W.K.Coombs Open discussion thread

[nightlife]

 I think the lever should have three pivit points.

[maw2432]

have a working model and making 30 more ...sorry to dis a point you  .... but if you did the sim your hooked .....

Bill,  so if you are making 30 more are you planning to sell these? 

[bourne]

I think the lever should have three pivit points.

Do you mean parallel motion http://en.wikipedia.org/wiki/Parallel_motion

I totally agree nightlife, my lever assembly I built last night is considerably upset by the change of angle of the face of the lever

After tinkering I have found I made a schoolboy error with the weight calculations for the pendulum. Instead of 45g. I needed 356g. to balance the lever 
This makes it very difficult to see how my thin pieces of aluminium are going to hold up against a pendulum of over 350g. spinning at any speed let alone the gentle swinging I was performing last night. I have yet to connect the upright to the carriage as per the beginning of this thread.

I did have a bit of play on the pendulum pivot, but this just allowed the pendulum to swing off axis and hit the upright.

I will say, with gentle controlled swinging the end off the arm was bobbing up and down in reaction to the pendulum, as expected.

So back to the drawing board for me, the lever does need to be a parallelogram to function correctly. Which makes this a far more complicated build.

It's never easy is it 

[maw2432]

Take a look at this video.. maybe there is way to change the pivot point with a lever action.

http://www.youtube.com/watch?v=w9P3Rh3Q_gI


Bill

[nightlife]

bourne, my picture is showing what the top of the lever would look like. I was afraid you were going to run into that problem but it really isn't going to be hard to fix. At least I hopenot. LOL
My picture was not a good one. I will try to post a better one. I was unable to get my parts last night. The hunnydo list took to much time. I will be getting them today.