Bernardo KF25L 3phase conversion. (G0704 type)

[M130]

I have done a 3Phase conversion on my G0704 type mill. I have also done a cnc conversion on this mill, but in this thread I will show the motor and belt drive conversion as I have not found many such conversions with 3phase motor and vfd. The plans for the belt drive are purchased from hossmachine and I have made the conversion based on those.
I'm using a Bevi 1hp/0.75 kw 50 Hz 4 pole motor and a 2.2 kw huangyang vfd. The motor is rated 1430 rpm/50hz and give about 2860 rpm/100hz.
Regards Morten

 

[M130]

It seems like I have solved the problem that I had with posting pictures.
The reason for doing this 3phase conversion is that i'm tired of the stock motor and controller. My mill was on the second motor and it was about to "sing on it's last tune" and I didn't want to pay for an expensive motor that just are going to last just a couple hours once again. I was a bit worried about having enough space on top of the mill for such a big motor, but it turned out to be enough. It turned out that in high ratio (1.08:1) is working perfectly but in low ratio (2.2:1) the motor hit the column.Because of that I have to make a new motorpulley to get shorter distance between motoraxle and spindle in low ratio. I hope my thread about this conversion would be interesting/ helpful for someone.
Morten

 

[Dalee]

Hi,

Interesting. I'm considering doing such a conversion on my G0704 when my original motor packs it in. I'm wondering how much that motor weighs and the horsepower/watts. And how is the low speed power for you? I'd like to be able to run 3"(75mm) slotting saws effectively.

Dale

 

[M130]

Hi,

Interesting. I'm considering doing such a conversion on my G0704 when my original motor packs it in. I'm wondering how much that motor weighs and the horsepower/watts. And how is the low speed power for you? I'd like to be able to run 3"(75mm) slotting saws effectively.

Dale

Thank you for being interested in my thread. The motor weights 13 kg (about 26 or so pounds I think) and have 1 hp / 0.75 kw. I have not used the mill that much after conversion, but I have made a wider motormount for it using 8mm endmill 1000 rpm 2mm deep of cut 1.08:1 ratio, feed 100 mm/min.(Posted a picture of the mount in my last post.) I also faced some steel with a 50mm 3 insert facemill, 0.25 mm deep of cut, feed 300mm/min 500 rpm 1.08:1 ratio. So far it seems that this motor outperforms the stock one big time!
The low ratio is 2.2:1 and have a rpm range of 65 - 1200 rpm. High ratio 1.08:1 have a range of about 130 - 2700 rpm. Unfortly I have very limited experience with slotting saws, so I can't tell if you can use 3" slotting saws.

Morten

 

[ibuildstuff4u]

Thanks for posting this! I'm in the middle of a CNC conversion my self and plan to use the same motor on my mill.

Keep the pictures coming! It's really nice to have something to reference when building something.

Dale P.

 

[M130]

Yesterday a usb to rs485 converter appeared.It is cheep one from ebay, but I think it can be used just fine as a link between the computer and the vfd. As you now understand I have planed to control the motor from mach3. I have done a bit of investigation on internet, and found that Huanyang vfd's doesn't use a standard modbus and therefore need a special plugin for mach3 to be controlled via rs485.
It will probably be a bit of trial and error.
Morten

 

[Dalee]

It seems like I have solved the problem that I had with posting pictures.
The reason for doing this 3phase conversion is that i'm tired of the stock motor and controller. My mill was on the second motor and it was about to "sing on it's last tune" and I didn't want to pay for an expensive motor that just are going to last just a couple hours once again. I was a bit worried about having enough space on top of the mill for such a big motor, but it turned out to be enough. It turned out that in high ratio (1.08:1) is working perfectly but in low ratio (2.2:1) the motor hit the column.Because of that I have to make a new motorpulley to get shorter distance between motoraxle and spindle in low ratio. I hope my thread about this conversion would be interesting/ helpful for someone.
Morten

Hi,

Thanks for the information! I want to keep the motor weight as low as possible to prevent sagging of the column. Your motor sounds pretty light.

HSS slotting saws need to run at 90 to 100rpms as a general rule. That's pretty slow. Pulley fit for the low rpms has always stumped me. I just can't seem to find a combination that I can make fit.

Dalee

 

[M130]

Today I managed to get my computer to control the vfd/motor. I got a bit woried when I took a look on the documentation for the usb-rs485 converter. It says that it doesn't suport windows8 and 10. I'm running mach3 on Windows 10. I thought I should give it a shot anyway. I conected the converter via a usb cable and windows asked for a driver .I allowed windows to serch for it on internett and luckily a workable driver was found and installed. Then I connected the converter to the vfd.I used a shielded cable for the conection with the shield grounded in one end. The converter have 3 conections that have to be made. One is conected to ground (marked GND), the one marked "A" is conected to RS+ in the vfd and "B" is conected to RS-. Then I had to change the vfd setup a bit. When I tried to control the vfd from mach3, all was functioning exept M5 comand (spindle stop).
After some research on www, I found that I had to change some settings in mach3.
The settings was found in config/ port&pins/spindle.make sure "disable spindle relays" is unchecked.The spin up/down delays was also changed to match the vfd setup.(5sec. for my setup) Finaly config/port&pins/port setup and axis selection :enable modbus inputoutput support and enable modbus plugin supported. That made all comands working.

Morten

 

[ibuildstuff4u]

Glad to hear you got it working. It's amazing how much time it can take to work out the kinks and get things running.

Today I scored a really nice VFD inverter from E bay. This model sells for around $500 from parts suppliers, but I got this one at auction for $150! It's brand new and seems to have a ton of extra features that the cheap inverters don't have. It's rated for up to a 3 hp motor and will allow me to hook it right up to my breakout board for speed control. Here is a link for the drive I got.

http://www.ebay.com/itm/LENZE-AC-TECH-VFD-AC-VARIABL-SPEED-DRIVE-ESV222N02YXB-3HP-208V-240V-1PH-3PH-IN-/111075344099

Now I just need to find a motor. It's a shame they don't make anything smaller than a 56C for a three phase 1hp motor.

Dale P.