Ballscrews are Manufactured in many Different Types, Grades, Pitches, Sizes, Etc.
CNC Machine Tool Ballscrews are generally Precision-Ground Assemblies Built to
Ten-Thousand of an Inch (.0001") Tolerances and usually have 2 Ballnuts Bolted and
Lightly Preloaded against each other so that there is Zero Slop & Backlash in Assembly.
The Strippit Company, with a only a couple of Exceptions like the FC24/20 and FC75/30,
has used Precision Ballscrews on all of their NC & CNC Punch, Laser, and Plasma Machines built over the last 50 years. Strippit has used Ballscrews Manufactured by
Sergeant, Barnes, Warner Precision, Beaver Precision, RBC, PGM, PSI, NSK, and Other Companies as Strippit really just can't make up their Mind what to use.
Your Company Should take Very Good Care of your Machine Ballscrews Because;
1 -- Each X & Y Axis of Every Machine Strippit has Ever Made used it's Own Unique Ballscrew.
So there has been Hundreds of Different Ballscrew Models used, most of which are
Not-Stocked, No Longer Made, or Available anywhere. You may Not be able to Quickly
and easily get a replacement! A Custom Made Ballscrew takes about 2 to 3 Months to Build!
(which they make in their Own Swiss Factory) to Build Any Length of Axis Travel on any
Machine Tool they wish! They Don't Need to Stock Hundreds of different Ballscrews.
2 -- If available, it will cost about $6000 to $10,000 to Replace a Worn-Out Ballscrew with a
New Ballscrew, 4 End-Bearings, 2 Hug-Nuts, Lube-Fittings, Coupling Ring-Fedders,
Seals, and Professional Installation.
If Properly Maintained, a Ballscrew can Last for Many Years, or even Decades!
To Maximize Ballscrew Life;
1 -- Keep Ballscrew Clean! A New Ballscrew will Shine like a Mirror! Keep it that Way!
2 -- Keep Ballscrew Oily! If your Machine has an Automatic Oiler, Check All Ballscrews Every
Week to make Sure it is Working! Often Oiler System is Not-Working Correctly or a Oil Line
is Broken, and your First indication of a Bad Lube Situation is when Ballscrew starts
making a Howling Noise because it's Already Ruined!
I Advise Oiling Both Ballscrews By-Hand, Every Day!!!
If your Machine does Not have a Oiler System, Make it the Operator's Job to Oil All Axis by
Hand Every Day! Use a Long-Handle 2 Inch Wide Paint-Brush with a Tin-Can filled with Oil,
and "Paint" Ballscrews with Oil.. This Oils Ballscrew and Loosens Dirt, and keeps
Ballscrew Clean by Flinging-Off Excess Oil and the Dirt with it.
Caution!!! Make Sure Machine is "OFF" !!!
Never Stick Your Hands & Arms into ANY Machine that is "ON" !!!
3 -- Use a Good Clean Oil like Mobil DTE-Heavy ISO-100 Weight Lube Oil.
You may have this Oil already as it is used in the Pressure Lube-Tank of older Strippit
Machines with Mechanical Press-Drives.
4 -- Do NOT Use Grease on the Ballscrew! It is Not Widely Known, but Grease on Hi-Speed
Ball Bearings will cause Balls to "Skid" instead of Rolling which will cause Rapid Failure
of Ballscrew Assembly. Grease will also Attract and Hold Dirt & Dust forming a
Black Grinding Compound that will cause Rapid Wear of Ballscrew assembly.
5 -- Do Grease the End-Bearings! Ballscrews are usually supported by 4 Bearings Mounted
inside 2 Castings with Grease Fittings at each End of Ballscrew. Grease these Bearings
once or twice a year. Strippit recommends Mobil EP1 Grease, but I use Mobil Mobilith
6 -- Reduce the X & Y Axis Speed! I prefer that Programmers put Commands into Each Part
Program to Slow Axis Speed so as to take this Out of Hands of your Operator-Of-The-Day.
In a HECC80-Control FC750, FC750/2, FC1000/1, FC1000/2, FC1250/45, FC1250/30/1500
I would Insert a F12 Code in the Block of Code where your First XY Move & Punch-Hit is.
For a HECC80/3 Control FC1000/3 Machine, use a F2 Code in the Same place as above.
Fanuc Controls can also have their Part Programs Modified with a Speed Reducing Code or
have Operator Adjust Speed Control on Control-Panel to Easily Reduce Axis Speed.
Bearing-Loads go up at a Square-Root of Speed Increase. So, for Example if you Reduced
Axis Speed to Half-Speed, you do Not Reduce Load by Half and Double Ballscrew Life,
you actually Reduced Load by a Factor of 4 and Increased Ballscrew Life by 4 Times!
So Reducing Speed has a Huge Influence on Ballscrew Life.
You also Benefit with Longer Servo-Motor & Servo-Drive Life, Less Tooling Problems like
Bad Punch-Stripping and Slug Pop-Up, and Increased Part Accuracy.
7 -- Promptly Repair Axis Slowdown Switches, Limit Switches, Resolver Feedback Packages,
and Encoders that can cause Axis to "Run-Away" and Crash causing Damage or Breakage.
And make sure Axis-Bumpers are on Machine and in Good Condition!
8 -- If Ballscrew is Replaced, make Sure it is Properly Installed & Aligned by an
Experienced Technician, as Improper Installation can cause Very Rapid Failure.