Wannabe Pics

A trio of Elvi!

Sent from my iPhone

Posted August 13, 2011

In the initial test runs of the WannaDolly, I could see that there was a glaring flaw in my plan. By eschewing the horizontally-mounted rollers typical of most "ladder dollies," I had introduced some veer perpendicular to the travel of the sled.

When combined with the slight flexing of the rails - when suspended between stands - the sled would have a slight drift to one side.

This would cause the wheels on one side to begin to rub the rail at either end of the run, results in noise and sudden braking.

I initially considered using pocket door rollers mounted horizontally to keep constant pressure on the rails and prevent drift. (Pocket door hangers are no doubt the inspiration for RigWheels, but can be found much cheaper.) However, that was still more than I wanted to spend on a solution.

So, leaning on the designs of roller coasters and dark rides, I chose to build adjustable bumpers to apply that pressure. Using some 1x2 garden stakes that I cut, tapered and sanded to fit and four counter- sunk carriage bolts, I mounted the bumpers underneath the sled, between the front an rear wheel assemblies. By adjusting a couple of nuts on each bolt, I positioned the bumpers to maintain an even distance between the wheels and rail on each side.

Now I only need to cover the bumpers in felt for a smooth, quiet ride.