The Geek Biker

Rambles of a geek that rides a bike

Monthly Archives: February 2014

Strawbot 3D printed upgrade

In a previous post (here), I displayed my version of the Harvey 1.0 Strawbot. I also mentioned that I did not have the correct elastics and that it made a big difference. So I thought, whilest the hunt continues for the correct sized ‘rubber’, what else can I use in my arsenal that is a man cave. How about plugging the holes?

So I jumped on the old computer box and quickly sketched something that looked like a plug to a hose. Now known as a straw plug. Because of the simplicity in the design, I didn’t need fancy blender or openscad to design what I needed. So I used Tinkercad. A very simple 3D design application to help people learn the basics of 3D modeling/printing and modding minecraft (fact).

Here is a simple plug I sketched up. The base has a radius of 3.5mm and a height of 1mm. Then a neck with a radius of 2 mm and height of 2mm. Then a reverse cone, radius 3mm and height of 2mm. And lastly a header cone with a radius of 3mm and a height of 3mm.

The idea is for the width of the cones to be just wider than the straws to act like a rivet and wedge into the straw and the foam. The size will differ on the types of straws used and the resolution of the 3D printer.

After a few copies and pastes, I ended up a with a set like below:

Printing time for this set is around 40 minutes (cool down time excluded).

Here is a photo of work in progress where I’ve replaced some of the elastics and straw protrusions with the plugs.

As you, the esteemed reader, can see, there are quite a few more holes to plug. Care must be taken to not bend the straws since the plugs should be a bit wider as mentioned. So after a few days, here it is:

I do still believe that the elastics are required as they add some tension to the structure and act as ‘ligaments’ to the joints. I think this just finishes it off a bit.