live in Finland), and a few in the US and Japan, China, Hong Kong, Taiwan etc.
If you can handle shipping (plus possible tax/customs fee) I might find where to get the parts you need.
I have got mine pretty much from all over the world, worked fine so far Ok, it sometimes takes weeks and weeks until you get the parts but it's worth it in the end

Hub

[ahren]

Glad the motor worked out for you! As an FYI, tons of people are doing dual drive gantries with two motors. Pretty much everyone building systems based on our rack and pinion drive is doing this. As others have mentioned, as long as you have appropriately sized motors that you don't try to drive too hard, this approach works quite well.

Best regards,

Ahren
CNCRouterParts

[Treischl]

Glad the motor worked out for you! As an FYI, tons of people are doing dual drive gantries with two motors. Pretty much everyone building systems based on our rack and pinion drive is doing this. As others have mentioned, as long as you have appropriately sized motors that you don't try to drive too hard, this approach works quite well.

Best regards,

Ahren
CNCRouterParts

Hello Ahren,

Have my machine running using your terrific parts! Lots of minor "cleanup" work to do, like cabling. Thanks to your parts, it was a very easy build. It would have been even faster if I had read a little closer and realized that your connector plates are sized for 1.5 wide extrusions! I could have just ordered them from you and had them weeks ago.

I am curious about your statement concerning driving a system "too hard", what would you consider too hard? I ran mine surfacing today at 300 IPM, depth of cut was 1/8 in pine, 5/8 width of cut. The motors were uncomfortably warm after about 10 minutes of run time. The Gecko box was fine. My understanding is that steppers will be hot to the touch?