[Pysiek]

Hello Guys

Recently I have put together my Little Machine Shop Hi-torque mill and the conversion kit from cncfusion.com . During the assembly I have dropped some steel balls from the ball nut. Can anyone tell me where I can buy the balls to replace the missing ones? And how to do it? I've send emails to cncfusion (since they have not provided the phone # ) but they have not answer me.

[Mad Welder]

Hello Guys

Recently I have put together my Little Machine Shop Hi-torque mill and the conversion kit from cncfusion.com . During the assembly I have dropped some steel balls from the ball nut. Can anyone tell me where I can buy the balls to replace the missing ones? And how to do it? I've send emails to cncfusion (since they have not provided the phone # ) but they have not answer me.

Ask Hosshttp://www.cnczone.com/forums/bencht...sss_g0704.html....sorry I just can't seem to find the link he used as he has purchased ball bearings and slightly oversized to reduce backlash....

Hope you can purchase your exact size......

[mcphill]

try mcmaster.com

[packrat]

There's a guy on Ebay that sells precision bearing balls, on size, under size and over size.
His prices are better than McMaster.

[hoss2006]

Ballscrew Ball Screw Balls 100 pcs 0.1265 mm3.2131 items in ToolSupply store on eBay!

or

Bal-tec Products Directory

You can remove the crossover tube and pack the new balls in that way or bring the nut to the end of the ballscrew
just exposing the balls an push them in that way.
There are videos on youtube.
Hoss

[79TigerPilot]

I had to replace the balls in my ball screw and found Bal-tec to be one of the few ball manufacturers remaining in the US that will sell small orders. I had a long conversation with the president which I really enjoyed. He told me all about balls and what I should watch for when replacing them.

Make sure you measure the balls closely as they are available in many sizes. You can get .12500 .124950 .124970 etc. Some ball screw folks use different balls sizes between circuits to preload the nut. In my case I had two sizes of balls .1250 and .12470. All the balls were out of my nut so I really wasn't sure how to put them back in. I took a guess and put the .1250's in one circuit and the .12497 in the second circuit, seems to work fine. Sometimes they alternate ball sizes, the smaller balls are just spacer balls since they take no load, this is used to reduce the drag. I have one large ball screw that does this but the spacer balls are nylon.

I learned in my long phone call that one should replace the entire set of balls and not just one or two balls and they should from the same batch. The reasoning goes like this: The balls are ground to a specific dimension but there is a tolerance about this number. A .1250 ball may actually be larger or smaller than this number by the tol limit but within a batch all the balls are matched to a much tighter tolerance. This keeps the load constant across all the balls. You don't want a mix of upper and lower limit balls since the upper limit balls would take all the load.

Bal-tec, Manufacturer of Precision Balls, Ball Bars, and Kinematic Components

If your ball nut has removable return tubes -- you just remove the tubes, counting the balls in the circuit so you know how may to replace -- if you have lost balls then just try to fill it up. Don't think you want it tight -one ball loose shouldn't matter. Clean every thing up really well, put the balls in one circuit at a time, turn the screw as you go. Fill the return tube use a little dabs of grease to keep the balls from falling out of the tube while you install it.

Good luck,
Craig

[Pysiek]

Guys thanks for all the replies. I found out that if you loose 6 balls or less I should be fine but since I lost more then 6 I have to replace them. Also Thomson not recommend to fill the nut with balls all the way. There have to be some room.
I do have the return tube. So I just remove it then put the balls in and turn the nut?
Can somebody point me to the videos on youtube? I can't find any.

[Ron Dunn]

So am I. My wife made me buy a Toyota Tarago.

[hoss2006]

Guys thanks for all the replies. I found out that if you loose 6 balls or less I should be fine but since I lost more then 6 I have to replace them. Also Thomson not recommend to fill the nut with balls all the way. There have to be some room.
I do have the return tube. So I just remove it then put the balls in and turn the nut?
Can somebody point me to the videos on youtube? I can't find any.

here's one.
Hoss

[ame="http://www.youtube.com/watch?v=8plIXSR5Nh8&feature=plcp&context=C234a1UDO EgsToPDskJKOf7AcX1Vvi6qYxQV4ea2"]G0704 Repacking Roton Ballnut.wmv - YouTube[/ame]

and my buddies

[ame="http://www.youtube.com/watch?v=cPOhAjmPADM"]34: Nook Ballnut loading - YouTube[/ame]

[Pysiek]

Hoss2006 thanks for the videos. They helped me a lot. I do have one more question. Lets say that my balls right now are .125 in dia. what size should I get then to replace them with bigger ones? How do I determine that? Now I'm thinking to replace ball in all 3 nuts.

[hoss2006]

Cncfusion offers the service of packing in oversize balls.
I don't know what they use since I've only done Roton nuts but a quick email
and they may tell you what size they use.
Hoss

[Pysiek]

my balls are .125 in dia anybody knows what size should I use for zero backlash? Kit is cncfusion X2 #2 kit.

[Mad Welder]

my balls are .125 in dia anybody knows what size should I use for zero backlash? Kit is cncfusion X2 #2 kit.

Have a quick relook at Hoss's video in post 9 below he says there are 0.125" stock and he's replacing them with 0.1263"

[Pysiek]

You know what I don't know why but I have hard time understanding what that guy is saying (chair) but thanks for the reply. I'm thinking to go with .1265 . Hoss's friend try it and said they work fine