horizontal weighing

 I just made a lifting element and put it between the scales and the nose, so that I could weigh the car with the chassis horizontal - parallel to the ground, and I got in. Total weight, with legs forward this time (I think I forgot last time), was 64Kg (60 with legs pulled up). That means that 10Kg have shifted backwards by lifting the nose. Interesting.

There will be a few kilo's front and back, but I think I need to be looking for a spring which will hold a stationary load of about 66Kg (145lbs)

the lever-weight enigma

Today I tried fitting the nose with the lighter spring augmenting the heavier one by rotating it spirally down inside it, and this improved things. 

It meant that the car stood largely horizontally, but unfortunately it sank forward about 1/2" with me sitting in it. So I took the front axle off and weighed the car at the front to work out what kind of work the ideal spring is going to have to be able to do.

My weight is around 84Kg and the kart is about 70Kg (with the 17Kg engine in front of the back axle), so our combined weight is about 150Kg. How, then, can it be that with me sitting in the kart and with scales under the nose of the kart (front axle removed), the total that the front spring must hold up (without compressing, until it is bounced) is only 68Kg?

I know this is about levers and moments and all that jazz, but I still find it a mystery. Can anyone explain?

designing removable back section around running gear

 

motorcycle spring

 On Jim Tanner's advice, I obtained a rear motorcycle spring and today fitted it in the kart's sliding pillar arrangement, but it is still not quite right. My car front is down a 1/2 inch at the front. I reckon I will slide the previous spring down the inside after work tomorrow, then see where we are.

Front suspension progress

Two springs make up the front suspension, an upper one and a lower one. But my range of springs is limited. I probably ought to work out the right spring mathematically, by weighing the car (with me in it) and by putting scales at the nose, using the rear axle as a pivot. But I just took a too long spring, compressed it and tried it. It isn't strong enough. Without me in the car it is nose-down. But it feels like real progress.

Photo by Robina Elizabeth Fry

 I like the effect that Robina Elizabeth Fry gets with her photos, using Photoshop.  This one looks a little like a painting.

Here are pictures from Sywell. Look at my friends' amazing cyclekarts

Of course, I couldn't drive with them this time. But can't wait to join them.

Les Amis de Bédélia

 Today I heard from Marc Périssé and am delighted to report that I am now 

member number n87 of 
Les Amis de Bédélia! 

Marc is the owner of the green Bédélia in this really great video on YouTube: L'aventure de la Bédélia. He is the president of the society.