Hello, Parking under the Pole, Disconnect and Handbox Contents

[cutejac]

  Hello to all, new in this Forum.

I have some issues with the LFEP where I need some more information. I plan to use my LFEP remotely in Namibia.

The scope shall be parked on the east side of Pier, Az.180°, Elev. 0°. When I slew to this Position, the scope moves under the pole. In this moment the indicated side of the scope changes from E to W. If all safety elements are inactive, slewing to this position is not a problem. But: After Unparking the scope always tries to slew to a given position in E direction and will not cross the pole in DE first. Any ideas to avoid this?

Second issue: I would like to customize the contents of the handbox, as I do not need PEC and similar. The function "save window" does not work as expected. After every start of the ASCOM Driver I get the same contents without modifications. How to save this?

Third issue: I use Maxim to connect with Telescope and focuser. After disconnecting in Maxim the Handbox often remains connected. In these cases the handbox can be killed only by shutting down the Computer. Whats wrong?


CS

Carsten

[Armando]

Hi Carsten,

The scope shall be parked on the east side of Pier, Az.180°, Elev. 0°. When I slew to this Position, the scope moves under the pole. In this moment the indicated side of the scope changes from E to W. If all safety elements are inactive, slewing to this position is not a problem. But: After Unparking the scope always tries to slew to a given position in E direction and will not cross the pole in DE first. Any ideas to avoid this?

I'm not sure I understood your issue.
Could you report the log messages shown inside the log panel?
Anyway if you want to cross the Pole by a GoTo you should keep "Enable GoTo Flip" option checked. So, is "Enable GoTo Flip" (in Flip/Park panel) checked?

Second issue: I would like to customize the contents of the handbox, as I do not need PEC and similar. The function "save window" does not work as expected. After every start of the ASCOM Driver I get the same contents without modifications. How to save this?

Did you try to customize and save the contents of the handbox by connecting to LFEP by "LFEP Standalone mode" program?

Third issue: I use Maxim to connect with Telescope and focuser. After disconnecting in Maxim the Handbox often remains connected. In these cases the handbox can be killed only by shutting down the Computer. Whats wrong?

Maybe there is a bug or some clients keep the LFEP ASCOM connection alive. You should overcome this issue by executing "LFEP Standalone mode" program and by a click on Disconnect button for each LFEP ASCOM connection that is unexpectedly still alive.

I hope it helps.

Clear Skies!
Armando

[cutejac]

Hi Armando,

thanks for the hints. Today I tried the Standalone LFEP program to fix the customizing issue. No results. Even with this program tha handbox always shows the same boxes ticked after saving and as well after restarting the PC. No customizing seems to be possible.

The other issues I will try later.

Regards

Carsten

[Armando]

Hi Carsten,

I just fixed the bug related to GUI customization. I also re-included the old help file (even if it's only in German and not updated).

Clear Skies!
Armando

[cutejac]

Hi Armando,

thanks for the Update. Now the handbox content can be customized as intended. I decided to park above the pole to simply avoid this issue.

Regards,

Carsten

[Armando]

Hi Carsten,

in any case I would suggest to switch to a different controller to achieve good tracking.
Except for mounts with high overall reduction ratio on RA, you'll find tracking not as good as expected.
This is obviously a severe LFEP firmware bug.

CS
Armando Beneduce

[cutejac]

Hi Armando,

thanks for the Information. Do you have a bit more details on this Problem?

Regards

Carsten

[Armando]

Hi Carsten,

I'm telling you my experience with LFEP:

I had an old EQ6 with EQ6 MCU update by Rajiva, old motors with Conrad 100:1 reduction ratio.
The only annoyance was the low GoTo speed (40X), because of the stock motors...

So I bought a LFEP; everything apparently fine except for GoTo speed, still low because of the motors.
So I bought SkyScan motors and found nice Goto but bad tracking:
http://forum.lfep.de/index.php?topic=36.0

By assuming the issue related to SkyScan gears I reverted back to old motors&Conrad 100:1 reduction.

But 40x GoTo speed was really annoying; so I tried to figure out what was wrong...
I started to think about LFEP issues...
http://forum.lfep.de/index.php?topic=297.0

Then I bought a Bellincioni mount powered by FS2:
300 teeth on RA worm wheel (in place of 180 on the EQ6);
4:1 reduction ratio by belt/pulleys (so no gears related issues);
Sanyo Denki 103 H548  04500 (nice stepper motor with 1.8° step angle, max bipolar current of 0.9A/phase).
A nice setup.

Nothing wrong expected by controlling it by LFEP in place of FS2.
So I removed the FS2 and tested the mount by LFEP. Tracking was not good. I had to revert back to FS2.

As I spent a lot of time to fix the ASCOM driver, to implement some nice features, and to overcome some known LFEP bugs by ASCOM itself, I still meant to make use of LFEP in place of FS2.
So a few days ago I made another test on LFEP to figure out definitely what is wrong.

I connected a Sanyo Denki 103 H548 04500 (I own a couple of spare motors bought for EQ6 that I never used) with no load to LFEP.
I observed accurately the pinion rotation.
Someone can argue stepper rotation is not good with no load (the detent torque is expected to affect microstep usefulness). But what I found is not related to speed variability on each full step: I found increasing/decreasing speed (exactly on each full pinion rotation, 50 intervals at lower speed alternating with 50 ones at higher speed). Step angle is 1.8° (i.e. 200 steps).
So no drift, no GoTo issue, good pointing, ... But bad tracking.

Increasing tracking current (e.g. setting as tracking current the current you would use only for GoTo) seems to reduce the issue.
And this made me thinking about the dead zone issue that affects stepper motors at low currents.
But... I think (I may be wrong) dead zone issue should manifest on each step. And I think (I may be wrong) the same would occur with resistance mismatch on the couple of sense resistors used for each motor.

So the issue I'm referring to seems related to LFEP firmware.

Using an higher overall reduction ratio will reduce the issue but won't solve it.
The amplitude of the error on the pinion side will be the same; the frequency will be greater on the "camera" side; the amplitude of the error in arcsec will be lower; GoTo speed will be affected (you'll be obliged to make motor rotating at higher rpm at sidereal speed - i.e. you'll find motor stall at higher GoTo speeds).

I reverted back to FS2.

Clear Skies!
Armando Beneduce