Volvo EC300D

[RCKiwi]

Alloy rubbing on alloy, even with a snifter of oil, never lasts. I'd opt for a plain old mild steel or brass rotary valve in an alloy housing.
Also, the back of the valve does not need to be in full surface contact with its shoulder in the block - try say reduce the rubbing shoulder area (smaller diametre step) as the amount of friction will be a result of such a large surface area. Having a smaller "rub area" will result in less friction but a downside may be higher wear rates - another good reason to add a anit-friction washer.
The bearing would be a good idea if say you are operating the valve by push rods, etc so to alleviate side load - if you're mounting servos inverted, direct inline as is popular with commercial, it may be additional un-needed machining.

Keep plugging away at it - there's a fix here I'm sure

[Vanisle]

In regards to elliot330's comments about his Jung pump versus the Damitz pump. The Jung pump in the ADT's is the IP1Z-HR3 (4001) .18cm3 pump which pumps 520ml/min at 20 bar and 3000rpm. This pump is the IPZ1-HR5 (4002) .30cm3 pump which pumps 890ml/min at 20 bar and 3000rpm. It is the same one in the Vario excavators (and the same one others have used in 1/8 scale).

As for the discussion about the valve design, no idea how to fix it but hopefully Reg can figure it out. We want to see this things working!

[RCP57]

WWWOOOOOOOOOOOOOOOO-HHOOOOOOOOOOOOOOO! It's alive!

It took a couple months longer than I had planned but it finally works!!!!!!!

Sorry I'm a little excited. Big thanks to my father inlaw for making another valve block for me. I haven't taken it out of the shop yet to dig any dirt and I'm here by myself so there isn't any video yet. It seems to have good power at 25 bar but I won't know until it's in the dirt I guess.

Here's a couple pics of the valve installed. I still need to get a filter and a couple other things.

Reg