[vroemm]

Hi..

I lost about 6 of the balls of a screw rod with ball bearing.
They are 2.38 mm round.
Do shops sell these balls as replacement ?

[mackeym]

i'm guessing you're talking about balls for a ball screw. 2.38mm=3/32" there are a bunch of ebay auctions selling 3/32" chrome steel balls. This kind of ball is commonly used in bearing based devices.

[stevehuckss396]

3/32 of an inch is .09375 converted to metric is 2.38125000000943. I get them 50 at a time on ebay. You might need to look for something more precision but 3/32 is common.

[neilw20]

What's with the 000000943 part.
How you gonna measure that accurate?
Let alone the 125 part which is less than half a tenth?
Get real.

[stevehuckss396]

What's with the 000000943 part.
How you gonna measure that accurate?
Let alone the 125 part which is less than half a tenth?
Get real.

That was a cut and paste from a mm to inch conversion program. get over it.

[skmetal7]

^ lol

[Khalid]

go to any pencil grinder repair shop get the bearing from them remove the balls from the bearing

[vroemm]

i'm guessing you're talking about balls for a ball screw. 2.38mm=3/32" there are a bunch of ebay auctions selling 3/32" chrome steel balls. This kind of ball is commonly used in bearing based devices.

What a relief.

Thanks !

[dhookings]

AAMOI how did you know that you lost exactly 6. I spilled a load of balls over my desk before I even knew what a ballscrew was. I don't know if any hit the floor, but I gathered up all that I could and refitted them by using grease. They were about 1mm diameter, smaller than yours. Anyway, I screwed it back on and could not feel any axial movement so reasembled the drive. Everything works fine, but now I wonder if the grease will cause problems some time and did I get them all back in?
Perhaps someone could advise?

Dave

[neilw20]

All grease is, is a medium to hold oil.
The problem with grease is dust and dirt get stuck on it more readily.

[vroemm]

AAMOI how did you know that you lost exactly 6.

I did not know exactly.

Luckily 100 balls of 2.381 mm cost only about 4 euro.
Pleasant surprise.

did I get them all back in?

I push the balls against each other, making room for the next one.
Until no ball will fit.
Then there will be a lot left over to play around with.

[rexstep]

You don't want to try to match new balls in with the originals. You need to replace all of them. If you add six new balls in and they're even .0001" larger than the ones you have, only the new ones will engage the screw properly while the originals will tend to float. If they're smaller even by a tenth, there's no point in having them.

-Rick L.

[vroemm]

You don't want to try to match new balls in with the originals. You need to replace all of them. If you add six new balls in and they're even .0001" larger than the ones you have, only the new ones will engage the screw properly while the originals will tend to float. If they're smaller even by a tenth, there's no point in having them.

Very good point.
I did not think of it.
Thanks.

Luckily i just bought the 100 balls, i need only 60 or so.

[dhookings]

Thanks guys,
I took the whole assembly out and there is definitely no axial play so I shall let sleeping dogs lie. If I do get trouble in future, I have some good pointers.


Dave

[neilw20]

Just because you can't feel any axial play, doesn't mean more than three balls are doing the job. If that's the case you will get excessive wear.

How much is the screw worth?
Toss out the old balls, if the answer to the above is greater than the cost of the new balls.

[dhookings]

Thanks,
I can see where you're coming from by your sig :-)

My apparent reluctance to do the right thing is not the thought of stripping down the drive mechanics, I can do that in my sleep now, or the cost.
I am not looking forward to measuring the balls, getting someone to supply them, and putting in the right number using some kind of temporary tube. I just get the feeling that I am more likely to cock things up in those processes than leaving things as they are. Also, this is all new to me and I don't want to be without my new toy for perhaps a week.
But then, there is the grease, which is a bad thing.
OK - I'll take the first step of emptying the balls and cleaning out the nut. Then I'll count them and see if I can work out how many there are compared with how many there should be.

Dave