Hello.
I just took some photo's of the work completed so far to make a complete pump unit.
My previous efforts at making impellers fell flat on it's face after I was sold some very second rate products. It was a bit like getting the carpet pulled out from underneath me as I wanted to help people and I wanted to develop a business, but the product that I was using was junk. I went to a different supplier who put me back on track with "Industrial" grade urethane. I could kick the first supplier for making me look like an idiot.
I also bought a lathe so I could turn the cores of the impellers using a billet piece of Delrin so there will be no weak spots and the unit will be super tough.
The new urethane is better than the old material in more ways than one. I could tell the difference as soon as I peeled it out of the mold. I have attached some pictures of a core as well as two pictures of an impeller. One of the pictures shows the flexibility of the new urethane.
I have also attached a picture showing my progress with the rest of the pump. The pump cover is ready to go and I am getting close to finishing the lower part of the pump. A few months back I received a question about getting a lower seal for this pump. It's a two sided seal that keeps the pump water and the gearbox fluid apart. I could not source this anywhere so I have modified my unit to accept a different seal. Another problem was getting a stainless plate for the pump so I have modified the plate so it is approximately 5mm thick and made of a rigid urethane. I had to mill down the lower pump section to accommodate this. What I have now is a urethane impeller running inside a urethane pump case and that is pressing down on a urethane plate. Hopefully, I should get a really low amount of friction and hardly any heat.
I was a bit dubious about posting pictures on the forum but I had a quick read of the rules and there are instructions of how to post pictures so I guess it's ok. I will remove them and replace them with a link if it causes any trouble.
Also, could everyone who has bought one of my previous disasters please contact me for a free replacement. Even if your unit is working fine, I would rather see you using one of these new impellers.
A new core straight off the lathe.
The finished impeller.
The flexibility is completely different from the previous units.
Here is my messy work bench with the current work in progress. I have a run of cores that have just been turned as well as the pump case laying on it's back. Next to that is the two halves of the lower part of the pump. The thin piece will be made of urethane and the lower section will either be rigid urethane or an epoxy that is similar to the original pump case.
I have also made new keys for the impellers and rubber plugs for the pump case that seals the aluminium tube that heads up to the engine.
Well, that's all for now. I'll drop by with an update after I have made some more progress.
All the best,
Scott.