We have 2 x Lake Lefroy Mini's,

The chassis spine on both is parallel to the ground.

The first one I built to the original plans - "Dangerous Goods" has 2 1/2" ground clearance under the chassis spine.

The other, built at the Esperance Skunkworks, [Chook's shed]- "Chook Chaser" has 3 3/4" ground clearance under the chassis spine.

stephen

More build pics....

2.0"sq tube
1.25"sq tube
1.0" set collars
.75" set collars
1.0"od x .75"id seamless tube
.75"od cold roll round bar
1.0"od cold roll round bar
.75"id hardened machine flat washers



.75" cold roll steering stem and .75"id x 1.0"od x 1.75" long head bushing. the bushing was .748"id so I had to machine it to .751" to fit the steering stem shaft


Bushing was also notched for 2.0"sq tube seam clearance


Drilled a .75" through hole 1.0" back from end and centered on one end of 2.0"sq tube


Installed and welded steering stem/head bushing inside 2.0"sq tube



Cut a .75" x .75" end plate for 2.0"sq tube. Tacked two shims to it in order to make it set back .125" inside tube


End plate ready to tack and weld in place. After the plate was tacked I used a chisel to break off the jig


Hardened washer welded to bottom of tube as a wear plate


End plate welded and stem installed


I cut a piece of 1.25"sq tube and center drilled a .75" through hole and welded the steering stem inside it. I left .125" protruding through the bottom for welding purposes. The stem is welded inside also.
Another hardened washer was welded to the top of the fork bar as a wear plate for the steering
It's turned at a 90 so you can see the configuration


That's it for now.

I gotta tell ya, that's the most work I've done in months

Will work on joining the spine to the rear axle next

Now that a serious blokes shed in the background

Gizmo said..

Now that a serious blokes shed in the background

Ya It's pretty nice having a place to do some serious work. It's an old milking barn. 3500 sq ft. We do almond harvesting and the barn was converted so we can do the winter service on the equipment. I only wish the floor was concrete, if you drop something small you better have another one cuz you'll never find it again. I'll post a pic from the end door because that's just a tiny part of it.

Today I cut a piece of 5/16" rope at 219.375" = 5.572m to make sure I am within the 5.6m rope rule.
I used bigger rope and just a little short to make sure I have some wiggle room and will always be within the limits of the rule. I'm sure I could squeeze another couple of inches of wheelbase out of it using the proper length/diameter rope but I will never have to worry about getting DQ'd for that.

The way I made a loop of rope the exact size I wanted is I cut the rope a .250" long and melted the ends together. Came out perfectly to the cut dimension above.

I also cut the mast step out of a piece of 2.375" gal. conduit and came up with some peddles.

Hey,
That's pretty good, SHOE-IN!

I think that's a winner.

KAONAONA said..

Today I cut a piece of 5/16" rope at 219.375" = 5.572m to make sure I am within the 5.6m rope rule.
I used bigger rope and just a little short to make sure I have some wiggle room and will always be within the limits of the rule. I'm sure I could squeeze another couple of inches of wheelbase out of it using the proper length/diameter rope but I will never have to worry about getting DQ'd for that.

The way I made a loop of rope the exact size I wanted is I cut the rope a .250" long and melted the ends together. Came out perfectly to the cut dimension above.

I also cut the mast step out of a piece of 2.375" gal. conduit and came up with some peddles.

thats actually a brilliant idea
that tube you used for the mast step is what you should use for the main spine of the chassis. square isnt very good at all
DObbin?

So how it the mast tube being supported to hold it up?

I will give it 10 minutes before it breaks.....

Think of this..... if the mast is 4m long and you have 50+kg of force to flex the mast to how you want / need it that means a mounting 200mm from the mast base will have to put up with 1000+kg force (20:1 ratio) than add some twisting force because of a jibe....... 10 minutes tops!!!!

Where is it that you think it's going to fail?

i will follow through with this build and keep all the material suggestions in mind for the next one. Besides, me being a big boy I need to go as light as possible next time, for sure! I weighed it today with me on it and it came out to 305#. Too heavy, no doubt.

That kind of sucks because it only weighs 49# by itself! I make turds bigger than that!!

my suggestion is to just follow the original proven plans and not to reinvent the wheel for your first yacht. and go out and enjoy sailing it not repairing it.

My pivot brackets are 1/2" thick but I think yours will be ok. My pivot pin is 1/2" high tensile and the base of your mast is almost exactly how I re-did mine successfully as previously I only drilled a 1/2" hole through the base of the mast tube - that is where the pin ripped out of the thin walled mast tube.

I would worry about up-sizing the adjusting the tie rod and its attachment to the mast post and chassis.

Whatever you do, if it fails then it takes only minutes to re-weld the failed spots. Enjoy the sailing...w

Test pilot 1 said...
I see you have used square tube for the spine. I suspect it will be too rigid. Round tube allows flexing along the spine storing the energy. As the flexing force reduces( either a gust of wind, direction change or even bumps in the terrain) the energy is transfered to the wheels as more power/speed.
Where is it that you think it's going to fail?
Where the rod is attached to mast step and steering head. If as it seems in your picture the rod has eyes at each end and if you attach at pivots you will have even less lateral support for the mast step. I hope your system works as you seem to have a light weight(minimal strength) design in mind. Again a flexible spine would help.

Think torsion. It may fail at the base of the mast where the round plate is welded to the mast base receiver tube unless you have side support that we can't see in mind. I broke my base plate off in the same spot and it was supported 13'' further up as well. To light of construction on my part and my poor welding skills didn't help either. I've also broken 2 of my mini's at the chassis axle junction due to torsion loads. One of them ripped the thin wall material out around the weld. For me it's all a learning process.

On a side note you might want to go this event next weekend at El Mirage. They sail at Elmo about every 2 weeks. It's a fun group of sailors. Mini guys in that group too. http://www.windwizards.org/

By the way I like your videos on you tube. You and Alan Watson get some pretty good footage. I love that winged unit you run. I thought you had a mini with a wing on it! Or was that Vic? That one is pretty sweet too.

My second build is getting under way and I'm planning in competing for the Americas Cup of land sailing next time around. I am also going to attend and race at as many events as I can in order to utilize all that I learn from the "old salts". I want to do well so their efforts to help me are not in vane. I appreciate all the input form other pilot/builders.

My plan is to have a two or three pilot "racing team" I will also try to help as many other pilots/builders/competitors to succeed, as I have been helped by others to succeed.

Thanks to all for your support!