Wet Testing!

I had some time today to build up a 'test rig' to prove the functionality of my water jacket.  Admittedly this is my second attempt at wet testing.  The first attempt involved the part printed in T-Glass material and that went south before I had done much of anything.  I ditched the T-Glass for Alloy 910 and a fine .1 mm layer height plus I tweaked the design a bit to give thicker walls to the part just to ensure there are no leaks from the walls or corners.  Turns out the Alloy 910 nylon works great!  Nylon is quickly becoming one of my favorite materials to work with.  It’s flexible rather than brittle, there are different kinds of nylon to suit particular needs and it prints very well.  I have yet to do many big parts but so far I've been pleased.    

My test rig involved my big rack mount power supply, a windshield washer reservoir/pump scavenged from a Mazda Miata (if there is one thing I have no shortage of, its Miata parts) and some tubing procured from the store.  I had to print an adapter to connect the 5mm ID tube from the pump to the 1/4" ID tube I'm using everywhere else which was no big deal.  

For the most part things worked great.  Water flowed into and out of the water jacket just as intended and there were no leaks from the water jacket itself.  The only leaks that did occur came from one of the barb fittings.  I think the leak is due to the way the printer does the two barb fittings jumping back and forth between them.  This leads to some material building up on the sides of each barb fitting which probably didn’t get cleaned off very well.  I think I might get some actual sealant to put on the barb fittings once I get hose lengths figured out so there will be no leaks at all.  

The RTV seal seemed to work great, in this static test at least.  While its really not the proper way to do a seal its quick and cheap.  I printed yet another part with tighter tolerances and made sure to clean the buildup off the sides of the barb fittings.  Since this test seems to work my next goal will be to validate that it works when attached to the heating element.  I could already tell that the flowing water really cooled down the aluminum in the part so it will be interesting to see what happens.