Bending, Bashing & Bodging! ...

Now there's a name for an engineering company! This entry brings us up to date with the Buggy building saga. So far, we've built the basis for the frame (aka chassis) and made the seat. The next thing to tackle is the roll-bar. This is a very simple design. It's just a loop of tubing that goes from one side of the buggy to the other. It is located in-line with the back of the seat and is tall enough to be above the head height of the tallest driver. Should be no trouble at all!

In order to make the roll-bar I went to my favourite online tool supplier and purchased a pipe-bender. This is basically a hand cranked hydraulic pump that forces the pipe to bend around a former of the correct size for the pipe being bent. I've seen these things used many times and it looks really easy.

Needless to say this was not as simple as I thought. I got a suitable length of the tubing I was using for the frame, measured where I wanted the first bend, put the correct former in the machine, aligned the tube in the pipe-bender, and cranked away! The good news is that the tube bent, the bad news is that it also flattened on the outside of the bend. This was not what I wanted. For the second attempt I cranked a little more slowly - same result. By now I was more than a little disappointed that my shiny new tool was not performing as I had expected. I got back on-line and sent a note to the manufacturer ...

The clue is in the words tube and pipe. To me, the two words mean the same thing. To an engineer, they are completely different! I'm still not really sure what the difference is, but its about the construction and dimensions (welded or not, wall thickness, etc), anyway, the upshot is, a pipe bender bends pipe but not tube! I was advised that I could bend tube with a thicker wall, so I went and bought some thicker tube - cut it to size, marked where the bend should be aligned it in the bender, crank the handle, crush the tube! The thicker tube had survived much more bending before it flattended so I redesigned the roll bar with one continuous bend, rather than a more conventional two bend design. This enabled me to complete the job with acceptable results (I'll add some pictures later so you can see what I've done). In the meantime if anyone can tell me what I'm doing wrong or how to get perfect bends every time, please contact me ASAP!

Next I made some brackets to hold the rear axle, attached the seat, and then started on the steering. The steering is pretty straightforward 'go-kart' type steering with a steering column attached to the frame, and track rods attached at one end to the front stub axles, and the other end to the steering column. You turn the steerng wheel, which turns the steering column, which pulls the track rod on one wheel and pushes the track rod on the other, the wheels then turn left or right depending on whether they are pulled or pushed.

In our case things were not quite as simple (theres a pattern emerging here!)! Having shortened the buggy from the original design, to accommodate my young son, the steering column has had to move to the front of the frame, which means the track rods interfere with the accelerator and brake pedals! After much head scratching the answer was to 'reverse' the original design and attach the track rods to the front of the steering column rather than the back, and then to swap the stub axles so the track rods attached at the front of those rather than the back (sounds complicated but is actually very simple, and makes no real difference to the basic design). This should give enough clearance to operate the brake and accelerator without interfering with the steering (but we'll only know for sure when we get to putting the pedals on!).

Sadly, I've not had much time over the last two weeks and progress has slowed to a standstill at the moment. Once the steering is finalized I can get on with looking at mounting the engine and attaching it to the back axle!

I'll take some pictures and add them to show what we've done so far.

Friends have suggested that it would have been cheaper and quicker to buy a buggy! but they have missed the point. I'm having a great time doing something I've no prior experience of, have to learn each skill as I need it, and am acquiring this knowledge and experience with my two sons. It's one of the few things where a father, a twenty-one year old, and an eight year old can work, learn and achieve something that none of them has any previous experience in. It may not be a great buggy, it may take far too long to build, and it may have cost a fortune by the time we have built it! But when its finished we shall all take great pride in having built it together - it might sound trite but I can't put a price on every minute I spend with my sons bashing and bending bits of steel!

Regards,

Nigel.