NEED HELP WITH TWIN HOOK UP
04-11-2011 | 06:31 PM
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From: edgemont,
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NEED HELP WITH TWIN HOOK UP
I am trying to put twin motors in a p-38 using turnigy 42/40 with hobbyking esc,s 50 amp 2- 2200 40-C turnigy lipo,s hooked esc,s to reciever #3 with y harness. tested both motors individually they worked fine. plugged in left motor to left battery. plugged right motor into right battery powered up motors and fried right esc. What did I do wrong.
04-12-2011 | 11:08 AM
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From: edgemont,
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RE: NEED HELP WITH TWIN HOOK UP
Walt thank you for the reply and in fo I am starting to understsnd the system better. Have been reading other threads and they talk about hooking the batteries pararell does that mean each battery to each motor or wire the batteries together than hook them to the motors. thanks again. DEM
04-14-2011 | 08:18 AM
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RE: NEED HELP WITH TWIN HOOK UP
ORIGINAL: oldflyrw11
Walt thank you for the reply and in fo I am starting to understsnd the system better. Have been reading other threads and they talk about hooking the batteries pararell does that mean each battery to each motor or wire the batteries together than hook them to the motors. thanks again. DEM
Walt thank you for the reply and in fo I am starting to understsnd the system better. Have been reading other threads and they talk about hooking the batteries pararell does that mean each battery to each motor or wire the batteries together than hook them to the motors. thanks again. DEM
You can wire motors and batteries in parallel forming one pool.
Benefit is both motors get exactly the same voltage so it is easier to keep them in synch.
Bad part is if that battery system fails you lose everything. But this doesn't happen often. I would lean toward parallel packs to feed both motors so voltage is uniform.
05-16-2011 | 04:51 PM
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RE: NEED HELP WITH TWIN HOOK UP
aeajr:
While we're on the subject of twins, I wanted to get your thoughts on what I've gleaned from various posts. Here 'tis:
1. I've been told a shottky diode in the red wire of each ESC throttle channel connection prevents them from "talking" to each other and the problems associated with that. Allows the ESCs to both supply power for the radio. I flew a P-38 with a pair of Astro 020s and ESCs just simply y'd together at the Rx and never had a problem. I'm still wondering about that.
2. Many twins require the batteries to be a great distance from the motors in order to get the CG. This requires lengthening some wires. The consensus seems to be that one should keep the battery to ESC wires as short as possible, and use long leads out to the motors. I'm told that voltage spikes happen if you do it differently and that the big caps in the ESC overheat and die. I asked my primary ESC supplier (Flightpower) about this, and they more or less don't really care, but yeah, long wires between ESC and motor is OK.
Thanks in advance for your thoughts on this.
I've got three E power conversions I've done recently. PM me if you'd like the details and the results.
Cheers
While we're on the subject of twins, I wanted to get your thoughts on what I've gleaned from various posts. Here 'tis:
1. I've been told a shottky diode in the red wire of each ESC throttle channel connection prevents them from "talking" to each other and the problems associated with that. Allows the ESCs to both supply power for the radio. I flew a P-38 with a pair of Astro 020s and ESCs just simply y'd together at the Rx and never had a problem. I'm still wondering about that.
2. Many twins require the batteries to be a great distance from the motors in order to get the CG. This requires lengthening some wires. The consensus seems to be that one should keep the battery to ESC wires as short as possible, and use long leads out to the motors. I'm told that voltage spikes happen if you do it differently and that the big caps in the ESC overheat and die. I asked my primary ESC supplier (Flightpower) about this, and they more or less don't really care, but yeah, long wires between ESC and motor is OK.
Thanks in advance for your thoughts on this.
I've got three E power conversions I've done recently. PM me if you'd like the details and the results.
Cheers
05-16-2011 | 07:33 PM
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RE: NEED HELP WITH TWIN HOOK UP
see my comments below in <span style="color: #ff0000">red</span>
ORIGINAL: Mustang Fever
aeajr:
While we're on the subject of twins, I wanted to get your thoughts on what I've gleaned from various posts. Here 'tis:
1. I've been told a shottky diode in the red wire of each ESC throttle channel connection prevents them from "talking" to each other and the problems associated with that.<span style="color: #ff0000">No idea. </span>Allows the ESCs to both supply power for the radio. I flew a P-38 with a pair of Astro 020s and ESCs just simply y'd together at the Rx and never had a problem. I'm still wondering about that. <span style="color: #ff0000">If an astro 20 is a brushed motor, you can run two of them on one ESC. Brushless motors don't generally work well sharing an ESC.</span>
2. Many twins require the batteries to be a great distance from the motors in order to get the CG. This requires lengthening some wires. The consensus seems to be that one should keep the battery to ESC wires as short as possible, and use long leads out to the motors. I'm told that voltage spikes happen if you do it differently and that the big caps in the ESC overheat and die. I asked my primary ESC supplier (Flightpower) about this, and they more or less don't really care, but yeah, long wires between ESC and motor is OK. <span style="color: #ff0000">I have no experience around this that I can share.</span>
Thanks in advance for your thoughts on this.
I've got three E power conversions I've done recently. PM me if you'd like the details and the results.
Cheers
aeajr:
While we're on the subject of twins, I wanted to get your thoughts on what I've gleaned from various posts. Here 'tis:
1. I've been told a shottky diode in the red wire of each ESC throttle channel connection prevents them from "talking" to each other and the problems associated with that.<span style="color: #ff0000">No idea. </span>Allows the ESCs to both supply power for the radio. I flew a P-38 with a pair of Astro 020s and ESCs just simply y'd together at the Rx and never had a problem. I'm still wondering about that. <span style="color: #ff0000">If an astro 20 is a brushed motor, you can run two of them on one ESC. Brushless motors don't generally work well sharing an ESC.</span>
2. Many twins require the batteries to be a great distance from the motors in order to get the CG. This requires lengthening some wires. The consensus seems to be that one should keep the battery to ESC wires as short as possible, and use long leads out to the motors. I'm told that voltage spikes happen if you do it differently and that the big caps in the ESC overheat and die. I asked my primary ESC supplier (Flightpower) about this, and they more or less don't really care, but yeah, long wires between ESC and motor is OK. <span style="color: #ff0000">I have no experience around this that I can share.</span>
Thanks in advance for your thoughts on this.
I've got three E power conversions I've done recently. PM me if you'd like the details and the results.
Cheers
05-17-2011 | 05:45 AM
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From: edgemont,
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RE: NEED HELP WITH TWIN HOOK UP
Sorry fellows. I haven't replied before this. just an update on my twin project. what I ended up doing was. hooked motors up to two esc's removed red wire on both and tied into # 3 channel with a y harness. used two 2200 three cellpacks tied into each esc and tied in a 2500 nickle metal battery into channel #1 I have checked and every thing seems be working. Haven't had a chance to fly it yet though because of weather non practice and sugeries. Will try to keep you all posted thank you DALE
05-19-2011 | 11:11 PM
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From: WareHertfordshire, UNITED KINGDOM
RE: NEED HELP WITH TWIN HOOK UP
Just to add my bit to the discussion on Shottky diodes, I have made up a test installation but not flown it. This is because the diode (handily produced in a two-in-one case) drops around half a volt. Hence an ESC supplied standard at 5V output gives only 4.5V at the receiver. I reckon a 6V supply would be needed for safety, supplying 5.5V through the diode... and I don't have ESCs that have switchable output.
I have always used two ESC BECs twinned in Y-lead without problems... hence I don't understand what the OP did wrong at the start of the thread! (From what info was given)
It is always wise however to ensure that each BEC is capable of supplying sufficient current for the onboard equipment on it's own since component tollerances may mean that one will turn out to be supplying most of the current anyway. Bear in mind too that running the onboard radio on a higher voltage will cause it to draw commensurately higher current - and plan for it.
I have always used two ESC BECs twinned in Y-lead without problems... hence I don't understand what the OP did wrong at the start of the thread! (From what info was given)
It is always wise however to ensure that each BEC is capable of supplying sufficient current for the onboard equipment on it's own since component tollerances may mean that one will turn out to be supplying most of the current anyway. Bear in mind too that running the onboard radio on a higher voltage will cause it to draw commensurately higher current - and plan for it.
