Play in the jack-arm?

nelson_b

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Strong 4375 driving a 2.4 m Channel Master dual focus offset + Invcom Quad C120 K/U l.n.b. + BSC 421 and Zinwell C band l.n.b.,s - DR HD F15 - TM5302 - Octagon SX88+Optima - GT Media V7 - HD receivers. + other dishes currently in use - Antique 3.0 m Prodelin P.F. - Channel Master 1.8 m offset - Channel Master. 1.2 m.
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Captain Jack said:
Yes I have enough bumps and bruises from this install and I am nowhere near enough done yet!

The nut is metal so either it's supposed to be like that or it's knackered. Ordered the bearing so will put it back together and see what it's like. Only a few quid loss if it doesn't help...but the bearing does have a fair bit of play in it.
Click to expand...


i,m sure it will be an improvement --
a picture below of a bearing i took out of a jack a couple of years ago -- as you can see its right on the point of total collapse :eek:
bearing.jpg
 
Captain Jack

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Wow! Mine's nowhere near that bad. But it is loose. I just ordered a open one not sealed...we'll see
 
Lazarus

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Strange really - when you consider the duty of bearings in dish actuators against other applications, you'd think wear and tear would be very light. Most of the time the bearing is totally quiescent.

I'm amazed at the state of the one in the pic!
 
hdp160

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Tivù said:
Strange really - when you consider the duty of bearings in dish actuators against other applications, you'd think wear and tear would be very light. Most of the time the bearing is totally quiescent.

I'm amazed at the state of the one in the pic!
Click to expand...


Totally agree. I think I would consider popping a traveling plastic sleeve over the rod before reassembly and adding a reservoir of grease for the rod to bath in somehow.
 
Captain Jack

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Yes, a sleeve will be put on there. Will stick some Molykote 54 grease on there - hopefully will keep it going for a while.
 
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PG-54 is a good general purpose grease if you have it to hand. But if your going to buy think about a small tube of marine grease better for low load outdoor usage IMHO.
 
Captain Jack

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Got the bearing today and fitted it but as expected, there is still a bit of play down to either the worn out nut or the rod (I am blaming the nut though). No chance of replacing that. The play is about 1mm so it's not too bad - will give it a go later and maybe refurbish the big heavy duty one.
 
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Not familiar with the kit, but would wrapping the threads with several turns of PTFE tape help reduce the play further?
 
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I could but wouldn't the tape be ripped to shreds quite quickly?
 
Lazarus

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Possibly (Probably, even!), but maybe there is some other material which is ductile enough to wrap easily and snugly but also be robust?

Just clutching at straws, I know.
 
Captain Jack

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Yeah, that's what I was looking for. I was thinking some sort of spray paint..something like Kurust or something. Will protect the rod (kinda) and add more leverage.

I am quite annoyed with jack arms though. Even my new proper SuperJack one last year had a bit of play in it - surely this shouldn't be acceptable. The big one that's currently on the back of the dish is a 36" one (, after finding the label that hasn't faded. Took the motor box off and inside it's pristine - mainly because it's protected by the rubber clarinet hose thing. The bearing is also OK but there's still play in it - again, I am guessing on the nut/rod....

Wonder if a nice heavy duty 24" one will be better?

SSS have a nice 1224 motor for sale... for £300... :eek:
 
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