can i run two or three BL motors on one esc ?

[treehugger]

well that is the question ? i have a highly classified project thats been on the boil for a while . i need a difinative answer before it goes before the finance committee (the wife )

regards Paul

[Bormac]

What are you up to now Paul? Taking on the world land speed record?

[treehugger]

dam jason you bugged my hobby room so much for classified
yes im building a twin EDF car its 1/8 scale of the thrust SSC im trying to keep the weight down i have two Kg of potential thrust and dont want the extra weight Ii want to run two 90mm EDF,s for thrust

OK IM OF TO SWEEP FOR BUGS

Paul

[treehugger]

so stop the press i just found the EDF for the job the spec claims 4 kilos of thrust that would give me 8 kilos total. my math weighs the components in at 600 grams

Paul
http://cgi.ebay.com/Wemotec-EDF-unit-Wemo-Midi-90mm-EDF-ducted-fan-jet-/280560197037?pt=Radio_Control_Parts_Accessories&hash=item4152b0ddad

[treehugger]

seems like a strange place to get the inspiration but it all started seeing this how i got to a scale thrust ssc who knows ? but that surfin
check out the shopping cart buggy

http://hackaday.com/2010/07/14/fankart-and-the-holyfkted-fan/

[budhatrain]

From my understanding you can't and possibly never will. BL motors are very different than brushed motors- kinda like apples and oranges if I can that. An electircal engineer friend of mine started to explain it to me but very quickly it started to sound like a peanuts cartoon with the teacher saying blah blah blah blah....

I even tried to look it up on wiki and its starting to come together: http://en.wikipedia.org/wiki/Brushless_DC_electric_motor

I hope I do not insult anyone who actually knows but: from my understanding it is summed up in this statement- "having electronic commutation systems, rather than mechanical commutators and brushes."

There are electrical impulses-programed and perfectly timed within a solid-state circuit board that push the stator around rather than brushes and comms with gaps in them to create timing and to propel the stator round and round. Because of that the esc or controller function is a more complex electical timing system for just one motor.

here's a cool statement I pulled from wikipedia:

"BLDC motors offer several advantages over brushed DC motors, including more torque per weight and efficiency, reliability, reduced noise, longer lifetime (no brush and commutator erosion), elimination of ionizing sparks from the commutator, more power, and overall reduction of electromagnetic interference (EMI). With no windings on the rotor, they are not subjected to centrifugal forces, and because the windings are supported by the housing, they can be cooled by conduction, requiring no airflow inside the motor for cooling. This in turn means that the motor's internals can be entirely enclosed and protected from dirt or other foreign matter.

The maximum power that can be applied to a BLDC motor is exceptionally high, limited almost exclusively by heat, which can weaken the magnets (Neodymium-iron-boron magnets typically demagnetize at temperatures lower than that of boiling water). A BLDC motor's main disadvantage is higher cost, which arises from two issues. First, BLDC motors require complex electronic speed controllers to run. Brushed DC motors can be regulated by a comparatively simple controller, such as a rheostat (variable resistor). However, this reduces efficiency because power is wasted in the rheostat. Second, some practical uses have not been well developed in the commercial sector. For example, in the Radio Control (RC) hobby, even commercial brushless motors are often hand-wound while brushed motors use armature coils which can be inexpensively machine-wound."


Hope that explains it well and is definitive enough for you. I do not see them being able to run dual motors on a single system.

[kaiser]

i hope someone releases a twin motor esc.

i want brushless in my clod! dammit!

[drbelleville]

You figure Novak or Tekin would come up with one for the Guys that run their clods at NRCTPA Events ! Do they offer any for the R/C Airplane crowd?

[Coelacanth]

i hope someone releases a twin motor esc.

i want brushless in my clod! dammit!

Don't they already? I could swear I've seen several on eBay...here's one example I just found.

http://www.horizonhobby.com/Products/Default.aspx?ProdID=LOSB0825

[drbelleville]

i hope someone releases a twin motor esc.

i want brushless in my clod! dammit!

Don't they already? I could swear I've seen several on eBay...here's one example I just found.

http://www.horizonhobby.com/Products/Default.aspx?ProdID=LOSB0825

Thats for the mini LST - and for two brushed motors

[Coelacanth]

i hope someone releases a twin motor esc.

i want brushless in my clod! dammit!

Don't they already? I could swear I've seen several on eBay...here's one example I just found.

http://www.horizonhobby.com/Products/Default.aspx?ProdID=LOSB0825

Thats for the mini LST - and for two brushed motors

Ah...my bad. How about 2 ESCs, each one powering a separate BL motor?

[kaiser]

i have seen guys do that with brushed in twin motor situations, i suppose you could do it with bl, gotta make sure they are set up identical.

[drbelleville]

i have seen guys do that with brushed in twin motor situations, i suppose you could do it with bl, gotta make sure they are set up identical.

I guess some of the best people to get with would be the crawler crowd!

[budhatrain]

There are esc that can handle dual brushed motors for sure: the easiest one to pick up is the evx-2 from traxxas and novak. Novak just came out with a new one for the crawler crowd. Castle Creations Mamba max can handle a BL motor or dual brushed motors too.

But I have never seen anything for a BL setup. Personally I run with a dual brushless set up for my clod- but that's two esc and two motors ($300). I use a y-harness on identical systems- which they have to be in this case otherwise you will tearup and weardown your drive train in a clod. That's what all the guys do at NRCTPA with their clods- mostly Castle Creations Sidewinder series. But you can do it with the traxxas system etc...

You could purchase two ezrun systems and the cost would be under $200.

But once again- the timing and function for a single esc to run two brushless motors is not available- because of the nature of BL motors.

[treehugger]

well thanks for all the imput guys.
I have started creeping around some rc plane sites to pic some brains ,the EDF,s im looking at will need up to 1000W plus doing some brain storming i think it will be better to just suck it up with the extra wieght i will be getting the fans early next week so im on excitment condition 5 at the mo .
i need to get the roller done in 2 weeks i already have the two EDF inclosures the lipo,s and servo s but just like any jet car everything is built around the engines
maybe the mods can move this to other make,s and models

regards Paul