Replicator 2 extruder replacement with no overheating issues

As many friends here, I was suffering overheating problems in the rep2 extruder mod downloaded from thingiverse. This heat causes a deformation in the extruder pieces and the system starts to lose strength and print worse with time.

Bored about this problem (I replinted 4 or 5 extruder mods) I decided to design an easy and cheap way to replace the extruder with same printing results as a new extruder mod but with no deformations due overheating.

I bought a plunger from farnell:
http://es.farnell.com/jsp/search/productdetail.jsp?SKU=1378331
and I used an spring from vanel I had at home:
https://www.vanel.com/spring-details.php?lang=spanish&ref=C.081.125.0100.I&sessionid=87222222128513e06795f3a9966294491120580088288434

I redesigned the extruder system to fit the spring and used the ball (only the ball) from the plunger bought in farnell.

As the spring was longer than needed I had to increase 2mm the size of the "casing" but as there was space it was no problem.

It work