It's about time I got back into building mode again. Almost got all the parts I need. This one will be to the new FISLY mini rules.
I will be going for lightness to make it airline luggage frendly. 25kg all up is the goal.
Just need to get some of those nice light plastic wheels. Hope to weld something up this weekend.
Most of the yachts you seem to build are "Y" frame, What is the reason you choose this style of construction rather than a straight axle yacht? ["T" Frame ]
And what are the positives and negatives you see of the "Y" Frame.
[Just asking a question that newcomers to the sport might be thinking]
you notice the difference when sailing over really rough ground, the Y frame tends to float
But of course you have to now tune the chassis to the pilot a lot more.
Remember hiko found clemcos Y frame almost unsailable as it was tuned to clemcos weight. if you build too flexible it could slow you down , too stiff and the yacht might tend to suddenly trip over itself . Y frames on minis are really science by experimentation. Kind of landsailing cutting edge art
We havent even started trialing any OTT chassis's yet.
On a smooth surface , like lefroy a Y frame might not give you an advantage, then again it might................
note the high degree of mights, maybe's and possibly's in this post
Y the Y frame? It's all about balance. Once you loose your balance when sailing a landyacht you automatically slow down to regain control. With the Y frame all the forces are spread evenly over the triangle of the footprint. It also gives the yacht longer legs which can store the power of the wind as they flex in the gusts and release it in the lulls. The only reason the skinny axle minis were hard to sail in a straight line was because the legs were flexing forward and aft as well as up and down. That is what I hope to correct with this build.
Clem can correct me if I am wrong here but there was two skinny y frame chassis
built A very skinny one and a just plain skinny one
I never got to sail the very skinny one Clem can comment on that
The skinny one I found not too bad downwind but a real handful upwind scary even
It wasnt helped by the stiff steering which made for jerky oversteering by me
anyway
Clem I think managed it OK but he is a lot lighter
Yes, there were two test runs with the skinny, I will call them legs. The first ones were 31mm fibreglass tubes with a timber dowel epoxy glued inside. They were very flexable. I liked the way it heeled over but the flexing was also 3 dimensional which made the yacht start swaying back and forth in the horizontal plane. I ended up spinning out after only sailing a 100meters or so. The second legs tested in the same frame were plain galv steel water pipe. Slightly larger 33mm od. They were the ones Hiko sailed. They suffered the same problem but nowhere near like the fibreglass ones. What I am aiming for with this new one is to get the heel effect without any forward and aft flexing.
Here's my simple welding jig for the Y frame channels.
The main spine neatly fitted into the channels ready for welding tomorrow.
I just love it When you Boffins talk dirty
This is what I like to hear and see experimentation and Thinking outside the box. Good stuff lads
Funny A couple of days back I was talking about to an acquaintance about the SR71 Blackbird and later got to thinking a cross bread Blackbird and Land Yacht. Hmm
It wouldn't really be about competing just fun and aesthetics. just cool fun.
Anyway playing with design and materials available is really good stuff and as much as I don't like admitting it Aussies can be Innovative.
I want to hear more dirty talk [}:)]
Ron
Got the main frame almost welded up today. Those skis do have a nice spring to them.
Do you think clem that the angled frame /ski junction point may introduce a twisting effect as the skis flex ?
How can it? as it is on the under side of the ski. I will have large washers on the nuts when it is finished.
Yes you are right my frame is the other way up Wasnt thinking straight there
Note to myself :engage brain before fingers
Fitted the seat and bolted on some wheels to test the spring. Only droped ablit 50-75 mm when I bonced on it. It should sit level once I put on the 400 x 8 wheels. I think I might flip the frame over. It will be easer to keep clean.
The other end of the ski could make a good second leaf to spread the load.
I might need that.
Finally got some wheels for the little critter. Went with the NZ made ones just to be loyal. Also was lucky enough to find some 400x8 Cheng Shin smoothys which fitted perfectly. Scarce as hens teeth I am told. They will be good on the beach but not sure how they will last on the salt. I am trying to fit it all into a nice airline package 25kg max so I can get over to WA later this year. So far all looking good. The wheels weighed 2.9kg each with bearings and spacers. Still a bit of welding to do on the mast post and fit the folding deck-chair type seat.
That is looking like a really compact package there Clemco.
Keep in mind that it not necessary or recommended to have the tyres inflated during air freighting.
They could explode and you could be arrested.
silly suggestion, If you leave those awful smoothie things at home and just bring some rims then fit some ribbed tyres here at $17 aus tyre and tube. that would very likely get your weight down. . ( and give me a chance)
Yeah! And do they have a Web or email address.
Are they better than those $25 Chinese Crap?
Ron
The last set of 8 x 4 ribbed tyres I bought came from Mullins wheels (as recommended by Paul)
I think they have distribution agencies in each state.
They were $16.00 for each ribbed tyre and tube ($64.00 for 4 tyres and tubes) but might have changed price since then.
Just make sure the tubes are the correct size- 2 of the tubes that came with the tyres were 8" x 3" while the other 2 were 8" x 4"
Ring them first so you can take correct cash.
yep , Mullins Wheels. you dont want the road ribbed, just the 4ply light duty ribbed
Got some wheels on at last.
I know, I have probably made it over complicated. It is to give me lots of adjustments to fine tune, then I make the simple one.
Testing the flex.
To set up the wheel alignment I strapped straight edges to the rear wheels set horizontal, then bounced on the frame to see if it would toe in or out. And guess what, TP1 you were right, it did toe in, but only slightly. I guess I will have to get it finished and test it on the beach to see how that effects performance. Then make the changes to correct it if needed.
Well partly TP1....... I also tried it with the stubs in front of the end of the ski axles, ( as in the last photo) and it still toed in but only half as much. 10mm each side. I guess I'll just have to sail it before I can make any sense of that.
Mast post welded off. Foot pedal and steering linkages attached. Now just have figure out how to attach the sling seat from the last model. Good wind forecast for Saturday so I am aiming to finish it off by Friday night!
