[abavery]

Lately I've been considering buying a 1-1.5hp vfd air cooled spindle to use as a motor for my X2 Mini Mill. I have the Little Machine Shop Belt Drive kit, and I'm thinking I could work up an aluminum mount for the VFD spindle, then turn a pulley that would mount to a piece of steel rod in whatever collet the spindle comes with. The reason for doing this instead of just boring out the head and mounting the VFD inside is that I am using the Tormach Tooling System and I really like it for its potential to let me add an ATC.


My question is, am I under thinking this? Any crucial bits I'm missing? Of course I would have to upgrade the bearings on the stock R8 Spindle and maybe limit the top speeds a bit, but I could gain tons of power for $300-400 if it panned out.




Thanks for any advice you can provide.

[mactec54]

Lately I've been considering buying a 1-1.5hp vfd air cooled spindle My question is, am I under thinking this? Any crucial bits I'm missing? Of course I would have to upgrade the bearings on the stock R8 Spindle and maybe limit the top speeds a bit, but I could gain tons of power for $300-400 if it panned out.

It would be a bad idea, the air cooled spindle has around 12,000 RPM minimum speed at best, depending on which one you got, and your R8 spindle is not up to running anywhere near that speed without some serious work done to it

The spindle motor would also have low torque at that speed and not enough to drive your R8 spindle to do any kind of work, so a bad idea all round

[abavery]

It would be a bad idea, the air cooled spindle has around 12,000 RPM minimum speed at best, depending on which one you got, and your R8 spindle is not up to running anywhere near that speed without some serious work done to it

The spindle motor would also have low torque at that speed and not enough to drive your R8 spindle to do any kind of work, so a bad idea all round

Fair enough. That is the kind of info I was looking for. Any chance you know of a motor I could mount up to get some additional power with a fairly simple install? I've seen people talking about throwing a treadmill motor on, but that won't get me the RPMs I'm hoping for. Ideally the machine would top out at 10k rpms like the Tormach 440. Perhaps the motor off a G0704?

Thanks for your help

[Fastest1]

Am I misunderstanding? Why would you want to mount the VFD in the head? It is a variable frequency drive. Sensitive electronics have no place in a messy environment.

Dont use a treadmill motor or a motor from a G0704. Both of those are poor solutions, even for the G0704. Stick with the 3 phase TEFC style motor and enjoy power, torque and continuous duty durability.

[abavery]

Am I misunderstanding? Why would you want to mount the VFD in the head? It is a variable frequency drive. Sensitive electronics have no place in a messy environment.

Dont use a treadmill motor or a motor from a G0704. Both of those are poor solutions, even for the G0704. Stick with the 3 phase TEFC style motor and enjoy power, torque and continuous duty durability.

My initial intention was not to mount the VFD to the head, but rather to mount the VFD spindle to the head in place of the existing motor. Then I would use that to drive the existing spindle. That has since been pointed out to be a bad solution.


Your suggestion of a TEFC motor is intriguing though. I'm pretty new to this and this seems like the best solution. I noticed Grizzly sells quite a few, though the RPMs are pretty low so I'd have to change up the pulley system substantially to get the higher RPMs I want. What would I use to power and control one of these? My garage isn't wired for 3 phase so that may be a limitation.

Thanks

[Fastest1]

First of all these are standard electric 3 phase motors. There is no reason to go to Grizzly.

You would need to select a frame size you feel acceptable. This is difficult with a small machine though I dont think the steppers capability to move it is a real issue. Z is not normally needed to be real fast unless 3D is the intended use. The D80 is being mentioned a bit. It seems to be a little smaller in physical size than a 56C.

The speed control would be done by a VFD. The VFD is not a spindle but it is an electronic device that allows manipulation of the amount of cycles sent. A 60 cycle signal might achieve 3750 rpm for example. Increasing the cycles to 120 might double the rpm to 7500. This could be as simple as rotating a knob, using a GCode or both. (btw dont quote me on the increase of rpm versus cycles, it is significantly higher but I am not sure if it is exactly linear) Also most electric motors are rated for well over their marked rpms. You can also set a maximum amount of cycles in the VFD parameters.

VFD's can be purchased for 1.5 hp motors and under in 120vac or 220 single phase input. If you need larger than 1.5 hp, you would most likely need to stick with a 220vac input supply. Again single phase input.

The VFD I use on my lathe is an AC Tech/ Lenze unit. I have no affiliation with them. It was reasonably priced and easy enough to figure out how to use.

[abavery]

That is exactly the kind of information I was looking for. Thanks a lot. I did a bit of research and the 56C seems to be larger than would maybe be ideal, but if it is what is available I can make it work. I can't seem to find many D80 sized motors for sale though. Are they substantially less common?


If I end up with a 56C it isn't a big deal. The motors I used for my conversion are 381oz motors which I believe to be a bit oversized for the X2, but I would like to do a bit of 3D machining so I may have to throw an air spring or something on top if I go with the bigger motor.

[hoss2006]

Come on, a 56c on an X2 is ridiculous. There is no way an X2 can handle a motor that size, they weigh 30-40 lbs. The mill is far too flexible to make use of that power. If you want to upgrade look at an X3 or SX3 motor/controller or the bldc motor/controller like on the SX2 from little machine shop.
Hoss

[Fastest1]

Hoss has quite a bit of experience with the X2, you might heed his advice. The 56c is big for a G0704 though it has been done.

[abavery]

Come on, a 56c on an X2 is ridiculous. There is no way an X2 can handle a motor that size, they weigh 30-40 lbs. The mill is far too flexible to make use of that power. If you want to upgrade look at an X3 or SX3 motor/controller or the bldc motor/controller like on the SX2 from little machine shop.
Hoss

The man himself. I actually am building the machine based on your X2 Freak DVD with some modifications. I didn't realize the 56C was that big. I was hoping to get up near 1hp, but if that is too much power then I won't bother with it. I should note that I'll be reinforcing the column to base connection with a nice bit of steel I'm having built for me if that helps. I've always heard that the flexibility in the X2 was in that connection so I am hoping that that connection being reinforced will help me take some better cuts with a more powerful motor. Long term I have some bigger toys in mind, but I want to push the X2 as far as I can before I get something more formidable.


With that said I looked at the 500watt controller/motor combo on Little Machine Shop and I was hoping to keep an upgrade well under $500. At that price point I'd rather keep the stock motor and sock that money away for a future machine upgrade.


Thanks

[abavery]

Would something like this be more appropriate?

High-Torque Stepper Motor, Stepper Motor, Driver, Stepper Motor kit, DC Servo Motor, DC Servo Motor kit, Stepper Motor Power Supply, CNC Router, Spindle, and other Components. Stepper Motor | Stepper Motor Driver | CNC Router | Laser Machine | 3D Prin

Or perhaps this, with some other sort of driver?

High-Torque Stepper Motor, Stepper Motor, Driver, Stepper Motor kit, DC Servo Motor, DC Servo Motor kit, Stepper Motor Power Supply, CNC Router, Spindle, and other Components. Stepper Motor | Stepper Motor Driver | CNC Router | Laser Machine | 3D Prin



Sorry for all the questions. I'm still trying to find out what I'm looking for.

[hoss2006]

I was going to suggest the first but you balked at $500 for the lms motor/controller.
Hoss

[abavery]

I was going to suggest the first but you balked at $500 for the lms motor/controller.
Hoss

My hesitation on the $500 lms system was that it doesn't seem like I'm making as big of a gain. The $600 kit is a 1.5hp motor that will likely be powerful enough to be worth transferring to whatever upgraded mill I pick next. At least that is my thought process on that one.

Did you have any thoughts on the second link I posted? The power is lower, but if I can pick up a controller for it for $130 or less it is half the price of the $600 combo.


Along those lines, since I'm doing the X2 Freak upgrades, will the weight of these motors cause any problems with the extended neck that the freak uses?



Thanks

[hoss2006]

That's good thinking ahead, you could reuse it on a g0704 later.
The weight of that motor shouldn't affect the head much but you'll need more than a 318 oz/in stepper for the z axis, a 570 with proper driver would work well.
Hoss

[abavery]

That's good thinking ahead, you could reuse it on a g0704 later.
The weight of that motor shouldn't affect the head much but you'll need more than a 318 oz/in stepper for the z axis, a 570 with proper driver would work well.
Hoss

The G0704 is what I'm likely aiming for down the road, so this motor would go onto that when the time comes.

If it makes a difference it's a 381 oz/in stepper, but I suspect it will still need some help if 570 is the size you're suggesting. I'm running a G540 for the motors. Would adding an air spring to help lift the head alleviate the need for a larger stepper?

Will any brushless DC work? And if I bought a separate motor, what should I look at to control it?


Thanks

[hoss2006]

right 381 oz/in would still be pretty weak for all the extra weight even with an air spring.
the other brushless would be cheaper with their controller though less than 1 hp and only 3k rpm.
you need to use their controller to be sure it's compatible just to be safe.
Hoss

[abavery]

It looks like I can get a 570 that runs at 3.5A just like my current motors, so it would be an easy swap.

If I went for the 3k rpm setup, could I get creative with the pulley sizes on the belt drive kit to get higher speeds at the spindle, or will I lose too much torque that way?

I am fortunate enough to have access to a machine shop with full size Haas mills through a family member. With that in mind, besides the steel column support, are there any other major upgrades I should make to the X2? I understand that the small frame has its limitations, but any upgrades I can make for the cost of material would be great.


Thanks