Problem with VBox III Accuracy

[Anole]

Very nice pix, Linuxman.
Still not sure what the "magnetic sensor probe" is, but I though it was usually a reed switch.
Doesn't seem to be, from the pictures. Possibly something with hall-effect?

Also, if you had four magnets on that brass arm instead of two, wouldn't that double the counts again?

And not having a Vbox, I really don't know the answer to these questions?
1). does it count 000-999?
2). does it count 0000-1999?
3). does it count from -999 through 000 to +999?
4). does it count from -1999 through 0000 to +1999?

1 = 1000 counts
2 = 2000 counts
3 = 2000 counts
4 = 4000 counts

I guess my suggestions above for getting multiple pulses per revolution of the motor don't play well if the counter is severely limited in total count range.

Oh, and one other thing that'll help you get more counts, at the cost of less throw, is:
... make the arm longer where the end of the actuator attaches to the dish.
Farther from the pivot point it is, the more counts (and throw) it will take to go from bird to bird.
At some point, you run out of throw on your 18" motor, and need a 24" or 36" unit.

Sounds like ya got it pretty well under control. - :up

 

[gabshere]

although i haven't fixed mine yet i think we will be limited to 000-999 in the counting
the v-box remembers the location in the numbers ( 000-999) so if you cross the threshold of numbes it would confuse the v-box ( i suspect). although i can't prove it. so if sat a was at 000 and sat z was 010 (1009 clicks away) i think it would only move 10 clicks instead of the 1009 clicks( if that makes any sence).

i haven't found a listing to tell me how many pulse counts the superjack does , my 18 inch HD moves about 400 clicks and i know the von weise i have list 48 pulse counts ( and i think thats per inch right??

 

[voomvoom]

OK Fred, now we want to see that Solid Aluminum Dish back on the Roof? Pronto! Or at least no later than Spring Training? HeHe....

Al

 

[linuxman]

Hey Anole,

And not having a Vbox, I really don't know the answer to these questions?
1). does it count 000-999?
2). does it count 0000-1999?
3). does it count from -999 through 000 to +999?
4). does it count from -1999 through 0000 to +1999?

I have all my VBoxes including this one at 000 for the center.

The Birdview has the longest range and goes from about 400? (don't remember exactly) on the East to about 500? (don't remember exactly) on the West which makes the 000 actually 1000, but the 4th digit does not display for a total of 1100 counts. My guess is that the VBoxes have a total of 2000 counts that they can remember.

Also, if you had four magnets on that brass arm instead of two, wouldn't that double the counts again?

Theoretically that would be correct.

OK Fred, now we want to see that Solid Aluminum Dish back on the Roof? Pronto! Or at least no later than Spring Training? HeHe....

That is my regret Al that the Solid Spun Aluminum is gone forever.

 

[Anole]

count this!

I spent some time searching last night, for a manual on any Vbox family member.
I started on the Sadoun site and here on our own manual's page.
Then, I went out on the net with Google.
Didn't find a manual, nor any specs that listed the count-range.
Was quite disappointed.

And as for the long-heralded Vbox V , I didn't run across that either.

Thanks to all the discussion, I've learned a lot about the actuators and Vboxes, so my cup is half full, as usual !

 

[linuxman]

Here is the manual on the VBox III.

I didn't know you were looking for a manual.

It doesn't have anything about the specs in it though.

I have the manual for the VBox II as well, but don't have a scanner.

View attachment vbox-III-manual.pdf

Don't remember where I got it.

 

[gabshere]

well i'm wrong again lol but that is good news on the counting

i did find out that the von weise v76-5 has a pulse count of 48
and the von weise you have fred was at 24 and i guess that doubled with the magnet so it should be at 48 now

now the specs on the superjacks is a little bit more vague some of them count 30 and others count 32

i never found out if this was 48 counts per inch or what ...... ???

 

[linuxman]

Hey George,

How many counts do you have between 93W and 95W?

If it is 6 it will be 24 count. If it is 9/10 it will be 32 count. If it is 12/13 it will be a 48 count.

That should be pretty close.

 

[gabshere]

i'm at work now but i think its about 8-10 clicks from 93 to 95 ( so your estimation would be right on)

my other problem is if i order a new actuator ( and i was looking at a HD 24" Superjack from Sadouns) if my modification to the 18 inch didn't double the count. but it doesn't tell me how many pulse counts it has

but i do have the actuator from my 10 ft dish its a von weise 24" V76-5 to fall back on if needed.

i will do some research before i order.
thanks --- it really helps with this enlighting thread

 

[linuxman]

Keep us posted George as to your experiment and what your research reveals.

Fred

 

[Anole]

color me red

Thanks for the Vbox III manual. It made good reading.
I looked in our Manual Department again just now, and suddenly I found it!
Oddly, it'd been there 4 months, and I guess I missed it.

The good news is, I found out how many counts it'll hold.
The answer seems to be 2000, based on my readings.
Page 8 or 9 has Resynchronize function, and the drawing shows 2000 total counts.

Total count limit-to-limit for that 24 inch motor:
24 counts per inch = 0576 - one magnet
48 counts per inch = 1152 - two magnets
72 counts per inch = 1728 - three magnets. (I like this solution!)


I should try to figure out how many total counts the little USALS motors do.
If it's considerably more, and I'll assume it is, then maybe graft that front end onto a Vbox, and have the best of both!
(that'd require a real H-to-H motor, of course)

 

[linuxman]

The answer seems to be 2000, based on my readings.
Page 8 or 9 has Resynchronize function, and the drawing shows 2000 total counts.

Hmmm!
I never even looked at the illustration.

Sometimes when working on a project you need 3 or 4 minds and lots of pairs of eyes to find the answer.

Thanks Anole!

Fred

 

[linuxman]

I had a conversation with Anole late yesterday about how to get more counts between satellites without modifying the actuator itself, or the magnets.

Anole suggested a possible solution by moving the point where the end of the actuator arm attaches to the dish thereby making the throw a little longer.

Most dishes that don't have H-H mounts follow two similar mounting rings. The one like my Unimesh 10 footer splits the mounting ring in half, and the other like my Perfect 10 7.5 footer which attaches offset of center.

Here are a couple of pictures to illustrate his proposal. (Sorry about the darkness on the 7.5 footer. It is 24F out with 25 mph winds. I am not going up to the roof for a clearer shot )





Anole, Is this what you were describing to do?

Also look closely at the P10 dish offset. See how the mount moves around the center piece?

BTW, I like the Santa hat on your Anole in your avatar!

Fred

 

[Anole]

Here is what I was thinking. . .
The pix below were taken from this page on the Sadoun site, but I've modified mine to show the relevant points.

In the first picture, the fixed plate locks the dish relative to the mount.
It would be replaced by the actuator (motor) if the dish were motorized, as shown in the 2nd picture.
See the mounting holes I've marked? ( A , B , & C )
The farther from the pivot point of the dish you put the end of the motor ( C ), the less throw you'll have and the more counts between birds.
See second picture, at the point marked: D .

I can see from your pictures that the end of the motor is attached to the big ring on the back of the dish.
In my drawings there is a flat or extruded bar that sticks out and could possibly be extended.
I hadn't contemplated the ring, and don't know a quick solution to get ya more motor travel.
For users with different mounts, which more resemble mine, it should be simple.


. . . and, see also post #31 above, for the clever 3-magnet idea. - :up

 

[Larry1]

Moving the attachment point further out from the centre will also reduce the effects of any play in the mechanism.

 

[linuxman]

Yes, I understood correctly. I just didn't illustrate the further out point. A small steel bracket could be made to move the attachment point further out pretty easily.

Your pictures are much clearer than mine.

Moving the attachment point further out from the centre will also reduce the effects of any play in the mechanism.

I think you are right Larry!

Thanks,
Fred

 

[gabshere]

whats weird i was thinking about things very like what ya'll are. one of my problems with the 18 inch superjack is that to get my far west sat of 148 ( and i've yet to get it tuned ) i had to move the mounting bracket to the highest point on the actuator arm. and it still gets to 58 W but i fear going much past that will strain the motor even though its a HD.

no mounting my actuartor bracket up so high on the arm, does it lessen my pushing pulling power. or am i just over thinking it. seems like it would be much better locked at least in the center of the arm.

now if i mount a small pice of l shaped steel about 1 ft longer ( going toward the arm) i would be able to safely go eastward several more sats.

i will have to think some more on the matter

 

[bryansr]

whats weird i was thinking about things very like what ya'll are. one of my problems with the 18 inch superjack is that to get my far west sat of 148 ( and i've yet to get it tuned ) i had to move the mounting bracket to the highest point on the actuator arm. and it still gets to 58 W but i fear going much past that will strain the motor even though its a HD.

no mounting my actuartor bracket up so high on the arm, does it lessen my pushing pulling power. or am i just over thinking it. seems like it would be much better locked at least in the center of the arm.

now if i mount a small pice of l shaped steel about 1 ft longer ( going toward the arm) i would be able to safely go eastward several more sats.

i will have to think some more on the matter

When I used to do a lot of C-band work I replaced ALL of the little 18 inch arms with 24 inch arms. I allways worked to get a longer sweep with the longer arm and I coud get more pulses to boot!!!!! It was a Win-Win situation. All of the 24 inch arms were a LOT more heavy duty then the wimpy little 18 inch arms I replaced. They were usually the last arm I put on the dish. A lot of the customers had replaced the 18 inch arms several times before I came along. I woulds also make sure the arm tracked STRAIGHT when it moved thru the arc. I had to adjust several that were left out of track and those dishes had worn out several arms too.

BryanSR

 

[gabshere]

yes i figured the 24 in HD had a higher count but i asked one of the sponsers here before i purchase . the 18 inch i have is a HD model and works great just doesn't count right.
i would hate to put out $$$ for a arm that might still have a counting problem( cause no pulse count is listed on the arms) so i will wait for now. and maybe get an answer back about the counts on a 24 inch HD.

the 18 inch model has a 30 or 32 pulse count which isn't enough to be accurate for the v-box III

 

[truckracer]

I put a 36" superjack HD on my 7.5' Sami mesh. (talking about overkill). It tracks way more accurately than my old 18".

I have my 36" mounted on the farthest outermost point of the polar mount ring and on the inner most bolt hole on the stationary part of the polar mount. This makes the arm extend the longest for the least amount of azimuth. I have a lot more counts between satellites but the dish moves a lot slower.

The equivalent of using 4wheel low gear in your truck . The gear ratio effect is much lower and more accurate.


I can now see 55 degrees to 139 degrees west.