Page 2 of 2
Re: Spirit GTR not initializing properly
Posted: Thu 02. Nov 2023 14:36:08
by ZeXx86
You can share your settings just by attaching the file from Spirit Settings software (Backup tab) in the post here.
Re: Spirit GTR not initializing properly
Posted: Thu 02. Nov 2023 22:11:15
by ZeXx86
After viewing your second video it look like servo firmware issue. It could be resolved after updating the servo.
Do you have any other servo from other brand?
I believe it will work well with other immediately.
Re: Spirit GTR not initializing properly
Posted: Tue 07. Nov 2023 20:58:52
by curmudgeon
I am using Theta Razor DH1 low profile cyclic servos, set to 760µs center pulse. I don't remember having initialization issues when the servos were set to 1520µs center pulse. I set the Spirit GTR back to Factory Settings and I did a whole new setup, and the initialization issue persists.
Considering that the helicopter is flying really well once the Spirit unit initializes, and that I am planning to replace the GTR units with W1 units as soon as the W1 units are available, I am thinking of leaving good enough alone for now. After replacing with W1 units, I can send you this GTR unit to test and verify.
Thank you for all your help!!
***************EDIT*******************
The problem turned out to be the Theta Razor DH1 Low Profile servos. The problem is NOT isolated to Spirit. This problem happens with VBar EVO units as well. The problem manifests only when these servos are programmed to 760µs center pulse. No issues at all when these servos are programmed to 1520µs center pulse. I have not tried other Theta servos to test, but so far (as of 02 Jan 2024), this issue seems to only affect the low profile standard size Theta servos and not other Theta servos.
Re: Spirit GTR not initializing properly
Posted: Tue 07. Nov 2023 21:30:11
by ZeXx86
Does it mean it works well with 1520 settings?
Does it mean you tested the very same servos and exact same settings with other Spirit unit and it worked correctly?
Re: Spirit GTR not initializing properly
Posted: Tue 07. Nov 2023 22:01:53
by curmudgeon
I flew the helicopter with the same electronic equipment (Spirit GTR, Theta cyclic servos, YGE BEC, etc) for 75+ flights without issues as a 580 size helicopter.
When I stretched the helicopter to a light weight 700 size heli, I decided to also try the 760µs center pulse on the cyclic servos with Theta servo programming box. After a few success flights, the helicopter leaned left and forward during a spoolup, and caused some damage. I attributed this to being fairly windy for a light weight and fairly floaty helicopter, and perhaps not having the collective stick at mid-stick. After I rebuilt the heli, the helicopter again leaned left and forward during spool-up. During this 2nd rebuild, that's when I noticed the initialization issue. My best guess is that the spool-up crashes were due to spooling up without verifying proper and complete Spirit FBL initialization.
Now that I know about this finicky initialization, and I found a good way around it, and the fact that the helicopter is flying well otherwise, AND the fact that I plan to replace the GTR units with W1 units as soon as they are available (hopefully soon

), am thinking of just shelving this "temporary" issue as good enough for now, and move on to other projects in the meantime.
***************EDIT*******************
The problem turned out to be the Theta Razor DH1 Low Profile servos. The problem is NOT isolated to Spirit. This problem happens with VBar EVO units as well. The problem manifests only when these servos are programmed to 760µs center pulse. No issues at all when these servos are programmed to 1520µs center pulse. I have not tried other Theta servos to test, but so far (as of 02 Jan 2024), this issue seems to only affect the low profile standard size Theta servos and not other Theta servos. I removed the YouTube videos as I do not want folks associating this issue with Spirit units when in fact it is a Theta servo issue.
Re: Spirit GTR not initializing properly
Posted: Tue 07. Nov 2023 22:07:34
by curmudgeon
ZeXx86 wrote:Does it mean you tested the very same servos and exact same settings with other Spirit unit and it worked correctly?
No, I have
not tested the same servos with the exact same settings with other Spirit units. All my other GTR units are matched with Xpert cyclic servos set to default 1520µs center pulse, and they are working superbly well.
***************EDIT*******************
The problem turned out to be the Theta Razor DH1 Low Profile servos. The problem is NOT isolated to Spirit. This problem happens with VBar EVO units as well. The problem manifests only when these servos are programmed to 760µs center pulse. No issues at all when these servos are programmed to 1520µs center pulse. I have not tried other Theta servos to test, but so far (as of 02 Jan 2024), this issue seems to only affect the low profile standard size Theta servos and not other Theta servos. I removed the YouTube videos as I do not want folks associating this issue with Spirit units when in fact it is a Theta servo issue.
Re: Spirit GTR not initializing properly
Posted: Wed 08. Nov 2023 8:03:05
by HeliMLM
did you try to go back to "former" center pulse/frequency with the servos? just to see if it's related to it or if it's another problem?
Re: Spirit GTR not initializing properly
Posted: Wed 08. Nov 2023 8:21:14
by ZeXx86
Thank you for explanation.
From your description it look like the issue is because of the 760us settings.
I fear there is bug in the servo firmware and should be reported to Theta manufacturer.
In other words it would happen with other GTR unit as well and also with W1. So waiting for other unit or shipping to us will very likely not resolve the problem.
Is it hard to reprogram the servo back to 1520 to verify the issue is there?
Re: Spirit GTR not initializing properly
Posted: Wed 08. Nov 2023 9:06:40
by curmudgeon
ZeXx86 wrote:Is it hard to reprogram the servo back to 1520 to verify the issue is there?
The problem with setting the servo back to 1520µs is that it will affect the servo centering ever so slightly (ask me how I know), so I will have to relevel the swash the swash and such. I'll certainly try it next time I crash it, but I think I'll suck it up for now. Thanks so much.
***************EDIT*******************
The problem turned out to be the Theta Razor DH1 Low Profile servos. The problem is NOT isolated to Spirit. This problem happens with VBar EVO units as well. The problem manifests only when these servos are programmed to 760µs center pulse. No issues at all when these servos are programmed to 1520µs center pulse. I have not tried other Theta servos to test, but so far (as of 02 Jan 2024), this issue seems to only affect the low profile standard size Theta servos and not other Theta servos. I removed the YouTube videos as I do not want folks associating this issue with Spirit units when in fact it is a Theta servo issue.
Re: Spirit GTR not initializing properly
Posted: Tue 02. Jan 2024 22:21:03
by curmudgeon
ZeXx86 wrote:...From your description it look like the issue is because of the 760us settings.
I fear there is bug in the servo firmware and should be reported to Theta manufacturer...
You are 100% correct. The problem turned out to be the Theta Razor DH1 Low Profile servos. The problem is NOT isolated to Spirit. This problem happens with VBar EVO units as well. The problem manifests only when these servos are programmed to 760µs center pulse. No issues at all when these servos are programmed to 1520µs center pulse. This problem seems well known in the Mikado VBar community, but I believe I am the first person who has posted on this issue on the Spirit forum. I have not tried other Theta servos to test, but so far (as of 02 Jan 2024), this issue seems to only affect the low profile standard size Theta servos and not other Theta servos. I removed the YouTube videos as I do not want folks associating this issue with Spirit units when in fact it is a Theta servo issue. Next for me is to inform Theta of this issue.
Thank you very much for all your help and producing such fine products that bring me much enjoyment.
John