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[klz]

As my last thread as been locked I thought I would open another, my brother as just sent me a video of the first run of my boat it looks like its sitting to low in the water so to start with I will try running it on 2 batteries.  in the video from about 43 seconds in she is flat out would you say this winter I go for a brushless upgrade as advised in the last thread.

I hope the link works.

http://vid1247.photobucket.com/albums/gg621/KLZ26/Boats/Life%20Boat%20done_zpspjfqiclj.mp4

[gingyer]

Well stating the obvious really nose heavy
A few questions...
How many batteries does the boat hold?
What size are the batteries ?
And
Does the motors need 36v?

[klz]

The boat takes 3 Y9-12 at 2.7kg each same as used in alarm systems, I have not tried it with only 2 batteries but will do once all the weed and algea have gone from the lake at the moment the only boats on the lake at swamp boats and Hover crafts.

 

[gingyer]

Hi there KLZ..
I am going to be brutal here rip the electrics out and start again!
12v 9 are a bit heavier what I was used to seeing which was a set up for 12-7 running 2 motors at 24v each
I will give you this information and then you can alter to suit

You should be able to get 4x 12v7a batteries in that hull with the motors.
Looking at the picture in the previous thread you have wasted the available space.


So take all the ESCs out the light switch and all the other bits of electrical kit, also any weights for ballast


Take it to the pond and see how many batteries you can fit in it to get it too the water line.
Get the batteries positioned roughly as follows

Between the 2 motors you should get 2 batteries on their side down the keel of the boat
Then at the stern where your ESCs are you should get another 2 batteries on their side.

The ESCs can be positioned in the bow area. The light switch positioned on your work bench
For making the cabling joints get some terminal block and mount that somewhere at the bow too

Now your model should have most of the weight to the rear and then light stuff up front

[TomHugill]

Ditch the SLA batteries, I would switch to lipos or NIMH if you don't fancy them.  You can lipos with with a brushed setup. You could probably also go brushless if you want more performance

[gingyer]

Tom,
If your ditching the SLAs for other types then you need to go and get a lot of ballast  To compensate.
klz has the batteries so all is required is a little repositioning
And he will get it working perfect

Colin

[klz]

Thank you for your replies, if the weed ever goes from the lake I will try it with 2 batteries then in the winter I will take it back to the workshop for a refit at that point I will desided if I switch it all around or go for a brushless upgrade.

[Time Bandit]

It generally looks too heavy to me or is that hull really laying so deep in the water?
It´s just running very slightly over hullspeed.

So I´d probabaly go for a brushless setup to at least reduce the motor weight.
If you want to ditch the SLA´s I´d use Headway Lifepo4 cells. Perfect for such kind of boats.

[Perkasaman2]

A cheaper option is to just source a pair of 5 pole '900' size motors. The wheelchair motors are very heavy and power hungry. They may be ok for use in a large tug but they cannot give the revs required. The 900 motors will run very well on 24volts with the right props and easily produce scale speed for this semi planing hull. The Aruns had a top speed of 18.5 knots although later RNLI boat types were quicker and are specced to achieve 25 knots.  Many Aruns with aluminium hulls were used by the Canadian Coastguard and they were quicker being capable of 20+ knots .
   
If you wish to calculate scale speed:

Actual speed (18.5) divided by the square root of the scale (12) = Answer (given in knots)


(To convert knots into mph multiply the answer by 1.15077945)

[destroyer42]

Hi KLZ,
Have a look at mine https://www.youtube.com/watch?v=m_ke1JjG1dw  running on 12v x 2 , brushless Emax motors, 2 x 60 amp fan cooled ESC's, all other functions running on x 1 12v nimh battery.
I run it on 12v for shows and 24v if I want to go mad around the lake which lasts about 30mins on 12v a couple of hours.

Destroyer42

[klz]

After seeing destroyer42's video I will order what Calimero advised on my first thread ... brushless it is