Not quite dinghy development, but pretty close, my newest toy, just finished it the other night, some minor hicups in the design needing refining, i need to make a sail with a tighter leech and add some weight to the extensions, but other than that she went a treat, we timed it over a measured distance and got 18 km/h on the first outing so far so good. Once ive refined it ill send the plans to anyone interested, it hasnt cost much to make at all.

That is very cool...... I think I want one. I can just point out the obvious really - just like your moth, the only thing stopping it going at light speed is drag with the ground, and drag with the air.

I suspect the air resistance is the greater factor by a long way, but much of it can't be solved. I think the rig should be as high aspect as the materials will allow, and you mentioned poor leech tension. Consider a selfvanging wishbone configuration which should save weight considerably.

It looks like you can easily lower the CofE of the rig, and as speed increses, I suppose more rake will be benifitial.

I can't see the materials, but if your rear axil (it loos like) is a metal which can flex, you will need to 'toe in' the rear wheels to reduce drag.

I don't know... like I said, cool toy.

Its a bit hard to tell how its built, but its look cool. When you get around to it I'd love a set of plans.

We did this a while ago and called the class the 1DL. We've all still got radio controlled landyachts down in the Southampton area. Here's a picture of us racing at Weymouth in 2002.

We've got all the stuff to build a load more of these and get the circuit going again in 2006. We had 20 out at the nationals in 2000 and it is such a laugh. We regularly clocked them over 30mph sustained speed (GPS).

To see more of the events we ran go to:

http://www.yachtsandyachting.com/classes/?s=42&c=124 - http://www.yachtsandyachting.com/classes/?s=42&c=124

Is it available as a kit?

Rick

Here's a picture of us racing at Poole:

I'm sure it could be - I've got around 10 half-built landyachts at the moment without the rig. The rules we made up had a one-design hull but the rig was open to design as long as the whole landyacht fitted inside a 1.5 m hight by 1 m long by .75 m wide box with the main sheeted fully on. We made a jig for producing the hulls so they were all the same and could mass produce them.

We could knock them up for around £250 quid with 44.1 Mhz RC gear, high speed and strength mainsheet serve (the expensive part) and carbon spars and back axle.

I've been waiting until I built my new garage / workshop until completing them. It would be great if the forum revived this class as it was such fun at the time!

I was hoping someone would notice that! It was actually Ben Vines (GBR-999) who misjudged his run-up to the start line (between the two cones). One of the hardest thing when racing is judging perspective when going at speed since you are looking at the racing from off the course. The best thing (for consistency) is to allow lots of room for roundings and when avoiding another landyacht. 

I've been thinking about making one too even after seeing a pic of one in the photo thread on here. I have some spare radio gear with tiny servos so I guess it would be pretty cheap.

I'd love to see any plans that are around before I go and re-invent the wheel designing/making one...

mine cost a lot less than that, and the following refinments are being made as we speak, new mainsail made from mylar (with graphics!!!) the wheels are actually inline skate wheels ias i felt given the proposed speeds that plastic on metal bearings would melt, so bearings were needed, however on a wet surface these do not grip enough so new wheels that are also bigger are being sourced. The steering is impecable, i was always concerned that it would need tweaking but it surprisingly doesnt! The aft axel is two concentric aluminium extrusions bonded and is super light but with less flex than a carbon axel which is why i chose it not only as its cheaper but also has some weight which is a big must in that area. With regards to the wishbone idea, i ruled that out as the rig is stayed and actually has a goosneck. The goosneck arrangement is also the kicker, its the same system used on the top end rc yachts if i change the mast then i may go for a gnav, but at present the kicker is bonded to the mast, the mast is also an alloy tube which has the bend characteristics believe it or not. The rig can have differnet tensions put on it for different winds (yes a bit of thought was put in after all) but heres the good bit, the rig tension is adjusted by just ONE screw K.I.S.S. (keep it simple stupid!) im going to take it to the strathclyde loch xmas regatta this weekend for sum post race fun and input.im happy with the mast position as it is and the hull length is fine. Im considering carbon spars but the sail refinements are what is limiting the speeds at the moment i beleive, another thought was to add a jib aswell, very high aspect, just to take a few more degrees upwind. So far it has been good fun just designing the rig and what not and playing around with it.

Here is myt big question, would anyone be interested in creating an unoficial development class for this, just for like post race day laughs, aswell as some actual rc events, but just to see who could come up with what, similar rules to the dinghy dev. classes, any interest?

more input greatly appreciated

For those of you interested, ive worked out to have cost around £100 so far to build the yacht including RC kit (and that does include a high torque servo!) The special servo is by ratio the most expensive part (£15) but you can get a pack that comes with the remote, the receiver and 2 normal servos (use 1 for the steering and the other is a spare) for £40 its 27Hz i think, it works perfectly well, although for racing them it may be worth installing the slightly more expensive 40Hz kit as you have more channels available sosignals dont get crossed! (could be amusing tho) The original sail was made from two skins of (believe it or not) transparent duck tape, stuck adhesive on adhesive side. Which seemed to work well as the battens could be put in the laminate, but ive now sourced a far superior material which i will test as soon as there is some damn wind! The sail shape is acheived with a home made sail block which allows you to get the draft of the sail aswell as the leech curve correct when made using panels, you wont get the same power from a one peice cut! its worth the extra effort. Im going to change the kicker to a gnav today and lower the centre of effort. I am still trying to source better wheels however, can anyone help??? Still playing with the idea of a high aspect jib, but better to get the main right first!!!

More photos coming soon (better quality this time!)