cat biuld

[zanda]

think its all getting out of hand. i will just stick with one battery for each esc

[zanda]

i have 2 kawada gtb 30 stock brushless kv 2000, 14400rpm (7.2)
im not sure what amp the esc is as i carnt read japanes
and i have 2 lse 4500mah/7.4v/15c li-po batt from my other boat i will most probley get 2 new batterys later on down the track .
if i was to post the instructions paper thats in japenies could some one try and inturpret it 4 me?

[zanda]

another pic

[ace028]

Looking good!

[Brod]

i have 2 kawada gtb 30 stock brushless kv 2000, 14400rpm (7.2)
im not sure what amp the esc is as i carnt read japanes
and i have 2 lse 4500mah/7.4v/15c li-po batt from my other boat i will most probley get 2 new batterys later on down the track .
if i was to post the instructions paper thats in japenies could some one try and inturpret it 4 me?

Zanda,connect your two 2S batt. packs in series to make a 4S pack and connect both speed controllers in parallel,get a 'y' extension lead and connect both speed controller bec leads in parallel and then to the RX.
Both esc's will be running of the same batt.pack ,both getting equal volts so running in better synchronization.
Brod...

[zanda]

Zanda,connect your two 2S batt. packs in series to make a 4S pack and connect both speed controllers in parallel,get a 'y' extension lead and connect both speed controller bec leads in parallel and then to the RX.
Both esc's will be running of the same batt.pack ,both getting equal volts so running in better synchronization.
Brod...

Any chance you could post a diagram or a pic of this set up ? thanks for your help

[CornelP]

That will be the first diagram in the drawing I posted, double voltage.

[Brod]

Yes Cornells first diagram is right for you,the red blocks being the speedcontrollers.
If you are not sure on the series/parallel thing,i suggest some reading up on the idea.Do some searches for good articles.If i can find some i'll post the links.
It will save alot of burn outs on your gear.
Brod..

[ozzie-crawl]

you mite want to look at his batteries, if he is running 2 2s 4500 15c packs in series he only has a constant amp draw of 67.5 amps (or 80%off=54a) so really he can only drawc about 25 amps for each esc/motor

[zanda]

Zanda,connect your two 2S batt. packs in series to make a 4S pack and connect both speed controllers in parallel,get a 'y' extension lead and connect both speed controller bec leads in parallel and then to the RX.
Both esc's will be running of the same batt.pack ,both getting equal volts so running in better synchronization.
Brod...

Electrically fig 2 is an open circuit, won't even power... fig 3 is a series that will give you the same thing as individual batteries wired direct to esc's. It will work, but if the ESC's are not perfectly balanced (this includes the motors/props), the voltage drop could cause your motors to run at different rpms, which you do not really want...
If you really want to do some wiring (although I do not see the point) you could put the batteries in series with ESC's in parallel or put everything in parallel.

i dont no what would be the best thing to do as its a twin brushless set up whats the best way to run it as you said CornelP you dont see the point .

[CornelP]

Well, the easy way to try is to make up some cables with female-female and male-male connectors, so you can try the different connections as you go. Start with single battery/esc than change to series/parallel. See the pic for details.
Again, this setup will give you higher voltage with less current...

[Brod]

you mite want to look at his batteries, if he is running 2 2s 4500 15c packs in series he only has a constant amp draw of 67.5 amps (or 80%off=54a) so really he can only drawc about 25 amps for each esc/motor

Agree,his packs only at 4500mah are going to struggle running two motors.
I kinda didnt mention it as its getting,again,out of hand for him.

If i were you Zanda i would go back to a single motor,single esc,single battery configuration,much simpler to wire, setup and run.and cheaper too.
If you dont know what you are doing stuff is definately going to BURN.
Brod..

[CornelP]

Brod is quite right here, one more thing to add: lighter!
I squeezed a 10xl with 2 x 2s 4000mAh 20C (series) into this hull, waiting for the maiden voyage...aaaaaaaaaaand writing this I just got the new 125A ESC, as my 70A could not cope with the motor.
Whoops! Your hull is smaller, i am doing the 30"...

[zanda]

the hulls lenght is 55cm and 21cm wide its not a mini cat if that helps my problem?
if i had a better lipo 1 or 2 would that work better ? if so what should i be looking at ?

[CornelP]

If you will use the 2 batteries in series over one motor and one ESC, it could turn out better. You can go one step up on the motor (bigger, if it fits) and it will be easier to mount, etc. In the sponsons, you can fit the batteries. See post 27 of 'Same 30"cat, limited experience'.