Hi Rowen,
simplest way with the videos is to copy the YouTube web links into your post.
Like I did with the three vids of my Sea Scout trials.
Then we can view them simply by clicking on the links. Or copying them into our browser.
Your results with the 2S and 3S are similar to my experience with the smaller Sea Scout 👍
Cheers, Doug 😎

Thanks Doug,
I tried that, but the later address superseded the and obliterated the earlier.
Anyway,our experiences seem very similar. Have decided to "standardize" on the 3S. The performance is clearly superior.
Will get a longer video on a much larger lake shortly and will post.
Rowen

Hmm! Don't understand what you mean there with 'later address' 🤔
So let's try my Sea Scout links and see what happens.
(I had taken the precaution of saving the links into a text file 😉)
So here's what I saved last year.

"Sea Scout trials, Ostpark Munich, 28th May 2018.

Pt1:
https://youtu.be/b0BWJ3duzDw
First run with a 3S LiPo
Pt2:
https://youtu.be/oMUlSOaAREM
'The competition'!

Pt3:
https://youtu.be/zPgYicA0yGw
'Final run', the Bier was getting warm."

I find that URL links work best on this site when they stand alone on a separate line, no other characters in the same line.

Cheers, Doug 😎
PS: Seems to work OK 😊

https://youtu.be/b0BWJ3duzDw

🔗

https://youtu.be/oMUlSOaAREM

🔗

https://youtu.be/zPgYicA0yGw

🔗

▶️

Checked out your You Tube vids Rowen, and she's looking nice on the water. I think she is riding more steadily and scale like on the 2s than the 3s. On the 3s flat out she's lifting too much in the stern and digging the bow in on the turn and leaning out plus getting a bit of torque roll (mind you you can always reduce throttle and get a better run time). Will be nice to see vid on a bigger pond. Now that's finished, what's next on the board ?

Doug,
Later meant the second or third address which obliterated the preceding one. Anyway,
will try your suggestion next time I post several videos.

Would agree to an extent.
The 3S though allows the motor speed to be reduced so the plane can be controlled. Either way after all the challenges she produced last year am happy with the outcome.
My next project is a model of one of the R.A.F. SEAL class, a LRRC which was the last launch used before the R.A.F. Marine branch was closed.
Just completed the hull sailing trials so will shelve project until next winter. Will eventually write a blog on it.
Really like your Fairmile and am very tempted to build one of those further down the line.

BRAVO ZULU, well done that man 👍
"Suspect this was because of the difficulty in coordinating acceleration, photographer and deceleration."
Practise makes perfect Rowen, esp. for the camera 'person'!

An altogether very nice job Sir 👍👍👍
Looking forward to the video very much.
Cheers, Doug 😎

Very nice, well done.

Looking fantastic Rowen, looks like she's all sorted. Can't wait for the video. Nice job. John b

Pics pics pics !! Even better a vid of the trials please Rowen.
Your results with the 2S vs 3S mirror mine with my Sea Scout trials last year.
2S was adequate to sedate. 3S turned her into a sport fishing boat 😀
https://www.youtube.com/watch?v=b0BWJ3duzDw&feature=youtu.be
https://www.youtube.com/watch?v=zPgYicA0yGw
I didn't argue 😉
You can always limit the throttle at the TX again, or restrain your thumb!!🤣
Cheers, Doug 😎
PS After my vid this popped up on You Tube . Spruce Goose lives! Magnificent.
https://www.youtube.com/watch?v=VgJkfPWyH_E

https://www.youtube.com/watch?v=b0BWJ3duzDw&feature=youtu.be

🔗

https://www.youtube.com/watch?v=zPgYicA0yGw

🔗

https://www.youtube.com/watch?v=VgJkfPWyH_E

🔗

▶️

Bit of torque roll there Doug, skipper might need moving to the starboard seat. Skipper hasn't been on the Schnapps by any chance? -re failure to give way (starboard rule) and collision with tubby yellow boat. A smaller prop might lessen the roll, plus trim tab, and as you mentioned, spray rails. Sounded like the tunefull scream of a 28mm out-runner? I had one in my 36"Maiami with a 25mm 3 blade which did a similar speed to your Scout (with no torque roll) but I temporarily put it back to brushed as I couldn't stand the noise. Also it was useless for on board videos for obvious reasons. Smaller props plus high rev capability give much nicer slow speed control, John B

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Hi
Would you please post how you set it up please.

I have both the Flysky and Turnigy units(same thing only a name change) and would like to add this into a plan build.

Canabus

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Canobus,
Have not done a circuit diagram yet, but can explain the Tx settings. if that will suffice can write something up shortly. The instructions are fairly sketchy.

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Canabus,
Hope this helps,
Rowen

Using the FS-I6X instruction Manual, dated 8/10/2018.
This Tx allows infinite experimenting with the various control functions and ultimately reverting to factory settings if dissatisfied with results.
After several attempts at setting the ELEVON function (V-TAIL could be similar, but the Tx channels would be different), decided this works best for me. it puts both brushless ESCs on the RH control lever. Moving it up operates both screws in the forward direction and down into reverse. Going from side to side speeds up or slows down the motors, so the boat goes in the direction the lever dictates. This was accomplished by:
1) Page 14/57 Establish the Tx Stick mode, mine was # 2.
2) Considering ELEVON, need to determine which layout allows the Aileron and Elevator controls to be operated by same lever.
3) Use Elevator for throttle (fwd & astern) and Aileron to “turn”. The Aileron will accelerate the motor on the outside of a turn.
4) Plug Port & Starboard motor ESCs into channels 1 & 2 respectively.
5) Refer to Para 5.10 and set Elevon mode on Tx.
6) Use channel 4 (LH lever side to side) for rudder and Channel 3 (LH lever up / down) for any other function needing proportional control. I am using it for the centre brushed motor.
This means that my control levers, which had previously had throttle on the LH lever and rudder on the right are now totally changed.
There is also an article in the March edition of Model Boats that explains the concept.

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She's looking very smart now Rowen, waiting for the video when you finish. I wouldn't worry too much about the weight as you have the width in the hull. My 36" ASR weighs around 6.5lbs all up but has a very narrow hull (tapers to only 5 1/8" on the waterline at the transom) and it planes just like the real thing, with the 2 28-45 2000kv in-runners, and 1x 2s 2200mah lipo per motor which gives me about an hour plus 'play time'.

Hi,
A very neat and tidy boat.

I made one of these many years ago but nowhere near to the standard off yours.
Excellent work well done.

Thanks all for the comments.
The weight is rather more than expected, but attribute it mainly to the centre brushed motor/shaft/screw arrangement.
Hoping to get some pictures later this week and will post them.
The extra weight does not seem to impede performance, so not that concerned.

Hi
I am working on a Precedent Perkasa 37" and I added two sets of double 10mm magnets to the front of the wheelhouse and one set at the stern.
I can lift the whole boat with battery by the wheelhouse.
I do not think it's going to come off !!!
Canabus

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Hi All
I have finally fix the boats turning problems by racking the rudder forward 8 degrees and making a new rudder blade with the leading edge straight.
The bow only dips slightly on the turns.
Canabus

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Hi Canabus, Do you have before and after photos as this sounds intriguing? A video would also be helpful if you have one.
Thanks
Rowen

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Yes also, I would love to see pictures. Very interested . I even went as far as fitting small wooden wedges on the rear of the under side corners of the hull. that was all trial and error from other modelers suggestions on the pond side. Prop swaps and all sorts.

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Hi
A few pics of my modify setup, no pics before hand.
Moving weight fore or adding ballast works better than wedges.
Only tested the boat by myself and I gave it a real workout.
Motor 3639-1100kv, 60A ESC, 5800mah Lipo and 37mm 3blade prop.
A 40mm 2blade works better and uses a bit less power.
Rudder blade size 30mm across the top, 22mm across the bottom, 45 deep and the shaft 10mm from the leading edge.
Sharpen the leading edge and the trialing edge flat.
This catches are air in the water and send it to the surface.
Canabus

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Hi. Been watching this build progress and the discussion. Having seen the recently posted pictures of the rudder installation it appears that your problem is probably caused by the rudder aspect. From the photos it appears that the rudder post is not mounted completely vertical. Thus when the blade is turned by the servo this will create an aileron or elevator effect on the water flow. Things behave very. Much the same in water as they do in the sir.

Regards
Kevin

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Hi All
The boat had the rudder completely vertical to start with and that is the problem.
With the rudder vertical the boat pulls the bow down in the turns which makes it sit up on the chine.
A planning hull attack angle is about four degrees to the water, but these boats like an angle of about six degrees.
The leading edge of the rudder and the angle of it governs bow lift or dip in the turns.
Also the balance point of the boat is as important as the rudder setup.
Canabus

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Thanks Canabus,
Guess will not know if I need to do something like that until we are back on the water in Spring, but food for thought.
Rowen

Hi
Did you consider building the superstructure using plastic sheet as plastic would bend around the curves.

Regards
Kevin

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Hi Kevin,
Yes I did, because of the complexity of the shape that was another technique that could have been used. I decided to use glass fibre as the cowl is around 7" wide and 3 1/2" deep. Considered a draw of that depth was beyond my skill and facilities with plastic sheet. if they are available it would have been a good approach.
The more I work with glass fibre the more forgiving it seems to be. Not many mistakes that cannot be disguised or corrected!
Rowen

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How true, how true Rowen👍😁

Good thinking Batman👍👍👍
I hate those slide switches as well. They're always the first thing to fail on my garden solar lights.
Nice trick with the relays, could also perhaps have used one double pole relay to replace the ESC switches? Otherwise they are energised but in an 'undefined' state 😲
Strange, I don't have your 'modulation' problems with the brushless (1000kV) in my Sea Scout!?
'Get-home'; agreed 👍, that's why I'm pondering squishing a centre motor into my PT Boat. it's all stripped out and in the 'C Check' dock 🤔 so now is the time!
All the best Rowen, cheers, Doug 😎

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Thanks Doug, always appreciate your thoughts.
The relays are in a NO mode, so only operate when selected. On the bench works fine.
Perhaps you do not have the same modulation issue as you are using 1000Kv and I am 2200. My motors respond rapidly, particularly around the fwd/rev position, so am always trying to accurately centre the lever.
The motors I choose have integral cooling jackets and are nicely made. if they had been available in a lower rating would have probably used that.
Good luck with the PT boat, looking forward to hearing what you decide with the powertrain.
Good luck with the "C" check oug. Best wishes R

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Good point with the kV rating Rowen 👍
I could try an experiment!
Don't know quite why (JFF I suppose😁) I also have a 3500kV motor to play with, WELL it was there and not expensive, WHAT could I do?
Guilty as charged yer honor🤔.
I could stick that in and see what happens. Maybe I'll have to fit stub wings and floats and turn it into a flying boat😁
Had figured the relays where NO. Hope you remembered the back emf diodes, s'pect you did😉 Guess they are triggered by servo and micro switch, or did you get fancy with transistor drivers?
Whatever, great idea👍
All the best, Doug 😎
PS Just a thought! if it's 'kV' problem you could try screwing your drive battery down a cell perhaps? Then maybe it wouldn't be so hyperactive.
Another thought (must be the tablets!) many ESCs and TXs let you programme the width / sensitivity of the neutral point. Check your manuals, worth a try.

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Ref the PTB Rowen,
I 'inherited' it for a reasonable sum and it came with two what I believe to be 2200s! Can't tell for sure as the labels are worn blank. Previous owner said it was 'too much a handful for him'. We'll see - sometime next spring 😉
If I fit a third motor I was thinking of a brushed 385. What did you fit?
Cheers, Doug

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Bet the PO had my problem!
I used a 550 as had a spare, the 385 should be OK
Will respond to your earlier post tomorrow. Must close for night now

G'night 😉

Rowen, here are a couple of things that may be of use to you (and others). The battery alarm will save you worrying about running out of steam as they can be set to beep at varying voltages to warn you of low battery, just put one on each batt balance lead and when one goes off (when an individual cell drops below the set voltage) it means start heading back. These can be picked up on Ebay for a few dollars. I use them on my planes as well and are audable from around 100m (these twin horns are the best) Secondly, re your ESC switches, these electronic switches (AliExpress) are great for this sort of thing (as long as you have enough aux switches on TX ) You can link them with a Y cable to work together or use them independantly for anything, (lights, pumps etc, - they can be operated by TX rotary switches as well) The ESC and 2000kv motor (HK) are the ones I am using in my ASR model and will work smoothly down to a crawl, the purple 1980 kv seems to have superseded these but I think they will be as good. The props are from Ali Express and are resin and available in L and R hand, are only a few bucks and perform perfectly while looking quite scale(ish). I painted them with an acrylic bronze which seems to have stayed on pretty well. Model weighs 2.8kg and will run at more than 10mph flat out with this set-up (using the 26mm L+R) props) which is silly speed and that's with 2x 2s 2200mah lipos (which will last till you get sick of it and still have 60% left)
I was just looking at your Daman set-up and noticed the wiring method from the batts to the ESCs. You might want to make your batt to ESC connections direct to your ESCs (as per original ESC lead length)as your capacitors may get a thrashing (spikes) due to the extra length/ resistance you have there. There is a general rule that you don't lengthen the batt to ESC wiring without adding a 220mf capacitor of same voltage as the ESC for every 4"of extra wire length (ESC to motor - not so much). Might want to check this out in case you fry your ESCs You probably have thought of this but thought I'd mention it, 'just in case' Might help with your modulation as well.
Have chucked in a vid of the HSL manouvering (first trials so wasn't perfect) and also the MTB (brushed) which I have just converted to a twin system (was twin but single Electronize unit) plus a sound unit. You may know that you can use as many RECs (bound to the same TX) for various purposes on the same boat (have run 2 boats together from the same TX) Might get you round the mixed brushless/ brushed problem with a bit of thought. Have you thought of changing your old HK silver 6DF TX to twin throttles, it's a piece of cake(as is the TGY 6x), just remove the aileron/rudder centering spring and make a friction plate as per throttle stick, and use the elevator channel as your other throttle. Set your ESCs and you can then use a twin system giving you perfect control. Saves a lot of hassle.

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Thanks jbkiwi and RN in Munich for your suggestions:
Have never used Ali Express, those components look interesting. Will follow up. I have used a battery alarm of the type suggested and it does work well. Have a couple for use once back on water.
The rule about adding a capacitor into the ESC circuit is new to me. Have ferrite rings fitted so will now explore adding capacitors too. Are these is series or parallel with the wiring?
The relays are not used with diodes or any electronic gubbins. Wanted to make the circuit as simple as possible for a Mechanical Engineer, so used one separate relay per ESC. The relay operation is controlled by a RC switch off another Rx channel. it seems to work. Am aware of the back feed possibilities and hope to have avoided them with the separate circuits. Appreciate any thoughts though, can add diodes if necessary.
Am using a new FLYSKY 10 Ch. Tx/Rx on this model which opens up a host of programming opportunities. Am experimenting with various features such an the interval between Fwd/Rv also limiting ESC response. As am now using the brushless motors essentially in unison, also toying with controlling the 2 x ESCs on a “Y” lead on a single control.
Much to think about, pity our winter has arrived early and the pond has been converted to a skating rink.

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Hi Rowen,
Re Relays. The so called 'back emf' (reverse voltage) is caused when you switch off the relay. The magnetic field collapses and the energy is releases as a voltage spike with opposite polarity to the 'pull in' voltage.
Since you are using an electronic switch this spike could damage the output transistor of the switch.😡
The diode is connected across the relay coil as a blocking diode, i.e. back to front wrt the operating voltage, and absorbs the spike. Each and any relay coil needs one! This is a manifestation of the induction effect which makes E-motors and generators work 😉

Capacitors: Parallel!!

An idea with the Y lead👍 You'll lose the 'tank' steering assistance function though.😲 Happy experimenting, cheers, Doug 😎
PS I use the same alarms, also good for testing batteries on the bench, and ESCs from the same Quicrun range (in my Sea Scout for example), reliable and simple to set up.
Even simpler if you buy the little programming card for them. Only a few bucks and well worth it. I've been wondering if it's the response of your ESCs which causes your 'modulation' problem! Remind me; which ESCs are you using?
PPS have a look here for an explanation of the suppression (flyback) diode and how to connect it 😊
https://www.wikiwand.com/en/Flyback_diode

https://www.wikiwand.com/en/Flyback_diode

🔗

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Don't know what happened to my last post but I'll try again. This link, https://www.rcgroups.com/forums/showthread.php?1148637-wire-... href='https://model-boats.com/search?q=tag:battery' onclick="loadpage('search?q=tag:battery'); return false;" class="taghighlight">battery may be a useful read and explain what I am on about (rough idea in pic). I don't think too many people are aware of some of the problems which can be caused by altering Batt to ESC wiring. I don't think its too much of a problem at lower voltages but see what you think.
Not sure if you have a throttle curve facility on your new TX but if it has, using that you can create a gentle start, ramping up steadily, no matter how fast you push the stick up. You can ram the stick up but it will only follow the curve you set. eg pic showing random curve (you can make this any shape you want to control any function) there are usually a number of curves you can set and save for throttle, rudder - anything you want to control automatically. Not sure about your TX but my 9xr even has a feature whereby you can slow the servo action down (I use that on my Piper Super Cub flaps which come down slowly in 2 stages (2 pos switch) and go up faster. Your new TX probably has a lot of these features and once you find how to use them it will open up a whole new world of fun. Another example of what you can do with these computer radios is, on one of my models I am using 'flapperons' to slow it for landing and as the ailerons come down the elevator is mixed to move up to compensate to stop the plane nosing down. it's pretty much endless what you can do. I'm still exploring after 8 yrs of computer radio use. I remember a guy somewhere talking about the flashing lights on his plane and saying it wasn't the lights on a flasher unit it was the TX telling them to flash.

https://www.rcgroups.com/forums/showthread.php?1148637-wire-lengths-between-ESC-motor-ESC-battery

🔗

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Doug,
Am using the HobbyKing 50A Boat ESC 4A UBEC along with their programming card. The diode explanation makes sense so will fit one.
jbkiwi
My battery -ESC and ESC -motor wires are short, probably around 4" each. The addition of capacitors as suggested is intriguing as have never heard of it before. Think it is easier to keep things together in a boat, whereas with an aircraft pitch trim becomes a factor. Am using 2S batteries with a 50A ESC, with the motor max current of 30 A. Have you any idea what size of capacitor I should use?
The Tx/Rx combinations are almost infinite as the ESCs are programmable too. Just wish the ice would go so can experiment!
Thanks both for your help, with this hobby you never stop learning.

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Hi Rowen,
You don't need capacitors at all, and certainly not in series with the wiring.
Whereas I can heartily endorse all that jbkiwi says about the possibilities of modern TXs, I've only scratched the surface of what my Spectrum and Turnigy sets can do, I can see no justification for the extra capacitors on ESC leads.
The length of the wires inside a typical model can not have a significant effect on the total resistance.
Given a typical resistance of 1m of copper wire with ca 1mm² cross sectional area of 0.02Ω (less for larger gauges) it ain't gonna make a happorth of difference whether you have 4" (10cm) or 40". Maybe a little more warmth but the capacitor can't change that.
I also can't see where the spikes he mentions should come from.
Also bear in mind that the ESC does not apply pure DC to the motor but a pulse train with a pulse repetition rate of around 8 to 10kHz. That's why the motors whistle and scream.
Adding capacitors to this could distort the pulses or reduce their peak value.

If the ESC is so bad that it produces big spikes when the pulses are switched on or off (which I doubt theses days) then junk it and buy a decent one.
On no account fit a capacitor in series with the wiring, unless it is a special Coaxial Capacitor, which are very big and relatively expensive. See pic.
I've only seen them on large electric motors on board ships where the much higher currents and longer cable runs involved than in models may play a role.
A very small value capacitor, in the picofarad range might help to short out any potential high frequency RF interference but I've never experienced the need to fit them. in this respect it could be more important that the length of the cable is not close to the wavelengths typically used by RC sets (12.5cm at 2.4GHz) so that it does not act like an antenna.
Cheers, Doug 😎
jbkiwi have looked at the link you posted but I'm not convinced considering the small lengths we use in our boats. Yes there will be some overshoot spikes in the pulse train but so severe as to damage anything is in my opinion highly unlikely, given a decent quality ESC in the first place.
Something else on that link just occurred to me. There is a pic of what looks like electrolytic (polarised) capacitors between the wires. This is fine for aircraft ESCs which only run forwards, and thus produce positive going pulses. in our boats with reverse the pulse will switch over to negative going. Which after a while could have an explosive effect on the electrolytics. it blows the cans off and produces an interesting snowstorm effect. Good party trick😁 but maybe not so super inside a model boat😡
IF you do fit them to a reversible ESC be sure to use tantalum capacitors which aren't so fussy.

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Doug, you are probably correct and good thought regarding the polarised caps , but I was just thinking that if the battery input was going through a fuse system as it appears in Rowens photos (difficult to see) it may have caused a slight problem. I have seen mentions of up to 12" between batt and ESC being no problem at lower Amps. You might notice that one of the inputs was from a guy from Castle Creations (USA) which I thought would give a bit of weight to the information. I have always gone with the ESC manufacturers suggestions regarding wire length and have never had a problem in boats or planes (mainly in planes,-18 most 'converted' to electric from IC -3 capable of pulling 1200W) it's great to be able to chuck ideas and info around, as we can all pick something out of it all which will solve a problem, or perhaps stop us from toasting an electronic component or whatever. BTW, I saw somewhere that extending the wires could cause stuttering and that was one other reason for mentioning the info, as I know Rowen's had a problem with that. I'm sure it will be ok as is,- if its working fine, and it's not going to be run flat out every day it will probably last for years. Probably me thinking on the cautious side as my personal approach to building is to use the K.I.S.S method (may not be the flashest but usually keeps me out of trouble) Regarding the quality of ESCs, you will find that many have the same internal bits just with different cases and colours, (same with chargers) HK is bad for this. Many I have seen use an Atmega chip and you can tell differences by the programming method (some you have to do 1 step and disconnect power before the next step, others just with stick forward center back center etc. Most boards are made in China (Castle Creations and a few others being exceptions) and what you get depends on the quality of assembly/soldering etc in the plant they are made in (if you want to see how many of these items are made in China check out Made in China.com and search ESCs for example. I have cheap ESCs I've used in my planes for years with no probs which look like the HK Red Brick ESCs (except blue) and they are better than the TGY branded ones at 3x the price, and really let the power through !. Even CC have apparently made boards for HK with different cases as have Hobbywing. it's really a case of "you pays ya money and ya takes ya chances". in saying that you are pretty safe with Hobbywing, Tamya, SkyRc, or Castle Creations (USA) but there are other better non China ones around but a a much bigger price. Hope we aren't overloading you Rowen, you might have to get into the 'anti-freeze' to soothe the brain in that cold weather. Another site for you to check out which I have found to be very good, with prices to match HK is RCEcho.com (Hong Kong) Have bought most of my aircraft ESCs from them (around 28 from 30A-120A with no probs)

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Mornin' JB,
Guess I'll have to remain 'agnostic' on this issue for now - I'm still to be convinced. This might explain a phenomenon I've noticed during testing of the Taycol Supermarine I've just renovated for Colin. More on that later in the 'Supermarine resurrection' blog.
I'll do some experiments using my digital scope and see if I can trap and measure these elusive spikes for various wire lengths😉
Can't comment on the guy from Castle, don't know them, except to say that I found his comments a bit vague and without explanation.
There are also contradictory posts on that link; some say before the ESC some after. Can't really see the point of putting the caps in front of the ESC, switching spikes SHOULD only appear on the output side I'll look at that on the scope, and after all a fuse to protect against fouled prop and jammed motor is standard fit between battery and ESC, or should be! So some wiring extension for that is essential. Also I would expect the battery to flatten any spikes that do appear at the ESC supply side.

As you say the internals of several 'manufacturers' ESCs are often the same. Nothing new, branding and badge engineering has been going on for decades for all sorts of things and no RC kit manufacturer / distributor produces his own components. Important factors are; quality of his own assembly and where does he buy his components - originals or cheap copies?

28 ESCs! Wow 😲 and I thought I had a lot!
As reported I have so far had good results with the Quicrun series, both brushed and brushless. Next one to test is their Dual Brushed version.
Prior to going brushless I used a lot of Graupner ESCs - made in Korea., never managed to blow one of them either, not even the little micro and pico jobs.

Thanks for raising this issue - I like a good debate and we can all learn something from it I hope👍 Plus; piquing my curiosity is always dangerous 😁
Greetings to Down Under from 'Up Over', cheers, 😎Doug
PS Further thought just struck me (Ouch😡); if this is really a dramatic problem why have I never seen any warnings about it in any ESC instructions? Yes, I'm THAT guy who actually reads the instructions!!

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Thanks all for your help and suggestions. Plenty to noodle over during our cold winter nights.
Rowen

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Spaghetti or Farfalle? 😁😁 bon appétit 👍

HI a chap in our club sails a Vosper mtb ,quite fast on a single screw , planes easily even on its brushed motor . every time he tries to turn at speed the boat dives bow going under water . we think the rudder , when the boat banks is taking on a horizontal conponent like an aeroplane elevator . we seem to use rudder sizes much larger in comparison to full size boats which wont help Cheers Ian

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Lot's of people disagree but I have had this happen and was advised to trim the leading edge off of the rudder as it acts as a brake and will cause the boat to dig in on the turn. I have trimmed mine and always do now when I build a new boat. I have enclosed a picture to give you an idea of how the rudder blade would look when trimmed. Once cut to this shape I then round the corners with a file. You may get answers saying i'm wrong but it has worked for me. Anything is worth a try,

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Thanks for your suggestions. Once we get back on the water in the Spring will investigate further. My last run in the fall indicated that the performance was now satisfactory and predictable. Cannot wait to try again and confirm.
This is my first foray into a high speed vessel and it gives plenty of food for thought as even minor adjustments can make a big impact

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Hi
Can we have a full picture of the rudder please.
I was going to angle the rudder back to get the bow to stay up in the turns.
We did this on tunnel hull boats years ago.
Canabus

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Glad it all worked out in the end Rowen 👍
Cheers, Doug 😎

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Thanks Doug. Seems to have, been a long and exciting road though!

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That's why we're all here ain't it! 👍😉
Doug 😎

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Wonderful stuffs. What's the pump to flow waters faster?

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Is it a car windscreen washer pump ?

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The pump was installed to give positive water flow even when stationary. Felt this would ensure cooling under most conditions. The plumbing is quite torturous and suspected there might be a significant head drop in the circuit.
With the wisdom of hindsight, probably overkill; the water scoop between propellers may prove adequate.

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Used a small 6 - 12 volt pump bought from E Bay. Have used windscreen washer pumps before, but they are relatively heavy and bulky. This was quite compact and light and were closer to my weight restriction.

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Thank you! Found this pump in Ali express.

Here's the link if anyone needs: Waterproof Ultra-quiet Water Pump 4.2W 240L/H Micro Brushless DC 12V Water Pump Car Submersible Fountain Aquarium Circulating
https://s.click.aliexpress.com/e/cVs7aajO

https://s.click.aliexpress.com/e/cVs7aajO

🔗

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I used this pump from E Bay which pumps well, and with the rubber mounts is quiet. 6-12v (I use a 2 cell LiPo which seems perfect) and am cooling 2 2000kv 28mm in-runners. Have tried a few different pumps and these have been the best so far. You have to be careful that you don't over pressurize your plumbing system, as if the hoses come off while running you can fill your boat up in no time. it's safest to adjust your pump voltage or piping to a 'neutral' pressure rather than risk hosing down your electrics. I used twin pick-ups behind the props and separate feeds, one for the pump and one direct in case the pump stopped or blocked.

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Great idea using separate feeds.One less worry.👍

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Never thought of using separate feeds, good idea. That pump looks like the one I used too.

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The only thing you might have to watch out for is back feed from the pump out the aux tube (when moving) if you don't set up the y joints (must be y not T ) to create a venturi effect from the pump side. Doesn't matter standing still but at speed a T junction might reduce the flow as the flows will be fighting each other slightly. The beauty of the twin system is that if you are running a lot at high speed you could turn the pump off to save power. The best place to position water intakes is I have found is directly behind the prop (I usually just squash the brass tube slightly, fair it, cut it off at 45 deg and set it to just sit in the prop wash). At lower speeds especially, the prop will help to push water into the tubes rather than just relying on speed alone. Never had a problem with pickups interfering with rudder effectiveness as long as you fair the pickups nicely

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