Model Boat Mayhem

Mess Deck: General Section => Chit-Chat => Topic started by: ando on August 02, 2008, 10:02:22 pm

Title: precedent thornycroft kd perkasa 37" wood
Post by: ando on August 02, 2008, 10:02:22 pm
Hi everyone     i,ve just brought this kit    and would like some help ( idea,s)  on how to add the electric motors and which motor s to use  ??    size ,  speedcontroller  battery etc     If anyone has some pictures of a model  ( insides )  i would be greatful 
         regards     Andy :)
Title: Re: precedent thornycroft kd perkasa 37" wood
Post by: Shipmate60 on August 02, 2008, 10:08:33 pm
How many motors/shafts are you going to use?

Bob
Title: Re: precedent thornycroft kd perkasa 37" wood
Post by: ando on August 02, 2008, 10:45:57 pm
Hello 
         Bob       i don,t now yet as all i,ve done is look in the kit and had read of the instructions !
   I am looking for advise    i,ve read some of the other messages about this kit and it seems the lighter the better ??
regards    Andy :)
Title: Re: precedent thornycroft kd perkasa 37" wood
Post by: Shipmate60 on August 02, 2008, 11:02:35 pm
ando,
You then have 2 main choices and lots of sub-choices.

Do you want to go I.C or Electric powered.
A lot of lake now operate an I.C. ban, but your local lake might not.

I.C. single engine with single shaft will make her fly out of the box.

Electric powered
1, 2, or 3 shaft brushed motors.
1 shaft Brushless.

Single shaft/motor is easier to fit, lighter and overall cheaper
Brushless, more power than brushed motor but overall more expensive.

Even built light on electric power she will get planing, but there will only be a fairly short duration, 20 mins or less!!
Brushless about the same but more power and speed, but added expense.

To get running correctly these models are not cheap to power as they require powerfull motors, high output speed controller(s) and high capacity racing batteries.

Bob
Title: Re: precedent thornycroft kd perkasa 37" wood
Post by: ando on August 02, 2008, 11:15:16 pm
Me  again     
             I was thinking of using a graupner 700 turbo and a single prop     but i am not sure what size blade   ( 2 or 3 ) bladed ??
       i,ve also not sure what power to use 12v   lead bat  or  9.6v 3300mah   nic-h    or even lipo bat   ???
       you sound like you know your stuff any advice is greatfuly recieved  !!
Title: Re: precedent thornycroft kd perkasa 37" wood
Post by: Shipmate60 on August 02, 2008, 11:39:14 pm
ando,
That is a good choice.
My preference would be a 700BB Turbo running on 12 volts MiNim racing pack.
I would use at least a 20 amp speed controller fused at 15 amps.
The only part I am a little unsure of is the 2 blade Prop size so would prefer to get some input from those that have this set up.
I would rather tell you I am a bit unsure than guess, its your money!!
I do know this set up works well with a 3 blade PropShop fast scale prop, but just as well with a 2 blade racing prop.

Bob
Title: Re: precedent thornycroft kd perkasa 37" wood
Post by: ando on August 03, 2008, 08:47:30 am
Hello  Bob
             is the 700bb turbo motor a  brushed  or   a  brushless motor ??
Title: Re: precedent thornycroft kd perkasa 37" wood
Post by: FullLeatherJacket on August 03, 2008, 09:33:07 am
Ando
It is brushed.
FLJ
Title: Re: precedent thornycroft kd perkasa 37" wood
Post by: djrobbo on August 03, 2008, 04:30:46 pm
Hi ando...i'll chip in here...i have a wooden aerokits fire tender of about the same size and i was running it on a 700 bb turbo with 9.6 nicad buggy packs...45mm prop
   
     running time was about 5 mins flat out before it ate the batteries :'(

         changed to a 600 speed eco with a 12 volt nim h battery........wow.....dammed thing is faster and gives me about 25 mins on a single battery pack

          as they say  you pays your money and takes your choice..



                      regards......bob.
Title: Re: precedent thornycroft kd perkasa 37" wood
Post by: ando on August 03, 2008, 09:30:22 pm
Hello
       hi    i welcome all comment s        O0
                                             
     i  have some   dry 12v lead batterys 7mah   ( rechargeable )   that i got from  work  they are out of some emergancy lights  i am not sure if the are suitable ????                     
Title: Re: precedent thornycroft kd perkasa 37" wood
Post by: red181 on August 04, 2008, 12:02:05 am
ando forget the lead acids mate, you need the power outpput of nimh or nicad, I prefer nimh, no memory effect, so you can top them up. Lead acid you have 7mah, I have a 34" Firretender, similar boat, it flies on 2 x 9.6v nimh to give 19.2v, 4600mah, 30 mins flat out with a few stops, graupner 700bb turbo, 12v, 3 blade 45mm prop.

A friend just fitted the new 9.6v 700 bbturbo neodym motor to a PT Boat like yours, its £10.00 more expensive than the standard 12v 700 bb turbo, the difference in performance using my two niimhs was amazing! I am ordering one, but...the stall current is massive, so you need a esc that can handle it
Title: Re: precedent thornycroft kd perkasa 37" wood
Post by: ando on August 04, 2008, 06:15:02 pm
hi      i think i,ll go with 2 x 9.6 nimh   3700mah   with  2x 600 speed eco,s !!    and see hoe it goes and for how long ??

             if anyone has any pictures   of their perkasa      i like to see them    and take note of lay out ( ref weight distribution ) etc.
              Regards   Andy :)   
Title: Re: precedent thornycroft kd perkasa 37" wood
Post by: andyn on August 05, 2008, 12:35:47 am
Andy, see my quite unsuccesful (only as yet I hope) plea for reference photos of the perkasa at http://www.modelboatmayhem.co.uk/forum/index.php?topic=12000.0 (http://www.modelboatmayhem.co.uk/forum/index.php?topic=12000.0)

It's the GRP version of yours, but should be of help.

I should note, probably not best for weight distribution, as there is an 7x4 inch peice of lead under the servo tray, as it has a big heavy gelly stuck in the front