The standard Lego Pneumatic cilinders are to small for some aims. I decided to make a larger version myself. 


The hardest part was to find a pipe and a bar with the correct inner en outside diameter. 
This is important, because you can reuse the original Lego seals. Finally I found them at 
a local do it yourself shop. 
The pipe is from aluminium and is 16 mm in diameter outside and exactly 12 mm diameter inside. 
Just like the original from Lego. Price: € 4,75, so it was very cheap.


The bar is actually an mow wire. The outside diameter is exactly 5 mm. Price: € 0,75. Also very cheap.


The glue was the most expensive part of al: € 9,50. I think that the glue is perfect 
to glue plastic and aluminium together.
 

When you disassemble and original Lego cylinder (picture 007), you will see that the top of the 
cilinder is a little bit narrower. The bar which moves inside the cilinder is also treats. 

Because I do not have an turn bank (and I do not want to buy one) I searched for a solution. 
I have a small battery drilling machine and I put the bar in de drilling machine just like you do
with the drills in your drilling machine. The bar was supported by a wooden cube with a 5 mm hole in it. 
I put the drilling machine on and together with 2 key files a modified the bar on the top and bottom. 
It works really good. It is not as precise as a turn bank, but for this job it is sufficient.

I made the modification on the aluminium pipe the same way: only problem was that the pipe does not fit 
in the drilling machine. I put a drill in the drilling machine and wrapped some toilet paper around the drill, 
just enough to fit firmly into the pipe.

The other parts of the modified cilinder are from the original Lego pneumatic cilinder: the seals, bottom brick, 
top air inlet and top. The are all glued together. 
Finally I put some oil in the cilinder and glued the last part on the cilinder.


When you want more information, please contact me: j g r o e n 9 9 4  a t  h o t m a i l . c o m