Reducing X and Y Axis Backlash on a RF-30 Mill/Drill

[rgsparber]

There are two sources of backlash on the X and Y axes. The most obvious one is the play between the leadscrew and its take up nut. There is an adjustment on the nut but first you have to be able to access it. A less obvious and possibly larger source of backlash is in the thrust bearings associated with each leadscrew. It can be shimmed out resulting in a dramatic decrease in backlash. Will it turn a leadscrew into ballscrew performance? Dream on...

http://rick.sparber.org/XYBR.pdf

I welcome your questions and comments. All of us are smarter than any one of us.

Rick

[kbalch]

Thanks Rick! I've added your X-Y Backlash Reduction Method to our CNC category, as well as to your builder page: Rick Sparber's Homemade Tools. Your receipt:

X-Y Backlash Reduction Method by Rick Sparber

tags: CNC, mill

[kbalch]

Hi Rick,

Great writeup, as always! Your X-Y Backlash Reduction Method is our 'Best Documented Build' for May, 2015!

You'll be receiving a $35 online gift card from GiftRocket.

Just send me (via PM) your email address and we'll get things processed directly.

Congrats!

Ken

[kbalch]

This thread has been moved to the Must Read subforum. Congrats (and thanks) to Rick for making such a valuable contribution!

[jimspac]

Play within the takeup nut assembly will also contribute to backlash. However, no moving assembly can function with zero backlash because without mechanical clearance it would be bound solid. Even ball screws have a small margin of clearance and hence a small margin of backlash

[rgsparber]

I completely agree. If you go back to the article and move up one level in the directory, you will see a series of articles dealing with the complete story. Thinking about leadscrew XYZ translation, roll, pitch, and yaw are all essential pieces of the puzzle.

Rick

[Okapi]

Hi Rick,
What value(english or metric) do you consider as acceptable on this type of mill/drill machine ?
As I don't know a lot about those, it interest me to give a value to my customers when they want a new lead-screw on this type of tool.
Thanks.
PG

[Tonyg]

Hi Rick,

Great succinct write up as always.

[rgsparber]

Hi Rick,
What value(english or metric) do you consider as acceptable on this type of mill/drill machine ?
As I don't know a lot about those, it interest me to give a value to my customers when they want a new lead-screw on this type of tool.
Thanks.
PG

Given that the leadscrew is steel and the nut is bronze, I expect that the leadscrew would never wear out. The nuts have take up adjustments but there is a LOT more to the story as explained in my articles. You can set the backlash to zero if the leadscrew is perfectly parallel to its ways.

Does that answer your question?

Rick

[Okapi]

Thanks Rick,
It answers partially but as you said it can be good as possible, despite I've seen this technology totally out of possibilities especially on Mikron lathes used in production, they have a nut fitted like the nut for the lead screw which is on the horizontal axis and not perpendicular as yours.
Making a lot of work on specific models we have for example a value on Schaublin of 15/100 millimeters on the scale as a standard, this was the sense of my question, as I use those values for others lathes or milling machines.
The best I can make on a normal nut/screw is on the Aciera F series with about 6/100 on the scale before it comes hard to operate, you said it can be less with this technique ?