Having fun building a kit

[Paul TParticipant @pault84577]

Are we being formal now?

[Bob Abell 2Participant @bobabell2]

Not really, it just seemed appropriate at the time

What motor will you be fitting?…………Brushless I hope……….They make a refreshing change

Bob

[Paul TParticipant @pault84577]

Bob

I am still musing over putting two brushless motors in,

I know it is against the best advice and it would probably blow up in my face but it will be a challenge fitting all the kit in such a small boat.

Paul

[Bob Abell 2Participant @bobabell2]

How wide is your hull?

SloMo2/Ellie hulls are 220 mm wide and two motors fitted easily

Bob

[Paul TParticipant @pault84577]

Bob

This boat is smaller and designed for only one motor and at its widest point the hull is 180mm wide, like all boats of its type it has a flared hull and it is actually very narrow at the waterline level.

Paul

[Dave MilbournParticipant @davemilbourn48782]

Don't. It will bite you.

[Dave MilbournParticipant @davemilbourn48782]

This is how it was explained to me by the owner of "Mirak", which is a full-size Huntsman 31:

The problem with twin props on this type of hull is cavitation in turns. A deep-vee leans over like a motorbike when you apply rudder, to the extent that the prop on the "up" side can partially break the surface of the water. This can result in cavitation and loss of thrust on that side – which is exactly the opposite of what you want to help the turn. If you look at the photo of Mirak (below) you'll see what look like trim tabs each side of the swim ladder. They aren't. They are there to try and minimise the effect of cavitation. With the much higher speed of electric motors cavitation is more likely than with lower-revving i/c engines.

Irrespective of whether a single prop is aesthetically offensive or the angle of the shaft is theoretically excessive, it places the prop well down in the water and there has never been a hint of this cavitation in any of my H31 models. I wouldn't want Paul to put a lot of effort into building a model only to find that the performance has been compromised by an "off-piste" modification.

Dave M

 

Edited By Dave Milbourn on 22/02/2017 09:04:18

[Paul TParticipant @pault84577]

Hi Dave

Thank you for your sage advice and the explanation from Miraks owner, please don't think that I am not mindful of your experience and know that I am taking your advice very seriously.

The reasoning behind my wish to use two motors is that I really wanted to make a model of Double Century (race number 200) which competed in the 1972 London to Monte Carlo race.

Paul

Edited By Paul T on 22/02/2017 12:21:26

[Dave MilbournParticipant @davemilbourn48782]

Suit yourself, old thing. You usually do.

BTW For Kevin's benefit "Double Century" isn't unique in having twin props – all H31's do. I like the colour scheme but I'm not keen on that clumsy radar mast and the long scoops (although necessary for the big engines) aren't as sexy as the eliptical ones. The original scoops were hammered by hand from copper but that made them a prime target for thieves and the price of replacing them in copper is eye-watering! Mirak's are GRP mouldings.

DM

[Paul TParticipant @pault84577]

Hi Dave

After your comments I am really unsure about fitting twins so it goes on the back burner whilst I build the hull.

I'm not keen on the radar mast so I'm researching into 200 to see if it ever put to sea without it, I would then base the model on that phase of its life.

I prefer the long scoops as I always thought the smaller eliptical ones looked out of proportion..

What's next off the line in your super duper workshop?

Paul

[Dave MilbournParticipant @davemilbourn48782]

Paul

Next off the line are 30 x P94's…. I'm avoiding them as the last bit of assembly is soldering the thick leads into the PCBs and screwing the heatsinks to the MOSFETs. I'd sooner watch Strictly…. ["No! Come on, Dave – anything but THAT!!!"]. On the subject of actual model boats my lips are sealed. If I told you then I'd have to kill you.

Ref "Double Century" (Hull #23) sans radar mast, here's a few pictures of exactly that. **LINK**

There's also an album of photos on the F.O.C. website for "100% PROOF" as per your picture, but that is a different boat (Hull #21).

Dave M

 

Edited By Dave Milbourn on 22/02/2017 14:10:13

[Paul TParticipant @pault84577]

Strictly, The Voice, I'm a Celeb, Britain has Talent, The Jump………..How many brain dead viewers are there in this country, all we seem to get is a never ending torrent of reality pap. Whats next 'Celeb watch my paint dry'

If you did tell me about your latest project then you would have to join the queue of people/things wanting to kill me.

Thanks for the link its exactly what I needed

[Paul TParticipant @pault84577]

I know that I have already said this but I am having lots of fun building this little kit.

Its very relaxing whiling away the afternoon putting the hull together when everything else has been done for you and I really would highly recommend this kit to everyone.

[Colin BishopModerator @colinbishop34627]

Glad you are enjoying it Paul. I'm sure his Guruship is a happy man.

Colin

[Dave MilbournParticipant @davemilbourn48782]

I really would highly recommend this kit to everyone.

While I very much appreciate Paul's comments I wouldn't recommend the kit as a first model. There are techniques involved which might be beyond a raw beginner's capability – certainly to start with e.g. steaming strips to curve; block-sanding; razor-planing; planking (just the roof).

DM

[Paul TParticipant @pault84577]

Hello Dave

Don't underestimate Kevins DIY capabilities nor undersell the very clear, step by step instructions that even a seven year old can follow.

I appreciate your comment about tools but I am managing with nothing more than a Stanley knife a flexible emery-board.(nail file) and cheap clamps.

It is a very easy model to build……..despite the odd design flaw

Paul

[Dave MilbournParticipant @davemilbourn48782]

Paul

Take it from me that Kevin's DIY abilities cannot be underestimated… Good luck with the nail-file.

Perhaps you'll list the 'design flaws' so that I don't make the same mistakes again?

DM

[Paul TParticipant @pault84577]

Dave

These 6in nail files are really good they can be used wet or dry and have two different grit sizes (one on each side) I use the 120/240 grit.

They are fantastically flexible and shift filler / wood very fast.

I bought a pack of 10 a couple of years ago and I'm still on the first one.

 

Re design flaws……..I have looked all over the drawings and can't find a drinks cabinet or cup holder anywhere, as an avid 'sun over the yardarm man' I expected your design to include some facility for holding the JD and Pimms.

Paul

Edited By Paul T on 24/02/2017 16:05:09

[Colin BishopModerator @colinbishop34627]

Check the ballast tanks Paul, you are thinking in the wrong capacity magnitudes.

Colin

[Dave MilbournParticipant @davemilbourn48782]

Paul

These links may prove useful to Kevin:

**LINK**

**LINK**

**LINK**

You are a lost cause, I fear.

Colin

You are quite correct. A full 1/16 scale bottle of JD wouldn't satisfy even the vague hint of a thirst, let alone a 1/16 scale 'tot' out of it. Poor old TT Thomason…

DM

[Paul TParticipant @pault84577]

Lost causes have the most fun.

I think I will include a drinks cubby in the cockpit and a cup holder near the wheel, not quite a gin palace but something in keeping with our illustrious guru's semi retired lifestyle.

st. J Thaddeus

[Paul TParticipant @pault84577]

Build update

I have been fitting the skin onto the frame which, in this case has been something of a revelation. In the past I have always fitted single piece skins and had the usual struggle with clamps and fixings whilst trying to get the things to fit.

But in this kit the skin is supplied in smaller sections of three to each chine, which firstly perplexed me as it seems counter intuitive to add more joints to a hull and risk the potential for leaks. However I have faith in the designer so I carried on as per the instructions.

What an absolute joy it was to fit this skin, all the joints are machine cut so they butt up perfectly and fitting the skin in sections meant less struggle and less clamping.

I needn't worry about leaks either as the entire hull is sheathed in fine cloth before painting.

At this point I should say that the design of butt joint and sheathing is more than adequate for the normal handling that you would expect from any careful model builder however I do have to worry about excessive miss-handling by my enthusiastic grandchildren so for my piece of mind I added a strengthener on the inside of each butt joint.

Paul

[Paul TParticipant @pault84577]

Hands up to cutting a corner by using a palm sander to smooth off the hull.

The design calls for balsa blocks in the bow and I have to say this is by far the best way to achieve the complex curves in this area. Easy to fit, easy to shape and easy to seal.

The last Huntsman type that I built was a 5ft Swordsman and the bow skin was formed out of 2mm ply, it was an absolute swine to bend the ply into these different shapes and I has to use quite a few mechanical fixings to keep the skin in place.

Now I have to sheath the hull with glass cloth so I will be on the lookout at Ellesmere Port.

Paul

[Paul TParticipant @pault84577]

Update

I have built the roofs out of scraps from the kit, not exactly as the designer intended but the results are the same.

The scraps were trimmed to make the edges straight and cut slightly over length then glued and clamped into position.

To make the roof edge come into line with the cabin walls the designer recommended cutting an angle into a couple of the roof planks.

Roughly filled with plastic wood (other fillers are available) and sanded back before the second surface filler.

Note the over length planks ready for trimming to the window profile.

Plastic wood is more difficult to apply than some other fillers but when sanded back it gives a smooth and waterproof surface.

The cockpit parts are a nice snug fit and required minimal sanding before fixing into position.

I took care to ensure the cabin walls were in the correct positions and flat to the deck as it would be easy to introduce an inadvertent twist in the structure. Its an easy process to fit temporary clamps and fixings to the hull upstand to hold the cabin walls in position but if you are unsure about how this is done the designer covers the process in detail.

A rough trim cuts the roof planks back and can now be profiled to match the window head. More surface filling and careful sanding will produce a nice crisp finish.

Paul

[Paul TParticipant @pault84577]

There is a review of this kit in Aprils edition of MMB, my copy has a crease through the name of whoever did the review so I don't know who did the write up but it seems accurate and unbiased.

[Author]

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