Todays Boating

[harry smith 1Participant @harrysmith1]

Dave

I agree with using brush motors in displacement hulls and slow boats.

As we all have a stock of these motors, I pulled apart an old cordless drill(dead NiCad's).

Motor 18 volts with a gearbox on the end, geared down to 550 rpm.

As for planning hulls it's what speed the owner requires(scale speed, quick, fast, dam fast or insane).

The other Saturday we rib one of our old member's that at 75 he would not handle a MFA Fantome with a brush cutter motor in it.

He put on a driving display was a speed nuts joy.

Pulled it into shore and handed over the controls to the owner and said" THAT'S HOW TO DRIVE LADS!!!"

[Dave MilbournParticipant @davemilbourn48782]

Harry

Hooray for the old geezer! It never ceases to amaze me how badly some folk drive their models. The tendency seems to be to forget completely that they have proportional control and to shove the throttle stick all the way up to the top of the box and treat the rudder command like a switch. Coupled with the fact that at least 50% of models are overpowered this leads to a most unrealistic performance – frequently to the point of being downright dangerous. OK – so model racing boats are designed to take corners the same way that houseflies do i.e. at 90° instantly and with no drop in speed, but many of the worst offenders are not sailing racing boats or are even in a race.
I was taught that the trick is to imagine you're at the helm of the real thing. A full-speed full-rudder turn would throw you and your passengers out of the boat and probably capsize it, and excess speed in a powerboat is akin to sitting on a pile-driver while someone aims a fire-hose at you. Smooth and steady are the two words to keep in mind.

On the other matter, I think that UK boat modellers have been spoiled for choice when it comes to brushed motors and speed controllers. It doesn't surprise me that Australian and US modellers have taken to brushless motors the way they have, as they are available for pennies from China and the carriage is heavily subsidised by the state. Compare the cost of a 35mm BL motor with a marine ESC bought into Sydney from China with that of importing a MFA geared 500 and Electronize ESC all the way from UK (Royal Mail postage GB£15.40). There's no contest.

DM

[Dodgy Geezer 1Participant @dodgygeezer1]

Posted by ashley needham on 02/07/2015 10:06:08:

……..

The issue is mainly finding small brushless motors with 2mm shafts to suit the push-on props I have, they tend to be 1 or 1.5mm and meant for geared applications.. Small props are an issue.

Ashley

Exactly what I have been saying for some time now:

**LINK**

I am now modifying original 4mm props to use 2mm or 3mm shafts. As small but powerful brushless use increases there will increasingly be a gap in the market for 3mm shafts and props to suit. I wonder if it will get filled….

[ashley needhamParticipant @ashleyneedham69188]

Dodgy. Indeed you have, and I agree with your sentiments that JUST POSSIBLY with the move to whole metric shafts (2,3,4 ,5mm etc) there might just be a sway to rationalise things a bit.

Doesnt seem likely as the flyboys have been at this for some years now and there seems to be no "standard" for air-prop centre holes as far as I can see.

Ashley

[Dodgy Geezer 1Participant @dodgygeezer1]

My problem is that there ARE small 2mm props, but these are essentially intended for 'plastic-fantastic' use with low-power brushed motors. I have been cutting down the RadioActive 2mm shaft/40mm diameter prop range to about 35mm, but the pitch is still too fine. I want to use 30mm 'X-type' props, but you can only get those in 4mm shaft sizes… and I really need 3mm.

The thing that is missing is a 3mm range. We only have light 2mm or heavy-duty 4mm…

[Trevor HollowayParticipant @trevorholloway99134]

You can get propshafts custom made to your requirements for length, size of thread on prop end and size of shaft at motor end or just select a suitable coupling at the motor.

[Dodgy Geezer 1Participant @dodgygeezer1]

Posted by Trevor Holloway on 02/07/2015 14:18:39:

You can get propshafts custom made to your requirements for length, size of thread on prop end and size of shaft at motor end or just select a suitable coupling at the motor.

Indeed you can. Here I'm talking about props for EeZeBilts, which are small and cheap. So my other requirements typically include:

Prop-tube maximum diameter – around 0.25"/6mm

Coupling length – less than 1". Also very light.

Cost – Free to around £1 for the prop – similar price for the prop-tube/shaft/coupling

Unsurprisingly, that means that all of my drive-train is usually custom-made by me, but high-speed props still have to be bought, and they don't make any cheap ones in 3mm. I might be able to get US ones at 1/8", but the postage costs would be high.

[harry smith 1Participant @harrysmith1]

Hi All

I looked at only the motor revs as per the model boat chart and found it easy to match the revs with brushless motors varying the change to Lipo batteries to 3S(7.4volts) and 4S(11.1 volts).

But with the brushless motors you would have go down in KV and revs because sheer power that they deliver.

E.g. 540 STD on 6 volts 6200rpm and 35mm 750kv motor on 2S is 5550rpm, but, in the same boat with the same prop the brushless would be quicker.

I will have to find a boat to test this on one today!!!

Or may be one of you fellows with a spare boat would like to have a crack???

You never know to you have a go!!!

PS Get a bit of warm weather up in England, we have started into WINTER!!!!!!!!

[ashley needhamParticipant @ashleyneedham69188]

Harry. Mustnt get carried away here. Not all brushless motors are equal, and they dont all deliver massive power. One would have to look at the spec. Theres no doubt most of them are more powerful than…I was going to say the equivalent…brushed motor….but there are no equivalents, by any measure..

Revolutions is relative; small prop large revs, large prop small revs.

If you want to go down with the Kv and thus revs, an increase in prop size would be called for to achieve the same performance as a brushed motor turning a (whatever) size prop…OR increase revs using same size prop for better performance. The only thing to bear in mind is the weight of boat in relation to the prop size and of course too many revs would need a change on prop form to compensate. No good driving a three blade brass prop at v high revs, would need an X prop or something.

Your example of a 750Kv motor….this would turn quite a big prop and an increase in performance would only be realised by increasing prop size as lesser revs on the same prop will make the boat go slower. UNLESS the standard 540 was slightly overloaded and not spinning the prop at max revs.

i read somewhere that for best efficiency you should aim (as a ball-park figure) to load the motor up to deliver 20% less revs loaded over the theoretical unloaded RPM figure. tricky to determine without a tacho.

I have two ….boats….and one has a 28mm brushless outrunner, the other a 35mm outrunner. On paper the Kv and max current values are similar, but the 35mm motor is likely to be actually twice as powerful, turning a much larger prop, despite showing on paper similare performance charcteristics.

Its a minefield out there. Theres also the number of poles and windings to take into account, affecting tourque…in fact , this is the figure that would be useful for boaters,,,the torque generated…but who would know how many newton/metres is needed for a 40mm plastic prop??.

Ashley

[ashley needhamParticipant @ashleyneedham69188]

Apols today. Played at our annual swing dance last night, got back v late didnt get up until late, raining when looking out the window. Ho hum.

Rubbed down the proj no2 again but the rain will make it a bit humid to risk re varnishing so thats on hold. Proj no1…I now have all the right size batts and having made foam holders for them the thing is good to go. Some minor paitnwork to be touched up and most importantly a logo needs to be produced and stuck on the hmfbergfndm either side.. I have a picture of the logo and may consider getting one of those transfer "kits"…..special paper and fixing spray..or would really like a vinyl sticker.. there must be firms who do this. will have a surf unless anyone knows one offhand…logo needs to be abouit 40mm or 50mm long, not very big.

Not telling you what as it will give the game away straightaway, its that sort of thing.

Ashley

[peter ward 6Participant @peterward6]

went to the pond at appx10.00 after the small showers of rain had passed through

no one boating at all whole place was like mary celeste !!

unfortunately the march of the summer weed appears to be appon us two thirds of the pond covered with

clumps of floating surface weed only a smallish area in fron of landing stage was usable only time will tell

if this is going to get as bad as last year

[ashley needhamParticipant @ashleyneedham69188]

Peter. Oh dear..sorry about that. I went to bed really really late (or early) and the got up late and then had to clear the car of gig gear…and it was raining ….

Weed… oh no. Better dust off that jet boat!! (or make another hull for it)

I will get the old flying boats ready for action, and the hovervan…and with any luck project no.X.

I think I may make new rudders for the ruddered flying boats, more weed resistant. I may even revamp the Sunderland a bit with two aircraft ESc and a v-tail mixer so that I am able to steer with the wing motors only and thus be completely weed-independant.

lastly the paddle wheeler… I can feel a quick paddler coming up just to see how they cope with the weed. Gosh, what cheap material should I make the hull from ???

Ashley

[ashley needhamParticipant @ashleyneedham69188]

Finally remembered where i was going wrong in the lettering department; Printing at home….a no-no, water based printer ink.. useless. The answer..print at work on a nice laser printer. Indelible lettering.

Re-did ferry signs (not that it matters too much) and it looks a lot tidier.

Even more important, the last logo`s (which shall be nameless) have been varnished, cut out with scalpel and stuck on proj No1 on the fjmkmhskdfkhnda and thats that now. Some minor small brush touch up reqd but will be at the pond, Lipos charged for a quick spin.(!)

Mick the sail MAY have his Victorian battleship down also for its first test. Should be really good, assuming he has a clear bit to sail it it.

I am awash with Lipo`s now and may have a selection of supercharged non-flying boats down to p;lay with besides poss the hovervan and Proj no1

Ashley

[harry smith 1Participant @harrysmith1]

Hi Ashley

So work is good for some things like printing!!!

We had a quiet morning at the canal ,only a small number of members, but, it's WINTER is Tasmania.

Beautiful morning a bit of the breeze down the canal.

Came home and added more bits to THE SEA HORNET 2015 Project.

Also modifying a plastic fantastic(ABS) from two motor off turn one for left turn and other for right turn.

So I add a brush ESC and a new old 27M radio from another boat.

Removed the trim rudder and waiting for one of the club members to made a custom rudder.

I repair a few of the NiCad packs, but, the ESC will handle 2-3S Lipo's .

So I will show the owner the new setup on NiCad's and Lipo's(2S and 3S).

[ashley needhamParticipant @ashleyneedham69188]

Harry. Winter in Tasmania. Its probably hotter than it is here!! Theres nothing like having a nice mornings boating and then coming home to fix all the bits that didnt work at the pond.

Work is good for earning money to make boats with, and printing of course, but it has its disadvantages…

Todays boating, A bit breezy but nice and sunny,,,,got a bit overcast later and at about 1115 it started to rain (very lightly)

Sunderland going a treat with my new tiny battery in place. Almost an hour on the pond with it and still going. What a difference in speed!!1 it really does go quite well now, and at full chat the wing floats are off the water. Unlike the BFB3 which refused to work, What was wrong??? dont know, as after a bit of fiddling at home with the wiring, unplugging/plugging up the Rx, it all started working again ????

Ferry out for a toddle, but the main news of the day was the first ever voyage of Proj No1.

This demonstated its credentials quite well, but then filled up with water….the water seeming to enter by a most unusual route through the dkljkgfrhets, and these are set up high…you really cant plan for everything. A couple of tiny cracks were seen in some of the hatches (not quite the right word) but these we thought were not the cause of the flooding. Its likley the wind was the issue, tipping the blasjkdlksjt over a bit. More work required, although it did look very good. Next time I need to try out some different props to see if there is any improvement in one critical aspect, the original prop was overloading the motor, although I have a feeling that if I could spin this properly then the hksddkfdjg aspect of the craft would improve immensly.

Ashley

[harry smith 1Participant @harrysmith1]

Hi Ashley

We had a good boating morning, but , low in the number of members.

One late model cabin cruiser with a fly bridge(back from a watery grave).

The twin motors and battery fixed but new receiver and two ESC's(the black soot over white paint is not pretty).

I ran my ABS ocean racer after a drive line full bearing replacement.

Ran a 37mm x 1.4 pitch metal 3 blade for the first time.

A bit quicker on 3S with the 3648-1450kv motor.

Played around with prop angle, trim tabs and balance point.

The boat is a bit more stable in a straight line, so, next it's back the 4S battery.

If the weather is OK in the morning we are taking the Spearfish out for a spin with a 37mm 3blade prop and a XK-3674-1900kv on 3S.

As it is a very stable boat I think it will handle the power(I will take the video camera).

[harry smith 1Participant @harrysmith1]

Hi Ashley

A few pics of a Spearfish on steroids in Prince of Wales Bay down south, south pass Australia, the heart shaped island called Tasmania( a warm 12F).

[ashley needhamParticipant @ashleyneedham69188]

Harry. Thats going well and no mistake. Sitting at quite a good angle. Would love to play with that in the rough. You just dont get decent waves on a lake or pond, not those big swells that you only get offshore (as it were) Another boater worldwide with a beautiful bit of water to boat on. Play with the perspective on your shots and it might just look like a big `un!

Weed; I forgot to mention this. There was not none on the pond Sunday despite being fully armed with weed proof boats/whatever. There was a very small amount but it had been blown across the far side.

Started project no3 now, as No1 is just about finished and No2 is being varnished (several weeks to go at least. More heavy duty woodwork on this one, but not as much as No1. Thinner MDF, 12mm this time, and my hand belt sander comes in very handy for the shaping, out in the garden and using a mask of course. I even dragged the big bandsaw out to use when doing the initial chopping up.

Ashley

[harry smith 1Participant @harrysmith1]

Hi Ashley

Only a ripple on the water and a very lazy breeze, that's mild.

I had my ABS Ocean Racer in 15-20 knot breeze and 4-6 inch swell, that was interesting and a handle full.

The boat only weighs 3lb wet and with 4S battery and 1450kv motor.

Pics from video camera and still framed on the computer with MWSnap.

[ashley needhamParticipant @ashleyneedham69188]

Lovely day today, bit breezy at the pond. Weed large p[atch far side about halfway out.

Firstly. Hovervan. Had a bit of a faff (thats the air coming out from underneath) on the main pond then portee`d it over to teh stream to try it out on weed…it being easy to recover in the event of a stuck situation. Pleased to say that it coped admirably with several large clumps when in hovering mode..weed over which it got stuck on without the lift motor.

Rescue LCM out as well as the Sunderland and BFB3. Mick the sail had his latest creation out for its first spin, an Invincible class battleship circa 1893. A semi ket from someone or other who he was not impressed with….fittings the issue, half were very good, the rest rubbish. Hull and other stuff (barring the string supplied for rigging I recall) very nice. Looked glorious and sailed a trest,. Such great colours,,,,white/buff superstructure and that cheeky little white boot-topping.

5 other boaters down, one succumbing to weed…along then with the lcm although that just limped back. happily the strong wind soon blew the affected boat back into shore.

This has inspired me to make a paddler…not the Victorian warship envisaged (at leasst, not yet) but a Victori8an Nile gunboat, loosley modelled on the "El fateh" yes really, look it up.

Built at Wivenhoe Shipyard in 1896 by Forrestt & Co. Ltd., together with 2 sister ships for the Kitchener Nile expedition against the forces of the Mahdi in the Sudan . With her sisters, 'El Fateh' was built in sections of steel and fitted with water tight bulkheads. Shipped to Alexandria in sections, the ships were transported up the Nile to Assouan where they were reassembled for action. 'EL FATEH' was commanded on the Nile by Lt. David Beatty R.N. later better known as Admiral Earl Beatty, commander of the Battle Cruisers at the Battle of Jutland.

It is a sternwheel boat, and while we wwere discussing paddles and weed I had a sudden inspiration, and decided to try a four bladed rear wheel…the idea being there would only be one blade in the water at any one time and so it would be less likjely to pick up weed, rather than having loads nof blades splashing about.

I realise this wont be efficient but thats not the point of it. I can always make another wheel to fit during weed free months, assuming the boat looks reasonable. I am not spending much time on it. It will be populated with circa Kitchener era soldiers in 54mm size from my collection to add interest. have started already..will use a 20mm thick ply base to effect a no (or very little) draught design, AND I just happen to have an MFA 2.5:1 geared 540 motor just the job for this. Only need some sort of drive now, thinking of plastic chain and sprockets??

Ashley

[Dave MilbournParticipant @davemilbourn48782]

Ashley

Motor might be a bit fast unless you run it on about half a volt! Have a shufti on this website – these guys have done it all ref paddlers **LINK**

Dave M

[Tony HadleyParticipant @tonyhadley]

Found this photograph of a model, and information about "El Fateh"

**LINK**

[ashley needhamParticipant @ashleyneedham69188]

DM. yes , having revisited the specs you are right, I will be looking for an alternative geared unit..poss a 30;1 motor or even just getting one of those gearboxes from Hobbies or Maplin.

Tony, yup, thats where I saw it. The paddler will only be LOOSLY based upon this vessel !! Mainly due to having a gash bit of 20mm ply 24 inches long which will do for the base. 7 inches wide and paddles supported on 1/2 inch square supports stuck to the base, pictures to follow.

Paddle wheel construction. Could be simply two sticks drilled centrally and stuck at right angles with paddles across (paddle diamete 4.5 inches, about 5 or 5.5 inches wide. Would like to use plastic as its much more waterproof, and I have some thickish stuff raided from a kitchen renovation somewherer which will do. With a circular strip of something or other stuck round the edge it should look ok… OR…I might even not do that so the only thing in the water is one paddle at a time…??

Depth of immersion could be critical, but that will have to be effected by either extra ballast or plating the underside with styrofoam to lift the hull a bit.

Ashley

[ashley needhamParticipant @ashleyneedham69188]

OK. 40:1 worm drive motor unit, plastic chain/sprocket set, and best of all, plastic axle brackets….will just screw onto the sticky out wood spars at the rear to hold the wheel axle. All from http://www.hobby.uk.com

All 4mm shaft size. Sprockets, choice of 10 20 30 tooth will give me additional gearing options. Motor unit 6v capable.

400 rpm on 6v on the gearbox alone, reduce to 200 rpm with a 10/20 tooth option should be about optimum. Motor plenty powerful enough with this sort of reduction.

Ashley

[harry smith 1Participant @harrysmith1]

Hi Ashley

I pulled an old cordless drill apart( the NiCad's are dead) the motor is 18 volts and the rpm's are 10,000.

The output shaft speed is 550rpm and its all the same diameter as the motor(about 40mm).

Good for a paddle wheeler or a tug boat!!!

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