Can anyone help me with this issue please.
Cabin cruiser 1m long; 4240 x 740 brushless motor; 5S lipo; 55mm prop.
Cruised happily for 15 mins, then made noise (not dissimilar to slipping coupling) and powered down to a stop. Would then only creep along. On inspection found all three fuse holders and 25A fuses had melted, but fuses not blown. The motor was not hot, nor was the ESC. Out of water seemed to operate OK. It was suggested that the prop might be too large, and caused the motor to go out of sync after a while.
So, what do you think might be happening ?
😉
Can anyone help me with this issue please.
Cabin cruiser 1m long; 4240 x 740 brushless motor; 5S lipo; 55mm prop.
Cruised happily for 15 mins, then made noise (not dissimilar to slipping coupling) and powered down to a stop. Would then only creep along. On inspection found all three fuse holders and 25A fuses had melted, but fuses not blown. The motor was not hot, nor was the ESC. Out of water seemed to operate OK. It was suggested that the prop might be too large, and caused the motor to go out of sync after a while.
So, what do you think might be happening ?
😉
Heartily agree Isaac👍
I'm also deeply disappointed that, despite all the informed and qualified advice that he received in this thread, he still insists on using the 3 fuses in the motor leads☹️
What possible "scientific" advice he could have been given to justify that is beyond me (an electrical/electronic engineer with over 40 years experience).
Cheers, Doug😎
Thanks DG.
To answer Doug and Isaac's points.
One factor that I had omitted to include is the displacement which is 8.5Kg. ie it is a heavy boat. My wish was to make this boat seriously fast, but not like one of the super-fast electrics.
Lastly, I am trying to take things one step at a time. In my last note you will have seen that I have prepared 'links' to use in place of the three motor fuses. I acknowledge there is good reason to remove these fuses, and this could be my next step. By changing just one item at a time I would expect to determine whether this item helps or not.
Whilst you had provided information on this issue Doug, much of it was way over my head. And, I had no prior knowledge of your expertise. My approach to problem solving is to ask 'why ?' five times. Old fashioned maybe, but it still relevant.
The questions raised by this blog demonstrate the difficulties in selecting appropriate equipment in the power chain. With the lack of clear or simple advice on this topic I used this forum to gather information, but have to allow that there are always differences of opinion.
Thank you all for your interest and input. 😉
Some weeks have passed and I have had one or two opportunities to further test and experiment with the power train set-up.
With the three fuses between motor and ESC removed I carried out trials using a watt meter, and different size props. The motor is rated at 50 amps max. and 870 watts max.power. The ESC is rated at 90 amps.
X40 prop pulled 25amps and 492 watts.
S45 prop pulled 21 amps and 419 watts.
X45 prop pulled 31 amps and 594 watts.
S50 prop pulled 27 amps and 505 watts.
All these values are safely within the parameters of the motor and ESC. I did not have the X50 or 55 sizes with me, but they should be next to test. In the original set up I was using an X55, and fuses between motor and ESC when they melted and the motor went out of sync.
In all the above cases I checked every component after fast running to see how cool or hot they had become, and the only heat detected was very slight warmth in the cables between motor and ESC, and a hint of warmth in the ESC. No problems arose.
I am pleased that the early issues have been resolved, and thank you one and all for your input without which I would have been floundering !
I can now look forward to years of enjoyment on the water. 😉
Some weeks have passed and I have had one or two opportunities to further test and experiment with the power train set-up.
With the three fuses between motor and ESC removed I carried out trials using a watt meter, and different size props. The motor is rated at 50 amps max. and 870 watts max.power. The ESC is rated at 90 amps.
X40 prop pulled 25amps and 492 watts.
S45 prop pulled 21 amps and 419 watts.
X45 prop pulled 31 amps and 594 watts.
S50 prop pulled 27 amps and 505 watts.
All these values are safely within the parameters of the motor and ESC. I did not have the X50 or 55 sizes with me, but they should be next to test. In the original set up I was using an X55, and fuses between motor and ESC when they melted and the motor went out of sync.
In all the above cases I checked every component after fast running to see how cool or hot they had become, and the only heat detected was very slight warmth in the cables between motor and ESC, and a hint of warmth in the ESC. No problems arose.
I am pleased that the early issues have been resolved, and thank you one and all for your input without which I would have been floundering !
I can now look forward to years of enjoyment on the water. 😉
I'm also deeply disappointed that, despite all the informed and qualified advice that he received in this thread, he still insists on using the 3 fuses in the motor leads☹️
What possible "scientific" advice he could have been given to justify that is beyond me (an electrical/electronic engineer with over 40 years experience).
Cheers, Doug😎
To answer Doug and Isaac's points.
One factor that I had omitted to include is the displacement which is 8.5Kg. ie it is a heavy boat. My wish was to make this boat seriously fast, but not like one of the super-fast electrics.
Lastly, I am trying to take things one step at a time. In my last note you will have seen that I have prepared 'links' to use in place of the three motor fuses. I acknowledge there is good reason to remove these fuses, and this could be my next step. By changing just one item at a time I would expect to determine whether this item helps or not.
Whilst you had provided information on this issue Doug, much of it was way over my head. And, I had no prior knowledge of your expertise. My approach to problem solving is to ask 'why ?' five times. Old fashioned maybe, but it still relevant.
The questions raised by this blog demonstrate the difficulties in selecting appropriate equipment in the power chain. With the lack of clear or simple advice on this topic I used this forum to gather information, but have to allow that there are always differences of opinion.
Thank you all for your interest and input. 😉