Guys,
Need help with my electrics and I am a green horn here
I am about to set up the subject model and at the end decided not to set it up with slimers and instead stick to recommended electric setup.
Now here is my query
1. The manual recommends three 150 W brushless motors. What choices I have locally and from abroad for these motors?
2. Hopw do I hook up these three motors? Do I need three ESC's and LiPo packs? How do I connect the ESC's to Rx if I am using more than one ESC and LiPo?
3. Any circuit diagram would be helpful
Thanks 

Saju,
Since you are already at the thread guess you would be first to help me out 

Captain

Please see the circuit.jpg attached. It shows you how to connect two batteries and 3 ESCs (cyan color). In addition only one ESC signal plug should be connected to the throttle channel of the Rx. The signal wire from that same plug alone should be connected to the other two ESCs. This is ofcourse assuming that at least one of the ESC's (the one plugged to the RX) should have a BEC (circuitry for creating 5v for powering the rx and the servos). If you are using a separate stand-alone BEC, then only the signal wire from the throttle channel should be connected to each of the ESCs.

Hope I have made things clearer. If you still have doubts please PM me

Capt ,
I have a twin star running quite well .
Come over and have a look , to me circuit diagrams always appear complicated .
With 3 motors it should be fairly similar .
What Saju has suggested is fairly straight forward  and a connector can be  arrived at using Dean Plug quite easily

I might be wrong but  with 3 motors I would prefer  opting for  a BEC  to power up the receiver rather than through the ESC. So I might prefer isolating  the BEC's of all three ESC's altogether and using a BEC with a separate 7.4V Battery to power the receiver .

Here is a a circuit diagram I use for the TWIN , you could use the BEC of one of the ESC's as well in a similar manner .

As for 150 watts motor we have a couple of options like the turborix 1050 ( I use these on my twin star ) or the 2212/13 .

sai

capt. you can buy your lipos from aircraft-world,there some pretty good deals going on like a 2200mah@7.4v for 9 change $

as for the ESC buy one which can be setup via PC so that one can synchronize all the 3 motors n the model would fly straight, check hobbycity

http://www.hobbycity.com/hobbycity/store/uh_listCategoriesAndProducts.asp?catname=hexTronik&idCategory=185&ParentCat=182

now for the BEC part please calculate your current like this example: assuming u got the plane from dhamaka which say one needs 6 servo

now stall current of each servo + receivers current + 3 ESC's current + some safety margin

more later
bye
sahil 

Quote from: sahilkit on September 10, 2009, 08:33:43 AM

as for the ESC buy one which can be setup via PC so that one can synchronize all the 3 motors n the model would fly straight, check hobbycity

sahil  

Capt ,
I prefer not getting involved in all this hitech stuff . I have 2 motors on the twin star flying well without any such requirement and in the case of the junkers in any case the 3rd motor is on the nose hence I don't see a problem  of the 3rd motor causing unwanted problems . Hence I will go a for a simple straight forward set up rather than complicate life with all this programing  etc  . In fact the Twin has just plain normal props and not pusher/ tractor combination.

So I would not recommend all this programing , in 3-4 years of electrics flying I have not felt the need till date to fiddle around with the ESC programing be it  a small foamy of a 60 size plane or a twin motor. On the contrary I have found that guys who have tried it have had major issues not knowing the programing issues properly and how to resolve their mistakes .
So unless you are confident of getting out of a programing mistake please don't take chances you could land up in issues altering the model performance  in the air which avoidable .

Sai

there is nothing hi-tech about these stuff instead of programming the ESC with a card or transmitter one can do it with PC  with some flexibility that's it or like sai says go for simple one's

QuoteI have found that guys who have tried it have had major issues not knowing the programing issues properly and how to resolve their mistakes .
So unless you are confident of getting out of a programing mistake please don't take chances

sai can you tell us as to what setup/problesm they were facing so that we can also learn from there mistakes or avoid then

sahil

Sahil ,
This is my observation , I have had several case of guys  going into programing mode by mistake during  stick movement and  once having set the ESC un knowingly into parameters they did not know  they then had the plane behaving in funny ways .
Sahil ,
Not all of us are technically knowledgeable  nor  savvy like you. So I have suggested to Capt. to keep it simple , but if he feels he has the capability to handle programing he could very well do it as you have suggested .

Further I can tell from my experience in Electrics till date and I think I have a significant exposure from small planes till 60 size INCLUDING TWIN MOTORS  that I HAVE NOT FELT THE NEED FOR  PROGRAMING TILL DATE that is my observation , I prefer to keep it simple.

I prefer the plug a fly  options that electrics offer.

sai

QuoteNot all of us are technically knowledgeable  nor  savvy like you.

well one has to learn about these stuff some way or the other right

Quote
Further I can tell from my experience in Electrics till date and I think I have a significant exposure from small planes till 60 size INCLUDING TWIN MOTORS  that I HAVE NOT FELT THE NEED FOR  PROGRAMING TILL DATE that is my observation , I prefer to keep it simple.

I prefer the plug a fly  options that electrics offer.

you are right one generally does not have to worry about programming n stuff unless needed.

QuoteThis is my observation , I have had several case of guys  going into programing mode by mistake during  stick movement and  once having set the ESC un knowingly into parameters they did not know  they then had the plane behaving in funny ways .

this is what I'm talking about if the person had known that something called programming existed he might have at least thought about it not that one need's to know about programming or go through all that process to get started  

sahil

Hi Manish,

Pls post some pictures of the bird. Love to see WW2 scale airplanes.

I hope you have got the idea of installing the 3 motor electric setup.. However, I bet it would be awesome with glow engines pulling it around...

-Ismail

hello saju

i have a question,in the circuit diagram u have posted two battery packs are connected parallel.

assuming one is using an lipo pack

1) what if there is a imbalance in the pack ?
2) how would the LVC system in ESC work
3) if one of the ESC'S cuts of early ?

sahil

Quote from: izmile on September 10, 2009, 01:37:51 PM
Hi Manish,

Pls post some pictures of the bird. Love to see WW2 scale airplanes.

I hope you have got the idea of installing the 3 motor electric setup.. However, I bet it would be awesome with glow engines pulling it around...

-Ismail

Ismail,
Will do a full build (assembly) thread for this one too.
Yes my initial idea was to put in three IC there but then I chickened out.
But then again, may still do it after having flown with those three motors

Curious to know that this looked like - found a video at RCG - http://www.rcgroups.com/forums/showthread.php?t=919216

http://homepage.mac.com/trevorhewson/home/modelflying/scale/junkers.htm
http://www.rcgroups.com/forums/showthread.php?t=853969
http://www.rcgroups.com/forums/showthread.php?t=125804
http://www.flyelectric.ukgateway.net/largesum.htm
http://www.silverarrowhobby.com/products_detail.php?title=Junkers%20Ju-52
http://www.rcscalebuilder.com

Quote from: sahilkit on September 10, 2009, 03:27:52 PM
hello saju

i have a question,in the circuit diagram u have posted two battery packs are connected parallel.

assuming one is using an lipo pack

1) what if there is a imbalance in the pack ?
2) how would the LVC system in ESC work
3) if one of the ESC'S cuts of early ?

1) what if there is a imbalance in the pack ?

I assume they are the same type of chemistry... so they would behave similarily. It is important that the cells are of similar chemistry, charge capacity (mah rating) and discharge rating. Otherwise they will not supply power efficiently and it may turn out that the cell with a higher voltage may shuffle charge to a cell with a lower charge. This is dangerous in the case of LIPO cells as they would go into an imbalance situation which could be dangerous.

how would the LVC system in ESC work
If you have read my writeup accompanying the circuit, I have made it very clear here.

Quote from: mpsaju on September 09, 2009, 10:56:05 PM
Captain

Please see the circuit.jpg attached. It shows you how to connect two batteries and 3 ESCs (cyan color). In addition only one ESC signal plug should be connected to the throttle channel of the Rx. The signal wire from that same plug alone should be connected to the other two ESCs. This is ofcourse assuming that at least one of the ESC's (the one plugged to the RX) should have a BEC (circuitry for creating 5v for powering the rx and the servos). If you are using a separate stand-alone BEC, then only the signal wire from the throttle channel should be connected to each of the ESCs.

Hope I have made things clearer. If you still have doubts please PM me

if one of the ESC'S cuts of early ?
If one of the escs cuts off earlier you have loss of power and of course you would better land as quick as you can... sure signs of battery giving up or loosing charge. No different to a situation where in a 3 engined system, one of the engines cuts off. In electrics, atleast after a time if the cells have a little time to recoup, one may have brief spurts of full thrust.

Sorry for answering so late... Yesterday, I was a little pre-occupied

Hope the above answers suffice... please ask if not

Saju

Manish

Think about one pack each for the main and wing motors. This way, if either battery fails, you would not have any yaw. No problem with parallel connections either. The battery for "engines" 1 & 3 could be of higher capacity than for #2.

Got the kit yesterday. The kit already provides  a set of wiring harness in a bundle which ressembles to me a crow's nest.
BTW the manual also recommends a circuit diagram where three motors, ESC's and only one LiPo is recommened.