Volvo EC300D

[ihbuilder]

Reg , dumb ? , do your valves turn with ease with no pressure ? Could be just a little lapping needed . I have a Robbe valve that is tight like that till I loosen up the top .

[RCP57]

Originally Posted by ihbuilder

Reg , dumb ? , do your valves turn with ease with no pressure ? Could be just a little lapping needed . I have a Robbe valve that is tight like that till I loosen up the top .

The valves turn with very little resistance with no pressure. They actually turn decent when their open too, it's just when you are trying to open them from the fully closed position or close them from the open position that they are too stiff. Have you had your Robbe valve apart? Does it look much different than what we're doin? I think that Ed is right and it is side loading the plug. I have some of my grandfathers hydraulic books and in them it says that rotary valves are hard to balance but there has to be a way!


Thanks for the help guys!

I just recieved some parts for my Tigercat so....

[ihbuilder]

Reg , the Robbe valve is exactly what your doing . I'm thinking you have more pressure then you need . do you have a pressure relief valve in somewhere ? If not , put 1 on the supply circuit after the valve . come out where the plug is ( assuming thats the supply side of your valve ) I haven't got to play with the stuff from Richard yet , but I plan to make a solid base for the valves much like the verio setup . they bring the supply from the pump through the valve into a pressure relief valve of some sort ( needle valve I think ) .

[doodlebug]

Ok, so you guy's have seen the valve innard's Now the question that I have is How can they be "pressure balanced'' to make accuation easier (less force)? Something to consider.
I've heard of pump's being "pressure balanced" as far as the seal's are concerned.

Just another brain cramp

Cheer's, Neil.

[Lil Giants]

0.3ml/rpm

2200rpm = 660ml

You running 3s lipo currently in your dumper Elliot with the Damitz pump?

You can run the pump from the gear switch and mix it. Set the rpm low when switching it on and the "mix" will speed it up when you activate the valves.

[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

[doodlebug]

Way to go Reg! look's great!
Cheer's, Neil.

[RCKiwi]

Good stuff- what was the plan in the end to fix your valve block problems?

[RCP57]

Originally Posted by RCKiwi

Good stuff- what was the plan in the end to fix your valve block problems?

HAHA.. Secrets... No just kiddin, We just made everything smaller. He went off of my basic design but made the bottom out of steel and the rotors slightly smaller. We also decided to put the cresents in the top of the rotor instead of the bottom. I'm not sure if this actually did anything or not but it didn't hurt it either. The top of the valve body is also the sevo mount on this one too.

Thanks for lookin

Reg

[RCKiwi]

Good stuff - very nicely made indeed. Thank you for sharing. Good bunch of jokers on this site there is!

[modelman]

Looking good!! All that plumbing would drive me CRAZZY Nice work

[RCP57]

....and the moment you've all (and by you've all I mean I've) been waiting for!

Still has some bugs and I'm not happy with my skills at this point but its working.

http://youtu.be/IF7e79S3X10 http://youtu.be/8OVJV29FAd0

Thanks for watching

Reg

[steamer]

Reg, she looks fantastic. I don't know why your complaining you should see me at the controls.
Rob

[Straywolf]

Man oh man this is just excellent, i wish i had half as much talent as everyone here. Great Job!!!!

Mike

[RCP57]

My planetary drive on the hydraulic pump started to let go in the second video that I posted a few days back so yesterday I put together a new one. The drive that I used this time is all steel (the ring gear was plastic on the last one) and I only used one set of planetaries instead of two. The pump now spins at around 5k so the movement is much faster and it is way more fun to operate! I had my calculations wrong on the original drive reduction so it was turning much slower than I thought( around 1300). At least now I can dial in the speed better through the mixing.
http://youtu.be/vaaAnRBHK4I

Oh... I also got a new toy last week...

[doodlebug]

IT'S ALIVE Great job Reg! Let the fun begin

Be patient, your's skill's will grow with time!

Cheer's, Neil

[RCP57]

Thanks guys. I took it over to the inlaws place last night and dug in some bark mulch. It worked pretty well in that verses the wet sand I was digging to begin with in the videos. As far as my skills go I'm sure they will improve but I still have the occasional brain fart on my 1:1 mini when I'm running it too so we'll see!

Reg

[Snochaser]

Great work Reg. You do one fine job on these builds!

Ben