My adventures while making a motorized x-axis feed for my Rong Fu mill

[Charles scozzari]

Maybe you can catch on on line for the right price. I was able to find two new ones on line at half price.

 

[ARC-170]

Precision Matthews has one for $300. That seems to be the best option. MSC, Travers, Shars (on Ebay) and Align have some as well. There's lots of cheaper ones from sellers like Vevor, AliExpress, and Temu, but I'm staying away from those. I need to check the torque specs as well; they all LOOK the same, but a careful reading of specs says they have different torque ratings.

I still might make one, since it seems like a good project to practice my skills on. I can show it to my college students, too. I only needed 10 kg-cm of force under a load to turn the handle so I'm not sure why these motors all need so much torque. I could compromise on speed and that would allow for more torque.

 

[RaisedByWolves]

Precision Matthews has one for $300. That seems to be the best option. MSC, Travers, Shars (on Ebay) and Align have some as well. There's lots of cheaper ones from sellers like Vevor, AliExpress, and Temu, but I'm staying away from those. I need to check the torque specs as well; they all LOOK the same, but a careful reading of specs says they have different torque ratings.

I still might make one, since it seems like a good project to practice my skills on. I can show it to my college students, too. I only needed 10 kg-cm of force under a load to turn the handle so I'm not sure why these motors all need so much torque. I could compromise on speed and that would allow for more torque.

I meant to post this yesterday but life tore me away from the internet.

Theres a lot more to this subject than you would think.

The force to turn the handwheel is only one component and it is IMO minor in the grand scheme of things. You need...Guessing here...10X the torque the "Handwheel" measurement would imply for several reasons.

Interrupted cuts will put much larger loads on the drive at certain times and this will cause heat in the motor. Dragging the table lock for both conventional and climb milling will also cause heat in the motor and drive. Rapid traverse will add heat especially when you forget to unlock the table after dragging the table lock.

All of those and more will be situations that may occur dozens of times an hour, and the motor size and drive capacity, not the torque output of the geared dive, are critical to a long lasting drive unit.

Basically, a smaller motor will not have the necessary "Duty cycle" of a properly sized motor.

 

[ARC-170]

I meant to post this yesterday but life tore me away from the internet.

Theres a lot more to this subject than you would think.

The force to turn the handwheel is only one component and it is IMO minor in the grand scheme of things. You need...Guessing here...10X the torque the "Handwheel" measurement would imply for several reasons.

Interrupted cuts will put much larger loads on the drive at certain times and this will cause heat in the motor. Dragging the table lock for both conventional and climb milling will also cause heat in the motor and drive. Rapid traverse will add heat especially when you forget to unlock the table after dragging the table lock.

All of those and more will be situations that may occur dozens of times an hour, and the motor size and drive capacity, not the torque output of the geared dive, are critical to a long lasting drive unit.

Basically, a smaller motor will not have the necessary "Duty cycle" of a properly sized motor.

Thanks, all good info. I kinda figured there was more to this. It occurs to me all the mills I saw with homemade power feeds were smaller than the RF-30. Many were European models that looked to be just a bit smaller than mine.

There's a local seller that has used electric motors of all types. I've messaged him to see if he has anything that might work, but have not heard back. In the meantime, I think my adventures are on hold. Stay tuned!

 

[Charles scozzari]

Just wondering, I don't follow what the reason for such a strong motor is. Are you going to direct drive the feed or are you going to use a geared reduction system. Why does your table need such an effort to turn that it burns up feed motors

 

[ARC-170]

Just wondering, I don't follow what the reason for such a strong motor is. Are you going to direct drive the feed or are you going to use a geared reduction system. Why does your table need such an effort to turn that it burns up feed motors

I looked at the specs for typical power feeds. They all list torques in the 150 to 780 in-lb range. The motors I'm looking at are significantly less. I'm not sure why, either, but as @RaisedByWolves explains in post #33, there's more to this. I'm not willing to spend money on a motor only to have it not work.

 

[Charles scozzari]

The machine certainly looks clean is there any chance the gibs are gummed up or set to tight. How much backlash? Is the screw tight from trying to compensate for to much backlash in the center where the feed screw is worn.