80/20 mill build

[SpeedsCustom]

Very well then. Look into Humidifier pads from Home Depot, they are great filters that do a good job with chips.

For future use or something...


-Jason

[LeeWay]

Well, Guys, I think I have burned through my first spindle bearing. It is the lower one doing some squawking. I added a bit of oil down through an upper hole and it quit. Sounds like a seal gone bad and a dry bearing.
These were the original X2 bearings. This head never did get hot at all. Likely not enough preload on them.
I ordered a new set from VBX. They should work fine.
I did get about a year out of these running an average 5 or 6 hours a day. That ain't bad at all really.

Now the key to this will be, can I remove and reinstall the bearings without removing the head?
I have 9" travel, so I should be able to do it without too much trouble.
That is something to consider when designing your own.
This one is trammed so well, I would rather forego doing that again right now.
It should take no more than about 1/2 hour to do.
We will see.

[asuratman]

Hello LeeWay,
What max RPM on X2? Can we just change bearing to get a higher RPM? I have my mill spindle about 3500 rpm. If rotating about 3000 rpm, its noisy an motor shaking. How you can get that high RPM? Let me know. Thanks. Asuratman.

[LeeWay]

I have the spindle running at 6600. I have a much larger motor and run a timing belt drive on it.
IIRC, the standard bearings that come with the X2 are rated about 7000 RPM.

The new ones I ordered are deep groove bearings like the originals. The lower bearing for an R-8 spindle is rated @ 35,000 RPM.

The upper bearing is this one, rated @ 10,000 RPM.

I started to get a ceramic bearing. I just didn't know if it would hold up on a mill.
It is nearly 10 times the price.
Anyone have any experience with ceramic bearings in a mill?

[pzzamakr1980]

Ceramic bearings do not handle shock well. For this reason they are not appropriate for certain applications, and I believe this would be one of them.

[LeeWay]

Thats what I was thinking. Especially for the lower bearing on the spindle. It takes the biggest brunt of force. Perhaps doable if I never crashed the thing. It is rare, but does happen. The new lower bearings should work fine. Thanks.

[acondit]

Originally Posted by LeeWay The new ones I ordered are deep groove bearings like the originals. The lower bearing for an R-8 spindle is rated @ 35,000 RPM. The upper bearing is this one, rated @ 10,000 RPM.

Lee,

Any idea why the larger bearing is rated 35000 rpm and the smaller one is only rated 10000 rpm?

Alan

[LeeWay]

I was thinking it might be a misprint, but that would be a bad place for such a misprint. That is quite a high rating for an $8 bearing.

[Jason3]

Originally Posted by LeeWay I was thinking it might be a misprint, but that would be a bad place for such a misprint. That is quite a high rating for an $8 bearing.

Hi Lee

The 6007-2RS has much smaller balls than the 6206-2RS. I think that might be why it's rated for a higher speed... Big difference though!

FWIW, my Kavo spindles have ceramic bearings, and they're a lot more rigid than the similarly sized NSK E3000 I have (The NSK has steel bearings, thought you can get a ceramic bearing spindle nose for them).

I don't think you'd have a problem with durability in this size with ceramic. They're more rugged than you might think, and will actually tolerate a larger load under fast acceleration or deceleration than steel bearings. Whether or not it's economically sensible is another question Apparently the full ceramic (not hybrid) bearings can run without any lubrication too, and will run cooler for longer. Defies belief, really!

Best regards,

Jason

[acondit]

Originally Posted by LeeWay I was thinking it might be a misprint, but that would be a bad place for such a misprint. That is quite a high rating for an $8 bearing.

Yeh, even the 10000 is impressive. I really wonder how long that it would actually last if run at 10000.

Alan

[LeeWay]

Thanks, Jason.
I have heard that the ceramic bearings are very nice. I have seen some before in some equipment and tools that I maintained. I think the upper bearing was over $100.00. The lower over $50.00. or vice versa. Not too high priced for a production machine at all. I would classify mine as a semi-production machine though. If I get another year out of the this cheaper bearing set, I will be happy, so really no need to even try the ceramics. I could not ask for a better machine to do what I do. It is a perfect fit for the need I had.
It's not that I was all that smart, but I got very lucky with the part buys and had the ability to change things around during the build and even after. It's pretty versatile. Bearings are consumables anyway I think as long as they don't cost an arm and leg.


Alan, I'll never know. I have a little trim router if I need anything faster than 6600.

[LeeWay]

I did get the new VBX bearings installed. They work better than ever. The sound is a lot quieter and even the cutting sound is a bunch less.
These are some decent bearings and dang near dirt cheap. They seem to fit a bit tighter than the OEM ones. I had to resort to the freezing and heating scenario to get them to install. Went together pretty well though. I was able to do it without removing the head. This makes it a breeze. No worries next time a bearing starts to fail. It took me 45 minutes, not counting the freezer time.
Cool!

This head is the one that was originally on my old X2. Still had the gears inside. All the gears came out easily save one. I used a chisel to bust it in two. These OEM bearings were NOT SEALED. They were only shielded. This is why when I added some oil, they quieted back down. I just took for granted that they were sealed. Still, they worked for a couple years in manual mode and a year CNC cutting steel, and sometimes running very close to their limit of 7000 @ 6600 RPM. The spindle with these old bearings never even got warm.
Now I know this is from a lack of preload. It contributed directly to the backlash I thought was all in the Z axis. Turns out that with a properly installed bearing set, I no longer have any backlash. NOT any that I can measure with my dial indicator.
This is why it sounds much better plunging into a steel cut. Just a lot more rigid. Cool!

This does warm up some now, but not too much to hold with your hand. 120 degrees F after running 6600 RPM for 30 minutes. I did a break in over two days. Started at 1000 and increased 500 every 30 minutes.
Back in business.