Topic: MMB Pilot Boat (Read 9476 times)

cuppa · « **on:** September 07, 2014, 10:44:06 am »

Could not resist starting the pilot boat - so far I have installed a brushless motor and water cooled mount along with the propshaft (I may fit a larger brushless motor though eventually) so here is the first picture:

Mad Scientist · « **Reply #1 on:** September 07, 2014, 08:31:06 pm »

Must be 'that time of year' - by coincidence, I just started a Traplet pilot boat. Thread to follow shortly.

Tom

cuppa · « **Reply #2 on:** September 07, 2014, 09:48:07 pm »

Hi Tom

Enjoy your build - I look forward to your build log. I was not going to build the pilot boat for while but the hull shape is so nice i just could not leave it be. Mark makes superb hulls and I just had to buy a pilot boat hull from him.
At the moment I am trying to bend 4mm I.D. brass tube to make a decent pickup for the water cooling.

Davenotdone · « **Reply #3 on:** September 08, 2014, 12:23:47 pm »

Wow............that motor looks so small in that hull. Thought of building something similar myself, are brushless motors really so powerful these days???? Look forward to your build, plenty of pics please, regards, Dave.

cuppa · « **Reply #4 on:** September 08, 2014, 02:05:23 pm »

Hi Dave

It is a 130W 1400kv motor. It is a simple matter though to fit a bigger motor if required at some point in the future.
Never built a brushless model boat before so I really have nothing to base brushless motor selection upon so I just used a motor I already had for the alignent and will probably try the boat with it and see what the result is. My guess is that it will be underpowered but i am just not sure and do not want to buy a motor until I have some experience to base the selection upon.

cuppa · « **Reply #5 on:** September 13, 2014, 05:17:04 pm »

Just re-read the specs of the motor and found it is rated at 200w. From what I can gather this is a little bit less than an OS 10 IC engine. I arrived at this by using a formula i found on the web for converting watts to BHP: watts divided by 750 multiplied by 1.5 = BHP so this motor should be about 0.4 bhp using that formula.

cuppa · « **Reply #6 on:** September 17, 2014, 04:34:46 pm »

Tried another brushless motor in it yesterday - a Ray 3536/06 as supplied by puffin models. OK it was just in a tank to provide a bit of load for the prop and test that the watercooling pickup actually works (thankfully and more by luck than judgement it does). What really impressed me was the low speed running of the outrunner - it ran so slowly i could count the propshaft revs. I had read that outrunners did not do slow running very well but this one does. So far I am impressed with this motor. happy days................

setsunakaede · « **Reply #7 on:** September 17, 2014, 05:01:24 pm »

Ah -- My experience is that outrunners (exceptions aside) are actually quite adequate slow running motors. It is the INrunners that are bad at slow revs and partial loads.

jarvo · « **Reply #8 on:** September 17, 2014, 07:08:07 pm »

Hi Cuppa

To late but when you wanted to bend your 4mm tubing without kinking, fill the tube with water then freeze it, bend the tube into any shape you want, allow to de-frost, BINGO

Regards

Mark

cuppa · « **Reply #9 on:** September 17, 2014, 07:52:12 pm »

Thanks Jarvo.

The way I did it in the end was to anneal the tube, then crimp one end and fill it with sugar prior to bending.

Cheers
Jon

essex2visuvesi · « **Reply #10 on:** September 17, 2014, 08:46:05 pm »

Quote from: Davenotdone on September 08, 2014, 12:23:47 pm

Wow............that motor looks so small in that hull. Thought of building something similar myself, are brushless motors really so powerful these days???? Look forward to your build, plenty of pics please, regards, Dave.

Yes they are, you get anyhere from 30-80% more power/torque (depending on motor choice) from a similarly sized brushless, so for example a 370 brushless will have similar power to a standard 540 brushed

cuppa · « **Reply #11 on:** September 18, 2014, 03:30:02 pm »

Here she is with the Foxy motor installed. Still working on the servo and RX mounts.

GLEANER · « **Reply #12 on:** September 19, 2014, 04:18:44 pm »

Cuppa,

I am quite new to this forum, and have been reading your posts regarding the Pilot Boat Model that you have started. Have you managed to acquire any drawings for the vessel you are modelling yet? Do you have enough information for your needs?

I may be in a position to help if you could do with some drawings.

Regards,

J

cuppa · « **Reply #13 on:** September 19, 2014, 06:37:47 pm »

Hi Gleaner

Thanks very much for your kind offer. In the end I produced my own set of drawings based upon the photographs I had collected from the web.
this is going to be what used to be called 'semi scale' rather than an attempt to exactly replicate a full size boat for several reasons - the main one being I simply don't have the skill to make an exact scale model and also that I want a model I can use without being too worried about it sustaining detail damage getting to the lake and also when my grandson uses it.

Cheers
Jon

GLEANER · « **Reply #14 on:** September 19, 2014, 06:48:34 pm »

Hi Cuppa,

No problem at all, and, quite understand. May I wish you every success with the project, and just to say I enjoy looking at your posts.

Kind regards,

John

cuppa · « **Reply #15 on:** September 20, 2014, 02:14:41 pm »

Here it is with the basic propulsion and radio systems in situ:

mark w · « **Reply #16 on:** September 23, 2014, 05:50:40 pm »

Mark

Netleyned · « **Reply #17 on:** September 23, 2014, 05:57:53 pm »

Very neat set up there Jon.

Just hope the shaft exit through the hull
is watertight.
Bit awkward to get at with the rudder
servo sat on it.

Ned

Davenotdone · « **Reply #18 on:** September 23, 2014, 08:11:51 pm »

Looking nice!! I used to have one of those couplings on my model boat ( Graupner Speed 400 running off a 7.2v stick battery ). Ran roughly and very noisy, no surprise really when you see how many moving parts there are in it. Bought one of MMB's rubber couplings and what a difference!! Smooth as silk and no noise. By all means try the one you have but you know where to go if you don't like it. Regards, Dave.

cuppa · « **Reply #19 on:** September 23, 2014, 08:56:33 pm »

Thanks for the advice Dave - all advice is very much appreciated. By happy coincidence I have an MMB heavy duty coupling in my parts box.
I will soon have to make a decision as to what superstructure to build. I have the fiberglass pilot boat cabin but I have another idea of making a superstructure resembling a PCF swift boat. Just not sure if I am going to build this to resemble a swift boat and then get another hull from Mark and build a pilot boat or if i should build it as a pilot boat and then build a PCF afterwards.

Davenotdone · « **Reply #20 on:** September 23, 2014, 10:24:11 pm »

I don't believe it!!!!

The boat i mentioned to you ( about the coupling ) that i am building at the moment is a sort of PCF Swift boat and my next model after this will be either yours or the Speedline models pilot boat!!! Small world eh? Regards, Dave.

cuppa · « **Reply #21 on:** September 23, 2014, 11:10:00 pm »

Quote from: Davenotdone on September 23, 2014, 10:24:11 pm

I don't believe it!!!! The boat i mentioned to you ( about the coupling ) that i am building at the moment is a sort of PCF Swift boat and my next model after this will be either yours or the Speedline models pilot boat!!! Small world eh? Regards, Dave.

Wow - it is indeed a small world!
Please post some pics of your PCF - it would be great to see them.

cuppa · « **Reply #22 on:** September 26, 2014, 05:20:06 pm »

Hull is now ready for a test run before I put the deck on (I like to be sure all is well as soon as possible). I am looking forward to it - I really like the shape of this hull. Have already tested it for water tightness in my grandson's paddling pool but I am keen to know exactly how the brushless system will suite the hull. As for the prop I just don't know so I am starting with a 35mm plastic two blade and may try a 40 mm plastic three blade as well to try and get some idea of which way to go. Battery will be a 5800mah 2 cell lipo.

cuppa · « **Reply #23 on:** September 28, 2014, 10:04:15 am »

Well the test run is done. No problems encountered at all. The water cooling works fine and the hull handles really nicely. motor was stone cold after a 15 minute run and the speed control was just slightly warm to the touch (i think I will water cool it just to be safe though). I did not try it at full throttle in deference to the fact it is an open hull at the moment but she was up on the plane at half throttle and i spent most of the run using a quarter throttle or less. i was concerned that the motor would be too small for the boat but those concerns have now evaporated. So far i am impressed with brushless outrunners in model boats and I think i will be using them in future projects.
I have just recharged the battery pack and it took 538ma to reach full capacity so for a 15 minute run not bad at all. Prop used was a 35mm two bladed plastic prop.
Mark (Mark's Model Bits) has done a fine job designing and laminating this hull and I am looking forward with renewed enthusiam to finishing it.

cuppa · « **Reply #24 on:** September 28, 2014, 10:22:43 am »

Here is a picture of the 'business end' as tested today...........

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Author Topic: MMB Pilot Boat (Read 9476 times)