NewConceptsCafé

It´s incredible how life can change suddenly, in the blink of an eye. And so sometimes we need to stop, have a coffee and reconsider things. Since one week ago I was working in the development of the Airbus A350 XWB tail cone. I wanted to know about planes so I looked for a project in aeronautics. It has been almost a year with a wonderful group of people solving lots of problems together and learning really a lot. Now it´s time for changes, but this will be another coffee…

This reminds me that I wanted to talk about a little group of people, a lot of ideas and a few knowhow… Welcome to the StreetDumper episode II: The Bikers Build Off!

First of all, what means are available to you? When you design or simply think about how to build something you have to follow some rules. The first it’s of course designing things you can easily build. The second it’s designing things you can afford.

When we started the design of the StreetDumper we had previously contacted the company that was going to build our parts. It was GrupoVolund, a heavy machinery and big boat engines company. Probably wasn´t the best choice but it was owned by my Mechanics Technology teacher of the university and I know he was the perfect person to help us. So we had some lathes, a plasma cut partner and NO tube bending machine.

As it was a really low cost project. We had to use the cheaper and most effective tool for saving money: the imagination.

We designed with straight profiles and a lot of welding. Tubes were not cut by CNC, we did them by printing the developments and fixing them to the row profile. Then we manually cut following the patern. It was a fast method and had an assumable error. As we designed mainly flat assemblies we welded parts to a plate as welding jig so we kept the main dimensions under control. Probably the biggest mistake was the choice of the steering bearings. We choose ball bearings able to assume certain axial load, so there was no efforts problem but we had to design fixers for the four ball races instead of using tapered roller or angular contact bearing or even rod ends as we were building a PROTOTYPE. It´s important to think about the dimension and the range of what you´re doing. We were building a dummy to show our system. For this kind of projects I recommend to use simply solutions.

When we were deciding how to design the bike I was a Mechanical Desktop 6 user but I decided to use Catia, even if it was absolutely new for me (now it´s almost my lifestyle) I try to learn in everything I do and this was an opportunity. It was really a good choice.

The coldest mornings in Alicante inside the coldest company were shaping the bike (we were lucky because Alicante is a kind of  paradise).

Do you remember I told that dimensions were under control? Well, before the assembly we thought they were! It was really a hard assembly. In fact I´m sure that the grain of the material is completely changed 6 years after… (Maybe it has some cracks).

We did what must never be done, painting before assembly! But in this case was a good idea because after assembly I think that the bike can’t be disassembled.

The main painting was made in a workshop. The painting of the brake caliper and the seat was made by us with a high temperature resistant spray and a lot of art (as we say in Spain)

For painting I hanged the parts from a piece of rope. Then I turned lot of times the part and let it turn freely and start painting moving up and down. So the paint does not accumulate in any place and the finish was almost professional.

Even if it sounds incredible we sent the pictures and a report of the bike to BMW and they call us for a meeting that we maintained in their headquarters in Munich. They were interested in the system and ask us to do a real bike, not a scooter, that was the kick start of the Demonstener D1200R.

6 years after I see this bike and I can only smile. But best of all was that it rode and rode well!!!

Special thanks to Felipe and Ramón from GrupoVolund. With their effort made this project possible.