How much arc would I gain (approx) ?

[Vipersan]

WHAT !!!! My Christina (Love of my Life) ...undergoing a s_x change OP ..
Not sure I'd Love her the same way afterwards....
lol

 

[Vipersan]

I've measured mine, and that part is 117cm

Hmmm ...certainly you have bragging rights with that Rima ..
I bet the ladies love you...

I measured mine once ...and I'm not telling !!!
lol
cheers for the info mate

 

[RimaNTSS]

ha ha, if I cut mine half out than we will have comparable length of ours.... actuators :-shh
Edit: Adding picture how I would try.

 

[Vipersan]

..Where you thinking something like this Huevos ..?
replace the extension mount bar with a 14 inch section of I section steel ...like a thin RSJ ...
to give lift and rigidity ..and mount the jack above the top of the polar mount..
??
A bit of a rough quick sketch ..proportions all wrong....but you get the Idea..

 

[Channel Hopper]

I wouldn't go down that route, with the actuator in a different plane to the moving parts you would need to reinforce everything to stop the flexing.

A small idea. Now you have drilled a second hole near the original pivot point on the dish side of the polarmount - ala this picture - http://www.satellites.co.uk/forums/topic/158734-how-much-arc-would-i-gain-approx/page-2# - why not make up a triangular plate with three holes and bolt it securely there. If you make it isoceles and get the longer two sides correct, you could mount the actuator backwards on it (gearbox nearest the reflector) and the worm part bolted to the back of the polarmount.

 

[Vipersan]

I wouldn't go down that route, with the actuator in a different plane to the moving parts you would need to reinforce everything to stop the flexing.

A small idea. Now you have drilled a second hole near the original pivot point on the dish side of the polarmount - ala this picture - http://www.satellites.co.uk/forums/topic/158734-how-much-arc-would-i-gain-approx/page-2# - why not make up a triangular plate with three holes and bolt it securely there. If you make it isoceles and get the longer two sides correct, you could mount the actuator backwards on it (gearbox nearest the reflector) and the worm part bolted to the back of the polarmount.

Sorry buddy ..I just can't visualise that one ..
At 58West the dish part of the mount is so close to the back edge of the polar mounts current clamp mount point with 95% of the jack hanging to the rear..
If the jack was reversed there would always be the bulk of the actuator seperating dish from mount ..so it couldn't be closed ?...unless I'm totally misunderstanding what you're saying..
If I am I appologise ..but I just don't get what you're saying.
rgds
VS

 

[Channel Hopper]

If the actuator is turned round so that the bolt of the worm drive end is now bolted on the polarmount end, the rose joint that clamps round it could be fitted to the dish backplate using a triangular piece of metal bolted to the two holes you have already made.

From the front of the dish the casual observer would see the gearbox protruding from the left of the reflector (or, as mentioned before you could consider puting the whole assembly on the Eastern side so that the actuator parts give a better tracking for the Eastern arc down to the horizon)

I'll sketch something when I get back in the office

 

[Vipersan]

If the actuator is turned round so that the bolt of the worm drive end is now bolted on the polarmount end, the rose joint that clamps round it could be fitted to the dish backplate using a triangular piece of metal bolted to the two holes you have already made.

From the front of the dish the casual observer would see the gearbox protruding from the left of the reflector (or, as mentioned before you could consider puting the whole assembly on the Eastern side so that the actuator parts give a better tracking for the Eastern arc down to the horizon)

I'll sketch something when I get back in the office

I think I see where youre going with the idea ..
That would certainly require /allow for a longer jack ...but remember the actuator would have to clear 1.2mtres from the dish centre ..so a very long isos plate would be needed projecting sideways not backwards ..otherwise it would push through the dish..
Would such a plate be rigid enough ?
I'll wait for the sketch....
Interesting idea but might not be practical..
cheers
VS

..oh and there would be little point in moving to the other side as I don't have clear line of sight beyond 57 East ...the futher we go East the less dish face in use..
62 East is just about practical ..beyond that is a pure gamble anyay.

 

[Channel Hopper]

It shouldn't have to be such a large isoceles as there is really no difference to what you already have, and the worm drive has worked for you so far (and you also have the stand-off from the rose joint itself to offset the distance from the backplate).

I would be inclined to do a dummy run initially though by hand turning the worm drive throughout the arc, just to check nothing touches the reflector.

 

[Vipersan]

Well in the modified 1W pic I attched ..the red triangle would definately not work ..
Everything projecting backwards in the photo would have to be projected forwards ..and would definately hit the dish itself ..
..ie effectively _through_ the dish itself...
The only way I can see to avoid this would be to extend the Iso sideways ..or move the anchor point for the worm drive inwards toward the polar mount body ..thus a much longer jack be required..

 

[Vipersan]

...The green triangle wouldn't work at 55West either ..
Even if It missed the dish ...the jack would project through the wall ...
And the same thing if the motor was on the East side of the dish ..
Sorry CH ..
Novel Idea but not practical in this situation..
rgds
VS

 

[Huevos]

VS, what is your local meridian? Also, does the actuator currently run into the mount before it is fully extended? If so how much extra travel does it have?

What are these lengths:
polar axis to spherical joint 1,
polar axis to spherical joint 2,
spherical joint to spherical joint with dish facing due south,
spherical joint to spherical joint with the actuator fully closed.

 

[Vipersan]

Location 53.5N 2.3W
..and yes it is very close to running into the mount at full extension (original mount hole)..maybe 2cm of travell left.
Still restricted from travelling those 2cm ..even though no longer limit switch restriction needed with jack located in new position...but cannot reach beyond say 55 East.
If returned to original mount position ..would have to use limit switch again to stop the jack hitting the mount beyond 62 East.
Certainly without the side extension strip on which the motor joint is mounted it would collide with the mount much earlier.
Sherical joint to Sperical joint
Dish due south is 50cm
Fully closed 11cm

polar axis distance with dish due south ..
To joint one jack end 44cm
To joint two ..motor end 38.5cm

These measurements are with the jack located in the recently drilled hole ..not the original mount point hole.
rgds
VS

 

[Vipersan]

New back mount plate planned..
I've found a suitable piece of steel which is wider than the original extension bar ,,
about 2/3rds the bars thickness but has two right angled folds ..which will give rigidity..
It will be bolted to the mount in positions marked in blue ..
The original mount position for the motor end rose joint marked in red ..which is equivalent to the current extension bar..
and will have the addition of another hole slightly further forward ..marked in green ..
hopefully I should be able to still receive 58W when the new Jack is fully closed ...but if not I can always return to the red position ..
The green position will afford slight forward movement equivialent to slight Eastward arc rotation ..and the slight forward positioning will reduce the risk of the jack hitting the mount when at maximum extension ..
All experimental ..but the new plate will give room for more options...and hopefully still retain rigidity.
rgds
VS

 

[Lazarus]

So glad you're back on form, Evan.

 

[Vipersan]

So glad you're back on form, Evan.

Cheers Gordon ..
Sadly not if my left hand is anything to go by ..
I'll have to be carefull using the angle grinder ....a bit of weakness and numbness in there..
but I'll be extra careful and get it done.

 

[Vipersan]

...Ok ..
contacted Red Apple ..they had a heavy duty 24 in stock ..now on order.
..spent this morning making my 'divine' plate..
Very holy geddit...
lol
will fit it this evening ..as I gotta go earn some wages soon..
rgds
VS

 

[Huevos]

VS, the way I see it you have the actuator on the wrong side of the dish. Look at the numbers. 58W - 2.3W (your location) = 55.7º from due south. Corrected for topographic that is 60.2º to the west of due south. Whereas 62E + 2.3W = 64.3º from due south. Corrected for topographic that is 69.1º to the east of due south. You'll still need the plate to get your rear spherical joint in the right position, but the 9º less rotation to the west would eliminate the problem of the actuator touching down on the polar mount.

Edit, I too can't picture CH's suggestion about attaching the actuator back to front, so I'm waiting to see the sketch.

 

[Vipersan]

VS, the way I see it you have the actuator on the wrong side of the dish. Look at the numbers. 58W - 2.3W (your location) = 55.7º from due south. Corrected for topographic that is 60.2º to the west of due south. Whereas 62E + 2.3W = 64.3º from due south. Corrected for topographic that is 69.1º to the east of due south. You'll still need the plate to get your rear spherical joint in the right position, but the 9º less rotation to the west would eliminate the problem of the actuator touching down on the polar mount.

Edit, I too can't picture CH's suggestion about attaching the actuator back to front, so I'm waiting to see the sketch.

I agree it would be better to have the actuator on t'other side at my location ..but I spend most of time dxing on the western side of the arc ...some seasonal restrictions in play to the East...so ..it's just preference really that I prefer the actuator less open for the most part of it's 'working' life.
rgds
VS

 

[RimaNTSS]

After I found proper place to fix 18' actuator I made a plate out of 5 (maybe 6) mm metal, painted it and attached it to original mount. Now this 1,5m PFA is tuned to 90*E-30*W, I think it is even possible to get 96,5*E-45*W, only worry about obstacles close to horizon.