Francoise Papon from France, sent me these plans of the Class 5 Sports.

Mr. Landyacht introduced me Christopher Roger, who was interested in spreading this plans in order to be able to have more competition in the future.
( apparently they need more class 5 sport pilots and landyachts.)

I really want to build it, but the plans are missing lots of information ( angles, measures etc.)

I am trying to figure out how to explain francoise in a mix between english, spanish and some loose french words about more details needed.


juan enrique

Side View



View from Above.

I know all that, for us is very diffcult too to be able to find the right material.

as an example we have only 3 aluminum mast, all the rest are windsurfing masts.

we want to build this class 5 sport chassis on regulars pipes and with bike or motorcycle wheels, no carbon fibers only regular fiberglass for the cockpit.

You have seen the sails we are using, the dacron sails are far away from our budgets. maybe some day fisly will accept windsurf masts, who knows.

in the mean time, the whole purpose os this is to have fun, and if possible to get more people involved in this activity.


regards


juan enrique

I pulled your drawings off the computer and put a few notes , meaured a few angles and drew a couple of sketches , managed 1 translation, I think you will need a good rear view to work on. the photo you have shows that you need to keep the whole rear half of the chassis as flat as possible at all times when designing it. I would suggest building a mock chassis out of seel scraps the same diameter as the final steel. then when you have all the angles right build a jig around it.


I would try the first yacht with a 8" wheelbarrow whel if you cant get a good 20" alloy wheel.
Enjoy , Paul

My experience is the same if you compare apples with apples and disregard the exotic
matierials some of the front runners overseas are built from the matierials are similar as any other landyacht
My class 5 weighs 60KG my mini weighs around 38KG and would be a fair representation of the matierial cost difference IMHO

aus230 weighs 56k with the NZ sail (windward) and 59k with English sail(R&J)fully rigged
cheers
aus230

Hi Blake (happy NEW Year by the way)
The R&J sail has much heaver battens and the material is thicker than the winward sail.They where both ordered to fit a yorker mast which Bill Naine from NZ (rocket builder)gave me the design for. I would have brought an aus sail but at the time I did not know where to get one, as it turns out the overseas sails where cheaper than the aus sails (postage is now a problem as the cost has got ridiculous)

R&J wanted to know what type of mast, what type of yacht, the weight,my weight, the surface it would be sailed on and the average wind speed of the area.(this is where I stuffed up a bit, I said around 15k ph and at and below that wind speed the yacht is very fast but above that it is a bit of a hand full.)

http://www.rjsails.co.uk/dinghy__land_yacht_sails.html

cheers
vic

my 5 comes in at 53kg with the steel rims and 51 with the plastic rims. my argentinian sail is quite heavy cloth but the foot is short so i lose 300gms on a shorter boom. I also tend to run a heavier tyre on rougher surfaces as my wallet isnt up to a daily tyre change

Pretty hard to do much of analysis on what the sprung weight is given that the whole chassis/frame is part of the system?
I do know in my own mind that a 5 of less than 50kg does not work very well, but Clem will respond to this with an opposite view!

aus230 said...

My understanding of unsprung weight is the wheel weight. In speedway we tried to keep anything that turned to as least weight as safe/possible as that is what required the use power to turn.(I guess that is why tire pressure is important to, if the Tyre pressure is to low it requires more power to turn)
cheers
aus230

According to all my design books on race cars, unsprung weight is defined more or less "any component of the vehicle which is not affected by the spring system"
So, on a speedway midget this includes, all the beam axles, steering componenets attached to the axle, 50% of the link from the steering box to the steering arm, wheels, tyres, hubs, spindles, the complete rear axle, 50% of the birdcage 50% of radius arms, 50% of the driveshaft etc. Why the 50%, because 50% is on the axle, the other end is attached to the (sprung) chassis, so 1/2 is sprung weight, 1/2 unsprung. On a wishbone car the ratio is a bit more complicated depending on where the suspension system is attached, NB not the spring itself, the system, so a pushrod or pullrod system it's where that attaches to the wishbones.
Hence my query over what is the unsprung portion of a LY. (Been playing with race cars for close on 45 years now, mainly formula cars) Landyachts were only since the early 80's, whoops, that's getting close to 40 years too!

Here we go again! He says as it raises it's Uggly Head!!!!

Could I dare say that in the case of Land Yachts with out some form of Independent Suspension that Un-sprung Weight is from the Axles out ie. Just the revolving part of the wheel. Being as the Axles are and Axle Carriers are Part of the Beams which are seen as "The Axle" are all part of the suspension unit, unlike normal modes of transport which have a myriad of Bits and pieces connected and indirectly connected to the Springs out side the Chassis and vehicle body. Consider the Body and Chassis to be one and the same with Coil or Leaf Spring Suspension one could say that anything connected in addition/Outside this part of the System could then be considered to be suspension or as Effecting the operation or adding to the weight the Suspension. Therefore anything not affixed to the Chassis is Classified as Un-sprung weight which we try to reduce so that the Wheels are forced more quickly back to the ground surface in an attempt to remove any Power Transfer loss between the wheels and the surface. If we could have un-sprung suspension that weighed ZERO then the Power Transfer would be close to zero. This is as we know impossible. However with Land Yacht design we do not have a normal suspension just a simple suspension system which incorporates the entire Axle which presses down on the un-suspended wheel.
Therefore it is I would say just the Rolling part of the wheel is Un-Sprung weight as the entirety of the Axle and Land Yacht Body is Suspended
Ron

aus230 said...

Hi Clem.
You have mentioned sand in your yacht before. Where do you place it?

As for unsprung weight on a land yacht, I would have thought it would only apply to the wheels, But that is only my understanding.
Cheers
aus230

The first 10kg bag I put behind my back support. If I need more I just pile it around my knee area or anywhere I can find room and still be comfortable in the yacht. I try to keep it away from my feet area for obvious reasons.
Unsprung weight? My understanding is; yes defiantly the wheels should be light, but also the extremities of the frame. i.e ends out by the wheels and top half of the mast, and defiantly the sail. Keep the weight low and centered. I see a class 5 frame and mast as one continuous springy unit.

I couldn't imagine too much movement at all with a 20+Kg weight belt on maybe I need to go workout

Test pilot 1 said...

If i needed more weight(yeah right - as if) i would try diving weight belt, that way i would still be able to transfer weight around by body movement which would more advantageous than static weight in one place

TP, serious question, how much do you really move around? IMHO moving backwards and forwards does have a very obvious effect, upwind speed better further back, forward to corner etc, sideways I think has a negative effect as the extra frontal area presented by your body is slower than the gain of moving your weight outboard has. Donkeys years back we had a group of 3 yachts on 90 Mile beach which would not move in relation to each other over a few kilometres (miles in those days) so we agreed on an experiment. One of the guys who really believed in stacking out agreed to try lying dead straight on the centreline, me, of mixed opinion would try "stacking" and the other who was of the "stay in the middle" would try stacking too. So we set off, after we were in formation, we assumed the agreed position. The "non stackers" slowed down markedly, the other went past. We then changed the deal around and tried a number of times, same result. It was all pretty dumb really as the guy who had always stacked out never did it again and went on to beat me at the Nationals, became NZ champ with his "new found speed", me... bridesmaid again!

Now there is an interesting term aerobrake Please explain.
Anyway what is this about added bulk?? Test Pilot you have 25/30kgs over me and you are talking more weight??? Out of curiosity what is the sail area of LY/class 5 in your Avatar?? AUS230 what is your sail area??
Ron

Oh! I thought that was just a Power Slide. I haven't quite made it to the Inverted Sail Bit but the rest well just about. Those Air Trac Tires are a bit gripy and turn you quickly anyway. It is good to know that, Logical when you think about it on wet Tarmac, I guess Wet Clay would be a bit like trying to sail a Land Yacht on Ice only messier
Ron

Now that I find Odd. I would have thought that Ice would have been of minimal friction to Them Little Black Doughnuts. But High Sideways Friction to Ice yachts.
Ron