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White Star BB''570''

Started on an easy build. A White Start from Billing Boats. As usually the build instruction is very basic, all is more ore less shown on the main drawing. I have skipped the original 3mm shaft and added a 4mm from Robbe incl. a 3 blade Graupner as used in my Classic. I'll be using a 1100KV Brushless motor with a 2S LiPo. The basic of the hull is now done.

5 years ago by Tica

Forum

All hooked up, nowt happens...

".. Worked through the instructions and it made beeping and squawking noises in what seemed the right places but still no reverse. The increase in revs does now cover the whole of the stick travel above the mid point so I has changed something. Lost the will to live after 2 hours so went and worked on something else. Steve..." Just a thought - may not be applicable, but we often share our reversible ESCs with the car fraternity. And some of them have an odd reverse. For some cars, you may be happy with straight forward and reverse, but for racing this is not ideal. Dropping into reverse if you move the stick/trigger back past neutral would make the car uncontrollable on a corner. instead, the racing car boys have a system whereby the forward stick increases speed, while 'reverse' performs dynamic braking by shorting the motor terminals (or perhaps even regenerative braking!). To a boaty, this would seem as if the forward stick worked, while reverse did nothing. These racing car ESC programs DO allow a proper reverse. The way you usually get to it is to bring the stick back to reverse, then forward to neutral, then back to reverse again. it's a two-stage process - call for reverse twice. if you go into reverse, then forward, then back again you won't get reverse - it has to be reverse, neutral, reverse. Which is fine if you are manoeuvring a car into a parking space, but rather clumsy for a boat....

5 years ago by DodgyGeezer

Directory

(Racing Boat) skytech H101

skytech racing boat with water cooled engine.lts capable of 18 knots ! it has a self righting function and came with a spare battery pack,prop,oil and spanner. hope to have some fun with my grandson. (Motor: 380 water cooled) (8/10)

5 years ago by keithtindley

Response

Modav Huntsman 31

Hi William, S, X35 !? No idea😲 I assume they are terms from the racing world which I have no particular interest in. My intention wasn't to make her into an offshore racer. As it is she's well over scale speed, but fun to run, and that's what counts ain' it? 😉 Gives a good long run time, 1 hour plus, using a Propdrive 2830 BL and a 3S 4Ah battery. All up weight 1974gm. LoA 24", beam 8.5". My prop is simply a 35mm ca 14 pitch from Raboesch. Actually wanted the one with a blunter hub but they weren't available when I wanted it. The pointed hub variant is actually more like as fitted to larger naval units in WW2. Sorry🤔 Cheers, Doug 😎

6 years ago by RNinMunich

Forum

Chinese props

Quote from rcgroups forum- "Yep, beryllium-copper in many s, 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!👍

6 years ago by RNinMunich

Forum

Brass bashin' Chris Craft deck fittings...

I was just searching for a model car pattern I made months ago for some mods and I found all the lovely etchings I'd done years ago, pre computer, for Riva and Chris-Craft models. These two pics show two brass patterns for the Riva vents and two of the white metal cast vents, one polished about 20 years ago, one done just now, to show that a well burnished casting will stay looking chrome even without lacquer. Then the two Chris Craft tread plates I had the great, good forethought to draw when I found I had a bit of space on the Riva fret. They are perfect, as are the Chris-Craft side flashes and all the Riva badges, even though they were done from hand drawn artwork, proving that Vector images are NOT essential as the pootah people will tell you. I shall mount these two on the typically wedge shaped base and have them cast. I also found a FUEL engraved cap cover which will go on my Chris-Craft filler. it happens to be bang on size wise! I'm cock ahoop! I knew I had these, but had no idea where to start looking. Thanks Mel for getting me started on the search for your Tecno F2 car, but sorry, couldn't find that devil. I have made some more Vincent bits, been to son's to play on his new steering wheel and pedals racing game ( I managed a whole lap of the proper Silverstone in a Lotus 25!) and dined out with the lady wife. What a great day. Martin

6 years ago by Westquay

Forum

Spektrum, new, useless...

Read further down and he clarifies that. Apart from that you can regard all brushed motors for models as 'In-runners' if you will! BTW: your last video was interesting, as far as it goes, for those into breaking the model boat speed record or competitive racing. For me the the boats themselves are totally boring, but that's just me 😉 I suspect that the majority of us here are more interested in scale modelling with a run time of more than 5 minutes. I believe Martin's planes are relatively small so I'm not sure if a small prop will be be a limiting factor. Choice will likely finally depend on the space available in the fuselage! Like I said 'Each to his own' 👍 Anyway, I'm convinced; leave the in-runners to the car racing boys😉 I only have outrunners anyway, even my Catalina arrived with two outrunners!! Mus check the 'Flying Wing' again😲 Thanks for the heads up! 'Tempus fugit' and progress too! Cheers, Doug 😎

6 years ago by RNinMunich

Forum

It's a sad day!.

I think one of the mistakes people make is to assume that they must run their models with others of a similar ilk. That rather means a club of some sort. I say organise a loose grouping and find a river. You can buy a little dinghy/outboard combo for very cheap as a rescue boat if you can't get to the sides all round. Since the river will have diesel and petrol boats on it, you're fine. Canal Locks can be ideal and many (most) are not manned by any pretence at a Jobswuff. Some rivers have no speed limit sections, such as the River Nene and, last I looked, the Yare. So join in. There's nothing sacrosanct about model boat ponds and anyway if the Council Nazis have decided No IC, they are no longer model boat ponds, since that was all there was at one time. I ran a model boat display on the Well Creek in the Fens a few years back and we had no other than the famous AMPS man, Miller Agnew,with his Rossi powered outboards on his gorgeous tunnel hulls, models of real F1 powerboats. He came with the Cambridge club whose secretary made a point at day's end of thanking me for asking them. They had never run on a river before and all loved it. They had R/C water skiing, racing, you name it and all thoroughly enjoyed it. in the end the Police had to move the traffic on the main road opposite who had stopped to watch. A Rossi powered F1 at full chat on a river only 20 feet wide is something to see. Apparently Mr. Agnew was heard to say that "this is proper model boating". So, go rivers, young man. My, we'll be running out of middle fingers in no time! Martin

6 years ago by Westquay

Response

H.M.S. BRAVE BORDERER

Thanks all for the responses. Donnieboy - have thought out the plumbing, which is simplified by using a cooling pump. See future episodes! Doug - appreciate the concern regarding the red ESC wires. Have been trying to understand the rationale behind that theory. if all ESCs share a common input voltage, i.e. from one battery, what would the connection of multiple red wires do? Can understand if there were several unique power sources, but that is not the case here. Perhaps with your electronics background you can explain. Colmar - Used the angle on the scale drawing. if it were good enough for Vosper, should be good enough for me! Think it close to 7 degrees anyway. Think short shafts with oilers should help. Have heard of bushings running dry and seizing with these high speed motors. The initial props are scale versions of the originals. Rather suspect they will not prove to be ideal. Have purchased some 2 blade racing style props for a future test. They have a much coarser pitch and are designed for high speed motors. Intend to use plastic props initially as they are cheap enough to experiment with. Perhaps others have a comments on the cavitation question?. Incidentally, this is my first high speed boat too, but there is much of information on both this web site and Model Boat Mayhem for guidance. Posting questions always generates useful information. Look widely though at all types of fast models, MTBs, RAF launches, E Boats etc. - it has all been done before!

6 years ago by Rowen

Directory

(Racing Boat) Interceptor

Zoom 1 (Interceptor) Mono boat. Built from a Glassfibre hull, brought on Ebay for £35 the hull is a slim mono racing type with a self-righting side cabin it runs a 1400W 14V 2958 4200KV Brushless Motor and 29-S Water Cooling Jacket with additional air cooling fan. I did not want to use a flexi drive as high maintenance and prone to failure so the shaft runs via two universal joint one at each end. the propeller is a 38mm copper alloy The ESC is a 200A and water cooled the twin rudders supply separate water one for the motor and one for the ESC. The rudder are positioned to reduce prop-walk and are hinged to prevent damage if hit a object in the water and ride adjustment. Turn fins and trim tabs for ride adjustment were provided by a spares kit for another boat. also foamed and added an inner sealed hatch, a rubber bump strip and safety loop. The Boat is fast and over-powered used at half throttle, may use a 7.4v lipo instead, the self righting works well. 20th April 2018 while running on 11.1v the boat stopped, no response on retrieval it was found that the manufacturers battery connector had melted and the connection lost see later pictures. the battery was made by FLOUREON and was a 35C with 5500mah capacity the 80A fuse had not blown. (Motor: 2958 watercooled) (ESC: Unknown 200A) (8/10)

6 years ago by CB90

Response

Devil in the detail!

I'm with you there Skydive 👍What Boatshed means is the part of the rudder in front of the stock. Thinks: are you building an Offshore Power Boat or a scale Lifeboat? If the former then follow Boatshed's recommendation. If the latter and the rudder is 'scale' then leave it alone. Any braking effect, which usually is only significant in a fast racing boat model or other fast planing types, can be diminished by reducing the rudder servo throw at the TX. One should also consider how the original behaved, maybe they did 'dig in' maybe not. There has to be a reason why such rudders were developed, and surely not just to annoy modellers 😁 One more minor point that struck me - Ouch 😭 Your prop struts! "not that it provides a huge amount of support but adds to the scale appearance." Even in a model they can be important. To help reduce potential whipping of the propshaft, especially if the model is overpowered. Actually in the originals they were vital, especially in larger vessels. The purpose of these struts, in larger vessels 'A' frames, is to provide support to the end of the shaft which carries the prop weighing several tons and, more important, to carry the bearing for the outer end of the shaft! Actually in the originals the shaft tube, or 'Stuffing Box' would not extend significantly beyond the hull. Thus the strut or A frame was vital for the shaft end bearing, fitted immediately in front of the prop for maximum stability. Attached pics of my HMS Belfast (sorry don't 'ave nutt'n smaller with this feature🤔) show the arrangement. Have witnessed such construction in various shipyards around the world. Last one in UK was the first T45, quite an experience! 😲 In the end she's your boat, if it feels good do it! 😉 I would leave the rudder alone if it is 'as fitted'. 👍 I make my struts and A frames from brass sheet and tube. Cheers Doug 😎 PS Stick with the brass Donnie! 👍

6 years ago by RNinMunich

Media

Zoom 1 (Interceptor)

Zoom 1 (Interceptor) Mono boat. Built from a Glassfibre hull, brought on Ebay for £35 the hull is a slim mono racing type with a self-righting side cabin it runs a 1400W 14V 2958 4200KV Brushless Motor and 29-S Water Cooling Jacket with additional air cooling fan. I did not want to use a flexi drive as high maintenance and prone to failure so the shaft runs via two universal joint one at each end. the propeller is a 38mm copper alloy The ESC is a 200W and water cooled the twin rudders supply separate water one for the motor and one for the ESC. The rudder are positioned to reduce prop-walk and are hinged to prevent damage if you hit a object in the water and also for ride adjustment. Turn fins and trim tabs for ride adjustment were provided by a spares kit for another boat. also foamed and added an inner sealed hatch, a rubber bump strip and safety loop.

6 years ago by CB90

Blog

Up Grade NDQ speed boat

This is not a build but a modification of a cheap Chinese boat just for fun, I got a bit bored of scratch building projects as they take so long especially as I am not retired yet. The NDQ 757 Coastal Brother 1:25 Radio Controlled Racing Power Boat cost about £25 each from Amazon. These boats have a basic 27mhz radio and two 380 type motors which have forward and reverse and you steer by powering one motor or both for straight ahead. I bought two of these boats as they are light and about 24 in long, one to convert/upgrade radio, esc and brushed motors. The second was to upgrade radio, esc for brushless motors. The brushed motor version I put in two higher rated motors (390) with cooling fans built in, but same motor diameter but longer body I had to modify the mounts, kept same couplings and shaft/propellers. I did remove trim tabs (fixed) and replaced the straight running adjuster for a racing rudder. The brushless version is the same but has brushless motors 2x 2845 2600KV sensor less Specifications: KV(RPM/Volt): 2600KV RPM: 50000 Max Current: 42A The boats ran well but trimming needs attention, as hull is curved up at the back so trim tabs down, to prevent proposing, in-fact at one stage the boat left the water, but need to distribute weight towards the bow. Tried on 3S (11.1v) for brushless went well but got slightly hot after 10 mins. 7.4v for brushed also got slightly hot after 10 mins., and went nearly as well as the brushless. Surprised!!

6 years ago by CB90

Forum

Too Powerful Brushless ?

Graham That sounds much better and will move your boat at a very fast speed. I must reiterate my previous advice repeated by BOATSHED regarding the extra support for the prop shaft at each end and adjacent to the bearing. Unlike brushed motors, brushless accelerate to their KV rating at a very fast rate and if your installation is not solid (as concrete) you will experience all kinds of problems, all costly, and often terminal (personal experience confirms this). Finally do get a wattmeter and check the amps and wattage whist holding the boat in the water. if either are above the rating for the motor, ESC or battery you need to reduce the prop size. I can't emphasize this enough as the consequence can be an explosion on the water and total loss of the boat and all its equipment. Asw you have mentioned 10000 mA I assume you will be using two 5000Ma batteries in parallel. This is OK providing you use and electronic coupler between the batteries to disconnect a discharged battery to ensure no one battery discharges below the recommended value. These are not cheap and personally I would use one battery and change to a new battery when the first was depleted. I accept that if you are in a racing situation this may not be possible, but I suspect as a newbie you are using for pleasure purposes. I hope you will now be able to proceed to install the new motor and prop shaft and supports as suggested. Please keep us posted and I look forward to seeing your model on the water

6 years ago by Dave M

Forum

Too Powerful Brushless ?

sorry to bore everyone with repeated info, as a similar question was posed recently. I agree with the fact that shaft is too thin, it very much looks llike a fibreglass very light racing boat set up, now this doesnt mean you cant go fast with your boat, but you need components that are up to lugging a big heavy lump of wood around the pond, not a lightweight feather😊 I have 5mm shafts, less whipping. and I have oilers so they are lubricated with oil rather than grease, just my preference. You can get these shafts from shg marine, they will supply with push in aceteal (probably spelt wrong!) water lubricated bearings, real cheap, so you can change then every season if you want. The shaft has to be supported, where it exits the hull, just put it through another piece of ply, and fill the void with epoxy, and double up the former thingy it goes through in the same way. (pic) The prop you used is the wrong blade type, thats probaly why it fell apart, plus the soldered on blades are a weak design for higher speed, simon higging is one piece, but at this stage, still testing, you can get plastic "x" blade ("s" blade are less speed)_ props again from shg marine for a few quid each, then you can test a few different sizes. if you jump in for an expensive brass one, and its wrong, its wasted money. As a starting point, 35mm, 40mm and 45mm, if you dont have any way of testing with data logging etc, you are doing short runs, with the smallest first, and seeing if the motor gets hot etc, and what sort of speed you are doing. My brushless motors are generally 800 to 900kv, and achieve 25mph in four foot heavy hulls, you want lower kv for torque, not high kv high rev motors. I got into thsi 10 years ago, thwere was NO advice around then as it was new tech in boats so I learnt the hard way😭 When (if) you go to a brass prop, the "cleaver" blade design (pic) works well, I did extensive testing with my Huntsman and fireboat and was lucky enough to have Simon Higgins testing props with me on my boats, again because what I was doing, large scale boats, but going very fast, was unique, and the cleaver design was the best at the time. Forget the fear of lipo, and brushless, they go as slow as your throttle stick is pushed, 👍

6 years ago by pmdevlin

Forum

Too Powerful Brushless ?

Hi Graham, all agreed with you post. But. The last photo looks like the blades are soldered or brazed on, that is a week point, but looking closely the blade appears to have sheared of above the hub. Your hull is not really a high speed hull, so a might cause instability, i would suggest a cast prop, (propshop) and possibly 3 blades 40 - 45mm with your 1100kv motor would give good speed combined with good run time. The 5mm upgrade is also a great idea. A rule of thumb is don't exceed the diameter of the motor. Mark

6 years ago by jarvo

Forum

Too Powerful Brushless ?

Hi Mark, i have a 4mm shaft fitted and the boat was out of the water at the time, it happened when i just touched the throttle! i thinking maybe a 5mm shaft would be good (less whipping)with a eller and a 1100kv motor with a rubber heavy duty coupling, i think that would be a good setup and will be suitable for a 3ft boat. i think the brass propeller is just not built for high revs, or was it a 1 off badly made propeller? anyway would that setup be good? thanks Graham

6 years ago by Traiderman

Forum

Too Powerful Brushless ?

HI Graham. Every picture tells a story!!! The motor is definitely wrong, its designed for racing, low torque, mega revs, not for scale boats. What diameter is the shaft tube??? looks thin??? did the prop shear in the water?? would explain the vibration and damage to the shaft mountings, try a Raboesch shaft, with a ballrace at the motor end, great quality, also they do a huge range of props, google the name there site will come up. Mark

6 years ago by jarvo

Forum

Too Powerful Brushless ?

Hi Mark, i don't have excess to a lathe, do they sell prop shafts already loaded with bearings? or s? Thanks for your help Graham

6 years ago by Traiderman

Forum

Too Powerful Brushless ?

HI there With that setup you are trying to make a boat fly :-) Several members of my local modelboat club is running the same setup as I do with my Classic. And that is a Graupner Compact 260Z 1380KV for the Classic 2S is more than enough and 3S will still make the Queen fly over the water. So a 1100KV on 3S with a 3 blade semi will do a great job. You could also cut down on amount of "S" on your existing setup and program the ESC to slow start.

6 years ago by Tica

Forum

Motor problem

Hi Richard, looking at the markings on the motor case, it might be a 550 type, and rated at 7.2 volts, so it would seem to be at the top end of its capacity, did you manage to get the prop diameter? also is it plastic or brass? A 600 motor is a bit larger size and power wise but would still fit your motor mount, they are common in power drills so usually have plenty of torque, but can be power hungry. A prop to suit would be about 40mm, 2 blade or 35mm 3 blade both in brass, plastic props tend to be racing types with deep cuffs on the blades, possibly the cause of the burnout! The 850 is a lot larger and more powerful but would need a new mount and again is power hungry, probably needing 12 volts as well. Have a look on ebay 600 motors are about £5, but check to see what the rating of your ESC is, needs to be at least 20amps, although if it survived cooking the old motor it must have a good rating. Add a 15 - 20 amp fuse for protection. Just had a thought, is the prop shaft stiff to turn? should spin freely without the motor connected, might have old oil or grease in the tube causing excessive drag, this could cook the motor as well. A pic of the prop and its size would be a great help. Hope this helps Mark

7 years ago by jarvo

Response

Jaydee

Hi Ian It's a and will use lots of power hence the heat. As you have a cabin cruiser it does not need such a coarse pitch prop and changing to a prop with a lesser pitch will improve your running time and produce less heat. Performance will depend on the chosen prop but should not be much different from what you already experience. As you already have a water cooler inlet and outlet you could just wrap some copper tube round the motor and connect with silicon tubing to keep the heat down Dave

7 years ago by Dave M

Response

Red Cat hydroplane

Hi, Ta for the info👍 Glad the burn-out problem is solved. Would like very much to know what make and model your BLs from HK were as I have just bought a couple from them 😲🤔 Mind you I'm not going racing so mine are only tiddlers like the Propdrive v2 28-30 1000kV. Cheers Doug 😎

7 years ago by RNinMunich

Forum

Crash Tender Shaft Tube Poistion

Hi Neil That link for the seal is for a flexishaft drive. Totally different to a propshaft and proptube. Used by the fast racing fraternity. I am not sure it would work in your setup. Anyone used one with a solid propshaft? Dave

7 years ago by Dave M

Forum

Overlander Typhoon 625

Used to be fitted to the Chinese imported fast gentleman's run arounds. Fast torky motor and I suspect a suitable alternative would be JP Pro Power 480 Electric Flight Motor http://jperkins.com/ Match it with one of Simons (ex Prop shop) s and you won't be disappointed. Dave

7 years ago by Dave M

Forum

propshafts

Hi Doug I agree a 600 is probably too heavy. Looking on Cornwall Model Boats site the motors sold for the kit (currently unavailable) look more like 400 size. I have used JP Power 480 motors in small craft and they are very punchy, light 92g and will work very well on 7.2v with a shaft diam 2.3mm. I agree the Raboesch prop shafts are good but to keep the weight down I would be looking at 3 or 4mm. Prop Shop have three bladed s specifically for this motor. Dave

7 years ago by Dave M

Media

Bademenuss

Altered Krick Lisa M model kit seeking realism. inspired on 1970s 40, 42 and 43 Hatteras, Uniflite and Viking Double Cabin American yachts. 9v LED navigation lights system. Approx. 1/20 scale. Real life boat could be nearly 39 x 13.7 feet. Similar real-life Hatteras 40 Double Cabin yacht measured 41 x 13.7 feet. Runs with NiMH 9.4v battery, an HPI Racing 1145 Gt 550 Motor 14.4V, and a 40mm 3 blade propeller.😁

7 years ago by Krampus

Forum

Fairy Huntsman

As this is a refurbishment chances are it was fitted with an IC engine in which case you need to remove all the gunge and heavy mounting blocks from inside the hull as well as checking the propshaft and bearings. If you can get the weight reduced then I would expect a speed 600 motor with a 30 to 40 mm prop should suffice. A 20/25 watt ESC powered by a NiMh would also be suitable and keep the weight down. if you use s the current will be greater than if you use brass 3 blade props, and the bigger the prop the greater the current. As a general rule the prop should have a diameter of no greater than that of the motor. The voltage of the NiMh must not exceed the max voltage the ESC can handle. A higher voltage will reduce the current draw so a 9.6v may be better than a 7.2v and give a longer run time. if you already have batteries for other models I would use those but SLA's are heavy and may hinder planing. if you already use LiPos then make sure your ESC can stand the voltage and has a built in cut off to protect the battery.

7 years ago by Dave M

Forum

Battery problems

My knowledge of "elecy" stuff is pretty limited, but I see that the model boat world (excluding racing types) is in the dark ages compared to planes, helis, cars etc when it comes to motors, batteries etc We have to reply a lot on testing, fiddling etc when it comes to gettingn a fast electric set up, in a scale heavy old wood boat😁 as there isnt much info out there. I tried testing over a long time, with one boat inparticular, and was lucky enough to have te use of eagle tree data logging, so could measure watts, amps, gps speed, voltage drop and so on, and analyse the resultsd on graphs etc back home on the pc. its amazing to see that sometime s the fastest set up isnt always the best when you compare run time, amp draw, heat, voltage draw etc, and what "looks fast" sometimes isnt as fast as you thought😊 This boat for example, 6kg, ply construction will do 25mph, after that torque roll is kicking in, and it want to roll over. I tested props over a long time, using cheap plastic "X" props, and with the results was then able to get a more efficient and visually pleasing brass cleaver 3 blade one. Ranging from 50mm to 55mm the amp draw went from 45a to 90a using same batteries!, and teh highest amp draw prop didnt produce the fastest speed, all interesting stuff. The boat is similar to the OP perkassa. I also went from direct drive, to a geared drive, and can change the characteristics of the boat using different cheap gears, eg., small lake, dont need top speed, so change to acceleration, big lake, lets give up acceleration and have top speed, and so on👍

7 years ago by pmdevlin

Forum

Battery problems

something is fundamentally wrong here, there is no way that motor/esc/battery combo should have fried the esc in your perkassa. I have a number of large scale boats with a fast brushless set up, I pull almost 90 amps with one of them, on the initial acceleration, using 6 cells, 120a esc and (here is the difference) a 900kv brushless motor. The racing guys use high kv motors, they need the high revs, with a heavier boat like yours, you need the revs, but also the torque, which is a lower kv motor Before you do anything else, buy something like this http://www.4-max.co.uk/wattmeter-budget.htm really cheap, but saves you a fortune. As many of previous posts have said, you need to measure what is going on, for example, the specs of you motor say max current is 100amps, you need to measure your amp draw. You know the esc was 160a with a burst of 200a, so should have been well within the capabilities of your set up, but we cant see the prop. if its too big, and too coarse, particularly holding the boat, the amp burst would have had to exceed 160a to pop the esc, which is also well over the motor specs. I doubt the hobby shop will do anything, as the fault could have been a multitude of things, Personally, I think that motor is way too high KV, and I'm saying this from experience of large, heavy scale boats, with fast brushless set ups. I would have expected it to rev very high, but not deliver a really fast top speed, but I could be wrong. Shame really as its quite an expensive set up there. Are you sure about the facts, holding that boat, and max throttle must have been pulling your arm off, I cant hold any of mine😱

7 years ago by pmdevlin

Forum

Battery problems

Hi Allan The motor and ESC seem well matched which points to the prop being too coarse a pitch. You have a large scale boat not a fast racing boat and I suggest you replace the prop with a brass three blade of 35-40mm. As we have suggested a wattmeter will help you determine which is the most suitable for your set up. My Sea Queen with a similar set up (40mm brass prop) draws 30 amp at full speed so well within your ESC and motor spec. I see you have water cooling and am wondering if this is working correctly. You should see a good flow of water from the exit port at all but the lowest speeds. The inlet scoop should be immediately behind and facing the prop with a good straight pipe run to the ESC and motor cooling points. Dave

7 years ago by Dave M

Forum

Battery problems

Hi Patto I agree with what has already been posted, but it would help if we knew the size and type of prop you are running with your brushless motor. Fast large s do not work well with brushless unless your battery can provide the very heavy sustained current required. As Haverlock suggests a Wattmeter will allow you to select the best prop for your set up. LiPo power will give you all the speed you need but at an initial high cost as they require special chargers and correct management. You could use NiMh batteries which are lighter than SLA and are more suited to high discharge currents. You can get these in 12v packs and 5000mAhr would be a good starting point. If your motor is cutting out it is more likely the ESC is the culprit due to too high current draw. Another possibility is that the propshaft is too tight, it should turn freely with no tight spots and have thrust washers at both ends. Dave

7 years ago by Dave M

Response

Bluebird K7

Hi midlife306 Welcome to the site. Impressive looking model and its will look spectacular once painted. is it mainly wood construction? if so are you intending to cover the wood inside and out to protect against water? If you are intending to use IC engines you need to find some where to sail as most waters prohibit their use mainly due to the noise and pollution. The hull is a fast racing hull that would suit a brushless set up with LiPos. There are many configurations and I suspect a surface piercing prop is one option. I suggest you find a local model boat club near to you and go and see if they run fast race boats. There is a section on this site for Model Boat Clubs that will help you find one locally.Hopefully they will be able to guide you into the best set up for this hull. I have a fellow club member who is really into speed and he sources his bits from Prestwich Model Centre but also from the States. Please keep us posted on progress and do keep asking for help and advice, it may just save you from making costly mistakes. Dave

7 years ago by Dave M

Forum

Battery Life

Keith I have just seen your post re the Phoenix. if this is the model then I suspect the prop is perhaps too large for the brushless motor which will be struggling to reach max revs. Net result will be high current and short run times. if you can get or borrow a watt meter this will tell you the current draw and watts whilst holding and running the boat in water. Trying different size props will identify the best match. Personally I dont use s type 2 blade s on my models with brushless as they tend to be too coarse pitch. A good 3 blade brass prop will give realistic speed and long running times. My Sea Queen has a similar motor to yours and gives me about 45 mins if I run at full throttle. Pic attached of the model and setup. I also have a 34" Crash tender with a similar setup so some pics attached Dave

7 years ago by Dave M

Forum

Brushless

Hi Brian I am not sure which model you are referring to but your description of period photos suggests it is from the late 1930's and yes they were not a planing hull. Does your model have one or two props? A few pics of the model would help, you can upload by clicking the yellow box to the left of this input panel. Brushless can be a bit daunting at first experience but they are not difficult to use once you are familiar. You will already have seen they have three input wires and these need to be connected to an individual Brushless ESC for each motor. Doesn't matter which wired connect to which socket on the ESC but if your prop spins the wrong way you can swop any two connections to change the directiopn. The kv rating refers to the unloaded speed of the motor for every volt you apply so for say a 1000kv motor supplied with 11.1volts the motor would spin at 11100 revs. There are two types of brushless motor "in-runners" and "out-runners". This refers to the construction used with in-runners generally being less bulky. The outrunners will produce more tork and can be more suited to slower speeds. if you need to water cool the in-runners have a jacket fitted around the motor body whilst the out-runners use a water cooled mounting attached to the bearing. Both are suitable but I personally prefer Out-runners. For your model I suspect an inrunner may be preferable due to the restricted space available. Unlike brushed motors brushless do not like being overloaded and work best when they can achieve their max efficiency at near max revs. They have a max watt rating which should not be exceeded (Watts = Amps x Volts). The casing may be marked with numbers 42-56 which is the diameter 42mm and length 56mm. In my 48" Sea Queen I use a 42 size 850Kv water cooled motor of 700 watts and it is happy driving a Prop Shop prop of 42mm at 45 amp on full throttle. To measure your wattage you need to acquire a Wattmeter to measure the actual current draw with the model in the water. This will give an indication of the max current at max load as you hold the model stationery. If the watts are greater than the motor's rating you need to reduce the prop size/pitch. I like scale props so use 3 bladed brass and avoid using racing plastic/nylon props as they can overload the motor. The ESC should also be of a sufficient rating to handle the running current, I usually try for at least a 50% margin ie 75amps for a 50amp max current. Finally your setup must be really secure (I know from personal experience) and free running. The revs produced are possibly higher than what you may have experience before and any fault can and will escalate very quickly. At high currents the motor coils will fry in about 2 seconds should anything stall the motor and you can expect to see smoke and a ruined motor. If you post some pics we can give you more detailed help on your particular setup. Dave

8 years ago by Dave M

Forum

Palm beach

Hi Derek Just looked on U-tube to see what this model looks like. As a fast speed boat it would really perform best with a brushless and LiPo. As you already have brushless ESCs this would seem to be your best option. If you are not using LiPos at present then you could use NiMhs whilst you experiment. You will not need a massive brushless motor. I don't know the exact size but a 35xx type may be suitable with a kv about the 1000 mark with your 12v battery. The prop is probably a two blade racing type which will be far to big for a brushless. Change to a smaller version so the motor is not overloaded. if you have or can borrow a watt/ampmeter you can measure the current and make sure it is below your motor and ESC max rating by testing whilst holding the boat prop in the water. Due to the high revs you do need to make sure your motor and shaft are well aligned and that the motor is very securely mounted. I speak from experience. Good luck Dave

8 years ago by Dave M

Forum

Left Hand props and shafts

You could always use a drive dog fitting that way the prop has no thread. Not needed on a scale boat but often used on high speed models. http://www.cornwallmodelboats.co.uk/acatalog/drive_dogs.html Just examples of the breed Props using dogs tend to be high speed s ( and SHARP ) very scale like if your doing a F1 offshore racer.

9 years ago by Haverlock

Forum

Left Hand props and shafts

HI Les Haverlock has already answered your question relating to the thread and I agree particularly with his advice to use a locknut. The use of the correct thread is very important if you are running a very fast and powerful racing type of model where the forces acting on the prop are not small and are best used to keep the prop on the shaft, even with a locknut. The use of a locknut on a scale model where both forwards and reverse may be used frequently should help keep the prop in place. As regards two props it is beneficial to use contra rotating props as the model will be more balanced under way and will also respond correctly to the rudder in both directions, as already advised by jgs43. If you are modelling a true scale model of an original, say a lifeboat, then it will be important to replicate the full size arrangement on your model.

9 years ago by Dave M

Forum

The best small racing yacht?

HI Robo 177 I have two Micro Magics and have been sailing them for over 5 years, I recently purchased a dragon force 65 which I have sailed twice to date, the micro Magic has a short fin length and a total draught of 18cm and is a very responsive yacht in light and heavy winds but takes a while to master, but once accomplished it is excellent to sail, and very easy to transport, a big plus for me is the hatch is easy to remove to replace batteries, and make internal adjustments if required, and only four easy turn finger clips (five on my racing model) Four weeks ago the weed problem was very prominent on the pond but the Micro Magic had no difficulty in sailing apart from two or three stands of weed around the fin after 2hrs of sailing ( the weed appears to be below the water surface ) Even the guys with the electric boats were having to remove weed regular from the propellers, The Dragon force 65 sails very well and handles well, but it would be unfair to try and give a proper comment on this until I have had more sailing time with her, the draught on the dragon force is 38cm both draughts are measured from my yachts as near as possible carrying a standard battery pack ( 4x1.5v Duracell AA) 2.4 G receiver But the deeper keel length did give me problems with submerged weed pushed to give a choice it would be the Micro Magic, for easy sailing on weeded water, and the dragon force for weed free water which all though not tested by me, I would believe it would faster and easier to control and master than the Micro Magic Both yachts look very good, and easy to transport with the Dragon force 65 more sleek in design, easy to sail which I believe gives the advantage of more responsive handling and quick learning experience for the novice sailor felix

9 years ago by felix

Response

F1 BUILD

HI Mike Welcome to the site. I suggest you research and find a suitable water where you can sail your boat. Many local venues do not allow IC engined boats on their waters so it is important you find a site before you finally choose your propulsion. There used to be fast offshore racing at New Brighton in the Mersey but I don't know if it is still functioning. Modern fast electric boats now use brushless motors which far out perform their brushed equivalent and have comparable power to weight ratios to IC motors. There are several fast electric suppliers who will be able to advice on the type and size of prop to suit your model. I suggest you Google to find your nearest supplier.

9 years ago by Dave M

Forum

Blowing fuses

HI Georgio I am not sure what boat you intend to install the 850 motors into. They are high power and high speed and will use a lot more amps than your existing motors. Also the motor shaft diameter may be larger than your existing motors so you will also need a couple of new brass inserts. Brushless are good for very fast models but can be difficult to reverse so are not as popular in scale models which may need to reverse frequently. There are setups that work better than others but as the technology was developed for model cars the norm is for the reverse to be preceded by a braking position. Effectively you have to select reverse return the stick to neutral then select reverse again. Some brushless controllers are forward only so can't be reversed at all. Batteries can be SLA or NiMh but many seeking the fastest speed opt for LiPo batteries as they are lighter and can deliver much greater power than any other form of battery. They need special chargers and you have to protect the batteries from under discharge. Many new ESC's now have a built in circuit that allows you to set the cut-off voltage. Unless you have a fast racing hull I suggest you stick with your SLA and NiMh batteries. If you do go with brushless you may well need to change the props to suit the brushless motors. Personally I suggest you stick with your brushless motors for now and consider brushless for your next model when you have a bit more experience. Cheers Dave

9 years ago by Dave M

Forum

Reluctant Crash Tender Sale

Reluctantly, I have to say goodbye to two old friends ! For health and other probs. I am no longer able to do much sailing anymore. I was a long time member of Mid-Thames MBC. Have two 46" Crash tenders of different pedigrees for sale. #1 Original Aerokits 46" boat built by me In 1960's using a "Taycol" motor and heavy NiFe batts. ! Two restorations, In 1980's and 2006. Now has 2 x "Bullet" 24v motors [1980's], auto cooling pump, and monitor pump.[monitors servo driven] Rigged as original "94" Heavy but easily achieves well above scale speed and planes. Won "Best In show" at Burton Fireboat Fun Day In 2009. #2 SemI scratch built 46" boat from 2007. Built on GRP hull and some pre-cut parts from Mike Mayhew at Waverley Models. Most of woodwork and metal fitts. made by me. GRP hull Is very close to Vosper profiles. Fitted with 2 x w/cooled Graupner 820BB race motors, auto cooling pump etc. Rigged as original "93" Both boats have 2 x "Electronise" 30A ESC'S and Futaba 40meg radios. Both fitted with Propshop 3 blade s. Both are In running order with cell packs etc. Packs may need replacing as duration now a bit tired. With a bit of a further update, both boats would still compete with the best ! For some pics and further data PM me. I am going to try to bring both boats to the Leicester Fireboat Funday next month If anyone Is Interested In them. Just need a sensible offer ! Good sailing !

10 years ago by robhenry

Forum

S.H.Grainger Formula Powerboat

HI mate Welcome to the forum, looking at your pictures, that looks like a Cigarette off shore racing boat, the hull looks intact as does the deck, definitely worth a new chance. How experienced a modeller are you? Some of the things that might need replacing are the prop shafts and rudders, motors, batteries, radio gear etc. Its first going to need a good cleaning, that will reveal what if any damage there is, if there are any parts missing, and wether those parts are critical. The web site is now SHG marine, was talking to the owners at the Blackpool show, they are going strong, go to the contact bar and go from there. Hope this helps to start Regards Mark

10 years ago by jarvo

Forum

Speed controller

Weather brushed or brushless, you need to know what the motor power consumption is, in watts. Then for peace of mind add extra capacity for the ESC, if you are running a power motor like a hot 540 racing type then you could be looking at 100 watts, on the other hand a scale model with mild motors could easily use a small 20 - 50 watt controller, which with care will last for years in many boats. I have 2 Electronize ESC which are 20 years old in my tugs, both running on 24 volts and a big 80mm props. Try to find out the wattage of the motors you are looking at, its on the box normally, then as a rough gauge double the value. Hope this helps Mark

10 years ago by jarvo

Forum

Motors overheating

HI Thom The motors you have selected I think are racing motors for cars, and tuned ones at that. the props your Arun will be using are quite big, so the motors are heavily loaded. 1. Check what amps are going though the motors, in guessing it will be 30 - 40 amps 2. Consider changing motors, possibly use car heater blower motors, cheap and don't use much juice Using heat sinks and or water cooling, fans etc is only putting a plaster on the problem, it won't fix it.. Regards Mark

10 years ago by jarvo

Forum

Brushless motors -Help!

HI Edward That would explain the prop size suggested. For performance brushless is the best solution. if you can build the model to be lightweight then you may not need very large motors. Regarding weight its the extra bits you add that can really add on to the overall weight. Light batteries will also help and whilst a large SLA will provide the power it comes at a heavy weight cost, plus the sheer size can make selecting the best position in the model difficult. Any weight forward of the motor will have to be lifted by the model before it will get on the plane and this is often the reason why some boats don't perform well. You do not need to use s and for scale appearance 3 bladed brass props look the part and will perform well at scale speed. I would be looking at 40mm /- 5mm as a starting point 😀

10 years ago by Dave M

Forum

Brushless motors -Help!

HI Cenbeth As advised above brushless motors are rated by Kv. However they also have a wattage rating (amps x volts) and this needs to be observed unless you want to destroy the motor. Is this a scale model you intend to build? I ask because you quote 58mm props and this will need large (expensive) motors and ESCs. Could be the advice is for a brushed motor setup. If you look through this site at other members models of Crash Tenders you will find several working examples and you would be well advised to use a similar setup. Reverse with brushless ESC's is possible but usually requires the use of a stick with a central off. You have to stop the motor select reverse for a second then select reverse again, when hopefully the motor will run backwards. The ESC's were developed for model car racing and the initial selection applies a braking effect. If you intend to have a very fast running model you will more than likely be using high wattage and water cooling of the motor and ESC will be advisable. Marine ESC's are available but make sure it is reversible and as Ian advises a least 50% higher capacity than the max motor current. Whilst in-runners may be easier to cool I use outrunners which can be cooled via a special mounting cooler. Outrunners provide a big flywheel effect due to their construction and I believe give better performance in a large model boat. I have seen in-runners used in smaller model (30") and they worked fine. As you may now realise this is not going to be a cheap option and as brushless are power hungry you will need good batteries. Top of the range are LiPo's but you need to manage their use and charging in accordance with the manufacturers guidlines. Special charges are a must and your ESC need to be programmed to prevent any over discharge. NiMh batteries will give good results but will not last as long for each sail. To get the best performance you really need to match the motor/ESC to the props and a useful tool is a wattmeter which will help you estimate how much power different set ups use. As I mentioned at the start you should not exceed the max motor rating - basically bigger coarser pitch props = higher current. When you find a setup you think would suit I suggest you ask the member concerned for further advice. Good luck, and please post details of your final selection 😀

10 years ago by Dave M

Forum

Brushless motors -Help!

Hi, Thank you for the advice, it is very helpful. I can see that this subject is one fraught with Imponderables. Looking at eBay I have seen so many brushless motors and trying to make sense of them has now become a little less daunting! The plans call for two 58mm dia props. I assume that these will have to be s as opposed to scale ones. Should I be looking for smaller props? Edward

10 years ago by cenbeth

Forum

St Helens model boat club 2014 club 500 race season starts s

SHMBC held a "shakedown" pre race event this morning. We have decided to change the usual format that served us well for three years, (pretty much the standard rules) and are now using a format that will level out the results and stop the fastest 3 disappear into the distance as they did in the previous 3 years. it worked well, and all in attendance had a good time. We held 2 heats, and an optional 3rd heat (for those that might have had a disaster in either of the first 2, or are lucky enough to have a 3rd charged battery :}) We now own a club boat, anybody fancy giving it a try is more than welcome to come along. er starts sunday 9th March, and every fortnight after that, from the main landing stage behind the cafe at Taylor Park St Helens, 9.30am arrival. Please visit the website for details http://www.sthelensmodelboatclub.co.uk/

10 years ago by pmdevlin

Forum

34'' GRP/Kitshak Crash tender

HI Zippy, welcome to the site. Just had a look at the Mtroniks site and see their ad says "The Genesis Hydra30 is best suited to small scale RC boats to be used at scale speeds." If this is the combo set, the rating is 1000Kv which at 7.2 volts will give you 7200 revs. This seems a little on the low side if you want a really fast model that planes easily. My 34" Fireboat uses a RC-Smart 3480 outrunner and a EZRun-60A-SL 60A Constant ESC. I use an 11.1v LiPo but it works well with a 7.2 NiMh. Prop is a brass 35mm 3 blade. My model weighs in at 1900gms all up so is fairly light. Weight is the biggest problem and you need to get the heavy bits (battery) towards the rear. You could use a 8.4 or 9.6v Nimh if the speed is too slow but this will come at the cost of extra weight so its a bit of a balancing act. Brushless motors like to run at high revs so avoid using too big or coarse a prop. The fast racing type 2 blade props will place too heavy a load for your purpose. Ideally you should invest in or borrow a Wattmeter to measure the current draw on your chosen set up. This will avoid you running the motor and ESC above their rated value. I have no experience of Mtronik brushless ESC's but use their brushed ESVs in many of my models and find them excellent value. Giant Shark have a large selection of brushless motors and setups and if you search the web you will find many more suppliers both in the UK and abroad. There is a section on this site Photo Gallery with a whole section relating to Fireboats and I suggest you have a browse to see what set up other use so you can have a better idea when searching. Good luck and do please post details and pics of your model. 😀

10 years ago by Dave M