If the beginning of each side of the ladders were longer over the apex, meaning they had more wieght, or if they had weight added to the ends, you wouldn't have to go to all the trouble of putting it on the pulley.
Hey Rhino
- Thread starter Skookum
- Start date
Skookum said:
now that everyone else is confused....lolYeah the original design was kind of set up that when lowered the entry and exit were level with the trail. If we raised it up some and weighted the entry ramp right it would work also....
"based on my scribbling...." haha.
The draw bridge sounds like a fun(and safe) stunt.
There's also the, "bi-directional" teeter which I've been planning on adding to the yard complex sometime soon.
A series of pullies connects the "static, tipped up" end of opposing teeters to the opposing, "tipped down" ends so that when you ride up one, the other comes down halfway to meet it at a stump or similar object in the middle. Kind of an, "X" in the rope. Fairly simple and kinda cool because it get's you that "drawbridge" effect.
A series of pullies connects the "static, tipped up" end of opposing teeters to the opposing, "tipped down" ends so that when you ride up one, the other comes down halfway to meet it at a stump or similar object in the middle. Kind of an, "X" in the rope. Fairly simple and kinda cool because it get's you that "drawbridge" effect.
Yep....I had a sketch from last nights meeting that had two large pulley/wheels that had a crossing rope (like an X) and weight on the pulley to lift the draw bridge back up. The bride spans meet in teh middle and as you leave the birdge it goes back up.Borneo said:
I had a poor first attmpt at a more complicated system....the crossing pully is the cleanest easiest way I figured to do it...That is what this accountant came up with last night....it doesn't seem very hard to make....though I would probably use some steal piping in places....for durability.
Hmmm, it's possible that Justin or Art got that one from me. I have the pullys and was going to make a mock-up but just have not gotten to it yet.
Yes, the pivots and the central "stop" should be pretty beefy as well as the rope or cable you use. Since it's moving and will be in the elements.
I always envisioned the opposing teeter dropping toward you in the same pace as you are riding as a pretty cool visual. Especially for something so simple from an engineering perspective. Timing both cables/ropes is probably the most important part.
It's probably too complicated for Colonnades though since I'm sure some fool would cut a cable for the fun of it. (Hehehe, watch the mountain biker fall!)
Yes, the pivots and the central "stop" should be pretty beefy as well as the rope or cable you use. Since it's moving and will be in the elements.
I always envisioned the opposing teeter dropping toward you in the same pace as you are riding as a pretty cool visual. Especially for something so simple from an engineering perspective. Timing both cables/ropes is probably the most important part.
It's probably too complicated for Colonnades though since I'm sure some fool would cut a cable for the fun of it. (Hehehe, watch the mountain biker fall!)
There wasn't a sketch other than what I scribbled out. There were other cool drawings of other stunts/obsticals....like logs and low skinnies, steps etc.Borneo said:
A pully/wheel of equal length on either side. OK I did a quick MSPaint.
Nothing is to scale or even straight. 
the pully/wheel when crossed will move the two bridge spans the same amount if the wheels are teh same size. Right? 
I am an accountant so be gentle. The red and black cables are separate and bolt to the wheel so there is no chance of slipping. I wieghted the wheels (shown in green to open the bridge back up when the rider has left....but that returnng can be handled differently like Skookum said. Especiallt if we want to elevate the stunt a little. I had originally though of it as the main pivot being at ground level...and not having any deck before the pivot.
A railing system can be used on the bridge to make it "safe"
(see yellow)Attachments
Nope. Close though.
The rope at the near end of one plank is attached to the far end of the other plank via an offset pulley directly under the innermost end of the plank. Two seperate ropes. Equidistant with one pully. Both planks wieghted to the outermost for return purposes. So, as the bike passes the fulcrum point and the plank raises behind you, the plank you ride on to falls at the same rate.
As long as the distances are equal and the pully/rope size and sension is equal, it should be a mirror image both directions.
I'm really surprised the engineering geeks at WWU have not done this at Galbraith aready.
But, like I said, it's probably not bombproof enough for under the freeway.
The rope at the near end of one plank is attached to the far end of the other plank via an offset pulley directly under the innermost end of the plank. Two seperate ropes. Equidistant with one pully. Both planks wieghted to the outermost for return purposes. So, as the bike passes the fulcrum point and the plank raises behind you, the plank you ride on to falls at the same rate.
As long as the distances are equal and the pully/rope size and sension is equal, it should be a mirror image both directions.
I'm really surprised the engineering geeks at WWU have not done this at Galbraith aready.
But, like I said, it's probably not bombproof enough for under the freeway.