Rotating nut plan/Diagram

[tpworks]

Does anyone know where I can locate a diagram or plan for a rotating nut
like the one used here? http://www.stirlingsteele.com/files/leftviewZaxis.jpg
I am converting a mini-mill and I think this is the best option because the screw stays out of the way of flying debris.

Tom.

[posix]

Ermm...yes...are you sure about that? Your screw will be exposed just the same if you think about it carefully, it's only that in your scenario the nut is rotating rather than the screw.

It's only where the lead screw is so long that it becomes heavy and wobbly that you use a rotating nut.

[tpworks]

Yes I'm sure about that. the screw would be attached to the top of the Z axis , not passing through it as seen in this picture. (http://www.stirlingsteele.com/files/leftviewZaxis.jpg)
eerrm, think before you reply.

[WayneHill]

Posix,

Jeff Davis sells plans for a rotating nut assembly.

http://www.homecnc.info/cncparts.htm
http://www.homecnc.info/cnc-main.html


If you look close at the pictures on his web site, you get an idea of
how it is setup.

[AustinT]

I too have been thinking about this. I wish someone would make a hollow shaft stepper with a built in ballscrew. The motor would crawl up and down the screw and would mount to a linear bearing system to carry the weight. Screw whip would not be an issue. To keep the dirt out I would use 2 pieces of convoluted tubing. For example a 8 foot screw would have two 4 foot pieces of tubing to protect the screw from dirt.

[tpworks]

There is a stepper that does that (linear actuator stepper)http://www.hsimotors.com/linear-actuators/
http://www.anaheimautomation.com/23A34Aactuators.htm

[AustinT]

Originally Posted by tpworks There is a stepper that does that (linear actuator stepper)http://www.hsimotors.com/linear-actuators/

Hi Yes I found that stepper just after my previous post. Why dont we see any of them used here at cnc?

[tpworks]

$$$ cost!

[H500]

A rotating nut is no harder to design than a static one. Just do it the usual way, except that the diameter is scaled up so that the ball screw will thru inside the rotating piece.

Because of the large diameters, the cost will be considerably higher, so it should only be done when necessary.

[tpworks]

Thanks Wayne Hill
and as for Posix I asked for plans or diagrams not critics if all you have to input is negativity then I suggest that you don't bother posting.
Enough said.

[posix]

As for tpworks I didn't criticise anything just asked whether you really needed the added complexity of making a rotating nut. And if you are a sensitive type I suggest you don't bother reading replies that you consider to be in a vicinity of even remotely seeming like they may contain an offensive thought and go suck on a thumb or something. Jeez...

[Evodyne]

Guys,

Hi. One of the benefits of the CNCzone site is the free exchange of ideas and experiences. This works best when we are open minded to the replies others offer, and when we are courteous and respectful in generating our own replies.

One of the less-desirable "jobs" of being a moderator is stepping in when things don't go so smoothly. Less desirable but important. Negative exchanges can quickly escalate and get out of control, so I really can't let them go on in my forums. Let the punches and counter-punches stop here and now. I have spoken.

Your friendly neighborhood moderator,

Evodyne