Alternative for ball screw

[TSJ]

While pricing a ball screw yesterday the supplier said there was a new alternative to using a ball screw made by a company called Nixen. Does any one have any experience with this product? According to their web suite they announced this product Aug 4th this year. I would use what they call a synchronized system with the servo motor attached to the gantry driving a shaft, each end of the shaft would have this Nexen system. Here is the compay web suite. To see the different attachment methods you have to open the .PDF pointed to on the suite.

http://www.nexengroup.com/nexen/jsp/.../news?id=@7995

Thanks for your advice in advance

[wcarrothers1]

Enteresting although how expencive.. Compaired to rack..

Also I don't find my racks to be all that loud so don't know how much of a benifit that would be..

But to be the first one on the block with a cool looking drive like that would be nice..


Also one down side I see is the smallest pitch diameter is 2" thus you are moving 2" x 3.14159265 = 6.2831853 travel per turn.. Thus you will need to gear that sucker way down for most servo's or steppers..

For example I'm using 1" diameter pinions resulting in 3.14159265 " per rev geared down 4:3 on the belt then through a 10:1 thompson planetary to the servo in my setup..

b.

[mxtras]

There have been threads on this product earlier this year on this site - back in Feb or March if I recall correctly.

I would definately take a chance on them based on their claims and the basic design.

Scott

[Bobbyr70]

I inqiured about the Nexen drive set up and they are pricey, but they are touting zero back lash and much increased durability over conventional gear and rack systems. Lube being the major difference. they have a special coating that is cryogenicaly applied. The roller pinoin is lubed instead and very well protected from the dust. They are replacing the wood router gear racks that are used in large production facilities. Quoted so far, no premature failures.
Conventional racks failing often due to sawdust and grease. Sounds like a much better design. I am pursuing this concept. I am building a 4x8 table and pricing versus durability is a major factor. The price quotes I have are 300+ for a 2" pinion and roughly 100 per foot for the premium rack. and this is on the smalest size they offer. It is more than enough for my application.
Maybe if I say enough here they might give me a salesmans discount?

[jcc3inc]

Sir,

While some of these new ideas seem ideal, we have to be a bit practical here! If you are a manufacturer of high end equipment which commands a premium price in the market, you might be able to justify the expense; however if you are a homebuilder or hobbyist who has a limited wallet for your hobby, stick with gear rack and pinion. You can buy a 6foot length of 1/2 x 1/2 rack for about $24. The pinion will add maybe $15 more (small quantity). And now let's say you use your machine 8 hours per day so that you need to replace both after one year's use. You have to spend the $39 all over again. That's a reasonable expense, I think. As to accuracy, I tested a 6 foot length of rack from Standard Steel Specialties and found it had an overall error of .006" in the 6 foot length.

If you want to see how businesses go at it, check into their products and you'll find that most large machines use gear rack.

Regards,
Jack C.