Help identifying X2 spindle wobble

Check your spindle on V blocks on the surface plate. A bit of paper between the spindle and the blocks will keep you from marring the spindle.

Bearings and spindle condition are a sticky bit of work. bearings are a case of you get what you pay for. Sealed bearings are crap. They are used in electric motors, and have shallow grooves. They are also cheap. Angular contact bearings are never sealed, and can be bought in different levels of precision. ABEC Class 5 is a common number for spindles if you aren't asking too much of them. ABEC Class 7 for high quality spindles. BTW, even electric motor bearings in sizes of a couple of inches ID are happy to run 6000 RPM.

A Bridgeport mill has a felt washer as a seal on top of the spindle cartridge. This is how the cartridge is lubricated. A few drops of oil next to the drawbar a couple of times per shift. The felt keeps the dust and crap out, and filters the oil.
 
willthedancer said:
Check your spindle on V blocks on the surface plate. A bit of paper between the spindle and the blocks will keep you from marring the spindle.

Bearings and spindle condition are a sticky bit of work. bearings are a case of you get what you pay for. Sealed bearings are crap. They are used in electric motors, and have shallow grooves. They are also cheap. Angular contact bearings are never sealed, and can be bought in different levels of precision. ABEC Class 5 is a common number for spindles if you aren't asking too much of them. ABEC Class 7 for high quality spindles. BTW, even electric motor bearings in sizes of a couple of inches ID are happy to run 6000 RPM.

A Bridgeport mill has a felt washer as a seal on top of the spindle cartridge. This is how the cartridge is lubricated. A few drops of oil next to the drawbar a couple of times per shift. The felt keeps the dust and crap out, and filters the oil.
Click to expand...

With the ABEC system, higher numbers are higher quality? I know you say you get what you pay for, and I am willing to pay, but I have no idea where to start on cost. Is a $40 bearing sufficient for this mill or should I go for one of the $150 ones? I don't know enough to determine what is decent and what is overkill, and searching brings up way too much info to wade through.
 
Quoted:
With the ABEC system, higher numbers are higher quality? I know you say you get what you pay for, and I am willing to pay, but I have no idea where to start on cost. Is a $40 bearing sufficient for this mill or should I go for one of the $150 ones? I don't know enough to determine what is decent and what is overkill, and searching brings up way too much info to wade through.


Yes, higher numbers are less runout, and more expensive. At least with ABEC ball bearings. Tapered rollers are another matter and completely nonsensical, and I won't confuse you with them today. you're probably good with class 5. To take advantage of them, the spindle bores and bearing fits on the spindle must be ROUND, meaning you can't measure a variance with your mics. The spindle needs to be straight within the limits of your test indicator. If these criteria are met, go with ABEC 5. If not, get class 3, angular contact, and expect some minor runout (less than .001).
 
Do you have the bearings out?
I just replaced all the bearings in my mill including the idler pulley.
I had no idea what I needed so just got them out and cross referenced them. I got all Koyo bearings for less than a hundred bucks.
 
Make friends with a sales engineer at a power transmission component supply house. If they are nice, you will get an education. I personally deal with McGuire bearing in Portland OR. Finding one who will take the time to help you make an informed decision is worth it.
 
shooter123456 said:
I am shopping for replacement bearings, and am completely lost on what I should be getting. I can't tell quality beyond the price really and have seen them from $10 to $500.

My question now is:

What makes a bearing high quality and how can I figure that out without spec sheets?
How much should I expect to spend for either angular contact bearings or deep groove bearings?
Would it be better to get a very high quality deep groove bearing or a mid range angular contact? Those seem to be about the same price.

Also, you suggested high quality bearings but then say going for more precision in a bearing might not be cost effective. That sounds contradictory, but maybe I just don't understand.

I appreciate your help with this.
Click to expand...

You need to pull the bearings and check the bearing designation, then look for the equivalent bearing, ideally an ABC 5 class bearing. The metric equivalent is a P5 class.

For the spindle bearings, try to find sealed angular contact bearings; yes, they are commonly available. Deep groove bearings are fine for the other bearings in the head.

You can call your local bearing suppliers or email bearing manufacturers like FAG, SKF, Nachi, etc
to see what they have. Once you know what you want, look for it on eBay or wherever you can find the best price.

As for price, it depends on how lucky you are. I replaced all the bearings in my head for about 150 bucks and used FAG sealed AC bearings on the spindle and Nachi deep groove bearings for the drive sleeve.

First thing to do is pull your bearings.
 
mikey said:
You need to pull the bearings and check the bearing designation, then look for the equivalent bearing, ideally an ABC 5 class bearing. The metric equivalent is a P5 class.

For the spindle bearings, try to find sealed angular contact bearings; yes, they are commonly available. Deep groove bearings are fine for the other bearings in the head.

You can call your local bearing suppliers or email bearing manufacturers like FAG, SKF, Nachi, etc
to see what they have. Once you know what you want, look for it on eBay or wherever you can find the best price.

As for price, it depends on how lucky you are. I replaced all the bearings in my head for about 150 bucks and used FAG sealed AC bearings on the spindle and Nachi deep groove bearings for the drive sleeve.

First thing to do is pull your bearings.
Click to expand...

I was planning to replace the top and bottom spindle bearings. Are there more bearings in the head I don't know about?
 
shooter123456 said:
I was planning to replace the top and bottom spindle bearings. Are there more bearings in the head I don't know about?
Click to expand...

Don't know, most spindles do. If yours just has upper and lower bearings then I suggest using ABEC5 bearings for both.
 
I think I got to the bottom of the spindle issues. First up was the pulley. When I placed the bottom of it on a surface plate, it rocked back and forth a ton. Not flat at all. Then the spindle nut that retains the pulley had burs in the bottom that were digging into the pulley and making it sit at an angle. I think the vibrating and knocking was caused by the pulley rocking back and forth as it rotated since it wasn't flat and wasn't retained well on top since it was only touching where the burrs were digging in.

I put the pulley in the lathe and faced off the area where the burrs were digging in, and faced the other end where it wasn't flat. I took the spindle nut and a piece of sandpaper on the surface plate and sanded the burrs off and made the bottom mostly flat. I also changed the spindle bearings for angular contact bearings. There is still a little vibration left that I think is from the belt being worn out. I will replace that soon and see if it changes anything. Unfortunately, I don't think there is anything I can do about the drawbar being eccentric since the inside of the spindle isn't bored well and is far from straight.

Anywho, I have some pictures.
RL6EK4j.jpg


Here are the new spindle bearings. They went on very easily and are rated for 13,000 RPM. One is Nacchi and the other is VXB brand. They were about $18 each and the Nacchi is way nicer than the VXB. Unfortunately, the Nacchi for that size was $70.
bIVDAMm.jpg
 
Shooter, what happened with the head vibrating and getting hot and the gritty sound? Did that all resolve with the spindle bearing change? Clearly, the wobbling pulley has been cleared, right?
 
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