Two Brushless motors on One ESC….YES!

[questtek]

Joe, I have a wrench to throw on your gears... how does the timing on the ESC act on the motors? Will it help with the sync?
And, how about the SENSORED ESCs/MOTORS, have you done any testing with those?
How are you?

Thanks

Missing your company on our lake runs........ Looks Like Mark and Tony will be down tomorrow and you ar always welcome (provided no rain!)

I have a programing card for the Seakings so we can test it out but so far I have just used the default timing mode. Also, no sensored motors..I do not have any to test. I want to get some good numbers based on all the suggestions given in the forum on 2 motor 2 esc and 2 motor 1 esc DIRECT comparisions. I think that will tell a lot, especially if additional testing with timing changs, sensored motors, etc can be justified.

[questtek]

Yes, having excellent results using mid-large helicopter ourtunners spinning boat props. High Torque and High RPM w/high efficiency.

I have yet to try two motors from one ESC, but if I did, I would try the Suppo 200 and two 3126 outrunners. I would ask the MFR, but I don't want to confuse him any more. He's having enough trouble filling orders accurately.

I have a HiModel (Suppo 200) ESC and two of those outrunners at 1600KV I will test after I get some apples-to-apples test data with my current outrunners and the SeaKing ESC. I was thinking of your application all along. (PS, the cost of copper plate and brass plate is the same at Industrial Metals in Ca for your cooling additions to the ESC's)

[questtek]

Here is a video of the direct performance comparisons via loaded bench testing of two motors with two ESC's and two motors with one ESC:

http://www.youtube.com/watch?v=9pP_VssT3lw&feature=youtube_gdata

The data summary is as follows: (you can verify it by the video of the testing):

Test #1 Data: 2 Motors 2 ESC’s
RPM Watts Force (grams)
8,025 60 217
9,500 97 330
11,500 154 490
12,700 208 619
13,600 255 720


Test #2 Data: 2 Motors 1 ESC’s
RPM Watts Force (grams)
8450 69 229
10000 105 320
11500 157 457
13350 225 619
14600 301 739



The plots are very close as you can imagine from the above data. These tests have told me what I needed to know to proceed on a couple of special projects. ESC timing changes affect both motors the same. Two motors can run on a single ESC even under modest mismatch of load conitions. Hope some of you will find these results useful for future creative or experimental projects.

[Make-a-Wake]

Very good read and quite interesting......................thanks for all your hard work!!

[questtek]

Attahed is a plot of the data for easy visual comparison....

[Make-a-Wake]

OK...........went over the thread again, cant find my answer:

Can one ESC power two motors with one reversed for a twin setup??????? Thanks

[graill]

OK...........went over the thread again, cant find my answer:

Can one ESC power two motors with one reversed for a twin setup??????? Thanks

No.

[FighterCat57]

OK...........went over the thread again, cant find my answer:

Can one ESC power two motors with one reversed for a twin setup??????? Thanks

Long Answer;
It can be done, but only with a dual driver dual fet board ESC. Basically two ESC's that run off of the same PWM signal and power leads. Each motor requires its own driver / fet setup and needs to operate independently. Especially if RPM is not exactly synchronized. IF the shaft is shared between two motors, in theory you can, but in reality one will pull more than the other and they will sorta fight each other since the kv between them is rarely exactly the same. Some have gotten away with using two motors off of a single ESC in light use applications.

Short Answer; no

[Make-a-Wake]

Thanks guys...............was hopin' i could.

[questtek]

PLEASE REMEMBER, THIS WAS DONE AS BASICALLY AN ACADEMIC EXERCISE ONLY. I just wanted to satisfy my technical side a bit when I did the experiments. While it is possible, (as I have shown for motors only running in the same rotational direction) it probably is rare if ever practical. For example, you could never power two 4072 brushless motors on a single Seaking 180. Academics over now..............

[6BOOST]

Out of interest, has anyone mentioned Fightercat's (Ben's) new twin motor esc? 2 motors, 1 esc If they handled more than 6s I'd have some on the way!

6BOOST

[Boaterguy]

Out of interest, has anyone mentioned Fightercat's (Ben's) new twin motor esc? 2 motors, 1 esc If they handled more than 6s I'd have some on the way!

6BOOST

you beat me to it, I was reading saying, these guys could all use one of em:

http://fightercatracing.com/index.php?page=shop.product_details&flypage=flypage.tpl&product_id=212&category_id=10&option=com_virtuemart&Itemid=1

[sundog]

Is this esc just a concept? Has anyone ever purchased/used one?. It states none are available, and there is no picture to be had. One noteworthy statement:

Timing in 1 degree increments 1-30 degrees (Timing MUST be properly set or will cause failure)

This is bothersome since most motors I've purchased don't give a recommended timing setting. We use a broad setting margin according to the amount of poles the motor has and whether it is an inrunner or an outrunner. I wouldn't want to burn up either the motor or the esc due to the setting being off a degree or two.

[Boaterguy]

This is bothersome since most motors I've purchased don't give a recommended timing setting. We use a broad setting margin according to the amount of poles the motor has and whether it is an inrunner or an outrunner. I wouldn't want to burn up either the motor or the esc due to the setting being off a degree or two.

You won't burn up the motor or ESC, you can change it a little (1 or 2 degrees) and see if you get a difference in amp draw/ speed. if it is bad, head backwards.

[sundog]

You won't burn up the motor or ESC, you can change it a little (1 or 2 degrees) and see if you get a difference in amp draw/ speed. if it is bad, head backwards.

It also states: IMPORTANT: Timing must be set prior to test/use. DO NOT RELY ON FACTORY DEFAULTS THIS IS NOT A PLUG AND PLAY ESC

So where do you start? Boaterguy, is your info speculation, or first hand with this esc? Without timing info from the motor manufacturer, you risk the 'failure' stated on the website.