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rung fu clone RF-45 ZX45 cnc conversion
- Thread starter jumps4
- Start date
- Joined
- Apr 30, 2012
- Messages
- 2,401
I have not posted anything about my mill in some time because there really wasnt anything to add.
but today i had decided it was time to take the time to locate some backlash it has been gaining.
i first removed all the bellows and covers to see the ways and clean them. there was still plenty of oil on everything and no swarf. i exspected to see some gray in the oil i was wiping off from the machine breaking in but the oil was really clean and no sign of any wear or scratches on all of the ways. so i relubed and rechecked the gib adjustment using the tormach method. you loosen everything so there is no friction. check your backlash writing it down then begin adjusting the gibs until the backlash starts to increase more and more as you snug it. back off just until you reach the first measurement and lock it down. it seemed to work well there is no gib play.
i then moved the indicator around to check to see where the backlash was:
on the y axis the mounting bolt for the ballnut mount was loose( i probably missed this being really tightened when i was building it ) and the thrust bearing needed a little adjustment. backlash went from .014 to .0015 all in the ballnut.
x axis needed the preload on the thrust bearing adjusted the set screws were not tight enough and it backed off. after setting preload it was back to .002 and all in the ballnut so that was good.
mach3 compensates for this amount just fine
z axis i lubed everything checked the gib and mounting screws and didnt disassemble the bearing mount to set preload because it is only .004 and i'll take that all apart another day for adjustment.
so far I'm still really happy with all of these cheap parts and everything is working very well
steve
but today i had decided it was time to take the time to locate some backlash it has been gaining.
i first removed all the bellows and covers to see the ways and clean them. there was still plenty of oil on everything and no swarf. i exspected to see some gray in the oil i was wiping off from the machine breaking in but the oil was really clean and no sign of any wear or scratches on all of the ways. so i relubed and rechecked the gib adjustment using the tormach method. you loosen everything so there is no friction. check your backlash writing it down then begin adjusting the gibs until the backlash starts to increase more and more as you snug it. back off just until you reach the first measurement and lock it down. it seemed to work well there is no gib play.
i then moved the indicator around to check to see where the backlash was:
on the y axis the mounting bolt for the ballnut mount was loose( i probably missed this being really tightened when i was building it ) and the thrust bearing needed a little adjustment. backlash went from .014 to .0015 all in the ballnut.
x axis needed the preload on the thrust bearing adjusted the set screws were not tight enough and it backed off. after setting preload it was back to .002 and all in the ballnut so that was good.
mach3 compensates for this amount just fine
z axis i lubed everything checked the gib and mounting screws and didnt disassemble the bearing mount to set preload because it is only .004 and i'll take that all apart another day for adjustment.
so far I'm still really happy with all of these cheap parts and everything is working very well
steve
- Joined
- Apr 30, 2012
- Messages
- 2,401
the 4 motor bolts go through the mounting plate and are drilled and tapped into the top of the column.
i had to grind the hole in the top of the column to make it rounder. to do that i used a grinding stone in a wood router. it worked well but be carefull if you try it that your stone is rated for the rpm.
steve
i had to grind the hole in the top of the column to make it rounder. to do that i used a grinding stone in a wood router. it worked well but be carefull if you try it that your stone is rated for the rpm.
steve
Hi there. New user here. First let me say that this is a great thread and you have a great build. I currently have a Grizzly G0704 converted to CNC, but want bigger. I am looking at getting a RF45 clone and doing similar to your build. I see from the posts that you used the motor kit with the 4200 oz-in Nema 42 and the DQ2722M driver for the Z-axis and 1600 oz-in NEMA 34 and DQ860MA drivers for the X and Y. That said, I have a few questions I hope you can answer.
1. I don't see a lot on the DQ2722M driver and I'm not sure how it works. Since it has AC input, I suppose it must rectify the AC into DC before the driver section. Do the specs say anything about what DC voltage is supplied to the motor?
2. Have you had any problems with the stepper/driver combo (Other than the broken wire I saw).
3. How smooth are the motors? For example do any of the motors exhibit a great deal of mid-band resonance?
4. I may have missed it, but what size ball screws did you use on X, Y, and Z axes?
Thanks for posting your build!!
1. I don't see a lot on the DQ2722M driver and I'm not sure how it works. Since it has AC input, I suppose it must rectify the AC into DC before the driver section. Do the specs say anything about what DC voltage is supplied to the motor?
2. Have you had any problems with the stepper/driver combo (Other than the broken wire I saw).
3. How smooth are the motors? For example do any of the motors exhibit a great deal of mid-band resonance?
4. I may have missed it, but what size ball screws did you use on X, Y, and Z axes?
Thanks for posting your build!!
- Joined
- Apr 30, 2012
- Messages
- 2,401
hi 109jb and thank you for your compliments
1. the dq2722m is 80v output I believe. the unit has its own power supply built in and works great. if they were not so costly i'd use them on everything.
2. everything has been working perfect with no mods since I built it... I have a friend that is about to start his own copy and there are no planned changes.
3. because of the excess power I have I was able to use a higher microstep so the motors are really smooth and quiet. no resonance in the speeds I operate at, I can run at 200ipm with no problems but I have everything set to 100 max for safety.
4. the ebay ballscrew set is item number 290649528399 and is 20mm on the z and 16mm on x and y. the bearing blocks in the kit required a shim to get a preload on the bearings and I have had that same problem on other kits I have bought. It's and easy fix.
any other questions feel free to ask
steve
- Joined
- Nov 8, 2013
- Messages
- 15
Re: rung fu clone RF-45 ZX45 cnc conversion - question regarding motor size
Hello All,
I've read this thread with great interest! I've got a ZX45, and from what I can see it's identical with jumps4s RF45. I'm in the process of planning my own conversion. I think I will build it pretty much the same way as described here. It seems so fasinating simple compared to other conversion I've read about. Great work on both the construction and the build!
My first (of many) question:
Now that you havre run this machine for a while, do you think the size of the motors is suitable? Or put another way: Can I get away with smaller motors? What would in that case be a suitable size?
Cheers!
Bernie
Hello All,
I've read this thread with great interest! I've got a ZX45, and from what I can see it's identical with jumps4s RF45. I'm in the process of planning my own conversion. I think I will build it pretty much the same way as described here. It seems so fasinating simple compared to other conversion I've read about. Great work on both the construction and the build!
My first (of many) question:
Now that you havre run this machine for a while, do you think the size of the motors is suitable? Or put another way: Can I get away with smaller motors? What would in that case be a suitable size?
Cheers!
Bernie
Last edited:
- Joined
- Apr 30, 2012
- Messages
- 2,401
hello Bernie
I have been using this machine without issue for over a year and to date there is not one thing I would change. The motor size has guaranteed repeatability and precision. I have never had a motor miss steps no matter the speed or cutting load I'm running. there is no heat problems in the motors.
If you want a really nice conversion that's not just a hobby light duty toy, don't cut cost on the motors you can keep the gibs snugged right up on this machine and hold some really close tolerances. After hours of running it will return exactly to zero and that means it has never missed any steps.
good luck with your build
steve
I have been using this machine without issue for over a year and to date there is not one thing I would change. The motor size has guaranteed repeatability and precision. I have never had a motor miss steps no matter the speed or cutting load I'm running. there is no heat problems in the motors.
If you want a really nice conversion that's not just a hobby light duty toy, don't cut cost on the motors you can keep the gibs snugged right up on this machine and hold some really close tolerances. After hours of running it will return exactly to zero and that means it has never missed any steps.
good luck with your build
steve