[mikemaat]

I ordered a couple chinese double ballnuts, and what I got was not what was pictured in the ad. Normally im used to seeing the double ball nuts that have the lock washer type spring in between with the locating tab keeping the second nut from spinning. Like this....



Instead, I was shipped a double ballnut that has both ballnuts set screwed to a sleeve between them. Before I return them, has anyone seen this type? Is it even truly a backlash reducing double ballnut or is it just simply two nuts fastened together? Is there a way to set the preload? Is it preloaded from factory? Any ideas??

[victorofga]

mike

it is in one mutual ""bushing"" after you ""tie"" together the two nut then you tie up the bushing.. so you can eliminate, or at least minimalize the backlash..

all ""preloaded"" ball nut works this way.. make closer or farer two regular ballnut..

how it is solved, that's pending on factories..

[mikemaat]

I understand that to preload a double ballnut you "closer or farther away" the nuts. What I dont understand, is how this is accomplished with the one I received. The normal one (first pic) is obvious, you just thread the second nut in or out and then tighten the tab down to keep it from moving. But I dont understand how the one in the second pic works...

[mikemaat]

Actually, rereading your post, are you saying that there is a wide "wiper" shared between the two nuts and i simply have to loosen the wiper screws, rotate the second nut out until i reach preload, then tighten the wiper screws back in?

[victorofga]

no...

one mutual bushing hold the two nut
as you tight agains each other and tie up the second, that will make the necessary preloading..

if you see the logic as preloaded ballnut works..
how it is performed.. that's a sendary question.. b

both ball nut has its own wiper.. wiper has no any affect and I did not mention..

[victorofga]

I magine a longer bushing than the first nut fit into.. with the flange

fit and mount the first nut, the secnd nut still can spin freely, but it is in same bushing.. don't imagine a broncze bushing for motors..
now you tie the second nut, without flange to the first already mounted and locked nut..
when it is on the proper position, no backlash then you tie the bushing up on the second nut..

its not weird.. its only simplified.. it could work same good like any other

if ti still not ok.. I try to make some drawing or model one..

[mikemaat]

I think we're getting lost in the language here but let me paraphrase and you can tell me if im correct.

So first I loosened the small set screws on the second ball nut, and then removed the second ballnut from the first. The first ballnut has a metal "bushing" still attached to it, coming out the back. Then I screw my first ballnut onto the ballscrew. Then I spin the second ballnut onto the bacllscrew and spin it up to the first. While holding the first ballnut locked in place, I spin the second one back out, just enough to take up the backlash. Then I put the set screws back in to attach the second ballnut to the first?

If this is right, the only question I have left is that the "bushing" has holes drilled down slightly where the set screw is currently screwed into. When I spin the second nut to preload it, those holes will no longer line up. Do I just tighten the set screw against the bushing even without the drilled out spot? Or should I drill a new one?

Im assuming of course you mean the middle piece in this picture is the bushing.

[victorofga]

:-)
you find it right.. my English possible the worst ever..

when I say bushing, I was thinking on a ""housing"" (?) ..
that has hole like the ground diameter of ballnuts , and first ballnut with flange fixed into... second spinned toward to the first and also ""locked "" in this hole..

that's why I was offering I make some drawing.. that shows everything..

==============================================

but.. I didn't know it has an insert.. and looks like that will make sameyes twist as much the second til it is eliminate the backlash and tie setscrew.. after it is tested and sure works well, then you can make a small sink for the set screw..

in my opinion, I would tie them closer as this spacer will hold securely the distance....
I believe it is not worse than the other picture.. diferent solution and I thin same good.. I think you made a good deal when you purchased this..

right now im cutting.. but later I really like to show I thinking.. that way setscrew not involved so anytime can be adjusted..
a few hour and returning..

thank you..