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the out runner motor blues
How would one go about controlling a 3 phase DC out runner motor without going thru the throttle channel or some other channel?
I have been experimenting with developing a working hydraulic system for my model airplanes. the systems so far have used a turbine model fuel pump. these pumps are very expensive, around 400. dollars. I have found a pump made in China that is intended for construction equipment modelers for around $125 but the speed control provided with the motor requires the use of one r/c radio channel. This is not necessary on my system as the pump is simply "on'' or "off" and this function is controlled automatically by a pressure switch. Call for the gear "up" and the pump comes on and runs until the gear cycle is finished then shuts off when the pressure reaches 100 psi. How can I do the same thing using an outrunner motor? |
Why not use a simple brushed motor?
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I'm trying to get away from brushed motors, that's the whole point, the brushes don't last long at the 15 amp load it takes to generate 100psi pressure.
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Originally Posted by Captainbob
(Post 12514740)
How would one go about controlling a 3 phase DC out runner motor without going thru the throttle channel or some other channel?
I have been experimenting with developing a working hydraulic system for my model airplanes. the systems so far have used a turbine model fuel pump. these pumps are very expensive, around 400. dollars. I have found a pump made in China that is intended for construction equipment modelers for around $125 but the speed control provided with the motor requires the use of one r/c radio channel. This is not necessary on my system as the pump is simply "on'' or "off" and this function is controlled automatically by a pressure switch. Call for the gear "up" and the pump comes on and runs until the gear cycle is finished then shuts off when the pressure reaches 100 psi. How can I do the same thing using an outrunner motor? This is easy to do and much cheaper than you have been doing it. Go to www.magomrc.com. They do both brushed and brushless pumps with integrated tanks for 98 euro if brushless or 91.99 euro for brushless. You need to look up the recent post on hydraulic systems for retracts where I showed the brushless system working using a pressure switch. http://www.rcuniverse.com/forum/rc-j...-retracts.html We all have plenty of channels these days so using one channel to arm a brushless system is not really an issue. John |
Originally Posted by Captainbob
(Post 12514740)
How would one go about controlling a 3 phase DC out runner motor without going thru the throttle channel or some other channel?
I have been experimenting with developing a working hydraulic system for my model airplanes. the systems so far have used a turbine model fuel pump. these pumps are very expensive, around 400. dollars. I have found a pump made in China that is intended for construction equipment modelers for around $125 but the speed control provided with the motor requires the use of one r/c radio channel. This is not necessary on my system as the pump is simply "on'' or "off" and this function is controlled automatically by a pressure switch. Call for the gear "up" and the pump comes on and runs until the gear cycle is finished then shuts off when the pressure reaches 100 psi. How can I do the same thing using an outrunner motor? Something like the adafruit trinket would be perfect. |
You can use a 555 timer to generate a pulse train to the motor controller that turns it on at a fixed speed determined by the characteristics of the pulse train. About half way down in this page https://www.jameco.com/jameco/worksh...-tutorial.html you will see a setup for an "Astable circuit" using a 555 that is controlled, on and off, by a single input. That should do what you need. Bob ps. RC pulses are 1.0 to 2.0 ms long and have a period of 20ms, so to run the pump at 1/2 speed, you'd need Th to be 1.5ms and Tl to be 18.5ms... |
https://www.droking.com/motor-controller/15w-brushless-motor-driver-dc-5-12v-1.5a-three-phase-brushless-sensored-controller-bldc-speed-control-switch-for-motor-hard-etc
You might have to remove the potentiometer and rig up an equivalent circuit through the pressure switch, don't know EDIT : sorry I did not see the 15 amp load of the OP, not sure what voltage. Anyway I dont think this will work but it gives you what to search for. |
If you really want to run without using a separate channel, you could operate the ESC using a manual servo controller. This could be left in the max running position with the pressure switched on and off via the pressure switch. This would leave you unable to switch off the ESC from the transmitter if anything went wrong, but would work. You would have to start and stop the servo controller at the beginning and end of each flight. The servo controllers are very cheap and only cost a few dollars and you need no other parts. I used them in testing on the bench with my system.
John |
Fellas,
thanks for all the helpful replys. I just got back from Toledo and will be trying some of these ideas. thanks for the help. f |
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