dual bldc motors on common drive shaft

[wannabeaflyer]

Hi guys i appologize if this has already been delt with but please could some one point me in the right direction to find out how the use of 2 smaller Brushless motors can be synched to drive a common output shaft similar to the configuration in the ( borrowed) Photo attached ... im would like to make a trail systemas proff of concept as it were for a Paramotor project ( going on the basis that 2 small motors could equate to one large motor in terms of Output) .

I realise i would need to ESC's etc and mechanically i have figured out how it can be done , But i came unstuck getting my head around how ESC's work and how the motors would perform given that the Respective controllers may not start each motor at the same point ?? been lurking here for a while and would love the new Tuningy CA120-80 motor but the Controllers still seem to be an issue

 

[Arlo1]

Hi guys i appologize if this has already been delt with but please could some one point me in the right direction to find out how the use of 2 smaller Brushless motors can be synched to drive a common output shaft similar to the configuration in the ( borrowed) Photo attached ... im would like to make a trail systemas proff of concept as it were for a Paramotor project ( going on the basis that 2 small motors could equate to one large motor in terms of Output) .

I realise i would need to ESC's etc and mechanically i have figured out how it can be done , But i came unstuck getting my head around how ESC's work and how the motors would perform given that the Respective controllers may not start each motor at the same point ?? been lurking here for a while and would love the new Tuningy CA120-80 motor but the Controllers still seem to be an issue

Can you make the picture bigger?
how small are they?

I think you will need to make sure the throttle works correctly and I think it would be better to use a torque throttle. Maybe having a CA output the throttle signal to each controller will work to make a speed based throttle system work on as a throttle. I have seen people have issues with connecting 2 controllers to one throttle so this is what I would look into first. Another option its to get the motors 100% locked exactly in sync and make a controller with 6 sets of H bridges instead of three and use three H bridges per motor. But it it VERY VERY hard to get 100% sync IE a 20mag motor has 3600 electrical deg rotation per REV! So if you are out 1deg mechanical its 10deg electrical and will load one motor way more then the other.

 

[Lebowski]

You need two torque based controllers running of a single throttle...

 

[wannabeaflyer]

Hi guys if i recall from tha rc group where i found this they were Hacker motors ( sorry not sure of the size but the aircraft was 1/4 scale), im looking to use something like the C80/100 turnigy workhorse , hard to come by over here in the UK but i beleive a company called giantshark do a comparable model ... all in all im looking to develop a drive system which can accomodate a standard wooden 32 -39" paramotor prop and the drive system able to produce maybe 12-15 KW -- at this stage im not looking for duration per say , the system i envisage will be to allow me to get height and then glide around and when too low regain height .. would have bought the new ROTOMAK 150 but worried about blowing up rather expensive controllers which is where you guys come in

 

[Lebowski]

another option is to rewind both motors such that the windings of both motors are in series, but for this to work they have
to be fixed (w.r.t. each other) mechanically. Then 1 controller would suffice.

This is the route I'm hoping to take with my triple stator motor.

 

[gwhy!1]

Hi guys if i recall from tha rc group where i found this they were Hacker motors ( sorry not sure of the size but the aircraft was 1/4 scale), im looking to use something like the C80/100 turnigy workhorse , hard to come by over here in the UK but i beleive a company called giantshark do a comparable model ... all in all im looking to develop a drive system which can accomodate a standard wooden 32 -39" paramotor prop and the drive system able to produce maybe 12-15 KW -- at this stage im not looking for duration per say , the system i envisage will be to allow me to get height and then glide around and when too low regain height .. would have bought the new ROTOMAK 150 but worried about blowing up rather expensive controllers which is where you guys come in

Yes giant do them http://www.giantshark.co.uk/advanced_search_result.php?keywords=80100&osCsid=805276b8612a0c1242affec105be9ccc and quite good turn around as well I have bought quite a few of the 8085's from them. I am using 2 6374's smaller motors for my current project ( but will be upgrading to 8085's soon and aiming for 15-20kw peak and a constant of around 10kw ) and my current setup produces around 8kw peak and a constant of around 5kw I am using 2 speed based e-bike controllers to drive them. I have had no issues with 1 throttle driving both controllers as long as they are wired correctly .

 

[athlon]

if you put the two motor in the same stating configuration and lock them mechanically so the will NEVER go out of sync you can just parallel the two motor together.

Before the test run just do a manual check the two motor should feel smooth and with the same cogging steps than the single , if they are hadr to turn then you have connected together the wrong phases.


Some producer use the paralle to make double power motor for example if you use 2 stator/rotor of the axial flux of the MARS ME0907 http://www.electricmotorsport.com/store/ems_ev_parts_motors_pmac.php

and stack it together in parallel you get a MARS 1012 http://www.electricmotorsport.com/store/ems_ev_parts_motors_pmac-dsr.php