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Author Topic: crash tender (Fireboat) refurb and brushless conversion start to finish project!  (Read 40689 times)

red181

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you've seen the difference in build quality!, Ill say no more %)
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red181

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motors are fitted to the boat, shafts where set up so that we had the right position, using a disc cut from 2mm plastcard, with a flat to rest on the upturned hull. We assumed the biggest diameter would be 55mm, we where then able to see where the prop tube would be inside the boat, as its direct drive no couplings etc, its easy to see where the motors needed to be, and cout the tube to the required length.

At the water end of the tube there are water lubricated glacier bearings, at top end ballrace bearings, then in the motor mount we have another ballrace, maybe a bit over engineered but more is better than less! :-))






A number of bulkheads have been cut away, to ease access and reduce weight, if this works without problems, I will be amazed!
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red181

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The cooling water will exit via the exhausts, I am hping it will create some sort of exhaust effect?


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derekwarner

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Hullo red181........I have no real knowledge of electrics or fast brushless  :o ...but have wondered for a time about the water cooling depicted in many models

The example here shows the water cooling manifold but appears to contact only the output shaft housing of the motor ???

Is it designed so the motor forces/draws air over the rotating [heat] mass toward the cooler [water cooled]  aluminium manifold?..... :o  or am I missing something?  :embarrassed: ....Derek
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Derek Warner

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Illawarra Live Steamers Co-op
Australia
www.ils.org.au

Norseman

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when they stop there is a latent heat build up at the front, so a cooling block between the motor and mount should help.
  :}
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red181

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Hi Derek, thanks for question,

so, there is a water pickup between the prop, and the rudder, two actually, one on each side. The props, and the forward movement of the boat, force water up the pickup (which is brass, but are readily available in plastic) , through silicon tube, I then fitted aluminium tubing, which takes the water up the boat, to another piece of silicon tubing, this connects to a nipple on the cooling alloy block, which sits between the motor and the motor mount.

The cooling blocks are drilled internally, in a fashion that the water flows through a "U" and back out of the mount via another nipple, then with silicon tubing again enters and exits the water cooled esc, then back down another alloy tube to the exit exhausts at rear.

The water is forced around the system by water pressure at the pickups only. If the motor was not an outrunner, ie, the outer can did not spin, I could use either the commonly available cooling coil that goes around the motor can, or a water jacket around the motor,
Hope that helps,

Paul :-)) 


You can see the two nipples on the cooling block, for exit and entrance of the tubes,




water pickups under the boat



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red181

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time to move on to the horrible job of making the boat water tight, and paint :((, I hate this bit,

As mentioned previously, we decided that we need to glass the hull, this will make sure the wood does not rot in the future, as we dont know how old the boat actually is.

 


This is the cloth to be used, its light, but strong, definitley a two man job, one to do the job, and one to get in the way (me!), the cloth shrinks and moves as the resin is applied, and starts to go off quite quickly, so its a bit of a race agianst time, very messy, but worth the effort.

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red181

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the hull was a bit of a job, getting the cloth and resin around the shafts and rudder positions, resin applied to the wood, then the cloth over this, then another coat of resin, next is the labourious job of sanding down {:-{










so the hull and deck are now glass clothed and resined, dont have to do the cabin sides, I have other plans for them, more later :-))
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red181

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very long winded job, sanding the glass fibre, ready for first paint, very boring! but worth thre effort :-))







First paint, at last, I have opted for halfords filler primer, dont know why, I was disappointed last time I used it  :((, but will give it another go. The hull is quite nice and flat, but I wanted a primer that will allow some good rubbing down to get rid of any imperfections,
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red181

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well my instincts where right, the halfords FILLER primer was rubbish! there wasnt any filler qualities at all, so off to my friend who has a car paint shop, call in afavour, no pics unfortunately, but he did filler primer, and the dusted over with matt black so I could see the imperfections, now I have something decent to work with.

The cabin sides, well if anyone is familiar with these aerokits boats, the cabin windows are never equal and straight, it really bugged me with my smaller 3 foot version, so I have decided to use 2mm plasticard, make new sides, with equal and straight windows, and epoxy these to the original ply sides, this should then make painting very easy as the surfgace will be flat, sound and will not need sealing

Luckily I have access to a milling machine, so making the sides with teh window cut outs is relatively easy once the job has been set out


 





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red181

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the new windows are now same level, straight and parallel, and same size, on the previous pic from the inside you can see how "out" the original windows where, my version of this boat is the very early one, number 93, before any of the refits. There are some subtle differences, on my version each window has its own "eyebrow", It was difficult making these, using plastcard strip heating with a heat gun and forming around a wooden mould that was made to fit in the window holes, tedious work!



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red181

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I had to do the sides in 3 pieces, the rear section was done second, this was quite easy as it was small and narrow, the fron section was harder, as it had quite a difficult shape, and a strange shape to the side window



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red181

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on to the wheelhouse now, these boats have rather unusal front windows, and on this model they need replacing, again using 2mm plasticard, I am unable to work with wood, I just cant knock a nail in straight!




off with the old, and in with the new. I had to strengthen the frame, it was all a bit flimsy, it was difficult trying to get the shape like the real thing!




new window sections fitted, and the sides are on,






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red181

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the window frames are next, these will bring the definition to the shape of the windows, I want to try and use lexan for the glazing, rather than thin plastic card, if all goes to plan, the boat will be fast, and the front windows need to be sturdy :}, i just cant decide how to do this, without getting paint on the glazing, so, I reckon make the frames, stick them on, paint the boat, then somehow do the glazing from the inside.

This itself might be too weak, the glazing could do with being on the outside, so its more secure, decisions! %%

 



I have cut the window frames using a milling machine, with a small bit so I get the internal radius neat, I will hand cut the exterior shape, as I can handle the exterior radius on my own!




they turned out quite nice! :-)) (not first attempt I hasten to add!)




fitted and primered, ready for paint
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gwa84the2nd

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looking very good so far keep up the ood work there bud ime counting the days to sea haw that drive train works out  :-))
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HS93 (RIP)

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it works fine http://www.youtube.com/watch?v=W1FShc3Mvuk&feature=plcp.  first runs some weeks
Peter
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gwa84the2nd

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thatle do the job then lol goas well need a longer run to see haw silly it gets he he  :-))
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richald

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it works fine http://www.youtube.com/watch?v=W1FShc3Mvuk&feature=plcp.  first runs some weeks
Peter

I think you're going to need a bigger pond !

Richard
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HS93 (RIP)

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the vid's was the very first runs he did not have enough rudder movement at the time. the lake is a  great lake for testing easy in and out of water plus you  could Paddle in it to get boat back in an emergency, Paul will fill you in on any runs on a lager lake

Peter
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Norseman

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Oh, I'd love to see you paddle in there Peter - preferably with a daft smile and a big pink candy floss in each hand. {-)
Maybe for the January page of the Mayhem Calendar ...... so much more exclusive than Pirrelli's

Dave
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red181

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I always have emergencies!! :} so being able to paddle in, and retrieve on all 4 sides of the lake is a massive advantage! :}

For the peeps that thrive on statistics (me..i love testing!! :embarrassed:) Before I stripped all the running gear out for the paint etc, the boat got a couple of runs on a large lake, with eagle tree data logging and gps installed.

I tried a number of props, all testing was done with 4 lipo cells per motor, unfortunately I never got a calm day, and had nobody to video, but it went really well, and I was very pleased that it was a very efficient setup, certainly compared with my Huntsman that is so amp hungry it heats the lake up %%

  





here we have screen dumps of an actual run, using X 52.5 props, max speed was 21mph, since then, on the next day, which was a bit calmer, I achieved 22.33 mph, and only 38.29 amps, on X 55mm props. I now have a pair of propshop props that I hope will reduce the amp draw
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red181

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Whilst the boat ran well in a straight direction, especially at speed on the plane, cornering was a different matter, off the plane it was nose-diving, the rudders acting as brakes, up to now the rudders are the standard shop bought type with no modifications, and the turning circle was like turning the Queen Elizabeth on the mersey, so so mods where in order




Gradually taking a bit off the front and back edge, I tried to keep the pivot point the same, it seems to have worked, as it turns far better now, particularly at slow speeds (it hurt typing that statement, I dont like "slow" :D)

Now, remember the exhausts?, functionally they are superb, everything is running nice and cool, the cooling blocks for the motors working perfect, and the ally pipes looking all nice, but... the water exiting the exhausts, even at full speed, is a dribble at best. If I disconnect the cooling system the motors very quickly start to run hot, so its def working, but I am not getting the visual effect I was hoping for, ah well! cant have everything, I suppose everything cool is the better outcome. We even tried putting the water out of the exhausts at a  90 degree angle hoping that would create a sort of spray effect, but no different. I disconnected the pipes from the back of the boat, and hung them over the deck by the motors, suddenly I have a big pressure of water, so I think its just down to the fact the boat is 4 foot long, and the water is travelling too far.

Pity I have no video, as the boat will not run again till its finished :-))
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red181

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All running gear now removed, and its back to painting and making things




I really wanted a dashboard to resemble the real thing, so decided to make my own. I possess no particular skills here, so for any other looking in, give things a go, sometimes the results are ok!

I looked for ages to find a steering wheel, as this seemed to be the centre piece of the dashboard, could not find one anywhere, so made one from brass rod, heated up and bend around a bit of scrap bar, spokes soft soldered into place, nad the centre boss was turned on a lathe.

 





The dials are cut from a downloaded picture, some plasticard on the top to look like the dial glass, the switches turned on a lathe from some alloy scrap, and the dash stained with ronseaL matt varnish, throttles and compass made from some scraps, when in the boat it will not be that visible, so final detail does not need to be too accurate, quite pleased with result!

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red181

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hull now painted, for some reason the pics look pink! buts its definitely red :}, the black took a while, I used plasticote, sometimes this paint goes on really nice and trouble free, but the black took ages to get right, painted, flatted with 1000 grit, painted again, etc, 5 times!. I decided to lacquer rather than do what I usually do, which is to flat and polish, to try and give the hull a deeper shine, and more resilient finish, so after 3 lacquer coats and flatting between each with 1000 grit, I then polished the final coat, it turned out fine, but very time consuming with a lot of wasted time letting the coats harden for a day or two




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red181

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The deck and superstructure is painted in BS631 Grey, as per the original Vosper plans. It looks a bit "green" to me, but its done now, I'm not doing it again!

The deck was painted first, before primer, with this




This "roughcoat" finish will give me the none slip deck finish. After practising on some scrap wood, I arrived at how many light coats produce the right texture, then painted over this with the BS631 Grey, hoping there would be no funny reaction with different paints, so far, it looks very good, hope it stays this way when the boat is in use %)







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