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[iantype-r]

Hello all,

I've fitted a 12v 3.2 amp into my 1/16th Trent. Did it's first ever sea trail and got about 10 mins max run time. I didn't feel it was running its max speed that it could do.  Probably due to the weight of the battery I guess.

Just wondered what other people are using in these boats,

Regards

Ian

[Tug-Kenny RIP]

That seems an awful short time.  it all depends on the motor and the current it draws, along with the size and type of prop.

If you have the room I would try a 7 amp/hr battery for size and weight and don't drive flat out, to see what the time afloat is.

Cheers

Ken

 

[iantype-r]

Yes was thinking about trying my 12v 7amp battery. I know it will be a bit heavy, but I'd prefer duration over speed.

Thanks for your reply,

Ian

[inertia]

The problem with SLA batteries isn't just their weight. They are not capable of supplying the sort of current which would be needed for the motors in a planing lifeboat model. We get away with them in models like tugs because these models use low-drain, high torque motors and can usefully carry the weight of a SLA as ballast.
You would be better in all respects to use NiMH or LiPo batteries, which are designed for high-current discharge rates. In the case of LiPo's this can be up to 65 times their nominal capacity e.g. 240A from a 3700maH pack. You would be lucky to get more than about 3.5A from a 7AH SLA battery.
DM

[mersey dave]

If you can it would be far better going brushless, I have a 52in Arun running on 14.8 volts with two 8 amp/hr batteries and as of yet they have never got below the minimum level and that's after 3-4 hours at the lake.
The motors are 850kv driving 55mm 4 blade brass props.

Regards Dave.

[iantype-r]

Thanks for the replys guys, much appreciated. It's further things to consider. May try the Lipo battery option first then look into maybe changing to different motors,

Regards

Ian

[chuffy]

My speedline 1/12 Severn is now back on the bench for completion now that I have sorted out the physical handling problems that have left it on the shelf for the six years.


I am running on 1x 36v lithium ion batteries produced by Bosch for their cordlessr rotary mowers, so no extra expense for me in that department.


Power consumption can be seen by the number of lights glowing in a built in display and to date I have come away from the water with two of the three lights still glowing and then come home and mowed two lawns!


With regards to running time, I haven't spent more than 20 mins on the water at any one time as at top speed she will cover the Wicksteed lake in about 5 seconds and I spend the rest of the time trying to stop shaking and practice manouvering in the harbour. I will however be taking her out on the big lake later in the year when I've got myself an inflatable.


I believe the motors were rewound by Kim Belcher?, to run on 36v. She is also fitted with SHG thrust bearings as, with an all up weight of 56 lbs there needs to be a sold transfer of thrust to the hull as she gets up on the plane very easily.


Paul.

[Robert Davies]

My Trent was built with the recommended (at that time) MFA 500 motors with 2.5/1 gearboxes. I initially ran it on a pair of 4300mah 9.6v NIMH stick packs in parallel (same volts, double the amps).

The performance on the above was sort of OK-ish…

So I bought a pair of Graupner Speed 600s (model no. 6310) and stripped the gearbox off the MFAs, fitted it to the 600s and…

Deary me! That goes well - Mental note: adjust the trim tabs!

The above runs for a couple of hours mixed running, and several actual miles in distance terms. I've never truly worked out how long it runs for, because I've got bored long before it has got 'tired'.

[Flundle (Speedline Models)]

A pair of 35 size out runners and a 3000mA, three cell lipo for each side will massively reduce the weight and increase runningtime. 30A car speed controllers will be fine.
On Hobby King, Turnigy 35 dia 1100kva motors are £12 ish and the controllers are about £11.
This keeps a 1/16 Seven going for ages.

[iantype-r]

Many thanks for the replys guys. I'm going to install some brusless gear so hopefully it will run a lot better/longer,


Cheers Ian