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[Bugsy]

Boat.
Scratch-built from blown-up plan.
One metre in length.

Powertrain.

Custom-made mounts.
Two XYH 35-42 motors 1100kv
Two Hobbywing 60A ESC
40mm three-blade props
8.4v NIMH battery. (I tried two batteries but it is too much weight in the boat)
Works very well much just a little too much power

.

[HS93 (RIP)]

Looks good any more pictures  and any of it sailing ? I have got a pair of similar motors from overlander but haven't run them yet they are in a 34" boat that is quite light and was concerned about what the speed would be. looks nice and neat, by the way what props have you used.

Peter

[Bugsy]

Thanks Peter

Props are 3-blade Rivabo

I'll get some photos posted tomorrow.

Gary.

[Bugsy]

http://www.youtube.com/watch?v=kBMZJ2EWUqA

Please be aware that this is my first attempt at a video so be kind

[grasshopper]

Nothing on the video to be ashamed of - it's all there.

The boat looks fantastic, build and performance excellent. The film quality is good, a few sound issues but generally speaking I'd be proud to put my name to any of your offerings.

[HS93 (RIP)]

that looks great you may want to move the weight about , try putting some forward, and do the motors get hot? if not by the sounds (allthough difficult with twins) you may want to try a bit more prop, although it will give a bit more speed it will also reduce the revs on slower runs.

by the way the video is great and it looks a really nice lake

Peter

[Bugsy]

Thanks guys

grasshopper:
I've not used 'iMovie' before (apple mac programme) so it very much a 'learning curve. The sound, apart from the 'dragster' bit is straight out of the camera so needs a bit of modification. That'll be lesson 2 

HS93:
I will try moving some weight around to achieve a better balance, thanks. The motors, esc's and battery run warm and I got nearly 20 minutes from a 3700 NIMH (8.4v) which is pretty good, I think. I'm not sure about the rudders though as I purchased large ones and cut then down to the scale on my blown-up plan. The boat can be difficult to turn at faster speeds doing almost a 'broach' in the turn. I think it will perform better with a thinner width and longer length, more blade like. I'm guessing, of course

[phillnjack]

If you put more blade on the rudders wyou will get much more lean in the turns.
I dont think it will be a good idea to have too much lean.

The boat looks very very nice, like said above the weight does need to go a tad forwards
this would also give you a nicer turn.
speed is very good,especially if both motors are comming off just the one battery.

amazing how quick the boat can stop.

seems like a very good all round set-up to me.

The sound of the motors is also pretty good, they dont sound like they are screaming to pieces
but maybe a slight less pitch could give even more run time.

The overall vid is very good. nice bit of camera work, and a very nice model to film.

what sort of price did the electric motors and esc cost ? 

you have definitelt built a very fine boat




phill 

[Bugsy]

Thanks for that Phil.
The motors cost £12.77 each and the esc's were £37.59 each Programming card was £5.48.

Motors: XYH35-42  1100kv Brushless Outrunner.
Escs: EZ-RUN 60A w/reverse program brushless.
Hobbywing Digital Programming Card.

All bought from Giant Cod.

The Esc's are car parts and come with a fan assembly which I have removed. The max voltage for the fans was 6v and I'm running 8.4v. They have a bec so the live on one side of the 'Y' lead is disabled.

Nothing runs hot just nicely warm.

.

[HS93 (RIP)]

you need to replace the fans as car  esc have very small heat sinks because they  have to fit in small spaces and need to be light, the fans make up for the smal size, you may find  it will overheat as the weather warms up, you can get watercooling  plates from the likes of R2 hobbies they are very cheap.

peter

[RaaArtyGunner]

From the uninitiated.

Understand a Brushless setup requires, brushlees electronic speed control yes/no. Y

What about batteries ? can nicads, Nimhs or Gell cells be used or do they have to be "Lipo" type etc

Also is 'brushless' more suited to "the need for speed"

[Bugsy]

you need to replace the fans as car  esc have very small heat sinks because they  have to fit in small spaces and need to be light, the fans make up for the small size, you may find  it will overheat as the weather warms up, you can get watercooling  plates from the likes of R2 hobbies they are very cheap.

peter

Thanks Peter,
My plan (I have a plan  ) was to try them without fans and replace them if need be. Why they weren't wired through the 'bec' circuit I don't know and my soldering skills are not good enough to re-solder them (the joints are tiny).
The simplest way (I think)  would be to use a separate small 6v battery to power just the fans which could be switched independently.
Or could I just plug them into a spare slot on my receiver ?

[Bugsy]

Following advice from HS93 I have this morning modified the interior to allow me to position the battery further forward. I've left space to allow for trial positioning and will replace the battery carrier when the optimum position is found.

Before:



After:

[HS93 (RIP)]

the only problem with the receiver idea is you may get some noise sent to the receiver causing interference, you could use this with a scoop or a couple of AA cells and a switch http://www.r2hobbies.com/eng/proddetail.php?prod=rcps81933_30

Peter

[HS93 (RIP)]

It's realy nice to see a neat boat setup, very nice..

Peter

[phillnjack]

NEAT

That is ubelievable, so nice to see it looking so neat.

i always plan a nice neat set up, but it ends up looking like steptoes scrap yard in my boats.




phill

[red181]

lovely setup! I would run 2 battery packs, as the motors will accomodate much higher voltages (Input Voltage : 7.4V~14.8V ), and this will then give longer run times, I would kill for excess of 20 mins in my brushless set up!

extra battery weight, whilst initially feels wrong to add weight, will sit the boat down and help with the turns, keep  the weight low in the boat. 1100kv will give some torque, so you could up the prop size as it will easily pull it, but keep an eye on temps and as mentioned, those car escs need the fans, current draw will be negligible if running 2 packs so I think you could go off the main batteries, or carry a small pack of 4 aa batterys, did the fans not connect directly to the esc and use the main feed anyway?

whilst the bigger props and extra battery will give more speed, you dont have to use it, but run time will increase. Invest in one (or2!) of these to monitor cheaply amp draw

http://www.4-max.co.uk/wattmeter-budget.htm

good lick!

[RaaArtyGunner]

From the uninitiated.

Understand a Brushless setup requires, brushlees electronic speed control yes/no. Y

What about batteries ? can nicads, Nimhs or Gell cells be used or do they have to be "Lipo" type etc

Also is 'brushless' more suited to "the need for speed"

Silence is deafening.
Conclusion, with no comment to the contrary, the initiated should stay away from brushless setups.

[HS93 (RIP)]

Silence is deafening.
Conclusion, with no comment to the contrary, the initiated should stay away from brushless setups.

sorry about that I miss read your post first time.
so yes you need a brushless speed controller and it can only controle 1 motor
any form of battery will do even an old motor cycle wet cell , BUT depending on how you are going to use the boat the choice of battery comes in if its a tug and you are not going to ask for big discharge demands anything will do, if you are racing light weight and Lo Polly is the way to go.

there is a very nice post by one of our AUS member about replacing his steam plant with a brushless set up and it is a fantastic job and very cheap

Peter

[Bugsy]

Silence is deafening.
Conclusion, with no comment to the contrary, the initiated should stay away from brushless setups.

I must apologise too RaaArtyGunner.  

I learnt to my cost that, as HS93 said, you must use a controller for each motor when going brushless ( I burnt out one motor trying to run two through one esc) and brushless escs for brushless motors.

http://www.modelboatmayhem.co.uk/forum/index.php?topic=28375.0

I use NMIH batteries and they give brilliant time on the water compared to using with brushed motors.

Gary.

[RaaArtyGunner]

I must apologise too RaaArtyGunner.  

I learnt to my cost that, as HS93 said, you must use a controller for each motor when going brushless ( I burnt out one motor trying to run two through one esc) and brushless escs for brushless motors.

http://www.modelboatmayhem.co.uk/forum/index.php?topic=28375.0

I use NMIH batteries and they give brilliant time on the water compared to using with brushed motors.

Gary.

Gary,
 )Thank you, had followed the earlier thread hence the query about batteries for use with brushless.

 

[Bugsy]

Just an update.

As suggested by HS93, I've re-installed the Esc fans and power them through a switched 6v battery. (Does seem a bit strange that the Hobbywing Esc's are capable of a large voltage but the fans have a max of only 6v.)

I've modded the inside to allow the fitting of one, or two batteries (the boat runs a bit 'wet' with two batteries). I can now position the battery in any one of a number of positions to adjust balance.

[red181]

have you run it since moving things around?, any thoughts on upping the voltage, I would love to see how it goes, or at least how much power is in reserve

[class37]

totally daft question I am sure, but do the fans blow air onto the ESCs or draw air away from them, or doesn't it matter ?

[Bugsy]

Red181:
Yes and it performs beautifully especially since I reversed the props. I have a least 30% more power than scale speed. My friend here in France built an identical boat and runs two 700bb Brushed motors. We can push along at pretty similar speeds, but my batteries last much, much longer.

class37:
The fans blow down over the Esc's. not really needed with current air temperatures but the summer will be a different matter.