blake52 said...

Hiko,
when the fork is angled up there is a sharper angle between the pivot and the fork (assuming the pivot angle is always the same) it seems like that would make a difference in the right to left movement for a given amount of rotation. I have to end the same way you did, "wouldn't it" since I can't seem to make my brain do the 3D analytical geometry. I keep building mental pictures of extreme versions and trying to draw conclusions. Time to build a model or have someone who has both types measure it.
Blake

Whether Im not understanding the description or not, but I don't think the fork shape or attachment point should make a difference to the lay-over steering you have drawn (great diagrams by the way ). All that should matter is the angle of the steering head shaft (assuming it has no lead or trail) wouldn't it? Even locating the headstem anywhere on this angled line wouldn't make a difference to the wheel movement (eg: the headstem was 1m from ground level, it would weaken the structure, but the wheels movement stays the same).

Did any of that make sense?

Makes perfect sense to me
I am also starting to appreciate how well my class5 steering was designed as well
Ron the explanations above should give you the place to attach your steering

This is a Nice Debate.
Am I to deduce from the above info' that I should place my steering connection somewhere along the Blue Line/Contact Patch Axis??

I tend to agree with Cisco on the Fork Construction lines.
Ron

On our Promo's the pushrod pivot point is about 25/30mm above and 125mm to the right of steering pivot. It is virtually set and forget type steering, though strong side winds will affect it.

Tight turns lose speed, not always the quickest sailing practice.
Cheers
aus230

AUS 230, Please be a little more astute in your perception of what you are reading. Just because one may own a Nuclear Bomb dos not mean that he has to use it. Whoever I do admit that they are a pretty thing to see go off.
Why is it that the most beautiful things are so dangerous???? Nuc's, UVA, UVB,Lazer,
Gorgeous Women, Land Yachts etc. .

I already said I like doing skids etc. Sure they may well Kill Speed but one doesn't have to do them whilst racing and I am more into fun than serious racing-----------I think.

Now Blake (Don't go to sleep too soon)[}:)]

You seem to be into Computer Prog's that do Real Stuff. Good. Now add a chassis to your 3D model and have the back wheels underpinned to a fixed point the articulate the steering the front wheels should be at a fixed point as well. Do not worry what the wheels are doing but see what the front of the chassis is doing. You may find with your stile of Front Forks there is a little less side ways motion
There are many ways to get to the same end result, I may be wrong. But I do like to apply Occum's Razor where I can.
Ron

Hiko said...

Nikrum said...

This is a Nice Debate.
Am I to deduce from the above info' that I should place my steering connection somewhere along the Blue Line/Contact Patch Axis??

Yes and about 70 to 100mm to the side

I agree with the 100mm off set but I don't think it has to be on the blue line. I try to position the flexy joint at the height of the center of the wheel and adjacent to the rear of the wheel. Seems to give me best leverage each way. What is also important is that the rod (or wires) are not less than horizontal to the ground when straight ahead to maintain a good angle to the steering pin.

I would suggest get rid of the 3/8" rod. Way too small and heavy. I thought you had just stuck that on so you see the movement of the arc more clearly. Better to use minimum 5/8" stainless tube, and as TP1 suggested adjust the nut on the steering pin to get just enough friction so the wheel doesn't fall over by itself.

I have tried running the wires through pulleys to get a 90 degree leverage on the steering pin. It added so much drag on the wire it was actually worse than a direct connection to the fork. Think about it; 2 wires + 2 pulleys + that quadrant thing. That's 5 things ! Occam would not be impressed.

Occum's Razor dressed up for an outing this arvo, a bit of a shake down



Say what you may about that pully system but I like it. Playing in light wind 12 to 15Kts I couldn't get sufficient speed to do broadsides but enough to make it interesting when getting close to the Chain Mesh Fence I had a couple or 3 hrs play and enjoyed every minute. The only disappointment is I had nobody to operate the camera and Land Yachts tend to get a bit misbehaved without a pilot

I studied the mast and mast Step and they seemed to be perfect Step 0 to no layover, sail full and wrinkle free
Ron

nebbian said...

Clemco said...


I agree with the 100mm off set but I don't think it has to be on the blue line. I try to position the flexy joint at the height of the center of the wheel and adjacent to the rear of the wheel. Seems to give me best leverage each way. What is also important is that the rod (or wires) are not less than horizontal to the ground when straight ahead to maintain a good angle to the steering pin.

Hi Clem,

Can you take a photo of this arrangement from the side? Be interested to see how far off the 'blue line' this is.

Almost the same off set as the the vertical view. I had to have it that high to keep the steering tube horizontal off the foot peddle. It works well.

Yes Lads but how heavy is the steering with that system?? From just looking at the system and my experimentation I tend to agree that the steering motion would not be proportional to peddle movement but the quadrant cable pull/pull steering is definitely proportional and smooth transition. I took Occum's Razor on a Shake Down this arvo and and tried to make and am Well pleased with it's behavior. The only way I could get the front or rear for that matter to even look like they were going to break out was to swing sharply (Full Lock) on gravel patches on the Tarmac. I am Highly Peeved that I didn't have a photographer with me. Her in-doors was asleep and you older ones should know that the Wise "Leave Sleeping Tigers Lay" It is probably that cowardly streak in me that will not take the risk on being ripped apart by the NZ/Scot's Baggage.

Hopefully very shortly I may coax her from the Den to deal with my demands.

I also like the feel of those Aircraft Tires, they grip well and don't scuff that easily.
I also must mention that the Steering setup isn't complete yet. That will happen when the sail maker decides to grace us with his presence again.

Ron

Ron
club88 front end
Cheers
Vic

That club88 wire steering system with large pulley wheels looks good. I now see that the problem with mine was probably the wheels were much too small and I lost all of the leverage. The quadrant looks a bit bulky but could act as a good mudguard.
May be worth trying on that top yacht Vic.

Gizmo said...

I saw this scooter the other day ... nice wheels and tyres 110/80-16
If you notice the steering is very similar to the angle of the layover steering of a landyacht [I think this was once mentioned that it was similar to a bike / motorcycle turning when moving ]

Those wheels look great for rears with some plastic sheet cut in a shallow conical shape added to the insides to keep hands out of spokes.