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How does an outrunner fare with heat when closed in? The one you are using is goint to be even more closed in as it has a box built round it. I have been reluctant with an outrunner in a hull for this reason. I have a Miss Geico with an inrunner which is fine as it has a water jacket.
[Score: 10/10] 42" Vosper Single Propellor (3 Blade 50mm) Geared to a Os 40 fourstroke (3 Blade) - Comments: I always liked the sound of a fourstroke engine so I thought I would replace the brushless motor in this boat with an aircraft Os 40fs which I converted with a water cooling jacket that I turned up on my lathe. I also made a reverse gearbox with a clutch, the gearbox is operated by a servo and works well, I also fitted a water pump so could still cool the engine while ticking over stationary, boat has been weathered and is fitted with lights and a searchlight that swivels around operated by another servo, there is also a cooling fan above the engine just to help keep things cool.
I would check out the water cooled back plates for the out- runners as they will possibly run real hot if at all loaded up without cooling, unless you have fans like aircraft propellers (even then and in open air they still get hot!) I would look at this seriously to avoid cooking your motors. Hobby King usually has various cooling parts, or EBay, Aliexpress, Banggood etc. Bit late now I suppose, but water cooled in-runners (around 2000kv 28mm diam) are a better idea for boats. You can buy in-runners and water jackets to fit them as I did but they need flushing after use with CRC or similar to avoid rust, (I'll be copper tube wrapping the next lot, then there are no worries)
If you are using 2 ESCs/BEC/UBECs with 2 plugged into 1 receiver you should remove the red wire from one of the plugs and tape it back to the lead, as both plugged in will possibly supply too much voltage for the receiver (you are getting double the voltage from 2 different sources) and this can cause the ESC to stutter . You should have no problems with Brushless out-runner motors as with the correct match with the ESC they should be as smooth as brushed. I have dual 2000kv 28/45 in-runners (with water jackets) and twin ESCs and 2 sound units using 1 receiver in my 64ft ASR model with no problems regarding proportional control (fwd or rev). I had a 28mm O/R in a Maiami ASR and it would crawl along (but the high noise was ear wrecking so have changed it back to brushed for now. I do have a similar slight high pitched squeal at certain speeds on one motor and this may be caused by the particular motor not 'syncing'properly with the ESC (Chinese cheap ESCs and HobbyKing /made in china motors) but short of changing that motor and ESC I am just putting up with it for now. The high pitched sync noise is fairly common and sometimes not fixable, (a number of my larger planes do it and its audible from 100m away (also amplified by a hull,-nice sound box). It can depend on the way a particular motor is wound (no 2 are identical) or even magnet placement/timing, as the may be hand wound by 2 very nice Chinese ladies at different ends of a bench ( just read some of the Hobby King motor reviews ) You could try changing the frequency on the ESC if it has that option as a higher motor Kv sometimes requires a higher frequency. Also make sure your ESC is set to the correct battery cell count. If it has an auto setting that should usually work best for general applications unless you are running fancy motors. Regarding interference, make sure you keep your aerial as far as poss from the motors and ESCs (even on 2.4 - I put mine right up in the bow) and there should be no problems. I have had 2 twin engined boats (my MTB & ASR) 1 brushed and 1 brushless running side by side 10" apart using the same radio for both (same type of Rec in each boat) with no problems at all. The bow down is probably prop shaft angle (the shallower the better) but if you are using counter rotating props you could try swapping props (inward rotation to outward) and motor rotation to see if it makes a difference. Also with 2800Kv motors you should be using small props (around 28-30mm diam 3 blade) as these motors are made to rev) as on a 2s battery they will be turning at around 20,000 dry and perhaps 18,000 wet (depending on prop) and if you load them too much they will cook with no cooling (assuming they are around 28mm dia ?) Only other thought - silicone couplings will squeal real loud if they slip.
Hi Onetenor Fuji 15 was a good glow engine which I don't think it is manufactured any more. Aero version max B.H.P was just below .40 when tested. If it was in a model aircraft it would have been around .20 to .25 depending on prop size which was good then for a small capacity glowplug . Marine versions when on the water put out a little less and the water cooled jacket was never as efficient as the finned cylinder jacket of the aero version. My two Aerokits boats, the Sea Commander and the Crash Tender are powered by single Speed 600 motors running on either 8.4 or 9.6 volt Ni Mh batteries. Performance is equal to that of marine diesel power such as the 2.46 Ed Racer and D.C 2.46 Rapier, the latter I used to watch in the fast steering events in the early 1960s at Fleetwood and Coronation Park in Crosby just outside Liverpool. Taycol powered versions would be obviously slower due to the additional weight were far more reliable and you did not have to put up with injuries from excessive use of a starting cord with kids watching and "extracting the urine" shouting "why wont it go mister". Boaty
This is my scratch built 36" RNZAF British Power Boat 64' HSL (arrived in NZ 1940). I actually went on board this vessel in 1968 when it was still in original form (the RNZAF having disposed of it in the 50s) This vessel is still around and has been recently re modelled (2nd time since early 70s) and I was lucky last year to have met the present owner and go on board (2nd time in 49yrs!)and take a few photos. The vessel was modified a number of times by the RNZAF over the years (air intakes, removal of the fore deck machine guns, wheelhouse turret etc so I sort of went in the middle. I found a few drawings of the type in an old mag which had side and top views plus the bulkheads and their positions, so I took them along to a copying shop and kept enlarging them until I had the desired proportions. This worked out quite well and using a few methods from other models I had built, managed to frame (ply) the hull and then fully strip plank it in balsa. It was then fiber glassed. The deck is ply, lined and varnish stained. The wheelhouse is varnished balsa and is removable for access (wheelhouse roof is also removable along with engine cover and foredeck access hatch, - small foredeck hatches open as well.). The wheelhouse interior has detail such as controls, instrument panels, skipper, steps to wardroom etc but is not too detailed as it is not seen. The boat has full lighting by remote switch, lights are all LED. All cowls rotate. The propulsion side has dual everything (motors, ESCs, sound units), would have had 3x but ran out of space! Motors are 28mm 2200Kv water jacketed in-runners (cooled by remotely switched pump) using 30A Chinese ESCs (have 5A BEC, Fwd and Rev). Twin sound units are 'GT Power' car units which have around 40 different sound selections, from Cosworths to diesels and are computer programmable (as well as manually on the unit ) for various functions. I am using one of the v8 sounds (8 cyls short in my application) which I think is as near as you are going to get to 3 Napier Sea Lions (for which there is obviously no sound available) They 'start' 'Idle' and are fully proportional in fwd and rev and can sound quite realistic (will attempt to put up a vid later). Batteries are 2x 2200mah 2s 20c LiPos which will last around 2hrs at least of sailing (they also run the sound units) Still have a few small things left to do (have just made wheelhouse air intakes) but don't want to get too fiddly. Just want to keep it a practical model.
Ah, now it's clean, it's easier to see. A Mills 1.3 Mk 2. A very good and much sought after engine. Much copied too! The water jacket is clearly an amateur jobbie. Not sure if Mills made a flywheel for marine use. Possibly for use on small tethered hydros and cars. The engine is worth more than all the rest of the boat put together! Nice job on the clean up. You could repair those mounting lugs with some of that aluminium solder I referred to recently. Cheers, Martin
The fins look like they haven't been touched, the home made water jacket is basically 2 brass washers with 4 screws clamping them tight to the alloy cylinder head, then a copper wrap around soldered on with 2 pipes soldered into the wrap. The fins were full of baked sludge, but luckily cleaned up with a fine needle and small swede brush. Cheers Colin.
Hugely long stroke, Colin and I've never seen such a long piston. I am truly astonished that you got even a fart out of it, much less a run. I'm assuming it was built as a marine engine or would you say the finned barrel of an aero engine has been turned down to fit the water jacket? A very large shouldered top to the crankcase. It really is a mystery. I can only suggest home made. Martin Edited to say it's 1.36 cc., so a bit of a nipper.
Well here it is, 10.35mm bore with 16.19mm stroke. The flywheel is 41mm dia and 12.5mm thick weighing in at 117gms. As you can see from the pictures it was a pain to strip, but as I was desoldering the water jacket the head came loose, so I unscrewed it. Then carefully stripped the rest and cleaned each piece, finally returned to the water jacket, I had to remove the outer sleeve then cut the screws to remove the top and bottom discs. Next I removed all the crap that was stuck in the fins and cleaned the cylinder head jacket. Finally re-assembled. All that work and still don't have any idea of the maker. There is a number on one of the mounting webs 685, on the other side is a number 2. But the Web is broken. The flywheel has RMA stamped on it and a letter J above it. So mateys what's the verdict. And god alone knows if I am able to rebuild the water jacket. Cheers Colin.
Thought U were goin' to hit the hay a while ago John!? 😉 Greetings from one model fan and insomniac to another👍 BTW agree with your comments about the water jacket. Sweat the screws out and the rest should be relatively easy. "In this the most perfect of all possible worlds"! Cheers All, Doug 😎 BTW: TELL me about those relays! For a year or so back in the early 70s I used to service and calibrate the radiation monitors at various nuclear research / power generation sites around England. The detectors tripped a relay via appropriate drivers, which then triggered the unit Nixie tube, etc, etc. My job was mainly cleaning and setting the relays and doing a calibration against 'normal' background count, cosmic radiation etc. To reassure folks; during the whole year - year and a half I never ever saw a count above background! But then - that was 46 years ago 😲
Colin, it could be that the jacket is just that, a coat, a covering that allows some water to take conductive heat away. One hopes that it isn't allowing water to touch the actual motor or grot will be your future! The way the jacket is made may give you an idea of how it operates and how best to get it apart. As it's copper, it'll only be soft soldered I would think judging by a lot of grey clag around! Worth doing though since clearly it's a runner, despite all the muck on it. But I would invest in some proper model diesel fuel, if you can justify the cost! Then you shouldn't get those 4" flames out of the stubs! Cheers, Martin
Well Martin, whoever built the water jacket didn't think it was necessary to be able to strip the motor, but I've been thinking about it and have decided to try and get the jacket off so that I can resurrect the poor wee beast, at least I'll know what engine it is. Usually the tick over was set at about 1500revs and the peek was about 2700/3000. I think that would be a tad too quick for a boat the prop would be cavitating at that speed. The boat is only 27 1/2" LOA with an 8"beam. Cheers Colin.
Fantastic stuff, Colin. If you can get that ancient engine to run on diesel from your car plus Methanol, you could get that kitchen nozzle going! Where did you just get some methanol from? I'd say the engine is something like an old ED Competition Special or similar with a very home made water jacket and even more home made exhaust wrapper, requiring tubes to be added to the 2 stubs and led to the stern or either side. Doug's yer man for anything lecktrickal. Is there actually anything of the original RC in there apart from that superb kitchen nozzle affair, which deserves to be preserved all on it's own. Control will have been vestigial at best as the engine has no throttle and the nozzle arrangement will not have had any level of proportionality to it. It will, at best, have been push the button and see where the boat ended up, knowing it could, at a a pinch, be brought back to where it started. At one time all RC was like that. My own REP set was left,centre, right, centre, etc. A wonderful throwback that must be preserved. I wish my local junk shops had stuff like that! Cheers, Martin