Lowest friction vertical axles?

[Jake's Oy]

I'd like to be able to hold a coin from the top and bottom and be able to flick it and have it spin with ease with no risk of having the coin fly off or become dislodged.

Not using the top or the bottom to put pressure on the coin will probably help a lot, so having solid "hands" will be important. I think I can handle that part.

I have some ideas for axles, but I wanted to make sure I wasn't reinventing the wheel.

Having it spin like a top is probably unlikely, but if it could at least make over 10 revolutions without looking like it's a struggle would be nice.

Adam

[Solo]

Sounds like an interesting challenge. I can't picture a setup where you could flick a coin effectively without sending it flying that doesn't use pressure from above and below. I don't think that's physically possible even.

[Mister Ed]

I don't think I'm quite grasping what you are looking for here.

I'm imagining that you are going to attach LEGO to the top and bottom of a coin somehow (seems doable especially if you allow the use of rubber bands), then attach the whole apparatus to some kind of axle mounted vertically. I'm not quite seeing the problem, but I haven't experimented. Wouldn't using a technic axle piece fitted through a technic brick w/ hole at the top and bottom spin freely enough? That seems simplest.

[Jake's Oy]

I don't think I'm quite grasping what you are looking for here.

I'm imagining that you are going to attach LEGO to the top and bottom of a coin somehow (seems doable especially if you allow the use of rubber bands), then attach the whole apparatus to some kind of axle mounted vertically. I'm not quite seeing the problem, but I haven't experimented. Wouldn't using a technic axle piece fitted through a technic brick w/ hole at the top and bottom spin freely enough? That seems simplest.

Quick mspaint =p

The coin is a half dollar, so I have a little space to work with as for clamps without becoming to unappealing.

My first thought lego turntable would be bad. Second though technic type axle would be good.

Then I started thinking of lego spinjas. Smaller scale if the bottom was a lego bulb or tiny antenna control without the arm sitting on a 2x4 lego plate with a hole on it. Or same oval curved under plate the spinjas use over a flat tile with a "fence" of those four bricks that make a circle. Sorry, I am still trying to learn all the names of the bricks =p

Sounds like an interesting challenge. I can't picture a setup where you could flick a coin effectively without sending it flying that doesn't use pressure from above and below. I don't think that's physically possible even.

Its not a requirement that no pressure comes from above or below. I just assume the less pressure it camps down, the easier it will spin. In my spinjitzu examples some upper pressure would probably be required. The design of the clamps will be pretty important and I feel like its easy to cheat on the clamps by applying force on the coin from the top and bottom to hold it in place, which would eat up its spin.

I am not above using a coin holder if I have to, but that would not be the preferred method. But it would give extra material to clamp on.





I am not keeping the over all idea and scope of the project secret because I want to surprise the community with anything.

Its a personal gift with a lot of emotional meaning I'd rather not have out in the open internet. I have no problems sharing by pm though.

[Solo]

First thought was technic half pins like this:

Obviously a sturdier frame would be better, but this seemed decent.

Alternatively, you could add clips:

This actually seemed less stable though. But something to get you started maybe.

(I didn't have a half dollar coin on hand but this seemed closest and the idea should work for any large coin)

[Jake's Oy]

Nice. If I can't get it to spin well, that really shows off the coin nicely.

[Jake's Oy]

Photobucket seems to have made my video tiny.

First mock up. I will probably change it. Coin is locked in solid and it can spin though, just a little bulkier than I was thinking.