EGIS motor

[dreambox1959]

Some news of my software developments for the EGIS engine:
- by optimizing the routines of the programs I managed the EGIS with an 89s52 (old), but I will continue to provide the AT89LP51 (recent and 12 times faster).
-I discovered a hazard that caused a few pulses to be lost and which had no effect with a classic jack: the classic jack has a pulse every 15 to 25ms, the EGIS every 800nS.
- with a 5° deceleration before the destination, the motor stops at +-1 pulses from the arrival! (there are 100 pulses per degree or 1 hundredths of a degree of error!!).
- I would like to thank again FEMI who had an EGIS engine in his garage and who gave it to me.

 

[dreambox1959]

I traded in my very noisy azimuth motor for one offered by FEMI. There are no more major noises.
The speed is different, the new engine runs a little slower! When I reduce the speed when approaching the destination it turns really very slowly and I stop at just the right value!! This is a good thing, but will this be the case with other EPR103 owners?
I decided to count only the high state of the motor pulses (as on EPS103) and we obtain 100 pulses per degree.
The value displayed corresponds to the angle multiplied by 100 from the EAST origin:
- due south 9000 = 90.00°
- due west 18000 = 180.00°
-full east = 0
The passage from east to west is done in less than a minute. When detecting the limits, I go at full speed until I detect the contact of the switch then I go back in reverse at very low speed to detect the release of the same switch.
This procedure is very reliable because after many attempts a value is obtained which only varies by 2 pulses.
The seed value can be set manually to best match its location.
The correspondence between the displayed index and the targeted position depends on its longitude and latitude, but this value is obtained on WEB sites.

 

[Hugocz]

May I ask how you connected the cables from the EPR203 motors in your construction? Are they screw terminals or a plug-in connector?
I would like to use a connector so that the unit can be easily disconnected and used for experiments. But I don't want to look for a connector for the appropriate current load if you already have that figured out.
You can't see your construction from the back anywhere.

 

[dreambox1959]

connectors like these

or these

my positionner

 

[Hugocz]

Splendor. I have never seen such a connector. But it's exactly what I was looking for. Thank you.

 

[dreambox1959]

a little video where i show how to set the egis motor for the first run with my positionner !

 

[dreambox1959]

I have built about fifteen positioners for polar mounts with double cylinders, all the users are very satisfied, and those who had a problem we were able to solve it.
On request of FEMI I made a special EGIS version: the interface for the motor pulses is more complex and the power supply is 24V and also I use a more powerful microprocessor (12 times more).
I even bought an EGIS engine from TRUST to develop this variant.
Currently the motor without parabola works perfectly (it was not very different from the model for actuators).
I only provided two copies of the EGIS version, one to FEMI the other to Aal41.
Unfortunately FEMI made a bad handling and had to burn out some components and he is not very comfortable with electronic troubleshooting. As for Aal41, thanks to the dedicated help of Frank (suedschwede66) we have made some progress but he is encountering problems that are difficult to determine from a distance.
I'm sorry that these two amateurs can't enjoy my device.

 

[dreambox1959]

The problem of UDO (Aal41) is solved thanks to the help of Frank (suedschwede66).
there was a bad wiring: the EGIS engine has several electric ground which must be connected at the engine level.
When at FEMI the electronic cards are at Frank for troubleshooting and verification.

 

[dreambox1959]

I reworked the handling of the positioner program for EGIS EPR103/203.
I had taken as a base 100 pulses/degree in AZ and 200 pulses per degree in EL, but it is 400 pulses per degree in EL.
On my model (improved by TRUST) when I look for the EST origin limit I go beyond 90° EST on the mount and coming back west until the release of the ORI-AZ switch I am almost perfectly at 90° EST.
so the azimuth index counter must be at 0 at this time, as the value must not be less than 0 (65536), so the minimum limit must be set at 200, the maximum limit can approach the value 18000 but 17000 would be better.
For the elevation, on my model when the ORI-EL switch is reached the front face of the aluminum bell is vertical (0°), by multiplying the angle of declination by 400 we obtain the value of the elevation index ( there is a non-linearity which means that the theoretical values will have to be adjusted).
So I slightly changed the procedure for finding the origin points:
-for the azimuth I go to the left (EST) until I meet the switch which is triggered, I stop the motor and go back at slow speed until I release the switch, at this moment I fix it 'index counter at 0000 then I ask for a move to the right of the value chosen in dial8b3 (200 recommended by me) to move away from this zone.
-for the elevation the procedure is quite similar, I straighten the upper plate of the motor until I meet the switch which is triggered, I stop the motor and go back at slow speed until I have the release of the switch, at this moment I set the counter index to 0000 then I ask for an upward movement of the value chosen in dial8b3 (200 recommended by me) to move away from this zone.

 

[dreambox1959]

I worked on polarotor management in the case of an AZ/EL mount like the EGIS engine.
Based on a chaparral corotor and with the basis that we use a dielectric for the circular C band.
The maximum polarization setting is about 55° east and west (but reversing the H and V setting through due south).
Moreover in the case of a circular polarization with a dielectric the values L and R remain almost identical (45° compared to the surface of the dielectric) I added a function on the TV/RADIO button which allows you to force the opposite polar to facilitate the setting of the opposite polar. With my corotor chaparral I get a stroke of +90° up to -90°

 

[Hugocz]

It is wise to separate the Polarization setting from the Skew setting.
Setting the polarization with one click is very convenient.
I set the skew in steps of 5° with one click. That's ±9 clicks at a maximum Skew range of ±45°.
It's a compromise for first attempts. A finer step increases the time needed to set up.
Also do you have a Skew setting in steps? How exactly?

 

[Hugocz]

I will also point out one feature of servomotors.
With modern servomotors, it is sufficient to send control pulses only for a short time. Even after switching off the pulses, the servomotor itself continues to rotate until it reaches the correct position.
But the Chaparral servo motor behaves differently. It rotates only as long as there is a signal on the data wire. If the signal is turned off before reaching the target position, the servo motor will stop in the middle of the travel.

 

[dreambox1959]

hugocz i don't know if chaparral will stop (because i had changed engine) but i send pulses only for the lnb that needs it and not for the universal lnb, it's a feature of my firmware.
I have 180 steps for skew (-90 to +90) in my system, I multiply the skew value by ten and add an offset, the pulse starts at 700µs and goes to 2.4mS.

 

[Hugocz]

hugocz i don't know if chaparral will stop (because i had changed engine) ...

Yes, I noticed you have a different servo in the photos than the Chaparral uses. Hence my warning. I think you have to respect the behavior of the original Chaparral servo.
It's a complication, of course. It is not possible to detect if the servo is already in the target position. Some reliable time constant must be established to turn off the signal for the servo.
At the same time, the control signal for the servo cannot be left on permanently. In this case, the servo makes unpleasant noises after reaching the target position.

 

[dreambox1959]

At the same time, the control signal for the servo cannot be left on permanently. In this case, the servo makes unpleasant noises after reaching the target position.

i had this case before but it came because pulse is not regular , but now it s OK and the servo is outside 30meters from my ears !!!!

 

[Hugocz]

If it does not affect the life of the servo. Unfortunately, I don't know that.

 

[dreambox1959]

I am finalizing an Excel spreadsheet to find all satellite positions from the SATXML list.

I had already done that for the polar mounts but for the EGIS engine or the AZ/EL mounts the calculations are different.

I used the formulas from the SATLEX.BE site which I integrated into an Excel spreadsheet.

If, like UDO or me, we want to have the index 9000 due south (90.00°) we must add a value that I call offset, it is this value that the motor must validate when it detects the AZ origin.

Same thing for the elevation when it detects the EL origin, this value will be determined by on-site testing (depending on the offset antenna or prime focus of its fixation etc.).

 

[dreambox1959]

The EGIS motor has a contact which detects the “0” or origin position on the AZ motor and on the EL motor.
My program uses these positions to initialize the AZ and EL counters.
If we wish to have 9000 due south and 14000 at maximum elevation due south, a value must be added to the AZ and EL counters to correspond to this goal.
In the example below (my personal installation) these values are 578 for AZ and 6131 for EL, the two counters take these values when we execute the origin search procedure.
These values are to be determined by local testing but will no longer change for a specific site.
When these values (1 and 2) are defined, they will allow all positions to be resynchronized in the event of a breakdown or mechanical intervention.
The true minimum limits must be greater than these numbers (3 and 4).

 

[dreambox1959]

Does anyone have an old LNB: dual band (9.75/10.6 or 9.75/10.75) single polarization, to associate with a mechanical polarotor?
I need it to carry out tests on an EGIS mount.
no need for a high-performance model (norsat) but rather an antique from the 2000s.

 

[Channel Hopper]

Yes, a number of them here, some NOS.