[tkalxx]

This new set of bearings sound terrible. I need to find a source for better bearings.

Which bearings are you running? SKF sells a set of tapered roller bearings that are rated to 11,000 and 14,000 rpm bottom/top respectively - they are more pricey at $40 a piece.

I'm finally committing to a redesign of my belt drive and motor combo and I'm struggling with deciding a max rpm for my high gear belt ratio. Theoretically I could get up to 10,000rpm with what I have spec'd out, the SKF bearings and a spindle oiler, but the more I read through your experiences the more I think that's a bad idea.

[ChrisAttebery]

Well, they are noisy and I can hear occasional popping at low speeds. The popping seems to go away at higher speeds but I think that it's just being masked by the motor and bearing whine. I tried oil at first and then packed them with Redline CV2 grease. The grease helped a little. I ran them in for about 30 minutes this morning. Compared to the AC bearings they are louder and don't sound nearly as smooth.

What noises they making?

[ChrisAttebery]

Which bearings are you running? SKF sells a set of tapered roller bearings that are rated to 11,000 and 14,000 rpm bottom/top respectively - they are more pricey at $40 a piece.

I'm finally committing to a redesign of my belt drive and motor combo and I'm struggling with deciding a max rpm for my high gear belt ratio. Theoretically I could get up to 10,000rpm with what I have spec'd out, the SKF bearings and a spindle oiler, but the more I read through your experiences the more I think that's a bad idea.

Which SKF part numbers are you looking at? I found FAG makes the 32005 and 32007 in their X-XL-P5 variant. I can't seem to find the 32005 though.

[tkalxx]

32005 X/Q BRG and 32007 X. They are available here in Canada through motion industries. I'll be ordering some for my spindle once I get my belt modifications done.

https://www.motioncanada.ca/products/sku/00132000
https://www.motioncanada.ca/products/sku/00131982

Looking directly at the SKF website, seems like their 32007 X bearing has a limiting speed of 10,000 and a reference speed of 8,500... Not 11,000 like I previously said. I would assume these are very similar to the Timken bearings you had previously.

[CL_MotoTech]

Unless you got a bad bearing, or somehow got dirt in the bearing, my guess is that it’s just an adjustment issue. Could it be that the bearing race wasn’t fully seated and the spindle is slightly loose now? I’ve done that one. That gives sort of rattling but inconsistent noise.

That said, tapers are likely to be noisier. They have far more surface area. It may be the trade off you have to make to get greater load tolerance. My spindle ins’t particularly loud, probably like 75dbA at 4 feet. I measured it at one point but it’s been a while, I can remeasure again if you want. My spindle makes some noise during warm up as I assume it moves the Vectra oil around but then quiets down. It’s almost like a ticking or a snapping, but it probably only takes like 30 seconds for that to go away. I generally give it about 5 minutes of warm up at like 3500rpm.

[ChrisAttebery]

I've rebuilt the spindle in this machine at least half a dozen times. I also put a new set of tapered roller bearings in my 13x40 gear head lathe. I *THINK* I understand what I'm doing by now. I tried adjusting the pre-load up and down and it didn't seem to help. These didn't feel that great out of the box, like some of the VXB AC bearings I had bad luck with.

I measured the sound level with SoundMeter X on my iPhone. It was around 84 dB at 18 inches from the head. The noise level isn't terrible but it makes a lot of ticking, popping noises and vibration I can feel through the head casting.

The outer races both slip fit into my quill. The upper bearing is a slip fit onto the spindle. The lower bearing has to be tapped onto the spindle with a piece of tubing and a hammer. I polished the lower journal. Maybe I should polish it a bit more.

I found P5 rated ZKL brand bearings on eBay for around $100/set. I also looked at FAG 32005 X-XL and 32007 XDY bearings at Applied Industrial. Both of those are rated for at least 11k rpm and the set was around $100.

[CL_MotoTech]

I wasn’t taking a whack at your abilities. I too have changed many a set. I even made a video that I never published titled The 20 Minute G0704 Spindle Bearing Change because I got so good at it. That said, mistakes happen. I know because I’m constantly messing up.

You own the bearings, they are in your spindle, I say run them and see what happens. Give them some oil and go to town. They might quiet down after some use. Or they might burn up.

[ChrisAttebery]

I wasn’t taking a whack at your abilities. I too have changed many a set. I even made a video that I never published titled The 20 Minute G0704 Spindle Bearing Change because I got so good at it. That said, mistakes happen. I know because I’m constantly messing up.

You own the bearings, they are in your spindle, I say run them and see what happens. Give them some oil and go to town. They might quiet down after some use. Or they might burn up.

No problem. I didn't take it as an insult. Let me put it this way, I've rebuilt RC engines that spun up to 35k rpm and were WAY more sensitive to misalignment since the early 90's. I actually did it as a paid service for a few years. I'm pretty confident in my ability to install bearings. Something isn't right with these Timkens. When I spin them by hand they feel like there's a gritty spot in them. Not as bad as the set I removed, but it's there. I can try to run them in and they might quiet down, but I don't think they will last very long.

That said the FAG bearings are available for about $120 shipped. I'm going to order a set and get it over with.

[CL_MotoTech]

That's cool, I ran Nitro in the early 2000's. Always a lot of fun. I wish I had those trucks still.

I raced karts in that time too, we ran 20k plus with a 100cc motors. We used ceramic main bearings, when they went it was spectacular.

[ChrisAttebery]

This morning I took the spindle all apart again. I cleaned both bearings thoroughly. I mounted the spindle in the 4 jaw, dialed it in, recut the shoulder that the lower bearing rests against, took a 1/2 thousands cut off the journal and then polished it.

The lower bearing still needs to be heated to slip onto the journal.

The I reassembled the spindle, lubed the bearings with Kluber grease, then set the preload so that the spindle will turn freely but doesn’t have any end play.

I took this video right after I got it reassembled.
https://youtu.be/6j-UG7H8o18

I bought two each of NSK HR32007XJP5 and NSK HR32005XJ bearings on eBay this morning. Hopefully they will be quieter and have less runout.

[CL_MotoTech]

Yep, that's gross. Sorry about your luck.

I measured my machine at 85dbA while cutting at 54ipm, 6k, .15" step over, and .5" deep, with three flute carbide. That was at approximately 18" from the spindle.

The bad news is that chips jammed the Y axis causing lost steps and it crashed so hard it broke the end mill in two places. That's a new one for me. At least we can commiserate on the absolute pain these machines can be sometimes. I have to figure out my way covers. They just aren't adequate anymore.

Good luck with those new bearings, surely if they suck you can at least return them.

[ChrisAttebery]

I received the NSK 32005 bearings over the weekend. I opened one and it feels a LOT smoother than even the good sets of Timkens ever did. The 32007 P5 is supposed to be here today. I haven't used my mill in over a week. I can't wait to swap out the bearings and get back to work.

[ChrisAttebery]

The 32007 showed up at lunch time so I went ahead and swapped the bearings. These NSK bearings are a LOT smoother than the Timkens. I pulled the idler bearing off the spindle pulley and put a new bearing in the spacer. I have the machine running a break in spindle bearings as I type. It's doing 15 minute long increments at 1000-6000rpm in 1000 rpm steps and then 15 minutes at 6750 rpm.

I tried running the 17144 seal and it created a lot of friction and heat. It's just too tight on the spindle. I ordered a pair of 17404 which are 1mm bigger ID. It sounds like a lot but the 17044 was pretty tight. Hopefully it will work out.

There are a lot of guys running the SFK 32005x/q and 32007x/q bearings with grease and getting years of use out of them. These bearings have a higher RPM rating (and less runout) than the standard 32005 and 32007s do. If these NSKs don't last I'll give those a shot. See the thread below.

https://www.cnczone.com/forums/bench...cnc-forum.html

[ChrisAttebery]

After the 2 hour break in the quill was 97F in a 67F garage (I love CA weather. I'm wearing shorts today). I measured the sound at 76dB at 6750 rpm. The spindle sounds so much better. I think this set of bearings even sounds better than the AC bearings did.

[CL_MotoTech]

That's awesome! I look forward to your reports!

I currently don't much care for this set of VXB sourced tapers I am now running. They aren't noisy, but they do run hot. So if you see good performance I might follow your path.

[ChrisAttebery]

I got the 17404 seal in last night. Even though it's spec'd for a 44.45mm shaft it still feels a bit tight on the spindle. I ran it for a bit and the spindle started getting warmer than I'm comfortable with. This seals are only rated for 3100 rpm and 100C anyway so it probably wasn't the best choice.

I did a little more research and found the SKF 45X65X8 CRW1 V. It's spec'd for a 45mm shaft, 10k rpm, and 200C. I'm pretty sure it will work. I ordered one this morning but it will be a week or so before it arrives.

https://www.skf.com/us/products/indu...5X8%20CRW1%20V

[CL_MotoTech]

It might be worth giving the seal a shot without the garter spring (assuming you can pluck it). Given that there is no pressure involved it will probably seal well enough without being preloaded. Then again, I could be totally wrong.

[ChrisAttebery]

I might give this a shot if I can get the seal out without destroying it. Actually I have a spare...

[ChrisAttebery]

Well, I destroyed the seal getting it out. I pulled the carter spring out of the spare and installed it. It runs a little cooler but it's still too hot. The new seal should be here this week. Hopefully it will run cooler. At this point I'd deal with a bit of leakage to get one that doesn't heat up the spindle.