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- Dec 3, 2013
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What are you using for drivers?
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Taking the CNC Plunge
- Thread starter TomS
- Start date
What are you using for drivers?
Same motors and drivers I have. They've worked flawlessly for me.
A suggestion and please don't take this the wrong way. You should start your own thread so you can track your build in one place and others can see your progress from the beginning up to it's conclusion. I and others are more than willing to help but it may get confusing if we respond to your build in my thread. And you won't get the exposure you need when asking for input. Again, I'm trying to be helpful.
Tom S.
I asked a few questions in another thread about adding a 3 phase motor and VFD to my PM-932 mill. Thanks to jbolt and mksj who were very helpful in answering my questions and providing valuable information. My plan is to do all of the mechanical work first then tackle the electrical and electronics last. I'm going with a Hitachi WJ VFD. The pulley ratio will be 2.5:1 which gets me to 9000 spindle rpm at 120 Hz. I will be replacing the spindle bearings with AC bearings. If 9000 poses a problem I can always reduce the large pulley diameter later. So off I went and started gathering materials.
More pictures and loads of questions to follow.
Tom S.
This is the motor mksj pointed out to me on eBay. It's a new in the box Marathon Black Max 2HP 3 phase inverter duty. Was able to snag it for $104 plus shipping.
Here's the material for the pulleys and one motor support rail. The second motor support rail was in the mill when I snapped these pictures. The piece in the lower left is my tool changer mount. Still have some work left to do on it.
It's not a good picture but this is the second motor support rail being machined.
More pictures and loads of questions to follow.
Tom S.
This is the motor mksj pointed out to me on eBay. It's a new in the box Marathon Black Max 2HP 3 phase inverter duty. Was able to snag it for $104 plus shipping.
Here's the material for the pulleys and one motor support rail. The second motor support rail was in the mill when I snapped these pictures. The piece in the lower left is my tool changer mount. Still have some work left to do on it.
It's not a good picture but this is the second motor support rail being machined.
Yes. The large pulley is 5" diameter and the small pulley is 2". At 30 Hz that gets me to 360 RPM.
Tom S.
Made some more progress today. I finished up the spline drive shaft modifications but not without a bit of trouble. Somewhere I read that most of the asian mill drills don't have hardened gears. Well I have one of the few mills that don't fall into that category. The gear on my shaft must have been in the Rc55+ range. With the hardness and interrupted cut I went through a few carbide inserts. I tried I22, C5 and C1 grades. C1 worked the best but still didn't last more than three passes. Once I got below the tooth root it machined fine. Anyway I got er done.
Tom S.
I opted to go with a snap ring to retain the spindle pulley rather than a nut. I'm going to bore the pulley for a .001" interference fit and with the drive key it's not going anywhere. I'll trim the top to length after the pulley is done.
The grooves next to the right hand snap ring and the one left of it are what's left of the undercuts on each side of the gear and hub. Next up is to order the bearings. These are going to be a little pricey (about $50 each) because I need bearings with non-contact seals. I can find bearings with contact seals for less than $10 each. My goal is to get to 9000 rpm but bearings with contact seals are limited to 7000 rpm. Non-contact seals are rated to 12000 rpm. Bearings are good to 15000. Seals are the limiting factor.
Tom S.
I opted to go with a snap ring to retain the spindle pulley rather than a nut. I'm going to bore the pulley for a .001" interference fit and with the drive key it's not going anywhere. I'll trim the top to length after the pulley is done.
The grooves next to the right hand snap ring and the one left of it are what's left of the undercuts on each side of the gear and hub. Next up is to order the bearings. These are going to be a little pricey (about $50 each) because I need bearings with non-contact seals. I can find bearings with contact seals for less than $10 each. My goal is to get to 9000 rpm but bearings with contact seals are limited to 7000 rpm. Non-contact seals are rated to 12000 rpm. Bearings are good to 15000. Seals are the limiting factor.
- Joined
- Dec 3, 2013
- Messages
- 1,849
Wish I had one of those yesterday. My tool holders take TNMG inserts. Usually they work fine on any material I throw at them.
Tom S.
More work completed on the belt drive conversion today. Got the bearings for the spindle splined sleeve. The guy at the local bearing house recommended I go with double shielded bearings instead of the non-contact sealed bearings. If they sling the grease out at high rpm I'm not going to be happy. We'll see.
Tom S.
Finished the motor and spindle pulleys.
Mocked up the parts on the mill to make sure everything fit before drilling and tapping the bolt holes for the motor plate and tool changer riser. Sure enough the sides of the gear head top cover aren't square to the top. Not a big deal just had to compensate for it when I laid out the holes.
Tom S.
Finished the motor and spindle pulleys.
Mocked up the parts on the mill to make sure everything fit before drilling and tapping the bolt holes for the motor plate and tool changer riser. Sure enough the sides of the gear head top cover aren't square to the top. Not a big deal just had to compensate for it when I laid out the holes.