Sometime back I posted pictures of my Fireboat questioning it's heritage. it is not a Vosper Mk II but could be the elusive Mk I.
I gave her a makeover earlier this year and thought I would post some pics.
Alan
HI Ian as promised some more photos
No 1 My First landing on water last Thursday eve.
No 2 Modified funnel, 2 extra vents on top and vents at side to allow the fan to push air out
No 3 Bow of boat the gun base is a CD with 1/8 square glued on sprayed Ford Dove Grey
No 4 I took this one Thursday Eve hence still in water!!
Hope they are OK for you
Brian
HI Ian, thanks. As regards LIPOs I use Turnigy 2200 $40-40c Discharge. I have doubled them up in the boat 4400 11.1v. So good capacity, no more power. No problems with the brushed engines. On my Veron Huntsman, 52" again, with a brushless no problems, but I have used 20-25c discharge and they puffed up, I can still use them on low powered aircraft, flying time is just down a tad. So get the biggest mAh battery you can afford, with the biggest discharge available you shouldn't have any problems, just don't get salt water near them. As far as costs a re concerned go for reputable supplier, I only use Turnigy, in the early days I used various suppliers but I was Ignorant and did most of the damage myself!! so I can't blame the battery, but I do know that Turnigy are pretty bullet proof, but if you want a recommendation I would go for A123's but make sure you can charge them from your existing charger, (LIFE4 is how I charge mine), good luck
Brian
Thanks for the info Brian- just gathering as much info and opinion as I can before I part with hard earned cash. The Turnigy Lipos seem to get mainly favourable reviews and they seem a bit cheaper than some. I suppose in the end I shall just have to try some and see what happens. Not sure whether my charger would charge A123's- I'd need to check- it's a Sigma intelligent Charger- pretty standard I think.
1959 kit built, restored two years ago,removed the ganette 15cc 4 stroke and replaced it with a bruhless motor which is a EMP 5065 410kv with a 100amp ESC and 4cell 5000 lipo turning a x70 two bladed prop, runs times up to 20 minutes, and a very good but over scale speed, will take a video of her next time a I take her out.
Second decent run with this boat- rather sedate I think. At the moment it's drawing 33amps (stationary, 16.5 amps each motor) with both motors running from a 12v Nimh pack. I want to get each motor running off a separate LiPo and then I could probably increase the prop size- still well within the esc rating and the motors are very cool after a run at the moment. it seems a bit back heavy and I'd like to get it running flatter- so will try moving the batteries more amidships.
HI Ian
See you are making good use of the wattmeter 😀
Like the video and agree the balance could benefit with a bit more weight amidships.
Listening to the video sound suggests your motors are not developing full power so I suspect the NiMh's are not capable of delivering the amps required.
You could try smaller props with the NiMh's to see if the performance Improves, could be your motors are working just below the optimum.
Dave, I found that the Nimh batteries were dropping off to around 9v at full power when measured with the wattmeter and this is why I want to go for Lipos, one on each motor. At the moment I'm taking everything from one pack and I think this is the limiting factor.
When I get my Lipos I will stick them in the middle and try larger props, probably 40mmS types to begin with, having measured what's going on with the wattmeter first. it may be that the existing props will do better if the batteries are delivering up what the motors want. You're right, there is still plenty of headroom with this setup.
Just got to rake up the cash for two largish capacity Lipos!
The wattmeter is a splendid purchase- I'd say essential for this type of thing.
Anyway, glad you liked the video- she still looks quite good toodling around at that speed.
First trial run after purchase off good old Ebay. Running 26kv motor and 11.1v lipo. its a little bit "skippy", but after returning to shore, it looks like it may simply be the height of the prop shaft, so now adjusted, ready for a second trial shortly....more to follow.
They can be very stable and get a higher level of speed over a mono hull. BUT ...... yep, there always has to be one............ I find that a mono hull can sail in any type of water condition, twin hulls, or tunnel hulls are better suited for calmer water. the main risk is for the hull to flip over backwards if thits the crest of a wave and the wind gets under the bows, the centre section then acts as a sail , wind catches it and lifts the hull nose up........... and over !
If you get the chance to sail one.......try it, they are good fun to sail, take a bit of concentration to get the best speed out of them, especially on turns.
Its like any boat, there are good things and bad in all of them to a degree.
Boats name is Who Ha
(Grand children) I'm afraid
Second trip on water in 30yrs plus it's what's known as long build
Upgraded from first sail from 3 blade 9.6v ni-cad to 4 blade 12v ni-mh
Speed and handling are fine for grand children at this time will wind it up at a later date
Built from a Veron plan, had to do the lofting myself!! Got two brushed motors in it at the moment, hope to maiden it tomorrow(2/9/12). Hash up of the Trinidad and Tobago boats. Not real scale but enjoyed making it.
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.
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
A Lesro Rapier built from a new kit undertaking its maiden voyage. Two 700 9.6v motors with two Mtroniks 40 amp esc's run on 12v with two 37.5mm props. The performance was somewhat disappointing. When the photo was taken I had a 14.4v pack in, forgetting the 12v limit on the esc's -but I got away with it!
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.
First trials after upgrading the hull to brushless motor, instead of original 550 size motor. this test was on a 2 cell 7.4v lipo, I did try a 3 cell, but the stretch of water we use isn't long enough, I run out of water too quickly, so for now, 2 cells power it is. its still a handfull on turns, as the turn fins will take some setting up to get the best out of them to maintain a degree of speed, rather than drag factor off the turn fins.
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.
