Something Technical

[Eddie PriceParticipant @eddieprice78041]

Hi, Rather than just saying hello to each other,perhaps you could help a beginner. I am scratch building a yacht from MMI plans. The article that goes with the plans suggested modifying a standard servo to become a sail winch. With a standard servo costing about £5 compared to a sail winch at £80 odd it seemed like a good idea. I have made the mod, but now wonder whether it really will work. I have a modified servo that will rotate in either direction, depending on the transmitter stick, but I don’t think it is possible to put limit switches on it to restrict sail movement. Is this likely to be a problem? I suppose one has to rely on visual sighting of the position of the sail, which is okay close up, but a problem when the boat is some distance away.

Has anyone tried this mod?

Eddie Price

[Former MemberParticipant @formermember51289]

[This posting has been removed]

[Eddie PriceParticipant @eddieprice78041]

Hi Glynn. I am a bit new to this. The article was in Marine Modelling Jan/Feb 1997 by Sandy Cousins. The original did not have any limit switches, and I agree that there is the possibility of the servo stalling. I have a couple of books on sail, R/C Racing Sailboats, and R/C Scale Sailing Models, both from Traplet, and they show wiring diagrams for sail winches that have limit switches. I am not sure; perhaps I should just buy a sail winch.

If you read this I do have another problem to do with the rigging. The yacht is from the 1920s, so perhaps the rigging is more elaborate than for modern yachts, but the plans show forward backstays and aft backstays. They would appear to restrict the movement of the mainsail to about +- 20 degrees of the centre line. Yet from photographs of the actual yacht on the water the mainsail was well out over the water. So when are these backstays used. Are they just for cruising and are they removed for racing?

[Former MemberParticipant @formermember51289]

[This posting has been removed]

[Peter De LaneParticipant @peterdelane70800]

Has anyone ever made a hull from paper or paper mache, and successfully sealed it?

[E HAIGParticipant @ehaig83795]

I am trying to help a young modeller get his boat back in the water.

Can you suggest the proper connections for using 2x micro switches operated by a cam to give stop/seart forward/reverse.

Thanks

[ManxmanParticipant @manxman]

Hi Peter

Its 4 months now since your post, any luck with the hull ?  Sorry I’ve never built one using this material (usually use matches) can’t be much different.  Do you have a cross cut shredder ? if so brilliant,  get you plastic bucket out and fill with diluted solution of PVA glue (use a waterproof version) and shred 3-4 Sun news papers (its what they were printed for!) and plunge into your bucket.  Leave for a couplle of days, stirring now and then (best with your hands) and you should end up with a nice mulch.  strain and your ready to make your hull.

Grab hold of a block of polystyrene (visit you local skip) and fashion this into your hull shape, remembering to make it slightly smaller to take the thickness of the mache. Get hold of a roll of clingfilm and cover the plug with it,  now spread your gunge evenly over the plug about a 1/4" thick and allow to dry completly (best part of a week), keep testing for dryness by tapping with your knuckle – should make a good solid sound when fully dry.  Remove plug and you’ll have a good solid hull, which will sand smooth. As to waterproofing 2-3 coats of normal oil based varnish will do, allowing each to dry prior to the next coat.

You can then paint over this with what ever colour paint you like (if using aerosols check spray on the inside first)

As I say, I’ve never used this material before but I’ve never had one of my matchstick boats fall apart on the lake ! – touch wood !

Cheers – Ken

[Eric Moffat 1Participant @ericmoffat1]

G’day Peter, 

 Vic Smeed designed a sailboat made of cardboard!  All he did was cut a cornflakes carton into strips and used them as planks on shadows.  when finished he painted the hull with oil paint.

I did the same but I painted it with fibreglass resin, much stiffer hull when set.

dead easy, give it a try,

Eric

[andrew hustlerParticipant @andrewhustler]

Eric.

Greetings from gods own country,Cardiff South Wales,You have just answerd a quesion for me as i’m building a large boat ,4ft 10 inches,i cant afford the ply as im out of work and was considerding using cardboard from cornflake boxes ,cover with tissue paper,like the model aroplanes,give it a coat of seal and sand cut back with fine wet an dry ,repeat and paint.

Would this do the job ok ?? or would i have to go swimming after her ??Dont fancy that as our local pond,roath park,well i would prob catch god knows what !!!!!!!!!!!!!

Happy boating

Andy

[Eric Moffat 1Participant @ericmoffat1]

G’day Andy,  I don’t know much about model aero. construction, but I reckon they may sacrifice some rigidity for weight.

I used very light f/glass sheet (not very expensive) & a couple of coats of glass resin (put a colour tint in it if you like). By the time you buy sealer & paint, you wont save much on price & with f/glass you will have a much more rigid hull, particularly  in the lenght you’re contemplating.

The sailboat I built was called a 36er ie 36" long and sails fine after almost 10 years in fact I have never painted it as the colour is the thickness of the hull. Yours being nearly 60"may be better with heavier cloth & an extra coat of resin but I’m sure you will finish up with a much better hull.

good luck with the build . We will look forward to regular progress reports .

Regards

Eric

[Eddie PriceParticipant @eddieprice78041]

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