Boarding Step

Originally, like so many 1930’s cars, the Riley had running boards. I think  most people know what they are – a flat surface between the front and rear wheels that you could stand on to get into the car. These were one of many things that were missing from the car when I bought it but  I do not need them. However our car doesnt have any doors so all passengers have to step over the side into ‘the cockpit’ and take their allocated seat. This is fine whilst we are young and limber (coughs theatrically) but we will get older and less limber and will need that step. Getting out is easy, you can just jump.

The challenge was to fabricate something that was elegant but very strong. I have a large sheet of 10mm thick steel which should achieve the strength and provide a suitably stable plate to then bolt the more aesthetic ‘Riley’ Aluminum step onto. My design is to bolt one end of the steel plate to the chassis *but* that means that weight on the step will send all the leverage onto the threads of the bolt – effectively standing on the plate will literally (over time) lever the bolts out of the mounting holes. The solution then is to have a vertical plate welded on so that the weight stress is now transferred to a shearing force through the bolt. That is significantly stronger.

Below you can see the plate cut and drilled to shape – the curve on the front face is actually symmetrical, the camera angle has foreshortened it.

As you can imagine, cutting and shaping 10mm thick steel takes some time, as does drilling and filing it to shape. You can therefore consider that fabricating these components consumed much of my day.
In the next picture you can see the concept of the design

The supporting plate was then offered up to the chassis rail, the mounting hole position transferred and then drilled and a thread cut into the holes to take 5/16th high tensile bolts. This was to enable me to unbolt the step at any time in the future should I want to. Welding it to the chassis would have been much stronger but would mean I was stuffed if I find over time that it is in the wrong place!
Below you can see the support plate bolted to the chassis and a hole drilled and threaded for the vertical support. This was bolted firmly into place and then a small weld was applied to the edges of the vertical support to set it in the right position ready for a full weld to be applied.

That done, the whole ‘bracket’ was sprayed black and left to dry. I fully expect the paint to erode off the bracket over time BUT it is nearly twice the thickness of the metal used in the chassis so I imagine it will last.

Finally, the picture below shows you the finished step. The Riley plate (custom made by a chap in Holland which I purchased a long time back at a Beaulieu Autojumble) is simply bolted to the bracket using stainless steel machine screws. It too is 10mm thick but it does not take any actual load because the bracket is almost as wide as the Riley Plate

Now all I have to do is make another one for the rear passenger which I may put on the other side of the car. But that can wait for a while until I know whether it will ever get used or not.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s