Himax, Jeti Spin 99, Motor Timing
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Himax, Jeti Spin 99, Motor Timing
Just wanted to post this for anyone who has been looking for information on settings with regard to motor timing on the Himax F3A motor. I recently ruined some battery packs as a result of poor motor timing selection and hope this prevents someone else from doing the same.
Specs: Jeti Spin 99, no brake, Himax F3A (older edition with fewer poles that the current one), 2 blade and 3 blade props
I have flown my 2m pattern plane for hundreds of flights with a 2 blade prop and a 28 deg timing setting. I know, very high, but the decision was based on the number of poles and comparison to other motors. And it worked well for a number of years. However, I now realize that it was very inefficient and I was pulling much higher amperage than necessary.
I switched to a 3 blade prop and dropped the motor curve to get similar thrust just by observing flights. This worked for a while, but I started to experience some hard battery cutoff sooner than expected. I checked the amperage at full throttle on the ground and it was almost 90A static. So I dropped down the motor curve to achieve 78A, static. By then the damage may have been done, but I was still experiencing hard cut offs.
A pattern expert suggested I look at timing and other settings. Turns out that was the ticket. I did an experiment on 18, 23, and 28 deg timing settings and found the 23 to be right. It dropped the amperage down to 63A static, plenty of thrust. After some 3 packs through similar conditions, I noticed that the mAh draw to be down over 25% from previous flight experience.
I'm pretty confident this fixed the problem and will help with less mAh used for the duration of the flight as well as lower max amperage.
My take away was that motor timing was causing the issue. The 2 blade prop was not as sensitive to the poor motor timing setting I had been using. The 3 blade was. I would have had better battery service with the proper timing setting on 2 blades as well, and probably more flight time.
Specs: Jeti Spin 99, no brake, Himax F3A (older edition with fewer poles that the current one), 2 blade and 3 blade props
I have flown my 2m pattern plane for hundreds of flights with a 2 blade prop and a 28 deg timing setting. I know, very high, but the decision was based on the number of poles and comparison to other motors. And it worked well for a number of years. However, I now realize that it was very inefficient and I was pulling much higher amperage than necessary.
I switched to a 3 blade prop and dropped the motor curve to get similar thrust just by observing flights. This worked for a while, but I started to experience some hard battery cutoff sooner than expected. I checked the amperage at full throttle on the ground and it was almost 90A static. So I dropped down the motor curve to achieve 78A, static. By then the damage may have been done, but I was still experiencing hard cut offs.
A pattern expert suggested I look at timing and other settings. Turns out that was the ticket. I did an experiment on 18, 23, and 28 deg timing settings and found the 23 to be right. It dropped the amperage down to 63A static, plenty of thrust. After some 3 packs through similar conditions, I noticed that the mAh draw to be down over 25% from previous flight experience.
I'm pretty confident this fixed the problem and will help with less mAh used for the duration of the flight as well as lower max amperage.
My take away was that motor timing was causing the issue. The 2 blade prop was not as sensitive to the poor motor timing setting I had been using. The 3 blade was. I would have had better battery service with the proper timing setting on 2 blades as well, and probably more flight time.
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I have run that combo for years 18 degree timing and frequency 8 kHz flawless never a problem static about 70 amps motor never more than warm after flight have some packs well over 100 flights on them no other issues Spin 99 is great ESC