Anyone familiar with Nexen roller pinions?

[lumberjack_jeff]

At first glance, the technology seems brilliant for our application.

http://www.nexengroup.com/nexen/prod/prod_main.jsp/product?pn=966687&mainpn=true

http://www.nexengroup.com/nexen/assets/prod_images/RPSIso.gif

[Gerald D]

Search this forum for nexen to see a lot has been said about it.

[ger21]

The previous post is probably a spammer who brought this thread back from the dead, but I have something to add.

I'm building my own design 4x8 router. I happened top stumble across a pair of used Nexen roller pinions on Ebay, and bought them $180 each.
I spent a few hours creating an AutoCAD macro that would draw the tooth profile for the rack, and cutout a sample rack from baltic birtch.
The idea was to machine the rack from 3/4" phenolic plate on our Morbidelli router at work.
The sample looks like it should work fine, but I need to machine a sample from phenolic to see how precise I can get it.

My original plan was to use a custom made version of the Servo Belt drive system. http://bell-everman.com/servobelt-linear-drive

I'm still on the fence as to which method I'll use, until I make a sample rack for the roller pinions.
But I think this could be a viable option if the rack can be fabricated accurately and cheaply enough.

One issue I ran into was that these pinions are rather large, and need to use some type of gear reduction. After a few days of searching, I picked up a pair of 21:1 planetary gearboxes with 0 backlash from Ebay. These will be used with 400w brushless servos.

[Jason Marsha]

That is a big pinion. What is the bore size for the shaft?

Jason

[ger21]

I think it's 30mm. But I don't need to mount it to a shaft. I turned an adapter to mount it to the face of the gearbox.

[Fox]

However good or bad those Nexen rollers are, I still think that the rack and pinion system is by far the most affordable, easy to maintain, install, to get, etc for a Mechmate user, like Gerald intended with his K.I.S.S design approach.

If anything I would rather upgrade to helical rack and pinion then a Nexen system I think. Still nice to see the outcome of your endeavors though.

[KenC]

IMHO, this is good when there is a space constrain.
If gearbox is needed, then that would defeat the space-saving advantage.