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Where do I get balls for my balls screws.

viper

Titanium
Joined
May 18, 2007
Location
nowhereville
Per another post, we are reballing two ballscrew nuts on our Haas. It was found that the size if nothing close to the normal .125 size. These are 5/32 or possibly "were" 4mm. My measurements are .1567 on Y and .1562 on Z. The Z balls look like total crap!! FOD killed my balls! I found debris in the nut and some balls are .004 small and pitted. The raceways all look perfect and we would be looking at a rebuild anyway so we are going for it.


So does anyone know where to get the balls to reload this critter? We should be off like a prom dress as soon as we can find balls. They should be grade 25, chrome steel, and sold in many odd sizes. We found one company, ball-tec, but they were a little high and we plan to buy a bunch and test to see what works the best. There is one ebay guy but I do not think he has odd sizes in the 5/32 area.
 
I guess that's what seperates the ballscrew rebuilders from the rest of us: they've got more balls than the average fellow :D

I think you'll just have to take your best guess and order bags in every tenth across a range that spans what you think you'll need. When you're done, sell off the remains on ebay, or on this website to the next guy who might be interested. You might have to take a 50% loss to make it attractive, but the next guy probably could buy and resell the set without further loss, so long as he replaces whatever size he depletes out of the set.
 
Tue dat. Believe me, we are working on numbers to isolate how much bigger we need to go so we do not have to buy the farm. I want to buy a range but within reason. I think what I will do today is install the balls out of the Y nut, in the Z nut since they are .0005 bigger and see where that puts me for comparison. In theory, they should be too big and be tight but we shall see.
 
You pretty much have to look at a specialty ballmaker.
5/32 is a standard size, and depending on grade you may or may not get a spread of tolerances you're looking for.
Sounds like though you want to size the balls to fit the nut. That is what the specialty ballmakers are for. They may make a 5/32 ball, but nowhere near at the price you're looking for. They WILL however make a ball from .1560 through .1570 in .0001 increments for the same price. This is their business. The large quantity ball shops don't do that, some don't even have the capability to do that.
If you ask a few ballscrew, linear way or precision bearing makers, you'll find that they order standard balls to load the nuts, and then they order a range of balls from .001 under to .001 over to "make a fit".
It really isn't the limit of the balls not being accurate enough, rather the races cannot possibly be made accurate enough to get the required results.

To answer your question though, try some of the ball distributors. They work with many specialty as well as standard ball shops. For one, there is Ballsupply in Avon CT. Their number is 860-673-3364.
 
Yep, you are right on. Even in the ball nut iteself, it has an inscribed ball diameter and then a + (number). I have no idea what the other number is but is does not add up to the ball count. One was .156+60 and one was .157+50. Obviously we are not a ballscrew co so we will take th extra time to get that little extra on these by trial and error.

I just got a mountain of info by reloading the Y balls in the Z nut because they were .0005 bigger. That pulled me down from .0035 backlash to .0018. That will really help us calculate where we need to be in final diameters. By the way guys, this is SIMPLE stuff. Loading that nut took all of 10min with a little Kluber spindle grease to hold the balls, slide my special cardboard tube in to hold them and install.

The thing that really gets me is all balls are the same diameter and each circuit seems to be missing exactly one ball. the count was 75 in each nut. I just reloaded what was here and it works but I would like to ask someone about that gap. Maybe that is how they can use the same diameter of balls without binding.
 
Yeah, I would leave some space, I can't see that a slight gap is going to hurt. Probably does some good actually, gives the balls a little room to roll without being preloaded against the ball ahead and behind.
 
was there info on that page I did not see? We are working to reball our own for now and look at a regrind later. These nuts are by steinmeyer and have a patented return thingy. they do not have the conventional return tubes. Just a relieved brass insert that allows the balls to skip over the thread and return. Pretty trick really,
 
Thomson Saginaw has a metric division. you might give them a shout. And if the balls are wore that bad with pits, What about the nut and the screw?
 
I examined the nut and screw with a magnifying glass and they look great. I know looks are not everything but I really think this will work well and save us some cash until we can test test the machine and see if it is worth putting more money into.
 
you mentioned some balls were .004 underside. this may be correct, it is common for some ballscrew mfg to have every other ball several thou undersize from the load carrying balls. it is suppose to allow the balls to roll better and not skid or jam
 
if the ballscrews are steinmeyer they are 4mm and you need grade 3 balls good to a micron someone told me to use grade 10 but i stay safe with the grade 3 although they are more expensive bal-tec precisionballs.com if you have internal return with 3 circuits then you may need the brass returns also and may have to melt the epoxy they put on it to replace them. good luck
 
The nuts were in very good shape. We did not see any need to replace the returns. We are very happy with the X and Y and pulled them down to new tolerances. the Z, however, did not tighen up enough and we will probably redo it one more time. The Z balls had very visible damage from debris. Because of the sound in the Z, we may get to regrind that axis but will try reballing it one more time.
 








 
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