Topic: Robbe PT15 - Anyone any recommendations to get planing !!! (Read 7817 times)

CJ · « **on:** June 06, 2012, 10:44:40 pm »

Evening all,

Well after tinkering to mass expense with my Fairmile, I decided my garage was looking too tidy so impulse bought a Robbe PT15 off e-bay !!

Was looking for a partner for my Fairmile so gonna look at a "loose" model of a Vosper MTB - probably the 55th flotilla cos I love the shark teeth !!

Anyway - as you can probably tell from the pics new electrics are needed - so......I would love to get her to plane nicely along, anyone have one or any ideas on what to use

Motor
Battery - I have easy access "free" to SLA but NIMH an or anything else an option
ESC
Propeller size

As always any thoughts appreciated, will try and put a "rennovation" build in warships too !!

Cheers

CJ

Shipmate60 · « **Reply #1 on:** June 06, 2012, 10:48:03 pm »

I put a stock 540 from MarksModelBits, a 32 mm 2 blade prop and a 7.2 volt battery pack.
I can get her 3/4 out of the water but on turns she "falls over" and the inside shoulder digs in.
I also have another one which I will fit with 2 of these motors, yes faster, but should be far more stable with 2 props in the water.

Bob

DickyD · « **Reply #2 on:** June 06, 2012, 11:25:51 pm »

Motor is a Deans Marine Kestral

Battery 9.6v racing pack cross wise behind motor.

35mm 2 blade prop.

CJ · « **Reply #3 on:** June 06, 2012, 11:36:37 pm »

Wow, thanks for the pics Richard, yeah looking real nice

Not sure I want to tip her over Bob !!

hope nothing too disastrous ?

Richard I can't find the kestrel ? Is it bigger or smaller than the 540 ?

Cheers Gents

CJ

DickyD · « **Reply #4 on:** June 06, 2012, 11:58:19 pm »

Kestral motor. http://www.deansmarine.co.uk/shop/product_info.php/cPath/5_13/products_id/200

Forgot to mention, I watercooled mine, simple enough job.

CJ · « **Reply #5 on:** June 07, 2012, 09:48:44 am »

Thanks for that Richard,

Is she watercooled cos you "need" to - does she run that hot ? Also what ESC are you using to run that ?

Cheers

CJ

CJ · « **Reply #6 on:** June 07, 2012, 12:25:07 pm »

Has anyone tried with 12v SLA at all ??

CJ

Martin (Admin) · « **Reply #7 on:** June 07, 2012, 01:03:57 pm »

A 'lead acid' battery may be a bit heavy for the PT-15.....

DickyD · « **Reply #8 on:** June 07, 2012, 01:08:46 pm »

Quote from: CJ on June 07, 2012, 12:25:07 pm

Has anyone tried with 12v SLA at all ??

CJ

SLA much to heavy CJ

Mtronics Viper 20 Esc

Warmish motor, thought better to be safe than sorry.

CJ · « **Reply #9 on:** June 07, 2012, 01:10:51 pm »

Thank you both,

I did think that this would be too heavy but was canvassing for opinions and experience, will go with Richard's suggestion and run up a 9600 then.

Will let you know how she gets on

Cheers

CJ

CJ · « **Reply #10 on:** June 07, 2012, 01:43:35 pm »

Richard,

Sorry

- where do you get your batteries from, I've just had a look around my local shops and everyone looks wierd at me

A link would be great please !!

CJ

DickyD · « **Reply #11 on:** June 07, 2012, 04:14:52 pm »

CJ loads of us use The Component Shop.

Excellent prices for goods and P&P

Excellent service, often next day delivery if ordered early enough.

They also do chargers etc.

http://www.component-shop.co.uk/html/large_packs.html

Ghost in the shell · « **Reply #12 on:** June 07, 2012, 06:30:43 pm »

Quote from: shipmate60 on June 06, 2012, 10:48:03 pm

I put a stock 540 from MarksModelBits, a 32 mm 2 blade prop and a 7.2 volt battery pack.
I can get her 3/4 out of the water but on turns she "falls over" and the inside shoulder digs in.
I also have another one which I will fit with 2 of these motors, yes faster, but should be far more stable with 2 props in the water.

Bob

you MAY be able to get 3 motors in there, full size one is a tripple screw i think

CJ · « **Reply #13 on:** June 07, 2012, 07:55:04 pm »

Thanks for that Richard, those prices certainly are impressive - will be placing an order tmrw so thank you

Ghost - sounds impressive but not sure my pilots license allows low flying boats locally

Also not sure I can get 3 in there plus my hands to do any work !!

CJ

john44 · « **Reply #14 on:** June 07, 2012, 08:06:13 pm »

Hi CJ, my PT15 runs off a car fan motor with a 3 blade 35mm prop and a 8.4v NiMh it probably planes to much
I was thinking of weighing the front down a bit so she turns safer at full speed.
Will post some photo,s After sailing her Sunday. Weather permitting.

john

hmsantrim · « **Reply #15 on:** June 07, 2012, 09:34:13 pm »

Hi CJ.
what size is the voltage of the geared motor you have in the hull at the moment. Can`t make it out but is it a robbe speed motor. ??

cheers Frank

CJ · « **Reply #16 on:** June 08, 2012, 10:06:32 am »

John,

Cheers for that, yeah would love to see a pic - fingers crossed weather allows you, weather permitting !!

Frank, yeah it is a Robbe 600....also had a Graupner in the box - will bench test them and see if they work at all, but really want her to get her out the water so happy to spend the money and get it right

Why did you want it if it works ??

CJ

Stan · « **Reply #17 on:** June 08, 2012, 10:16:05 am »

Hi CJ.Many thanks for the p/m. If i can find the picture of mine i will send it to you via e/mail.

Stan

hmsantrim · « **Reply #18 on:** June 08, 2012, 08:11:49 pm »

Hi CJ.
Ok I would take the geared end off the motor and make it direct drive. The motor is rated for up to 9.6v which is what you will run it on. I run a 36in perkassa on a pair on 9.6v
packs joined together to increase amps / running time. The motor is a 9.6v BB turbo and it planes. I have upped a pix of the harness I put together to join the packs and the boat on
the plane. The prop is a 50mm X racing prop. You could do the same on yours make it fly. Single motor is all you need.

cheers Frank.

CJ · « **Reply #19 on:** June 08, 2012, 10:52:12 pm »

Thanks again Stan, yeah would love to see a pic

Frank, thank you for the info...funny enough the 50mm X racing prop seems to be the recommended from the messages here and the p/m's too.

Yes I am going to rip the geared motor and I have a deans marine kestrel en route based on the majority vote, again 9.6v battery back on its way too based on what is recommended.

Interesting though that you recommend two batteries, thanks for the pic I may set it up to try....out of interest where have you got those both placed in your perkasa ?

Cheers

CJ

DickyD · « **Reply #20 on:** June 08, 2012, 10:58:49 pm »

CJ I had a larger prop on mine to start with, kept blowing fuses and not enough speed.

2 blade smaller prop far better and more speed.

Quite often smaller 2 blade prop will give more speed than 3 blade larger prop.

CJ · « **Reply #21 on:** June 08, 2012, 11:17:25 pm »

Richard is yours a standard 2 blade, X or S ....may try both see which one gets her airborne

Cheers

CJ

Shipmate60 · « **Reply #22 on:** June 08, 2012, 11:36:23 pm »

CJ,
If she is too fast you will get the symptoms of mine.
On turns she will fall away and the front shoulder will dig in.
You need a bit of hull in the water to give her stability.

Bob

CJ · « **Reply #23 on:** June 08, 2012, 11:43:03 pm »

Thanks Bob, yeah I'm somewhere between planing and airborne....think as I've got the motor and battery set en route they seem to make sense, will try a few props and see with trial and error what happens

Cheers

CJ

Shipmate60 · « **Reply #24 on:** June 08, 2012, 11:58:32 pm »

If you want her fast trim tabs on the transom would keep the bow down a little so more of the hull in the water.

Bob

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Author Topic: Robbe PT15 - Anyone any recommendations to get planing !!! (Read 7817 times)