Fixing SLS Bugs

[PC1515]

Hi Everyone,
I hope to tap into the collective experience that you all bring to this great site. I am trying to get a Let SLS 18 to work reliably in DG1000. So far I have adjusted the stopper to be very close to the prop tip under power. The prop hits the stopper moving the pylon back by hand very early in the retraction, even so, the prop still misses in the air. I note that the prop windmills quite slowly at gliding speeds and wonder if this is the source of the miss. I am thinking of slowing the pylon retraction or as an alternative selecting retract with the motor still running at low power. The micro that cuts power to the motor activates just as the prop touches the stopper on the ground. Is there something I am missing in the setup or is there a trick to get more reliable function?
Thanks for looking
Peter

[lenb]

Hi Peter,
While I'm not up to speed on the design of the LET SLS, but would setting the brake on the ESC a bit more "hard" lend any help to getting the prop to stop for sequencing?
If I remember there is a rubber piece that lifts up and the tip of the prop bumps up against it for alignment for retraction?

Len

[PC1515]

Hi Len,
Thanks for your reply. You are correct. The stopper lifts to catch the prop as the pylon moves aft. I am not sure that brake would help as the prop has to strike the stopper - I feel it would be less likely to hit the stopper the slower it turns.
Thanks again.
Peter

[PC1515]

Hi Everyone,
Well I have been thinking hard on a solution and although not tested yet, a change in approach has produced a possible solution. Up to now, I have been retracting the pylon with the prop windmilling expecting it to stop as it retracts - not pretty. What I perhaps should've been doing was seeking to stop the prop from windmilling in the vertical position before selecting retract. This might work (probably as it was designed to work) because with the pylon selected up, the servo does not drive the pylon all the way forward. When the power comes on it pulls in the last little bit of pylon forward movement. What I have done is adjust the stopper to contact the prop in the extended power off position (was setting it to just clear previously) and clear the prop with the motor running and pulling the pylon full forward (the stopper drops a little lower as the pylon moves forward. Hopefully the pylon will drop slightly backwards in the air with no power on and the prop will stop vertical against the stopper. Retracting should then be a doddle. Will test it out and let you know how it goes!
Cheers
Peter

[PC1515]

Hi Everyone,
Put in three flights and the SLS worked just fine with the adjusted setup as described above. The prop stops windmilling with power off and the subsequent retraction was straightforward. Start up was no problem with the prop pulling the pylon fwd instantly. To make this work I had to increase the diameter of the stopper with silicon tape.
Cheers
Peter

[Steve P]

Glad you found a solution!

[lenb]

Excellent Peter,
Thank you posted the problem and solution for others to use as a resource should someone have the same issue.