Recirculating ball leadscrew in Autohelm 5000

[castaway]

Does any one know anything about these things. On my very old AH5000 the action (in and out on the linear drive) was getting quite notchy so I stripped it down, and it was indeed almost dry of any lubricant, which may well have been the cause.

However all the balls fell out and I think I caught them all in the bucket I was working over...but does anyone know how much slack there should be in the spiral of ball bearings that live in the 'screw' ie should they be hard packed in or should there be plenty of slack to allow allow them to shunt around.

Perhaps I should say that I would not have started on this course had I felt that the unit was any use in its present state!!

Thanks Nick

 

[hightech]

You will need a specialist tool to re-assemble the leadscrew (very expensive) and all the balls!, without it you have a dead drive unit!

 

[Avocet]

You could try the RS website in "Mechanical components" and search for "ballscrew" or "linear actuator". You might find a similar component thatcould be pressed into service.

 

[castaway]

In fact getting the balls/lead screw back together is not a problem, I've done this a couple of times whilst learning about it...very cheap sticky grease works as an admirable substitute for thr expensive tool in best PBO fashion.

Its really just wanting to know how much slack there should be between the balls in the race...ie no slack.. 1 ball or more.etc..

Thanks Nick

 

[Blueboatman]

This is a very general comment,..but..,in general ,with these recirculating ball races and spirals ,there should be a gap equivalent to just less than one ball's diameter upon reassembly,ie you cannot quite get another ball into the caging .. What you want is that the balls move and rotate freely,that there are no notches or wear spots on the arm and sleeve. (And no balls left over ,been there ).My old autohelm had about 3/16 lateral movement at the helm end when on full extension,ie you could sometimes see the body of the unit wobble around when working ,but it moved in/out freely.
If all else fails ,I wonder if Raytheon/Autohelm's service dept would talk to you or offer up the old service sheet for this .Good Luck.

 

[castaway]

Thats great thanks for that info more or less what I was expecting

regds Nick.