Todays Boating

[harry smith 1Participant @harrysmith1]

Hi Ashley

The 3000kv motor on 7.2volts would be pulling over 21000 rpm, about the same as in my Sea Hornet 1900 kv on 3S(11.1volts).

The MFA Fantome has had an engine upgrade from one G60/500kv on 6S 6000mah with a 4 blade 60mm prop.

He has added another G60/500 on 6S with two 3 blade 60mm props.

A bit of prop torque with the counter rotating props, but on the onboard GPS clocked 43 kmh.

The ESC rudder mixer worked well at very slow speed turns in it's own length.

I think I snapped a few shots with the camera!!!

Post them if they look OK.

Harry

[ashley needhamParticipant @ashleyneedham69188]

The 3000Kv motor on a 9.6v Nimh stick used to push the KM along at a very high rate of knots. The ESC and motor used to get very warm (water-cooled ) and the battery even hotter!!! New installation is also water cooled but obv on a lower voltage so I am hoping this will not get quite so warm. I think that the motor is probably more suited to a surface piercing setup as being such a high Kv, so I shall try smaller props at first.

The Fantome I have has MFA 800 motors fitted, approx. 5000 rpm. To get an increase in performance suitable for such a bulky boat and considering the confines of our pond (and battery life) then a modest rev increase should be all that is needed. I am not sure that these 35mm motors will turn an x50 prop or will they??

I see that the g60 is a 50mm motor of awesome power…on 6s….

Ashley

[harry smith 1Participant @harrysmith1]

Hi Ashley

On the 3000kv, if is not surface prop drop to a 2 blade 32mm, I am not running water cooling in my boats and Tassie water is a bit warmer!!!

As for the Fantome, twin 3639-750kv(600watts) on 2S twin Lipo's and twin ESCs(with rudder/ESC mixer)would get 5550 rpm using 2 blade 40-50mm props on direct drive(no gearbox).

Get ESCs which handle to motor max in voltages( a few more bucks, but cheaper than buying more ESCs).

Then if you wish to up the voltage( le turbo charge) it's a batteries and reprogram the ESC.

Yes the Fantome is a bulky boat, but, the battery life is Lipo batteries.

Twin 5800mah with a C rating to equal to motor current or better(in this case on 3639-750kv) 35C, run time would be 1/2 an hour or more(1/2 an hour if you drive it like it's stolen).

I looked at my pics from today and the Fantome was too fast for me and my camera!!!!

harry

[harry smith 1Participant @harrysmith1]

Hi Ashley

The only pics that turned out of the Fantome are the install.

[ashley needhamParticipant @ashleyneedham69188]

Well. Some shenanigans on the pond today and no mistake!! Firstly the Fantome: This was running perfectly if a bit slow on 9.6 Nimh, and not an awful lot faster on a 3s Lipo…not as fast as I remember on my 12v Nimh? but it was a while ago. So far so good.

Seahawk. Powered up…plopped in water and….. no drive…motor coupling grub screw loose (how did this happen) drifted the 8 foot back to shore. Tightened up…speeded off into the wide sea, on a 7.2V Nimh battery. Tried two other props…probably best performance on an s40mm prop. Well speedy, faster than I remember on a 12v Nimh battery. Came back in, installed a 3s in a moment of madness and promptly blew the double coupling apart. Silly me I should have known thoise plastic jobs were not up to it. Another 10 foot drift to the jetty.

Peters Boston harbour ferry/pilot ship (or something) broke down and drifted into the floating weedy mat (duckweed) and stopped. Tried to rescue with the large lander but no joy. Narrowly missed getting stuck myself, however Peter had his waders so not a problem, only 20 foot from shore and the water barely reached his knees. I had forgotten to bring my pole, which would have reached easily.

Trevor…mod on the DDR (Dingy dire raft) working to a degree but still more work to be done. PT boat out and going well..UNTIL…in another moment of madness, a 3s Lipo was tried. Iain had his heavily weathered tug out, complete with fake smoke generator, but all of a sudden Trevor has a REAL smoke generator. New motor please.

The foam flyer had an outing, and I had put a new prop on it…slightly smaller but with fatter blades. It seemed to be going well, but would not turn left¬¬¬ It would sort of turn right, but not very well. I was worried about going into the weed (don't know why, as it travels over weed with impunity) but instead just motored into the bank for retrieval. Put the old prop back on and steering was restored, really odd, amazed that the different prop would have such an effect. I purchased these other props to put on the re-engined BHA (speed 400`s now fitted) and it goes really well. They are handed mind you.

Iain left smartly, probably bored as his boats were running all ok. Rest of us left with repairs of various types to carry out. I shall have to get a proper coupling for the Seahawk and move the motor a bit.

Ashley

[ashley needhamParticipant @ashleyneedham69188]

Today has been a submarine day. The Oberon was de-boxed for some mods.

Not a mod as such but there was a bit of touching-up to do. An easy job, the whole thing is matt-black¬

Next the receiver was changed (27meg) to one with a shorter Ariel wire. The method of exit from the sealing Perspex lid was changed from an araldited in wire, to a brass pipe… stub soldered on a flat bit and glued in…then a short length of silicone tube to connect this to the plastic tube that runs up the conning tower . The silicone allows the assembly to bend so it can be stowed in the box, and the ariel wire simply shoves up through the assembly and up into the long tube and appears above the boat. This ensures reception and gives an indication of how well (flat) or deep it is diving.

Lastly, I have made a circular hatch in the sealing cover, about an inch round, sealed by a small square of Perspex and another grease soaked felt gasket, 4 screws holding it shut fixing into a wooden collar underneath. This will give me access to turn the esc on and off, and ventilate the interior of the boat to let the steam out, without having to undo all 14 screws and take the main hatch off. It means I can actually prep the sub for sailing at home before coming out, and all I need to do at the pond is turn it on and do up 4 screws, easy. The interior gets very hot from the motor and ESC, it is a small space with no natural ventilation and there is a smidgen of water admitted by the shaft, and this turns into vapour….cant do the receiver any good. Not had a problem yet, but between runs I can at least ventilate the interior and suck up any water if there is any worth sucking up.

I looked at the Seahawk, but realised that the Graupner out-drive assembly uses another u/j to allow the rudder leg to pivot. I have a Huco coupling there, and these are marginally shorter than the "usual" red ones. Cornwall model boats lists a Raboesch needle coupling and I will have to find out how long this is. It is no good beefing up the inner coupling if I cant beef up the outer one. From memory this was a steel jobbie, but wore very quickly, hence the Huco replacement.

Ashley

[ashley needhamParticipant @ashleyneedham69188]

As I have a band job this afternoon I bottled out from testing the Oberon (in case, just in case) and so took the MINTANIC (as its only 4 foot long!!) which performed perfectly as usual. Didn't take the 6vSLA to power it though as I had some nimhs charged, but this is what it was built to take, a pair of 4.5 Ahr sla, . 6v is all it needs and they double as ballast.
Today I had two 7.2 sticks in the centre and loads of lead at the front. The SLA are getting on now and I should use them more, I have still half a dozen boats more than happy with these batteries including HMS Midge, which is still fairly rapid even with and SLA on board, as the boat is very light.

The Titanic box also had a makeover with a bit of ply covering the front of the open box (to make it a proper box) and a flash new blue emulsion paint job. Smart.

Speaking of the Midge, it is in hand in the loft for some touching up. I have varnished the deck in clear satin as the deck finish was looking a bit flaky and will be repainting the sides in matt black again as there is some paint loss at the deck edges. I have noticed this on older models and think it is the sanding sealer. This goes very hard after a long time and the paint does not seem to stick to is and flakes off. Its ok for a ships side, but the Titanic (for instance) is covered in portholes and windows all over, and I would not like to re-do them all.

It may be that a coat of non-yellowing clear matt/satin varnish is the way to go, to stick all the underneath paint together?? WHEN it comes to it on the MIN I shall try this.

No sign of the Terrapin on the log in the pond but unusually two young Heron were perched there. It ithe rut for the deer at the park and the air is full of bellowing males (and that's just the boaters¬¬!!!)

Ashley

[ashley needhamParticipant @ashleyneedham69188]

SPEAKING of flaking paint, the Midge has been affected by this and I have it in the loft to touch up

In this case I have decided to scrape the loose bits off and paint the deck and over the edge with satin clear varnish. This will re-seal the deck, which is showing signs of age, and seal those top hull edges. One coat of matt black has been applied one side and it all looks back to new.

Brushless motors. I seem to have a clutch of boats now with brushless motors. Funny how "new" technology catches up with you. It is easy really, simply match the Kv of the motor to the battery of choice and check the max current draw figure, as compared to the brushed motor you WOULD have used. Harry is the exception `cos he would work this out and add a 0 on to the watts figure and use this as the motor requirement.

Ashley

[Dave MilbournParticipant @davemilbourn48782]

Harry is the exception `cos he would work this out and add a 0 on to the watts figure and use this as the motor requirement.

This is known as "Larrikin's First Law". Follow it ONLY if you have the reflexes of a Typhoon pilot and a 'test lake' at least the size of Windermere.

Larrikin's Second Law states that model speed should be equal to the reciprocal of its scale to the real vessel. That means if the real vessel can travel at 30 knots then a 1/12 scale model should be able to do 12 times that speed, or 360 knots. That's around 600 feet per second… Add 50% if the crew figures look really mean!

Larrikin's Third Law says that if the battery overheats and explodes before the bearings melt and the motor seizes completely and before the speed controller begins a fireworks display to rival Sydney Harbour Bridge on New Year's Eve then you weren't using enough cells. Have a beer and buy some more.

Harry
Do what you do, dude. The world needs more larrikins.

Dave M

[Paul TParticipant @pault84577]

My copy of the magazine arrived this morning and it is very confusing as there is a piece about reptiles, specifically a Terrapin, I always understood these animals were odd but 'wet effect' plywood and Action Man wheels were certainly not part the wildlife programmes that I have seen.

But the article gets worse as the writer goes into great detail listing the atrocities that were carried out on some innocent soldiers, frightening to relate but these poor individuals were literally carved up simply to ensure a snug fit inside the Terrapin.

I am shocked and will be writing to my MP …..

Paul

now who is my MP this week?

[ashley needhamParticipant @ashleyneedham69188]

I had no idea DM was a humourist. I am picking myself up off the floor as I have LARFED so much. Good on yer.

Paul T. You have no idea what I get up to in the workshop with action men.

I was a bit gutted by not having motorised the wheels, but there really was no room. Paul F likes to use "posed picture" when the thing is photographed on land/half out of the water and this is fair enough he is quite right. However as the boats spend most of their time OUT of the water I would submit that the craft is a model (like an Airfix model) to be looked at on the grassy knoll as a model of something or other, and hence the pictures of it posing pretending to be actually climbing in or out are quite valid. It is a personal taste thing. Unfortunately with this model when in action, most of it is underwater and not seen, and it is not quite so impressive when water borne.

So saying, the agility of the boat/lorry is uncanny, it really does turn on a sixpence (you are all old enough, probably to remember silver sixpences) and motors along far better than the shape would suggest. I have no computer package, I plop them in the water and am always surprised by what they do. You wait and see the next one…oh boy !!!

Ashley. Likes to use stuff hanging about in the shed.

[harry smith 1Participant @harrysmith1]

Yes Ashley, I had a good laugh at Dave's written Larrikin Law's.

Sorry that Law number three has not happen, but, I had have one bearing replaced in one motor!!

The English Watt add 0 equals a Chinese Watt as per forum sites and Hobbyking.

Senior

In

Retirement

Harry the Larikin

[harry smith 1Participant @harrysmith1]

To The Un believers!!

Rs 540 to 35mm brushless( Turnigy 3648-1450kv(5mm shaft) and Trackstar 17T 2400kv(3.175mm shaft)!!!

[ashley needhamParticipant @ashleyneedham69188]

Harry, not disbelieving, but that's proof positive!

​Do you connect the water-cooling inlet/outlet to the cars radiator?

Ashley

[harry smith 1Participant @harrysmith1]

Hi Ashley

The connections are for the turbo inter cooling for the twin turbo's!!!

You have pick up Dave's humour ?

I was thinking about model trains, but, all that training was too much for this old fellow!!!

The Larrikin

[ashley needhamParticipant @ashleyneedham69188]

It is v wet and damp here, cant see tomorrow being better but u never know. I will be subbing tomorrow assuming it is not raining, to test out the mods on the Oberon. I will only take the usual lander along as an extra UNLESS it is really nice in which case proj No3 will have an outing.

Proj No4 was of course the terrapin, now "outed". It is nippy but no one could say it was fast (as befits a lorry in the water) . I seriously considered making this out of man-made board, just to silence detractors but thought it may have been a step too far for the readers sensitivity. BUT don't tempt me….

Updates;

Proj No1 languishes with performance issues, and a non-functioning side propulsion/thruster/thingy. This has been ongoing for a while now and will be probably my most spectacular build for a number of reasons. Did I mention MDF? I think so, and lots of it.

Proj 3 suffers from TOO MUCH performance for its own good. What did DM say about Tornado pilots and large lakes?

Proj No2 has been finished and presented and is a spectacular performer. (large lake required)

Proj No5 is ready barring pictures of it at speed, but is also waiting for someone else to complete their builds. It is fairly fast. Unusually Proj 5 is being written up in conjunction with a n other builder`s boat (s). The inspiration for No5 is on the back of this "other" project, and the same builder is also making a spin-off of the original. These are exciting projects, fairly different despite they claim to represent the samel thing, but there is a jolly good reason for this! As it happens proj3 is almost entirely guesswork in its dimensions and modus operandii and proj 5 is not far behind!

Projects 1 2 3 5 are also brushless powered, and Lipo`d to boot. Hows that for keeping up with the times?

Ashley

Edited By ashley needham on 01/10/2016 19:04:16

[Bob Abell 2Participant @bobabell2]

Hello Ashley

I like your very nice write up in this month's ModelBoats Magazine

The amphibious Thornycroft Terrapin project

It's just you, all over……Army….Soldiers…….Hardboard and Kharky paint…….Or is it lime?

A fun project

Bob

[ashley needhamParticipant @ashleyneedham69188]

Bob, Thanks for that. No lime here…either wood or paint! Yes, army green and soldiers, the sort of thing I would have made for Berengar to play with when he was smaller.

​I used 4mm ply and didn't notice at the time the apparent state of it. Materially it was fine, but it looks manky in the photos. There was no reason NOT to use it, it was otherwise perfect. Photos of the bow have some very light filling, mostly to fill the grain, but it is minimal..

Today, the Oberon was unserviceable due to the motor. The 540 shows signs of melting nylon around the rear bearing, and it would not turn over when connected directly to the battery. SO it was LCT time, loaded with universal carriers, Timpo, probably £25 quid's worth each one!!

Trevor had the DDR (dastardly dingy rascal) dons and oh boy does it go !!!! WHEN the nose lifts out of the water. All 3 of the current project craft exhibit the same nose dive tendencies on start up. Tricky to cure whilst staying true to the originals….

However the pond is weed free, so that's something.

Ashley

[ashley needhamParticipant @ashleyneedham69188]

Like everybody else I have a box full of motors, from varied sources. Some are new, a lot are out of "things". Most of these have no markings. I should throw them away as I am unlikely to use them.
You know what its like…you want a so and so size motor, there are two of unknown origin in the box which you decide are too risky to use and buy a new one…

I have several 540/600 types. one of which, and it is an unmarked one, I have put in the sub !. It is of 600 size, and does not seem to rev as much as a known "standard" 540. I will try it with the wattmeter first. It has a nice cooling fan which should be useful in the sub wafting the air about. How can I put a heat sink in the non-flooded compartment? The sides and bottom of the compartment are a nice insulating balsa, the top is thick Perspex. If it were aluminium it would be cold as its underwater.

We chatted about the demise of the Planet r/c set and what a bu##er this was. I am going to stick with 27m for as along as. I have three Ranger tx, and loads of RX..in any case a compatible RX from Howe's is only £8.

Several models need a 2.4G set as there is little room for an ariel, but most of the boats have absolutely no problem accommodating one so that's that.

Interesting article about Hobbies magazine in MB. Like the bit about the Hydroplane. A fretwork plan (to appeal to all those fretwork fiends) no doubt. BUT I wonder how many have been built?? With the pathetic motor, a dry battery AND a home made prop one can make a guess at the likely performance. I think it would be no good making one with modern gear, it is likely to simply flip over.

I await numerous replies from chaps who ACTUALLY made one and can vouch for the incredible performance. I would like to be proved wrong. Further, it is almost something I might like to try, at twice plan size. Can I get a plan from somewhere?

Ashley

[Ian JopsonParticipant @ianjopson21383]

Posted by ashley needham on 03/10/2016 17:41:31:

Interesting article about Hobbies magazine in MB. Like the bit about the Hydroplane. A fretwork plan (to appeal to all those fretwork fiends) no doubt. BUT I wonder how many have been built?? With the pathetic motor, a dry battery AND a home made prop one can make a guess at the likely performance. I think it would be no good making one with modern gear, it is likely to simply flip over.

I await numerous replies from chaps who ACTUALLY made one and can vouch for the incredible performance. I would like to be proved wrong. Further, it is almost something I might like to try, at twice plan size. Can I get a plan from somewhere?

Ashley

I can let you have a copy of the plan if you want one! As a collector of Hobbies designs (not just boats) I found the article interesting too. I'm still looking for a plan they issued in the early 1930s for a 31inch battleship but think I have most of their other vessels.

[ashley needhamParticipant @ashleyneedham69188]

Ian, that would be fantastic. I will PM you. Ashley

[ashley needhamParticipant @ashleyneedham69188]

Ian, that dapper chap has a plan of this wondrous beast and is prepared to send a copy, what a good geezer.

​The boat is approx. 14 by 3 1/2, A bit small, but doubled up gives 28 by 7, more like it!. I did see on the small picture in the mag that there was a stabilising keel incorporated, very interesting. I have no doubt that the plan is deliberately skeletal to appeal to the fretsaw boys, as there is frequent mention of fretsaw work being used in any number of their projects.

​It is long and thin, and I could forsee stability issues. Probably there were NO stability issues in 1948 as the small motor and home-made prop would not have propelled it very fast, or at least. fast enough to have a stability issue. Coupled with the fact that it is a free-running design and thus would not twist and turn maniacially like wot the boats do today. It may also be that it is not as tall as I am expecting it to be, which would also help.

​I have too many boats and projects that rely on good weather to function properly and would not particularly want to add yet another one to the shelf, so scaling up a bit would be good and getting that authentic simple home-made look would be important. I would not go down the entirely balsa route though at a larger size. I think a modest performance is all that would be necessary, not very fast, to add to the period look.
​Wonder what colours would be best for that "period" look? Cream, pale green or blue ….

​Winter is coming on, new roof on the now draught proof workshop…loads of space….
​Ashley

[Dave MilbournParticipant @davemilbourn48782]

Wonder what colours would be best for that "period" look? Cream, pale green or blue ….

P38 and Lime Green??? Aaaaaaaaaaaaaaaaaaargh!

How about Off-White and Wedgwood Blue?

DM

[ashley needhamParticipant @ashleyneedham69188]

DM. LG is going nowhere near this.

​Off white has to be one colour. Wedgwood blue is very nice. I think when the time comes I will print off a few line drawings and colour them in to see what's best.

Ashley

[Paul TParticipant @pault84577]

Old English White and Forest Green with details picked out in Black.

Ford Anglia Blue and White is also nice.

All Red with a White Stripe (dress the crew with jumpers and 1980s hair styles)

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