WheelchairDriver

Out of interest, do you fabricate your own oversized castor forks, or where do you source them?
Many thanks & keep up the fantastic work

Who me?

What do you mean by oversized?

The majority of full sized chairs/casters on rear drive chairs are either 3.00 x 4 so 10" inch diameter. Or 280/250 x 4 so 9" inch. So you can get forks from almost any manufacturer that has rear drive chairs.

I think he means the forks on the front wheels.

I made mine from a segment of 4 1/2 inch 5mm wall tube
and 4mm steel side plates as I couldn't find any used ones around when I was building.
I wimped out on the bearing spindles and used ones I salvaged from a scrapped Invacare mid drive chair.

I drilled the holes before welding and bolted the side plates and tube segments in a simple jig to hold it all square whilst welding it up.
I lucked into a pair of f35 forks so I will probably use those on my next build rather than spend the time.

How many millimeters in diameter is the cylinder?
What and how many bearings does that fork mount?

He says 4.5 inch above. So 4.5 x 24.2 = mm...

1" = 25.4 mm

You use inches with different...

Thanks folk,
much appreciated

Sorry, typo! Been converting 25.4 since school. Was taught both in the 70s...

martin007 wrote:How many millimeters in diameter is the cylinder?
What and how many bearings does that fork mount?

The hunk of pipe is Just over 114 mm OD with 5mm wall thickness. The turret mounts on the wheelchair were turned from 2 inch (51mm) heavy weight tube bored each end to take 6001-2rs ball bearings 28mm od with 12mm bore. The spindles came from a scrap invacare chair just to save a bit of work. The wheel spindles are done BM style going right through the forks and fixed with stainless flanged set screws.

Just for completeness this is the spindle, the short threaded end was cut off and the remaining stub press fitted and welded to the fork.

This is the jig used to hold the parts while welding.

OK.