Disaster!!

[Vipersan]

That's a shame - three steps forward and one back, it seems.

Can't help you with a supplier, I'm afraid.

It IS a shame Gordon ...as it probably could be repaired ...if I can find a suitable ballbearing 'race'...
rgds
VS

 

[Lazarus]

It IS a shame Gordon ...as it probably could be repaired ...if I can find a suitable ballbearing 'race'...
rgds
VS

Well can you engage macro mode and bung up a couple of pics?

You never know what else might use similar bearings.


And a certain gentleman hasn't asked how he can enter your Ball Race ................... so far.

 

[sonnetpete]

Well can you engage macro mode and bung up a couple of pics?

You never know what else might use similar bearings.


And a certain gentleman hasn't asked how he can enter your Ball Race ................... so far.

..............as if!!

BTW, being somewhat vertically challenged, I'd appreciate an explanation of how to get out of 'Macro Mode'...I seem to have been stuck there for the last 60 years

 

[wod]

I've got 12" actuator in the shed not being used that you can have.

Not sure how much it cost to post to you. It's never used so is new like.

 

[Vipersan]

Thanks Wod ..
..but just had a call back from my local sat shop ...
He has an 8 inch in stock ..New for £20

I'm gonna check the reach needed to anchor the actuator at mid extension ..
If the 8 inch will do the job its just a trip to his shop ..a 1/4 of a mile away to pick it up ..
..no postage ..and better still ..no waiting ..
;)
If it proves to be unsuitable ..ie ..not long enough ..then I will definately take you up on your kind offer..

rgds
VS

 

[wod]

no probs, as I have 2 of them which I dont need that are just taking up space and thought you might have been interested.

you are doing very well to get this back up and running to say your health is not good at the moment.

 

[Vipersan]

Hi Wod ..
Please don't think me ungrateful ..
I do appreciate your offer ...but I am getting very tired lately ..
..as you say ..I blame this on health issues ..plus the speed and amount of effort I have put into this project of late..
Quite simply ..I want to get the job finished as soon as possible now..
I have hospital appointments and multiple tests coming up ...so just want to take advantage of the calm and pleasant break in the weather to get the job done 'n dusted ..
The fact that I may be able to go get a replacent actuator tomorrow gives me the weekend to get it fitted ...and up and running..
Hopefully the job will be completed before my series of hospital appointments..
Again my grateful thanks
VS

 

[Huevos]

He has an 8 inch in stock ..New for £20

You're not going to get far with 8 inches, you'e going to need 18" or more I would have thought.

BTW, being somewhat vertically challenged, I'd appreciate an explanation of how to get out of 'Macro Mode'...I seem to have been stuck there for the last 60 years

Macro means big, enormous, huge... not small.

 

[Vipersan]

I'm surprised to hear you say that Huevos ..
Elevation control only takes about 2 inches of movement on the previous 12 inch jack ...

...unless of course ..you intended it as a double entendre...
;)
rgds
VS

 

[wod]

didn't know that so little was used of it so 8" will be fine then if its strong enough to hold the dish ?

how do you control the elevation of dish with actuator, with another vbox ?

I'd like an all in one unit to control the dish but guess pro grade gear will be quite a lot in cost

 

[Vipersan]

didn't know that so little was used of it so 8" will be fine then if its strong enough to hold the dish ?

how do you control the elevation of dish with actuator, with another vbox ?

I'd like an all in one unit to control the dish but guess pro grade gear will be quite a lot in cost

Hi Wod ..
I currently use an old Echostar AP3000 receiver...though I have also used an old NEC stand alone positioner in the past ..
I hope one day to replace the Echostar with another V box ..working on the theory that I can send one signal from any of the receivers ...(diseqc 1.2) ...down the LNB feed ...which will loop back and be split between both V-boxes ...thus moving both actuators ..and therefore setting both the position on the arc ...and the elevation offset on any given bird ..
Providing both v boxes are set say to position 1 ..for bird A ...position 2 for Bird B ..etc etc ..
This will fully automate the process ..at a minimal cost..


As to the 8 inch jack being strong enough ..
I may take CH's advice and employ a counterweight at some point..
rgds
VS

 

[sonnetpete]

Macro means big, enormous, huge... not small.

My mistake, it's just when you take photo's like that, the effect is to make the subject appear much larger.

You're not going to get far with 8 inches, you'e going to need 18" or more I would have thought.

I refer my honorable friend to my previous answer.

 

[Huevos]

My mistake, it's just when you take photo's like that, the effect is to make the subject appear much larger.

Macro in photography means that the image recorded on the film is bigger than the real object. So if you took a picture of a postage stamp and after the film was developed you laid the postage stamp on the film the real postage stamp would be smaller than the image on the film... hence a macro image = bigger than the real thing.

 

[Huevos]

I'm surprised to hear you say that Huevos ..
Elevation control only takes about 2 inches of movement on the previous 12 inch jack ...

This thread is so long and I'm not following it well. I thought you were talking about the polar actuator.

By the way what does the elevation actuator control? Polar axis or declination?

 

[Vipersan]

This thread is so long and I'm not following it well. I thought you were talking about the polar actuator.

By the way what does the elevation actuator control? Polar axis or declination?

Hi Huevos ..
Elevation control ...is in my case in charge of declination not the polar offset...I just refer to it as elevation
It just allows me a little more accuracy for fringe reception...
...and of course would allow me to access inclined 'birds'
rgds
VS

rgds

 

[Channel Hopper]

Polarmounts do not lend themselves easily to dual axis tracking for elevation control. You would need to dismantle and modify the main retaining bolt for slip movement (bearings) and replace the lock bolt(s) with the correct diameter threaded rod, spacers and some locknuts around the lower motor rose-joint.

On a dish of the size and weight (and now high up) you now have working, minimal unwanted play will require a lot of thought/machining.

I'll post some pictures of what I had to do with the Ajak mount on the 3.7m, both actuators are obviously a bit more substantial.

 

[Vipersan]

Polarmounts do not lend themselves easily to dual axis tracking for elevation control. You would need to dismantle and modify the main retaining bolt for slip movement (bearings) and replace the lock bolt(s) with the correct diameter threaded rod, spacers and some locknuts around the lower motor rose-joint.

On a dish of the size and weight (and now high up) you now have working, minimal unwanted play will require a lot of thought/machining.

I'll post some pictures of what I had to do with the Ajak mount on the 3.7m, both actuators are obviously a bit more substantial.

Thanks CH ...pictures are always better than words imo..
..so any you post will certainly be scrutinised for ideas ;)

As you know I have had the declination jack working successfully previously ..but I take your point about it not being substantial ..and the declination jack is working harder against gravity ..
I can of course always lock the declination bolts up easily if I encounter high winds as theyare at a workable height and just requires half a turn with a big spanner.

rgds
VS

 

[Channel Hopper]

.but I take your point about it not being substantial ..and the declination jack is working harder against gravity ..

I can't see your images of the declination adaption in the links, but I am guessing the bearings self destructed as the worm drive was in constant tension.

 

[Vipersan]

Hi CH ..
The pictures pre-disaster can be seen in this thread

http://www.satellites.co.uk/forums/threads/added-elevation-control-to-the-1-8m-dish.141456/

post 7

I know its a bit crude ...and in an ideal world the pivot bolt should be fitted with bearings ...but if left untightened ..just enough to allow the small amount of movement neccssary it works quite well..
ie ..no binding at all ..
My worst fear is wear between the pivot bolt and the mount itself ..
..but of course it doesn't get moved that often so movement is only occasional and minimal

I examined the mentioned pivot point for wear when I dimantled the mount ...and didn't see anything of note..

also when I took the declination jack apart ..it was fairly obvious that water ingress was the culprit ..and that rust had seized the worm ....and that driving the motor against the rust had destroyed the bearing race..


rgds
VS

 

[Channel Hopper]

I examined the mentioned pivot point for wear when I dimantled the mount ...and didn't see anything of note..

also when I took the declination jack apart ..it was fairly obvious that water ingress was the culprit ..and that rust had seized the worm ....and that driving the motor against the rust had destroyed the bearing race.

The jack could have been installed the other way round to prevent water running down the driveshaft.

The problem with leaving the bolts slightly undone is not the wear on the surfaces as such, afterall many gearboxes rely on nothing more than shims running up against the cogs. The problem starts with the difference in diameter of the bolt and the hole it runs through, which across the polarmount can mean a twisting movement of the dish, enlarging the hole over time. The wear will be a quarter or so of what it is on a 3.7m dish though.