Brian,
Ouch! Sounds a bit expensive.On the advice of Dave M on this forum I bought myself a wattmeter and it certainly takes the guesswork out. I went through three esc's on my Lesro Sportsman before I got it right- hopefully! Also spent a good deal of time anxiously waiting for my Rapier to drift back to shore after it popped a fuse- twice. Now I know what the limits are and I just didn't have a big enough fuse in.

I'm having just what you describe with batteries being too far astern- I'm going out Monday to try them in the middle of the boat. Also hoping to get some LiPos when I have decided on a make.

Hope the new motors and fans work out and that you get some good shots on the water eventually.

All the best...Ian

HI Ian, well the original motors came from a discount store, £2.00 each from memory, they work Ok in my USS Crokett, but I have no glazing and the hot air can escape! I think the sequence went like got hot, melted fan, fan fell off, jammed Motor, fuse blew. I couldn't get any water cooling pre bent from Westbourne so will make my own tomorrow. I have opened up the funnel a bit more on the side and place louvres over the hole, I will get a photo. I did use LIPOs (turnigy 3cell 3500) but now have gone over to A123's much better I have 3 in series X 3 in parellel Giving 6600 MAmps @ 10.4volts.These are very safe batteries, almost unbreakable, I use them in my planes they weigh a little more than LIPOs but a lot less than Gel cells about a quarter and can be forces charged but you would have to sail all day to flatten them. Thanks for your interest, speak to you soon, Brian

I would try and leave the cooling slots fully open, to allow air to circulate through the motor internals. Same goes for any air slots in the front face of the motor, always try and make a hole on the motor mount [if none in], to aid airflow through the motor.
if you cover the slots up, you are only adding to the internal temperature of the motor you are trying to cool.

Thanks. I suppose it's obvious when you think about it. The motor mounts do have slots in the front face.

Mmmm.... turn fins? Perhaps he means a 'dagger plate' a vertical fin that should help prevent the boat from rolling and filpping on turns. Just theorizing I'm not sure though if two would be the answer, I wonder if they might actually hinder. With a single plate of the right size placed centrally the boat would be still be restrained from too much sideways roll yet not lose any directional control being able to pivot on the single plate, where as two plates would tend to act like two fixed rudders and be hinder to turning. I also fly planes and I agree with Dave M about fine control, if using a computerized radio dialing in both rates and expotential helps compensate for over enthusiastic waggling of the sticks and is nearly always required for fast craft particularly first time out. Anyway that sure looks like fun, that's a serious handful and on just 7 volts, well done!

Dagger boards are onl;y used on sail boats, turn fins are a fine edges plate, fitted to the transom, and adjustable in height/depth to the water, so it gives less "bite" when running straight, but digs in on turns to get the hull to bite in to the water.

A rudder is fitted, so there is no way of fitting one of these centrally my freind, they have to fit either side/one side of the transom.
"trimming the radio" does not cater for the movement on a fast boat, thats purely down to the person behind the sticks at the time!
The "end game" on the video was when the rudder dug in too deeply and the boat just spun around due to an "over steer" moment........... thast just what can happen when playing around setting up brushless systems.

Reminds me of my old navy days!

BRAVO ZULU! REALLY COOL SIR.

Thanks Dave

The Fireboat had it first run yesterday with the donated Johnson 888 motor and the original prop. Speed was satisfactory, just nicely on the plane and the battery lasted well, a 7.2V Nimh 3000, so I am happy with that. Controller was a donated Robbe minI 200. Unfortunately although this gave speed/stop control there was no reverse. it has pot adj for 'speed' and 'stop', which I adjusted, but Perhaps it was never designed to give reverse?

Another project is a very old 1950 damaged 'ASL'hull. I have the original drawing titled 'British Power Boat' who were the builders in wartime. it has a 'whaleback' cabin surmounted by 2 machine guns in turrets. These I have cut from radio valves.
Its a most unusual looking boat.

Looks like you are in for some serious fun. You may be able to get the best performance if you have or can borrow a wattmeter to see the effect of different battery / prop set ups. Brushless motors and LiPo's don't like it if you exceed their power ratings.
Looking forward to hearing the results, or maybe a video of the boat on the water.
Good luck 😀

Hi! Fellow modelers, The Vosper kit was matketed by KeilKraft a British agent some time during the 60's, I actually was their agent in South America, but I believe that now they are no longer in business. it is a beautiful model. I did have a good run at my previous home in Guyana, in a cane field then flooded, it worked beautifully with the diesel engine/ screw prop assembly by Graupner. Now I have to look at electric of which I know very little., but I am hoping that the model shop will help when I am ready. Thanks Ray

HI Ray, The sail at Cwmbran today was a success the boat out performed the previous setup. Several members run Vosper fireboats all running electric power, one with a gearbox 2:1 reduction and two models like mine with 700 size electric my run time on 7.2 volt 3600Mah battery is about 30 to 35 minutes with some fast runs, shorter with all fast running. On 9.6 volt 3700Mah (4.8 x 2 in series) runtime is about the same but model is very quick. On 11.1 volt Lipo 2200Mah battery run time is about 15 to 20 minutes but very very quick. I buy most of the Johnson motors that I use on Ebay the prices vary but all are cheap and I have had no problems with any of them. Our Club is all Electric, but that does not mean slow boats. Electric power has evolved in leaps and bounds over the last few years.
Regards Graham

HI

Yes it is...I scratch built it using a GRP 'workboat' hull as a base. I used a simple drawing from the 'Jolie Brise' book blown up to size. I altered the bow, stern and the keel to match the drawing. The rig is slightly undersize and simple the keel is deeper, the deck layout is very approximate taken from photos but simplified to make it more robust for sailing. it has a winch for sail control and the rudder is controlled from the tiller via lines and blocks to a servo under the cabin top.

As you probably know the boat was bought as a Le Havre Pilot boat by EG Martin who then instigated the Fasnet Race, which Jolie Brise won 3 times.

Thanks for recognising it.....best regards Frank

HI Frank I have built model of jolie brise from plans I got from France made few years ago as static model, I have made uo a false keel that I can fit as and when I get round to making sails, have provision for steering via chords running thro the deck in tubes to the steering servo, as yet no thought as to how to install sail winch as have only small openings where hatches fit. you are right about her being pilot cutter and winning fastnet 3 times, she was however built by Monsieur Paumelle in 1913, I hope at some time to get her on the water.
Regards Chiffs