Play in the jack-arm?

[Captain Jack]

Hi,

Ever since buying my 18" Jaeger SuperJack arm, it has always suffered from a bit of play. It's maybe 1-2mm but when amplified onto a 1.2m dish, it can sometimes mean a difference between a lock and no-lock.

I inherited another jack-arm with a polar mount and that one does not have any play in it. Is this acceptable and is there anything I can do minimise this play? I had it apart a while ago but couldn't see anything that could be adjusted....

Cheers
CJ

 

[nelson_b]

hi - c.j.
the play is usually in the roller bearing - and cant be adjusted -
if the jack is old enough the bearing can be easily replaced by unscrewing a retaining plug -
if its a newer one, the bearings are staked in position (the play could also be caused by it not being staked firmly) -- and wihlst not impossible to replace its not exactly easy - a bit of drilling and a small welding job - when i did one last year

cheers --

 

[Captain Jack]

It's a newer one with cog wheels stacked on top of each other. I found no way to adjust them....

What exactly did you drill/weld there?

 

[nelson_b]

It's a newer one with cog wheels stacked on top of each other. I found no way to adjust them....

What exactly did you drill/weld there?

no not in the gearbox -- never had trouble there -
the play problem is usually in the bearing in the rod/arm - can explain better with pictures -
will try to find some photos i took , and post them after work tomorrow

regards

 

[RimaNTSS]

Play in the actuator is usually in those 2 joins. Perhaps it is possible to buy them separately from actuator.

 

[Captain Jack]

It's definitely not there - if anything, it's a little too tight. I've arrowed where the play is...

 

[RimaNTSS]

That also could be that resulting play consist of play1+play2+play3+play4 where 1 and 2 are ball-joins, 3- nut and treaded bar, and 4 - possible play in polar mount. Perhaps, changing of actuator to new one can help. Or there is another, procedural option: always approach weak satellites from one side, for example from East to West. For strong signals one positioner click does not really matters.

 

[Captain Jack]

That also could be that resulting play consist of play1+play2+play3+play4 where 1 and 2 are ball-joins, 3- nut and treaded bar, and 4 - possible play in polar mount. Perhaps, changing of actuator to new one can help. Or there is another, procedural option: always approach weak satellites from one side, for example from East to West. For strong signals one positioner click does not really matters.

Ah yeah, that's what I need to get to to see what's happening there... Don't really want a new jack as this one is just over a year old and it did it from the start.

And yes, that's what I do with weak sats - drive to them from the side I maximised the signal from. It's only maybe two or three clicks out if I drive from another side but still annoying having to do this.

 

[RimaNTSS]

but still annoying having to do this.

Nothing is perfect in this world :-shifty

 

[nelson_b]

hi -
yes i agree with "RimaNTSS" to check the nut and threaded bar -- a likely place to wear if its been short of grease.

on the ones that i have repaired the main cause of play has been in the bearing at the end of the bar - (see picture) - easy and cheap to replace on the older actuators - not so easy on the newer ones because of the way the bearing is held in place in the outer tube -- my most recent one had been badly staked into its position,and the whole bearing was moving a couple of m.m. in the tube causing even more play .

regards --

 

[Channel Hopper]

It's also a dirty job, wear gloves as you don't know how contaminated (or the origin/type of) the 'grease' is.

 

[Captain Jack]

So, I'd like to fix the jack arm that I have rather than get a new one. The bearing is definitely loose but I cannot see a way to undo it. There's a nylock nut but it won't turn in either direction.

Also, how do I separate the inner tube from the outer one? The "eye" stops it going out and I guess the eye is welded on somehow?

 

[nelson_b]

So, I'd like to fix the jack arm that I have rather than get a new one. The bearing is definitely loose but I cannot see a way to undo it. There's a nylock nut but it won't turn in either direction.

Also, how do I separate the inner tube from the outer one? The "eye" stops it going out and I guess the eye is welded on somehow?

View attachment 56560 View attachment 56561

hi c.j.
remove the pin at the end of the shaft --------
the nut should come off (must just be tight) normal anticlockwise thread to undo -
wrap some cloth round the thread on the rod to protect it - then grip it in a vise or use some mole grips to hold it firm -- then use a long ring spanner on the nut for best leverage --

once the nut and bearing is removed the inner tube and the threaded rod will all go out the other way -- like when the jack is fully extended .

i have some pics somewhere -- if i can find them --too much stuff on this p.c. --- l.o.l.

good luck ---

 

[nelson_b]

hi - some pics here of a mini jack --- similar arrangement to yours --
this jack has a crappy spacer to retain the bearing in the outer tube -- older better jacks have a screw in retainer -- yours probably has --
some newer jacks have the bearing "staked" in position and have a shaped lug instead of a drive pin -- to try to render them "un-repairable "

 

[Captain Jack]

Thanks nelson! I managed to get it off - after slamming my nail shut.. ouchie.



One thing I still can't get off is the plastic cap thing at the other end - it's stuck somehow and I cannot get any leverage on it. Does it just snap out or screw out?



Will I gain anything from separating the two rods? I will obviously be able to clean it better but is the nut replaceable? It's relatively OK but a tiny bit loose in the barrel.

Lastly the bearing. How do I interpret the numbers on its side? It says "6201/LHT23". I guess 6201 is the size and LHT23 is ?? Would I gain anything from getting rubber or metal sealed ones? Also, some come with "higher internal clearance" (C3) - what does this mean?

 

[hdp160]

Short term quick solution is to put a bungee cord (or 2) on the rim of your dish to a convenient point on the arm or fence or wherever.

These will stabilise the dish when it stops by taking out the play.

As an afterthought a string with a weight would also work.

 

[Captain Jack]

OK, I've managed to separate everything. Also figured out bearing sizes but no idea what LHT23 is still.

The rod is quite rusted in a few places. Will try cleaning it with something but also found that there's play between the nut and the threaded rod. Is there any way to minimise that? Maybe by coating the rod in something that hardens and add a bit more "leverage"?

 

[Captain Jack]

Short term quick solution is to put a bungee cord (or 2) on the rim of your dish to a convenient point on the arm or fence or wherever.

These will stabilise the dish when it stops by taking out the play.

As an afterthought a string with a weight would also work.

That's not a bad idea, actually. If my refurbishment efforts fail, I'll do something like this.

 

[nelson_b]

hi - c.j.
if the plastic cap/seal at the end of the outer tube is not broken i would leave it in place -- its not a part you can purchase as far as i know -- i had to make something to do the job one time .

bearing sizes etc -- i have a company locally who amongst other things supply bearings - and if they cannot interpret the numbers - they just measure the inner and outer of the old bearing - to get the size .

i,v never had - play problems with the nut on the threaded rod so far, on any that i have repaired . the wear will probably be in the nut rather than the threaded rod .
the one on the mini jack in the photos has a plastic nut ( is yours metal or plastic ?) that looks to be staked in position in the inner tube -- so not so easy to replace -- if i did need to i would replace with a metal nut - ground down if needed --- to fit into the end of the tube , and carefully weld it to the end of tube .

cheers --

ps - this install has given you a few injuries - l.o.l.

 

[Captain Jack]

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.