Advice Needed VBOX positioner numbers \ Actuator inches

[Manikm909]

hi guys

my 24inch jack is using 19 inches of the 24 to go from 54.9e to 45w - leaving 5 inches spare, but wouldnt want to max it, so lets say 4 inches - is there a way to calculate inches of jack per degree? or is it a matter of going to a sat marking, and then going to a sat 10 degrees away and measuring the difference?

also, on the vbox, i reset it at the start (fully retracted) so its a ZERO, at 45w its on 868 .....if i went to a satellite, like 58w for example, is it possible for the VBOX to get to 999 and then go back to ZERO, (which is 54.9 EAST ! for argument sake) as it tries to reach 58w, and then be REALLT confused - on a millenium bug level

thanks!!!

 

[femi]

It depends on Actuator (see its description). For me it's between 3 and 5 pulses per degree, but it's not quite linear. Due to the mechanics alone, it does not matter from which side a position is approached, this can also vary by 2-3 pulses.
If necessary, you could install an "extension", but the values also change.

 

[a33]

is there a way to calculate inches of jack per degree?

Equation and principle is here: Design for a Positioner with DiSEqC Decoder

The triangle arm length ratio, and its effect at what part of the arc you have the most inches per degree, was discussed more recently, e.g. in this post (in your own thread): Just Sharing This - My Channel Master 1.8 project.
(edited, because I linked the equation-link twice, by accident!)

The total actuator length difference for a 0-180 rotation (between fully re-tracted and fully extended) can also be calculated with the triangle arm lengths.

Greetz,
A33

Edited twice

 

[ozumo]

My V-Box has an indicator next to the count display, when it goes over 999 the LED lights up giving you another 0 to 999 (+dot). What would happen when you pass 999+dot (equal to 1999) I don't know.

 

[moonbase]

hi guys

my 24inch jack is using 19 inches of the 24 to go from 54.9e to 45w - leaving 5 inches spare, but wouldnt want to max it, so lets say 4 inches - is there a way to calculate inches of jack per degree? or is it a matter of going to a sat marking, and then going to a sat 10 degrees away and measuring the difference?

also, on the vbox, i reset it at the start (fully retracted) so its a ZERO, at 45w its on 868 .....if i went to a satellite, like 58w for example, is it possible for the VBOX to get to 999 and then go back to ZERO, (which is 54.9 EAST ! for argument sake) as it tries to reach 58w, and then be REALLT confused - on a millenium bug level

thanks!!!

Why not zero the v-box on 0.0 South?
It would count down into the 900...800...700 range for East and up into the 100...200...300 range for West.

Or ditch them v-boxes and go for another type of controller such as a Research Concepts RC2000 dual axis job, available on eBay for sensible wad sometimes.

 

[scopus]

Why not zero the v-box on 0.0 South?
It would count down into the 900...800...700 range for East and up into the 100...200...300 range for West.

Or ditch them v-boxes and go for another type of controller such as a Research Concepts RC2000 dual axis job, available on eBay for sensible wad sometimes.

I ditched my V Boxes for the RC2000..never looked back..far superior.

 

[Manikm909]

Why not zero the v-box on 0.0 South?
It would count down into the 900...800...700 range for East and up into the 100...200...300 range for West.

Or ditch them v-boxes and go for another type of controller such as a Research Concepts RC2000 dual axis job, available on eBay for sensible wad sometimes.

so simple when you think of it! thanks

 

[dreambox1959]

in fact my positioner counts from 0 to 4000 (2000 in the south) it manages 2 actuators + an lnb changer made with a diseqc rotor.
for a SAT DXer I make a special model with 4 actuators (2 for azimuth 1 for elevation and 1 for a special lnb changer) it can memorize 200 or 250 positions + skew for corotor. it's cheaper than an RC2000.
for an exact calculation on a polar mount I made an excel sheet for this, all you have to do is measure the length between axes

 

[dreambox1959]

for an exact calculation on a polar mount I made an excel sheet for this, all you have to do is measure the length between axes

 

[John]

I ditched my V Boxes for the RC2000..never looked back..far superior.

Agreed, they are big but rock solid in operation - mine hasn't skipped a beat in many years of operation

 

[moonbase]

I ditched my V Boxes for the RC2000..never looked back..far superior.

Agreed, they are big but rock solid in operation - mine hasn't skipped a beat in many years of operation

I have a spare second hand Research Concepts RC2000 unit for sale 'ere at huge wad.
It comes with the additional high power circuit board for control of polarity servo motors such as the Seavey etc.

Enquiries welcome from all and sundry including dreamers, two bob merchants and tyre kickers.

 

[a33]

my 24inch jack is using 19 inches of the 24 to go from 54.9e to 45w - leaving 5 inches spare, but wouldnt want to max it, so lets say 4 inches

The total actuator length difference for a 0-180 rotation (between fully re-tracted and fully extended) can also be calculated with the triangle arm lengths.

It was also in the thread Design for a Positioner with DiSEqC Decoder

The theoretical max range for the actuator length would be from (Radius - DishpivotAxis, or TA - ABB ) to (Radius + DishpivotAxis, or TA +ABB ), for my triangle T-A-BB. Though this maximum (of 0 - 180 degrees), of course, must NEVER be reached.

So the max range would be 2*TA, or 2*ABB, whichever of those is the smallest number.

(That is because in the quote above, " TA - ABB " should in fact be the absolute value of TA - ABB,
so: abs(TA - ABB ), or in mathematical symbols: |TA - ABB | .)

Greetz,
A33

Edited.

 

[John]

I have a spare second hand Research Concepts RC2000 unit for sale 'ere at huge wad.
It comes with the additional high power circuit board for control of polarity servo motors such as the Seavey etc.

Enquiries welcome from all and sundry including dreamers, two bob merchants and tyre kickers.