Veldas Lifeboat.JPG

[Chris PearceParticipant @chrispearce30862]

Oh my here we go.. TLA’s FLA… Went looking for info, on some of the RNLB fleet and found my name sake The Christopher Pearce a seven class, a nice story to go with it.

Hopeful if we move to a bigger place will be able to start to make these lovely boats,

Ducky. cheers for that, did it work for you?

[DuckyParticipant @ducky]

Hi Chris,

Yes it did work for me and here to prove it is the good lady with her Wyeforce Tug (by Model Slipway who also do nice Lifeboats by the way) at our yearly visit to Lyme Park in 2007 ,this is a National Trust venue which is now closed to the club because the Trust tell us they are worried some child might fall in the water at a later date after seeing us there sailing !! What is the country coming to with this compensation culture,perhaps they should fill it in and then it won’t be a danger Hey.

Ducky

[Chris PearceParticipant @chrispearce30862]

Hi Ducky.

 LOL, I spoke with her ladyship, she said that We don’t have much room to keep her model she wants yet….  I know what I want.. 1:12 seven class.

We tend to sail our boats on the Boating pool at Bushy park, it a bit green with the bird and deer poo, but I don’t think they will close it down just yet…..  so the trust must think that… a child, some when in the past watching model boats, could fall in the water in future because of the the mind bending fun fueling excitment. good grief… ban the boats…  bah humbug. Turn it into a sand pit and put model cars on to race…… nitro… yeeea

.. ChrisP

[Chris PearceParticipant @chrispearce30862]

Hi All,

Just getting the parts for conversion of the RTR Seven Lifeboat, does anybody know what the lengths are for the prop shafts should be, on the props Alan used the plastic props 25mm, looking to use brass 20 or 25, any recommendations?

Cheers ChrisP

[Alan PooleParticipant @alanpoole81825]

Hi Chris,

 I used the small 4mm OD,Graupner shafts, 4 1/2ins-110mm long. The shaft dia is 2mm and the thread of this cuts into the original plastic props making a secure fit. I believe that the Prop shop will supply better cast props that will be more efficient and with a 2mm thread.

At a recent meeting, I saw a conversion which used a single prop, this performed beautifully on a speed 400 motor geared down by 2:1, Obviously a single prop is not accurate but if you are looking for performance then this might be an option. The weight is also less which is critical with this model.

good luck with whatever you decide to do….Regards  Alan.

[Chris PearceParticipant @chrispearce30862]

Hello Alan and all,

You seemed to have put a few ideas in my head, I’m looking at a Graupner 2349 mini jet, would this be a turn up for the books, Not sure how it would work , would you need a 3 channel controller. How does it turn the unit and put it in to reverse.

Alan I have very little in the way of tools would you, recommend for this task?

[ashley needhamParticipant @ashleyneedham69188]

Chris. You are a lad! having had a very quick surf to see what this mini jet unit is, i see it is sized for a 500 or 600 motor. I think it would be most suitable if you want to convert your life boat into a hydroplane.

These jet units normally require cutouts underneath the hull and at the rear, a reasonable amount of work.. a mini drill type tool I would have thought would be useful in this case. Ashley

[Chris PearceParticipant @chrispearce30862]

Morning, LOL

I was just wondering after Alan opened it up with the single prop conversion, I suppose a 385 wouldn’t work!

Hydroplane mmm it wouldn’t be that bad with a 385 would it! question is how do you control it, maybe I need to stick on the open forum.

For the cutting out on the Seven, I suppose a frett saw would be handy?

[Mike DavidsonParticipant @mikedavidson22772]

    Here’s a good one for you, MMI is a new nemonic standing for Man Machine Interface, for example, the keyboard you are angrily prodding with your stubby little digits,or pigs’ tits as the RAF so rudely call the fingers of a clumsy person, but it seems so apt to me, being the technician that has to fix it when the operator breaks it, now, where were we ?, oh yes, the underpowered lifeboat, my suggestion is to buy a brushless motor, one of the type that will do 40+ thousand RPM, and a really low pitch propellor, here you have a combination that will cavitate like mad making loads of bubbles and not doing a lot in the propulsion stakes, so you will have a gyro stabilisedfloating platformBUT you can be  sensible, and choose a less powerful motor which turns at a lower RPM, and a utility propellor should make a less frantic combination. There is also the subject of enduraance that needs a little thought, once a motor goes above ten thousand revs/min, the power consumption goes up like a standard firework  if there is a whizzy thing in the water, sorry Ashley, so your model will go walkies and you will have to go paddling to get it back or ask Jimbo to drive his bait boatover it and drop a fish hook on it in order to tow it home, 

 I bet he would charge salvage if he did. Now there’s a position for you in all the model boat clubs, salvage officerwith a bait boat, grappling hook  nylon parachute cord and a winchand you would see many more doing what I do, incorporating positive buoyancy into the models by embedding ping pong ballsinto the build, still, keep bashing away at your MM I’s, keep the good idea’s coming Mike    D

[ashley needhamParticipant @ashleyneedham69188]

Mike. waders, cheaper than paying salvage..

chris. Yes a fretsaw might do it but it would be very tricky. You can get cheap mini-drill things, and they make really short work of cutting holes etc. Dont forget you also need to cut out the box holding the original radio gear in it, and trim a few melted over studs to free some of the bodywork, and a fretsaw will NOT do for that. I think its an investment. If you are going to do more work on any other boats… like your underpowered fishing boat, with the inacessable rudder servo, it will be a godsend.

Not sure about your comments on the 385…this is a lower powered motor than I think you are thinking of. They spin 40mm props ok at 6v but lack the revs to power smaller props, like wot you need on the RtR lifeboat. I have one (lifeboat) which I will eventually get round to modding, and I will use a pair of speed 280`s and 25mm props on it.

I like the idea of going very fast tho…….Ashley

[Chris PearceParticipant @chrispearce30862]

Just filled in the slots on the seven with plastic weld and some of the left over plastic appears soft at he mo, will it go hard, it’s been 5 hours since placed it in.

Alan,

Did you have any problems like this, I was planning on have 2 rudders behind the pod holes, if the filler doesn’t go hard, will have to use the one in the centre,  Alan will this have any great adverse affect on the steerage?

[Mike DavidsonParticipant @mikedavidson22772]

 The rudder works best when in the direct flow of water from the prop.No matter what, a rudder only works when there is a decent flow of water past it, ask any sailor who has been becalmed,you can turn the rudder as much as you like, the only result will be little eddy currents astern. S if you place your rudder midships,I think the best thing to do is bolt it to the transom my andsom so it is as far astern as you can get it. moments about an axis and all that  mechanical stuff, but if you do that, there will be no harm in placing it directlybehind the propellor so to coin a well known phrase or saying, suck it and see

getting the fittings to scale might be a bit of a headache…………………Mike     D

[Alan PooleParticipant @alanpoole81825]

Hi Chris,

 You will have enough of the original hull behind the pod slots to get a pair of rudders in behind the props, look at the pictures in the article in MMI. The rudders do not project any lower than the bilge keels, this then protects them from any damage. they are home made rudders. And yes, you need a good water flow over the rudders to provide any steerage way and being able to apply power through the props over the rudder blades directly is the best way to maintain control at all speeds.

The old pod slots were filled with pieces of plasticard glued in progressively, this gives the plastic weld glue a chance to harden, you may find it takes a long time to cure a large hole filled all at once.  

Regards  Alan…

[Chris PearceParticipant @chrispearce30862]

Hi all,

Thanks for top tips, The plastic weld finely set this evening, and have now drilled out two 8mm holes for the rudders posts.

used instant resin for the shafts, They didn’t seem long enough so the uni joints are  pushed out over the back wall of the former circuit housing. 

The rudders are small but appear to be to long rrrrr 41 mm!!, Simon at the prop shop has done some 23mm brass props so, if nothing else is to scale, then they are.

Step learn curve..

Update you later

Cheers ChrisP

[Chris PearceParticipant @chrispearce30862]

Alan,

Question for you you say 12Volts for the power, what kind of speed are we looking at and how does the model fare in the water.?

Would 7.2v be any good or would this be slow, with the 2 385’s?

cheers

ChrisP

[Chris PearceParticipant @chrispearce30862]

BUMP

Anyone on my last re 2x 385

[ashley needhamParticipant @ashleyneedham69188]

Chris. Its a hard question to answer unless you have actually used this combination.  23mm props are quite small, and a 385 on 6v or 7.2v does not rotate particularly fast…so the thrust from this combination will not be so fantastic. Saying that however the boat is small and should go along ok,depends how fast you want to go,that old nutshell. On 12v I would have no hesitation in saying this combo would be fine. My personal preference would have been to use a pair of speed 280`s on 6v with such small props.

Ashley

[Chris PearceParticipant @chrispearce30862]

Hello all,

Test it out in the testing tank lots of thrust with the 2 385s, using a 9.6v batt charged up, but when I walk away with the controller it starts to judder/ stops and starts, when 10 feet away nothing.

Should I use a servo battery ?

the controller is full charged, the receiver box is 8 inches from ESC, also used 9v box of non chargerables but still the same result.

Chris

[ashley needhamParticipant @ashleyneedham69188]

Oh dear chris. A question like that is asking for a degree course in electronics to be added to your post !!

there are several LONG running threads on this problem. But I recon a few basic checks will sort you out.

Motors should be capacitored up,motor wires from each motor twisted together. The leads for all the stuff should be seperate as far as poss, The ariel wire from the reciever should be not tangled up or knotted, just laid out as much as poss AWAY from the ESc and motors, Are u using an ariel, like a seperate wire thing ?? try lifting the reciever out of the hill and streching out the ariel wire to see if its simply a question of  placement of bits. I dont think youi were using a seperate reciever batt pack were you? If the esc has a BEC facility, you dont want the reciever pack.    

Yes i would agree that the 385`s on 9.6v will give the revs needed for some adequate shove with your toddy props. HOWEVER, the number of models I have tested in the bath and thought " oh yes thats o.k", but when out on the pond have been disapointingly slow…. Ashley.

[Alan PooleParticipant @alanpoole81825]

Keep it going Ashley!

[ashley needhamParticipant @ashleyneedham69188]

No more on the subject of control from me !,  Chris knows where we will be on Sunday mornings if more info is required! (large panel of  "experts" by the pond desperate to divulge the arcane knowledge of "model boats"!!!)  There`s no doubt about it, I have had problems in the past and someone else looks at it and sees the fault straight away..sometimes you just cant see for looking. Also I find that by the pond everyone will be carrying spares of one sort or another and you can swap bits/try new bits out to sort some things out there and then, rather than buy these things to see that they dont work, or dont work as well as you hoped for.    WHILE I am at it. It suprising the number of poeple who boat do not carry their toolkits around, or their box of bits. Its no good just carrying a few things around, as the bit/tool you will really need by the pond is ALWAYS the one left at home.

I might start a thread entitled "what do you carry in your pondside toolkit " ?? Ashley

[Chris PearceParticipant @chrispearce30862]

Hi Alan ,Ashley and all,

The Seven works…. very well went out on the Boating pool, good turn of speed and tight turning circle, the problem was the transmitter, have used the old battery bay and slotted in a 9.6v battery haven’t tried it out for long, but very impressed. I’m off to Scotland for a bit so will take it up there with the kids.

There was so much for me to learn on this conversion, and patiance of a saint was one of them, now for the next one

As for tools on the water side just have a mobile workshop……… called Ashley LOL 

So thank you for the help, will update when I get back, sure to have some points to put on, Oh on the test, I had half a cup of water in the boat…  so I replaced the bow screw seems tighter.

Catch you all soon Shippers…..

ChrisP

[DuckyParticipant @ducky]

 Who would have thought that my wife’s little lifeboat would have generated so many views on this subject 4,611 to date,can’t believe it !.

Ducky

[ashley needhamParticipant @ashleyneedham69188]

Ducky, Any thread with a lifeboat in is bound to get a lot of views!!

As it was raining and cold all day yesterday i have hacked my Severn about now in preparation for fitting a proper remote control. I weighed all the bits I have cut out and it comes to about 270Grams. A standard servo, twin 3mm brass tubes/shafts and 25mm brass props,2x speed 280 motors and a Viper marine ESC comes to about 250, so I recon I should be about ok to the standard waterline. I may even add just a few bits of lead in the bottom to get a bit more stability.

I have turned the standard boat over in a breeze before now, but by moving the drive batteries from thier position fairly high up to sitting on the bottom of the hull should improve things a bit. Its a shame that as a real boat, lifeboats go out in any sea, but model lifeboats are relatively  top heavy and less seaworthy in a strong wind/waves. I had forgotten the very neat battery holder with plug that comes with this boat, very handy although I will use a set of ordinary plastic wrapped NiMh batteries, as i happen to have a set of 6x AA already.   Ashley

[Chris PearceParticipant @chrispearce30862]

Well I’ve finished what I can on the seven, still a slight leak from the rudder stems, I cut them to down a bit to short,

currently powered by a 12v 3000a batt with 2 x mfa 385 motors, with 2, 23mm 3 bladed brass props, giving a good result.

some good lessons learn’t, would I do it again mmm maybe.

ChrisP

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