Forums > Land Yacht Sailing Construction

grass/bean stubble machine

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Created by oldMXer > 9 months ago, 2 Feb 2011
oldMXer
130 posts
2 Feb 2011 10:15PM
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after much thought have decided to build a new craft that can take advantage of the best winds available in my area, have access to a grass airstrip and plenty of farm ground with bean stubble, and a frozen lake with 6" snow (not very good for ice yachting). all within a minute from door. tired of driving ($$) to asphalt venues in area, poor quality winds because of shadowing. will be in the open and hopefully have some kick a@% wind. have ordered some 10" aluminum atv rims, atv front sand tires (ams whipsnake) and hubs with 3/4" tapered roller bearings. if info i found on net is accurate should beat bigfoot tire weight, plus larger rolling diameter. want machine to measure close to lefroy specs, maybe plus 10%. wheel diameter 22x8. 6 sq meter sail.
wondering what difficulties will i encounter using this large of a wheel for steering? hoping to use 30 degree layover setup. any experience out there?

desertyank
1260 posts
2 Feb 2011 10:47PM
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No experience with it, but it sounds interesting. It should work, and those tires/wheels should roll over almost anything you can hit too.

If the front tire has a fairly round profile, the 30 deg steering should work as well.

Post pics as you proceed!

cisco
QLD, 12321 posts
3 Feb 2011 4:00AM
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I sail a lot on a local football field (grass). The area has two or three football fields marked out when they have a big meeting.

My LLF Mini sails well on it with the 8" trolley type wheels as does my blokart with 6" wheels.

I think the atv rims with tapered roller bearings will end up being too heavy.

oldMXer
130 posts
3 Feb 2011 6:42AM
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rear axle constructed from leaf spring off toyota pickup truck. has 2" deflection with my full weight on it. can add another leaf to fine tune action if needed (slimmed width wise). the grass here is kinda spongy, barrow tires just dont have a chance. really want to run this in a bean field which is pretty rough. would take picture but have foot of snow on ground. also use some front suspension. has anyone seen popeyethewelders kite buggys? he builds some really sharp machines. he uses what he calls leading link on his front ends. i think it would adapt well to 30 degree layover steering.



Nikrum
TAS, 1972 posts
3 Feb 2011 12:22PM
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Wayhay! You moving to Mongolia and going into Mongolian Archery???? Looks Like it would serve well as a Bow
It will be interesting to see how that works under rough conditions.. Don't spend roo much time being fired across that Bean patch.[}:)]
Ron

cisco
QLD, 12321 posts
3 Feb 2011 2:32PM
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oldMXer said...

rear axle constructed from leaf spring off toyota pickup truck. has 2" deflection with my full weight on it. can add another leaf to fine tune action if needed (slimmed width wise). the grass here is kinda spongy, barrow tires just dont have a chance.


You are right about spongey surfaces. Land Yachts hardly have a chance on them unless you have big foot tyres.

Looks like you are committed to your design idea and it looks very interesting.

Keep us posted with lots of pics please.

Hiko
1229 posts
3 Feb 2011 1:14PM
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oldMXer said...

rear axle constructed from leaf spring off toyota pickup truck. has 2" deflection with my full weight on it. can add another leaf to fine tune action if needed



My Ski axle mini deflects 1" with my weight on it your 2" might be good on rough ground

oldMXer
130 posts
3 Feb 2011 6:36PM
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funny you said that Ron. within in seconds of bolting together it was held in the archer's position, short discussion followed on stringing it up!! decided didn't have strength (or energy) to pull it back. thought crossbow also.
on your rig hiko, how much flex do you get to the leeward side in a gust/strong wind? trying to imagine how this will feel loaded, wondering if it will/can lift a wheel?

Test pilot 1
WA, 1430 posts
3 Feb 2011 7:47PM
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oldMXer said...

funny you said that Ron. within in seconds of bolting together it was held in the archer's position, short discussion followed on stringing it up!! decided didn't have strength (or energy) to pull it back. thought crossbow also.
on your rig hiko, how much flex do you get to the leeward side in a gust/strong wind? trying to imagine how this will feel loaded, wondering if it will/can lift a wheel?

If you think you're not strong enough, turn it into a compound bow. You know, the type with pulleys at each end [}:)]

aus230
WA, 1659 posts
3 Feb 2011 9:30PM
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made a cross bow using a light car spring when i was a kid, plan was in popular mechanics
cheers

landyacht
WA, 5921 posts
4 Feb 2011 4:23PM
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my experience with fat front tyres is that they develop a speed wobble.
the OD was much smaller, so you will now be the one to do the experiment. given tthe type of tyres you will be using , i dont think you will need any suspension, as the tyres are the suspension(IMHO)

Nikrum
TAS, 1972 posts
4 Feb 2011 8:43PM
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aus230 said...

made a cross bow using a light car spring when i was a kid, plan was in popular mechanics
cheers


Crikey aus, how old are you??? I had a set of plans using the same.. Never did get to build it though.
Ron

Chook2
WA, 1244 posts
4 Feb 2011 8:03PM
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Me too, I never got round to building one.
I found the plans when I was young in a heap of books my uncle gave me.
A lot of work to build and I had push bikes to ride!!!
Looks interesting though!!!!!
www.vintageprojects.com/archery/crossbow-leaf-spring.pdf

oldMXer
130 posts
4 Feb 2011 11:12PM
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only experience with speed wobble was with dirt bikes, you don't want to have it. think steering head angle plays a large role, and suspension.

aus230
WA, 1659 posts
4 Feb 2011 11:37PM
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That old site has some great stuff on it maybe not about land yachts but some very interesting projects
Cheers
aus230

www.vintageprojects.com/

Test pilot 1
WA, 1430 posts
4 Feb 2011 11:53PM
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aus230 said...

made a cross bow using a light car spring when i was a kid, plan was in popular mechanics
cheers


When I was younger, a couple of my mates ad I built rather large arbalist using 3 of the largest leafs from a trucks rear suspension. We had it set up on a carriage using the front wheels unit with the steering knuckles welded solid. Using a hand winch to arm it and a wire sling redirected through 2 pulleys we were able to put a 6'x1" steel bolt from a large cable drum right through a car body at 25 yards.[}:)]
We had screwed angle adjustment and could aim with a slewing screw. It was towed as "trailer"(a false trailer body covered it).
We would take it to the CMF firing range at Lake Yindalgooda. Firing was by long rope as it had the kick of a clydesdale and had sprained the wrist of the first one to fire it. After about 6 months it finally self distructed when the main leaf fractured and shredded the tyres.
We dutifully cremated it and threw it down an old mine shaft out at Bulong.

oldMXer
130 posts
5 Feb 2011 2:34PM
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front suspension idea, mono fork. action could be tuned with bolt tension, density or thickness of bushe. mounted top, front ,bottom of steering tee.

hills
SA, 1622 posts
5 Feb 2011 6:11PM
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Far out, I thought I'd logged onto the wrong forum for a second there. Here's one of my bows if you want a plan to follow



I thought there was a thread about using springs for axles some time ago and it was discussed how you would probably have to stop the axle from twisting and thus affecting the wheel alignment.

Hiko
1229 posts
5 Feb 2011 4:20PM
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Select to expand quote


Here is a front suspension fork I built a few years ago for my class 5
It worked ok using sections of carbon sail battens for the springs

Nikrum
TAS, 1972 posts
5 Feb 2011 7:20PM
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That is a nice looking bit of gear Hills. I used to run a Bow Tech Conny (Constitution) until 12 or 18months ago. I lost interest due to Club Bias's and stupidity.

Ron

nebbian
WA, 6277 posts
5 Feb 2011 5:00PM
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oldMXer said...

front suspension idea, mono fork. action could be tuned with bolt tension, density or thickness of bushe. mounted top, front ,bottom of steering tee.




Nice drawing

What stops the fork from twisting around, rotating around the grade 8 1/2" bolt?
(up and out of the page in the drawing)

oldMXer
130 posts
5 Feb 2011 7:33PM
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there are 2 bolts, fork is an ell shape attached to the steering "T".

Gizmo
SA, 2865 posts
6 Feb 2011 12:08AM
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How difficult was it to drill through the leaf spring?

oldMXer
130 posts
5 Feb 2011 10:50PM
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definitely doable with normal bits. did two with a hand drill, two with a drill press, looking back had less trouble with hand drill. think i work hardened it on drill press. had to rattail last little bit on all 4 holes.

Neumo
6 posts
6 Feb 2011 8:00AM
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Hi all. Long time reader, first post. I found this old thread a week or two ago and it has some good info along a similar use of spring steel. www.seabreeze.com.au/forums/Land-Yacht-Sailing/Construction/My-design-for-a-C5-with-swept-forward-axles/
Might be worth a read, even has some advice for drilling spring steel with a cobalt bit.
Andrew

hills
SA, 1622 posts
6 Feb 2011 10:58AM
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Thanks Andrew and welcome to the forum!! That is the thread I was referring to but I couldn't find it.

Nikrum said...

That is a nice looking bit of gear Hills. I used to run a Bow Tech Conny (Constitution) until 12 or 18months ago. I lost interest due to Club Bias's and stupidity.
Ron


Thanks Ron, that's my new Hoyt TurboHawk. I also have an old PSE Infinity and a couple of recurves, but I'd better not hijack the thread any more - sorry 'bout that!



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"grass/bean stubble machine" started by oldMXer