G0704 Spindle Mods and balancing ... Very cool!!!

[CL_MotoTech]

Awe man that's no fun.. Yeah I went through that whole deal to many times, my gear of not knowing what motor to get and VFD to get with it was a task list that never seemed to take priority so I followed the pack with the year mill motor, then the BLDC, and after finally digging in to learn what I needed with the 3ph AC motor did it and my only regret is that it wasn't the very first motor upgrade I did.. sure would have saved me a bunch of time and money..Lol. Let me know if I can answer any questions you may have!

Chris

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It looks like the manufacturer is going to replace the VFD under warranty. So that's nice.

I ordered the taper roller bearings and plan to switch back to those, i've never been comfortable with the preload on the AC bearings. Though they run cool and quiet, I just don't think they provide as a tight tolerance as a taper. In the down time I am going to repack the X ballnut and tram the entire thing up. I'm also going to address the spindle vibration issue probably by machining the spindle bearing carrier and making a virbation damper type device for the top of the quill spline. Hopefully when I am back up and running the machine will all around be better.

[lcvette]

It looks like the manufacturer is going to replace the VFD under warranty. So that's nice.

I ordered the taper roller bearings and plan to switch back to those, i've never been comfortable with the preload on the AC bearings. Though they run cool and quiet, I just don't think they provide as a tight tolerance as a taper. In the down time I am going to repack the X ballnut and tram the entire thing up. I'm also going to address the spindle vibration issue probably by machining the spindle bearing carrier and making a virbation damper type device for the top of the quill spline. Hopefully when I am back up and running the machine will all around be better.

That's good news on the VFD!

Few things I noticed while going through mine in order to cure several of the vibration issues I had. The quill barrel casting was horrendously out of balance and a significant chunk of rotating mass to boot. I suggest chucking it in a lathe and at least turning it true in the out of balance areas, this helps alot at higher rpm but is negligible in stock form at low rpm.

Another concern was how the spindle cartridge is held in the headstock by the set screw. Because it's not a super tight tolerance fit and is designed to slide for quill operation, when you go straight CNC and tighten the set screw it is off center ever so slightly by the fit gap of the two parts. If you loosen that set screw slightly while running the spindle (be safe make sure it doesn't drop out) you can hear a change in the sound of the bearings.. quiets down when loosened and allowed to self center. I cleaned the headstock bore thoroughly and used some shim stock wrapped around the spindle cartridge to get it closer to concentric. Not an easy task as the shim stock likes to tear while installing but after a few tries it went in. This helped alot also.

My tapered roller bearings are very quiet, as much so as the AC bearings were at least, I don't think once you get everything sorted it will be a problem. My only big noise maker now is the cooling fan on the TEFC motor. Wish I had bought two of the 1.5hp inverter duty motors while they were available..Lol but it's not enough of a noise that I could justify what was what working great.!

I also replaced the upper will bearings which now run dead cool. For the vibration damper, I made the spindle pulley such that it puts fit into the quill barrel and the center bore was a snug fit to the spindle shaft. This does three things, it helps make the upper portion of the spindle shaft fully supported so it doesn't wobble, and it helps alleviate the spline engagement rattle. The last thing however is that it made the alignment of the Spindle cartridge and will barrel much more critical. Now that those things have all been addressed, my finishes and noise levels have never been better. If you take your time and follow suit I'm sure you will enjoy the same benefits!

Hope that helps!

[CL_MotoTech]

That's good news on the VFD!

Few things I noticed while going through mine in order to cure several of the vibration issues I had. The quill barrel casting was horrendously out of balance and a significant chunk of rotating mass to boot. I suggest chucking it in a lathe and at least turning it true in the out of balance areas, this helps alot at higher rpm but is negligible in stock form at low rpm.

Another concern was how the spindle cartridge is held in the headstock by the set screw. Because it's not a super tight tolerance fit and is designed to slide for quill operation, when you go straight CNC and tighten the set screw it is off center ever so slightly by the fit gap of the two parts. If you loosen that set screw slightly while running the spindle (be safe make sure it doesn't drop out) you can hear a change in the sound of the bearings.. quiets down when loosened and allowed to self center. I cleaned the headstock bore thoroughly and used some shim stock wrapped around the spindle cartridge to get it closer to concentric. Not an easy task as the shim stock likes to tear while installing but after a few tries it went in. This helped alot also.

My tapered roller bearings are very quiet, as much so as the AC bearings were at least, I don't think once you get everything sorted it will be a problem. My only big noise maker now is the cooling fan on the TEFC motor. Wish I had bought two of the 1.5hp inverter duty motors while they were available..Lol but it's not enough of a noise that I could justify what was what working great.!

I also replaced the upper will bearings which now run dead cool. For the vibration damper, I made the spindle pulley such that it puts fit into the quill barrel and the center bore was a snug fit to the spindle shaft. This does three things, it helps make the upper portion of the spindle shaft fully supported so it doesn't wobble, and it helps alleviate the spline engagement rattle. The last thing however is that it made the alignment of the Spindle cartridge and will barrel much more critical. Now that those things have all been addressed, my finishes and noise levels have never been better. If you take your time and follow suit I'm sure you will enjoy the same benefits!

Hope that helps!

Yeahm I;m going to make use of my buddies lathe and do some work on that quill barrel. I considered buying the one from BTP, but $95 plus shipping is just expensive enough that I can spend an hour over the lathe and feel decent about it.

I certainly have the issue with the headstock screw. I have observed the noise change many times exactly as you describe. I however wasn't sure what a decent solution would but your shim stock method is perfect. I was considering adding an opposing set screw, but threading these cheap castings has always been problematical.

I have a vibration damper I made out of a thick .75" PTFE. It's decent, but I am going to cut a new one that will hopefully be an improvement. I like the PTFE for it though, it has nice damping properties.

[gcofieldd]

I also replaced the upper will bearings which now run dead cool. For the vibration damper, I made the spindle pulley such that it puts fit into the quill barrel and the center bore was a snug fit to the spindle shaft. This does three things, it helps make the upper portion of the spindle shaft fully supported so it doesn't wobble, and it helps alleviate the spline engagement rattle. The last thing however is that it made the alignment of the Spindle cartridge and will barrel much more critical. Now that those things have all been addressed, my finishes and noise levels have never been better. If you take your time and follow suit I'm sure you will enjoy the same benefits!
Hope that helps!

Icvette,

For your quill bearings did you use open, shielded or sealed? Just curious, mine are shielded. I think I have some miss alignment between the top and bottom quill bearings. Before I installed the quill in the head it spun freely but after installation there is a noticeable drag.

I am probably going to build a new head and switch to a Tormach 10K spindle.

[lcvette]

Icvette,

For your quill bearings did you use open, shielded or sealed? Just curious, mine are shielded. I think I have some miss alignment between the top and bottom quill bearings. Before I installed the quill in the head it spun freely but after installation there is a noticeable drag.

I am probably going to build a new head and switch to a Tormach 10K spindle.

Shielded... Figured they would be fine over sealed being up top. Mine spun freely up top even after installation, that bore should be concentric because they used a step bearing size and it should have been noted in one setup. But I guess you never know.

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