Kid Crane Video

[WoodMarvels.com]

http://www.youtube.com/watch?v=ol0TSLWzUIw

Awesome project that I want to make plans for with my ShopBot Desktop (now that I know how to index). I have one questions, how did he get the crane to spin around using the petals?

Things I do not want my design to have as it gets complicated for no reason:
-two sets of teethed gears 90 degrees of one another (how I think he did it)
-using chains or other exterior hardware like castor wheels (other then rope)

Anybody have any other ideas on how to accomplish a spinning movement using nothing but rope and wood that would work well enough to spin an 80KG man around? My design would be "upsized" and strengthened for adult use!

Jon

[bleeth]

If you want to try a rope based belt you can change the direction of it with idler pulleys but I can imagine it "slipping" when trying to move a lot of weight.
The bevel gears are an easy cut with a cnc and you should have enough z on the desktop.

[WoodMarvels.com]

Thanks Dave, I was thinking of bevel gears (didn't know that was the name of those things) but want to stay away from this when cutting things out of plywood due to strength concerns - if I had an additive 3D metal printer - probably the best solution.

I really like the idler pulley idea (didn't know the name of that either!) and that might work with enough tension as I can actually have 2-3 twisting around to get the angles I need for the swivel base. I think if I put a rubber band going around it first followed by a rope, there would be plenty of friction grip to minimize slippage. It's still a very good solution and having a locking bracket to increase or decrease tension might just do the trick.

Reason for these built-in limitations is that I sell plans around the world, rubber bands and rope are easy to find along with plywood (6mm) but anything else, especially with language barriers is just enough trouble for me wanting to design around having to use anything specialized. Besides, no reason to use any nails or screws if guides cut at the same time do just as good if not a better job of keeping everything together with glue.

Great solution... onto designing!

Jon

[hh_woodworking]

How about rubber wheel vertically and a horizontal metal contact plate. Use system is use in snapper riding mowers to transfer power and direction

[WoodMarvels.com]

Hi Ed, if you are in the middle of nowhere, where are you going to find a rubber wheel and metal plate? What size and how/where to cut? Easy if you live next to Home Depot in LA but not if you live in Sudan or Chile. This is why I try to get 99% of the model cut with the CNC machine customers are buying plans for - rubber bands and rope are easy to come by so those are my only exceptions.

I think that might work as well though making the wheel with the shopbot with a rubber band around it - using the idler pulleys from higher-up to transfer power. Will be fun to see the results.

Jon

[jerry_stanek]

The rubber wheel could just press against the bottom plate.

[chiloquinruss]

Here tis! Russ

http://www.instructables.com/id/Kid-Crane-Riding-Toy/

[chiloquinruss]

And one more just for fun! Russ

http://www.vintageprojects.com/kids/backhoe-plans.html

[sailfl]

It is amazing what people will share. The crane is a very nice design.