Problem- Roton Anti-Backlash Nuts Too Tight

[ttjarrett]

Hi All.

I am currently building a self designed MDF 3 axis machine (http://www.cnczone.com/forums/showthread.php?t=71807) and have a question about Roton Anti-backlash nuts.

I decided to go with their "High-Lead" 1/2 X .200 screw (because the ball screw was out of my budget) and anti-backlash nuts for my machine, and after recieving my products and testing the nuts on the screw, I feel that they are too tight.

Has anyone else run into this problem? The nuts have a spring loaded mechanism that eliminates the backlash, but it seems too strong for the nuts; they are very tight on the screw. I may have to replace the springs to reduce friction on the screw, but I'm not too sure.

Advice would be much appreciated!

Toby

[ger21]

Try lubricating the screws and then see how tight they are. Also, if they are cold, they'll get looser when they warm up. I'd try them in actual use before making any changes.

[ttjarrett]

Originally Posted by ger21 Try lubricating the screws and then see how tight they are. Also, if they are cold, they'll get looser when they warm up. I'd try them in actual use before making any changes.

Hi Gerry,

I did lubricate the screw, but I didn't work the nut enough to make it warm. Once I have completed the build of my machine I shall run the screws with my drill attached to the screw end or something like that for a while and see it they loosen up then.

Thanks for the advice!

Toby

[johnmac]

You can also clean all the lube off and run it with your drill, dry. That will help seat the threads in the anti-backlash portion of the nut to the screw threads.

I made a nut out of delrin plastic that was way too tight. After running it dry with my drill, it polished the screw threads and fit just about right.

John

[FandZ]

This a quote from dumpster cnc faq

"What if my nuts are too tight?
Umm... ok... They shouldn't be too tight, only snug and you should be able to turn them with a finger and thumb, you shouldn't have to grip them for them to turn. All lead screws are not created equally, if you use a different supplier than I recommend (sometimes even the same supplier!), they may fit differently. We've had good luck when I suggest to file 2 or 3 notches around the last 2-3 threads of the lead screw and force it through the back of the leadnut only under the flange area, basically working as a custom tap; it usually doesn't take much. You are welcome to try this, otherwise, you can return them and I'll see if I can open them up here."

http://www.dumpstercnc.com/

Juat FYI, I just bought some from a member that have never been used. They were tight. I screwed them on and off several times. And that loosened them a good bit. The edge of acme rod was a little sharp so it took threadsized strings off of the inside of the of the derlin nut. It made it a ton better.

I just tried it with my power drill like johnmac mentioned. Now it is like butter. @ more axis to go