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Not the cheapest, but available...RC Tech in Llandrindod Wells. Couldn't find the Chinese one again and didn't want the wait for the slow boat. Switch Electronics couldn't be arsed to answer the 'phone on a Friday morning, so they were out too. Should be here on Monday. Martin
Good to hear you are making progress with the noise. My ESCs are not programmable as far as I know (There may be a card somewhere). They were cheap Chinese waterproof car/Buggy ESCs with Fwd and Rev which I wanted for independent drives but for the price and how well they work, you can't beat them (about NZ $20 each) They have a very soft start (you can count the revs) programmed in as std, and the only problem I have found is that they sometimes won't go straight into reverse without quickly nudging forward and back, (just need to drive in a scale manner and it's fine.) I'll put a pic of the unit and motor in (also a brushed one I am using in the MTB (x2) which work perfectly only NZ $9.00) They have braking, FWD, FWD+REV and batt type adjustable by jumpers. Throttle set-up is simple with full FWD and partial Rev set by the sticks. Both types are 30A and never even get warm. I purchased some fans for them but have never used them. The brushless units have a fan plug on them. The squealing I have may just require a switching frequency change on the ESC (8kHz/16kHz -more RF noise on 16kHz but more efficient) but I don't think I have that option (do you have that option to try on your set-up ? might be worth a crack). The sound units muffle it a bit anyhow. Boat runs at 10mph (GPS) flat out (looks way off scale) but only needs about 1/4 - 3/4 throttle for normal cruising. Will try to put up an external vid soon. Transmitter is easily modded to twin throttles,- excellent cheap set for boats ( later model has internal aerial)
Starting a bit backwards here as have posted more recently with some ideas. If you are going to have a twin brushless system using 1 REC, you probably should have twin 2200Mah 2s lipos, a power lead (I use a JST plug set) taken from the input leads of ONE ESC (not the batt leads) (I break into them and solder the JST leads on ) run those to a UBEC and then to your REC switch then to your receiver. If your ESCs have a built in BEC, withdraw the red power wires from the BEC receiver plugs and tape them back as you now don't need the power from these. If your TX is 2 stick 4/6ch etc and is capable of being changed to 2 throttle sticks (provision for ratchet strip - copy if necessary - on opposite gimbal - ie using set up as mode 1&2 throttle) you can use the existing throttle and elevator stick to give full independent control with either rudder or aileron Ch for rudder. The Chinese ESCs I use have a power switch as well as BECs which is handy. I would keep the brushed system separate from the brushless altogether with its own battery (or try power from the other batt as described above) otherwise you may be trying to mix 3 phase and single phase at some point. If you are using 2.4 you could use another paired 3ch receiver (does work, as mentioned in my later post) to only run the brushless throttle from a rotary sw on your TX (if you have that )
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 Martin, Apropos mini Milling machines; this is the one I use. https://www.youtube.com/watch?v=qffdG_d2fJ0https://www.axminster.co.uk/proxxon-mf-70-milling-machine-37... Pics show using it to mill my new Sea Scout propshaft to secure the grub screws in the motor coupling. I just changed the tool holder from collets to a proper chuck. I also bought the little machine vice which clamps to the table, and the dividing head. There is also a CNC (putah driven version - ain't got that far yet, bit expensive😉) But this little job has served me well for several years now, very happy with it👍 I also use it as a precision drill press; e.g. to make the new phosphor bronze brushes for my Taycol target renovation. See last pic. Have also recently used it to make the little gearbox so I can fit the renovated Taycol Target into my ancient Billing Danish fish cutter 'Gina2'. See, I don't just do the 'Grey Fleet', sometimes I also mess with wood😁 Cheers, Doug 😎
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.
looking at the bulkheads I would suggest that the structure is meant to be built upside down on a building board. Each bulkhead should be fastened to a piece of 12mm sq timber then fasten to the base board at the appropriate spacing keeping them upright and square, then the keel can be glued in place followed by the chines keeping all the structure square and true. Just a thought. Ill post a picture of a similar vessel I am building at present in this way, but will be tomorrow.
Nah CB90, stainless s nice, but too heavy. This Chinese ally one is like a feather. Enables faster acceleration, which is what you want with a light outboard powered kneeler. Never seen a stainless prop. Ally, brass, bronze or plastic, plus the ancient twisted tin plate one on my 58 year old Sea Urchin. Martin
All of this over props! I'm glad I use scaled brass props. For my Tugs! I don't need sharp edges for them! If you know there's a possible danger in sharping the prop. You do so at your own risk! Stay away from beryllium props.... Cheers, Ed
Hi Martin, "how the hell would you know?" For a start you can look here. https://www.wikiwand.com/en/Brass Or quite bluntly ask the supplier / manufacturer. But as I say above, only seems to affect the extreme performance racing guys. Cheers, Doug 😎 BTW; OP?
Apart from Octura, how the hell would you know? I use CZ 120 and CZ 121 grade brass for all my work. I once had a lump of cast bronze stick which I used for a crankcase. It was harder than steel and hated being soldered, but it was the right size. I've worked with brass for over 50 years and never had a problem. But then, I've used cadmium silver solder without a problem too! Martin
Quote from rcgroups forum- "Yep, beryllium-copper in many racing props, like Octura's. No problem for "scale" brass/bronze props. " Seems only to be a problem for the extreme racing performance guys! Conclusion: Buy European!👍
dont know if this is a sales pitch to make them sound sexy as the element is used on things like the space shuttle and missile technology its also used in industrial spotwelder electrodes where it is alloyed with copper ,it is a carcinogenic and used to be called sweet metal due to the sweet taste if injected through taste ,personally I would just avoid it and purchase normal brass props .cheers Marky