Spindle Motor to RC BLDC Upgrade?

I’ve seen the slightly larger NEMA 17 motor replacement, and the whole spindle assembly replacement, so I’m wondering if anyone has attempted replacing only the current NEMA 17 motor with something much more powerful, like a few hundred watts or beyond. I don’t think anyone makes NEMA 17 BLDC motors beyond about 120W, but with some adapters it should be possible to mount an RC BLDC motors that are cheap and powerful, at a reasonable size and right RPM.

ODrive have some interesting products and information. In the meantime, how far can one push the stock spindle on the Nomad? And at what point would the stepper motors or the rigidity of the machine become the limiting factor?

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While the Nomad at first look seems terribly unbalanced with its 70 watt spindle, its hard to not love after really seeing what it can do even in stock form.

The machine has a great bone structure and I was able to get over 30 pounds of pull from the stock drive system. Once defaults are overwritten, rapid feed speeds of 300ipm are possible. The spindle is geared very well for the power and has enough torque to finesse just about anything with the right driver.

It was never meant to be a chip ripping monster, but more of a sharp scalpel. Imo more power could increase the performace a bit I’m not familiar with the limits of the stock spindle driver.

To really wake this guy up it needs more speed if you really got the chip greed. Problem though, without some type of active cooling (confirmed through heat camera) the stock spindle bearing stack probably cant survive prolonged higher rpm.

Stock 0.125 at 10k = 375 sfm . That’s not even close to what people think of hsm capable machines. So ditch the nemas and throw on an er11 40,000rpm. You can greatly increase MRR while keeping loads very manageable.

Oh, I continous ramped a 0.250 single flute through a 1" block of 6061 on a bone stock machine.

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Saw your comment right after I put down an order for the motor and drive system. It’s quite a beefy motor, but I’ll be limited by my power supply. Maxing out the biggest power supply I’m considering getting, theoretical number of the motor is 6480RPM and a max torque of 0.95Nm, 650W. The stock motor lists 4000RPM and 0.125Nm. From what I can tell, torque isn’t close to the limiting factor. I’ll limit the current on the driver and see what it does.

It is my understand as well that more RPM is needed for higher MMR. I don’t want to modify the Nomad permanently in any way, so I’m planning to add another belt and pulley to adapt the motor. This should let me change the gearing - so I could potentially go to 30k RPM or faster. Again, I wouldn’t start with that.

It’s great to see what you do with stock machines. Really shows what’s more important than power. Would be great to hear your tips on the Nomad.

Also, since you speak highly of the bone structure, do you think a better motor and spindle capable of much higher RPM would dramatically improve the capability? Just curious.

By all means, modify and see what happens! However, like I said, I’m pretty sure the stock spindle won’t be able to take 30,000 without modifications. Honestly I haven’t heard of anyone regearing but every bit would help.

The carbide guys would know better but the preload might have to change and mostly likely need a heatsink.

My biggest tip on the nomad is to learn with the stock power and then increase once you learn the machine. A true understanding is what separates most users. If you already have CNC experience then it’s a different story.

A few people have tried adding spindles and EMI seems to be a limiting factor. I would hate to disable a machine because it not reliable. A 30,000 rpm er11 would be very balanced if a “dream nomad” was to be built.

nice to hear you chime in on your Nomad @Vince.Fab

you mention increasing defaults to 300ipm (7,620mm)? no issues or vibrations on the stock screws?
concern if the screws can keep up without issue - especially on big parts when it can accelerate to that top end speed regularly

i would imagine you can chase down higher end bearings for the stock spindle (ceramic maybe) to deal with the heat. bearings being the limiting factor in most motor applications, generally. machine some heatsinks and hose clamp them if you’re feelin frisky . EMI and the coupling/belt driving to the stock spindle would be my concerns with a bigger motor addition.

The feed testing was right when I recieved it and it was flashed back to stock soon after. So no longterm testing at high feeds but ide imagine it would be fine…if you are ok with the fact that your leadnuts will probably wear out much faster.

This is stock with an additional heatsink already…friction/heat :slightly_smiling_face:

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oh ok, just teasing us with the feedrate bump.

300ipm was needed if 30,000rpm was even going to be considered imo. One day I’ll upgrade it but today I’m poor so its back to making money things.

It has the potential

I remember there was a picture of a disassembled spindle somewhere. Would be nice to know more details about the specs of the spindle and its components.

Have no idea about how bad the EMI is going to be. Will see how that goes. Worst case I go back to stock motor, since there won’t be any permanent modification. Also eyeing other motion controllers like the UCCNC. Really more for the sake of learning than anything wrong with the stock board, other than lacking some QoL features. That’s a plan for another day, but it could take care of any EMI problem?

Belt drive wise, according to some documents I could find the stock 2GT type might be enough, and there’s also the bigger 3GT.

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