Re: Volvo EC300D
 

Thanks Steve, The valve block that I made is a little larger then but not much. The ports are just under 1/8 and the cresents are 1/8 because that was the smallest cutter I had. I would love to see what the Meinhardt valves look like on the inside that seem to be in a lot of the German machines. Flow was the main reason that my Father inlaw and I designed the valve he made for me so large but I guess the inside of the fittings are so small that maybe it isn't necessary? I use 5/32-10/32 push to connect fittings on the valve and rams. I did drill one out so that the ID of the fitting matched that of the hose and it still looks to be strong so I will drill the rest out and see if it makes a difference in flow or speed.

Thanks again for the help! I'll keep tryin! I have a lot more time and patience than money so I have to figure it out the hard way:eek:.

Re: Volvo EC300D
 

Are you able to machine in a teflon shim on the back side of the rotary valve to help reduce friction? The larger you go with these part circular ways in the rotary head, the more force required to rotate it against the thrust created by a larger area in the circular ways. Sort of think that the circular ways or the "pressure in" way (when closed) is sort of a piston, and pressure here will cause the rotary head to thrust against the shoulder in the valve block - make sense?
ha - now Ive read it back I'm not sure it does - clear as mud!:o
Glenn

Re: Volvo EC300D
 

now that Glenn mentioned it ;) Right on , that my be an issue with the robbe valves I have , they're only designed for 10 bar max and have no way to limit friction between the rotor and head housing . 30 bar , 435 PSI is a lot of pressure :eek:

Re: Volvo EC300D
 

Wow 30 bar is a lot of pressure... what are you're hoses rated at?

Another option is mixing your pump to your valves in the radio.

Run the pump at 1/4 to 1/2 speed when the valves are closed, then when you operate the boom, stick or bucket the pump ramps up, in most digital radios you can program this.

Are you using the 0.3 or 0.46 Jung pump?

Elliot.

Re: Volvo EC300D
 

You guys are right about the friction issue for sure. The valve my father inlaw made has 1 3/8 plugs:eek:. I haven't figured it out but at 28 bar thats a huge amount of force! Another problem with it is that it's all aluminum and even with oil in it starts to score itself under that pressure. The one I made is so much smaller (plugs are .680)and with the plugs made of brass seems to be a little better but my machining skills are not that great so it leaks down too much. My father inlaw is coming over tonight so that I can show him what I've made. Hopefully he can make something similar on the cnc at work.

We were tossing around the idea of running a bearing in the top of the valve body to help with the side load on the plug but I think maybe a shim washer of some kind as mentioned may be easier. I think I will ask him to make this valve from steel as well so that it wears better. Weight is not an issue anyway here.

The pump is a 0.3, and my hoses are rated at around 300psi working pressure, 1200psi bursting pressure. I think the pump is a little small for the size of my cylinders. I'm picking up a larger, higher rpm motor from the hobby shop today so we'll see if that picks up the volume. I'm using a DX8 but I had planned on running the pump off of the gear switch because it's the only channel left. Can I still mix the pump if I do that? It will probably help if I can.

Thanks for all the help guys! I really appreciate it!

Reg

Thanks

Re: Volvo EC300D
 

FYI...

I've seen the inside of a Damitz valve and they are approx 8mm in diameter.

I recently changed my pump to a Damitz brushless pump (flow rate 450L a minute), Mr Damitz explained to me that its not about pressure, but about volume... albeit you still need pressure to lift a heavy object. ( I know very little about hydraulics :-) )

As an example, the release valve in my dumper is set to 10 bar, the steering is quicker than is was with a Jung pump running at 16bar, yet it'll still tip my daughter out the back and she weighes 17kgs aka 40lbs.

Without checking the flow rates of the Jung, I assume 0.3 equals 300l a minute?

With regards to the gear channel, you'd need to check whether you can mix that channel in your radio.

Re: Volvo EC300D
 

At 1500rpm and 20 bar this pump is supposed to move 440ml, it ruffly doubles at 3000rpm. I'm running a double planetary(at least 6:1) so my pump speed is pretty low. I think with the motor I plan to buy today and my current reduction I should be able to spin the pump at around 2200 max. With the relief set at 28 bar it has a fair amount of power so if I can get the volume up it should be OK. If need be I'll have to turn the pressure down but at 20 bar it will only drag itself across the smooth concrete until the stick is at 90 degrees. This machine is about the same size as a Vario so it requires a lot of juice!

Reg

Re: Volvo EC300D
 

Ok, so you guy's have seen the valve innard's:eek: Now the question that I have is:confused: 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:eek:

Cheer's, Neil.

Re: Volvo EC300D
 

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.

Re: Volvo EC300D
 

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 :cool:

Re: Volvo EC300D
 

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!

Re: Volvo EC300D
 

WWWOOOOOOOOOOOOOOOO-HHOOOOOOOOOOOOOOO!:eek: 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

Re: Volvo EC300D
 

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

Re: Volvo EC300D
 

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

Re: Volvo EC300D
 

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

Re: Volvo EC300D
 

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

Re: Volvo EC300D
 

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

Re: Volvo EC300D
 

....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.:cool:

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

Thanks for watching

Reg

Re: Volvo EC300D
 

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

Re: Volvo EC300D
 

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

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

Cheer's, Neil

Re: Volvo EC300D
 

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!:o

Reg

Re: Volvo EC300D
 

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

Ben

Re: Volvo EC300D
 

Nice work Reg! Glad you got it going. Now you can hire it out to clear land.

Re: Volvo EC300D
 

Not quite yet Richard... I need a truck and lowbed to transport it first;)

Re: Volvo EC300D
 

Man - that last vid looks awesome! I reckon if you sat an operator in it and turned down the volume, you'd be hard pressed to say it was a model at all!:cool:

Re: Volvo EC300D
 

Just watched the vid ,Outstanding job on the Volvo !!!!:D
Love it, awesome build ,congrats on your excavator!!:D:):D:):cool:

Re: Volvo EC300D
 

Thanks guys,

I was hoping to get some play time in this afternoon but now it's raining here. Just finished pulling over some trees that were too close to my shop with my Dad and his 955K. I think it is more fun to play with the 1:1 stuff and build the models any way.:D

Well I guess I'll go do some welding:cool:

Reg

Re: Volvo EC300D
 

wow Reg ... just watched video looks great man.. if I ever finish this friggen autocar . I will have to head out your way and you can throw a load or too on it .

Re: Volvo EC300D
 

Thanks

Sounds great to me you're not too far away!... Are you finished yet? How bout now?:D

Reg

Re: Volvo EC300D
 

no not far away at all you are in Sooke right ? lol no not finished yet .between running a real Excavator all day (job) and I am ball field 6 nights a week right now so time limited .. but soon.

Re: Volvo EC300D
 

I had a little time for some digging yesterday before it started to rain. I started a cut in the side hill for a new haul road.:cool:

http://youtu.be/x6F8w6YukSM

Reg

Re: Volvo EC300D
 

Well Done Reg!!! An xllnt accomplished build with not much for special tools, but rather oodles of skill! You should be proud! :cool:

Now to tweak the radio to get it running at optium performance! ;)

Recap:

What voltage are you running?

Are your valve servos opening at 100%?

What size plumbing (ID) to your cyls?

What pressure were you running at in your last vid?

What was its finally weight tally?

I use the dual rates for the stick/bucket/swing, no such option on the dx8 for the throttle (boom) unfortunately, but can adjust throttle curve. I have the boom servo valve @100% for up, but approx 60% for down so the boom doesn't drop too fast. Using Dual Rates on the other three, you can tweak the valve openings for various digging operations.. like when loading a trk & don't want too fast of movement vs everything wide open for digging & piling.

I couldn't hear any pump esc freeze in any of your two vids, but it could happen with the brushless if rpm drops too low. I assume you have the pump on Aux 1 or 3? If 3pos switch is down to turn off pump, you could set the middle position to operate @10 to 15% so the pump rpm never fully stops. Then with the Mix on, pump with go to full speed with the servo valves are activated. With Mix off, pump will turn slow for more precise movements.

Re: Volvo EC300D
 

Thanks very much!

So to try and answer all of your questions...

12 volts, I believe so, 5/32 OD not sure of ID, 30 bar in the GoPro vid, and 50lbs.

I have the pump running off of the gear switch and the mixing set so that the pump is off in the up position if the sticks and Aux3 are centered (Aux1-2 operate the tracks and Aux3 thumb) and wide open in the down position. I'm using a 3300kv motor and an 11:1 reduction so the pump has no problem starting and running very low rpm with little stick movement although it may be a little slow up top. I will mess with some more stuff as I get more familiar with how it operates as is. Overall I am pretty happy with how it works considering the only thing "off the shelf" is the hydraulic pump(not including the drive). I'm buying a mill next week so hopefully I can do everything myself from now on. Maybe one day I will be furtunate enough to sell some of the stuff I make but time will tell!

Thanks again!

Re: Volvo EC300D
 

Great video liked the sound inside the cab. GREAT BUILD

Re: Volvo EC300D
 

Nice video-I like the on-board view. I think your operating skills are fine. With a little more stick time you will be an expert.

Re: Volvo EC300D
 

3300kv x 12v / 11 = 3600rpm ..is that how it goes?

A 12v battery would be 13.5v, there abouts with a full charge = 4050rpm

5/32 is about 4mm, which may likely be 2.5mm ID.. virtually the same as I have.. but your hyds movement is so much slower. :confused:

I run on 4s lipo... 600kv x 16.8v / 2.5 reduction = 4032rpm

I'm at approx 24-26 bar. (manual suggested not to exceed 25bar)

I watched a vid of my 850 from last summer when I just got it running, the movement is noticably slower than it is today.. it must be just the way I tweaked the radio settings, can't think offhand what other variable there might be. :confused:

You could set your gear channel to be 20% to 50% when "on" and the Mix will boost it to maxium speed with 2 hyd channel movements.

I don't know, maybe I'm talking out of turn here and you don't want it different than it currently is.. ? :o

Re: Volvo EC300D
 

It is a little slower than I would like thats for sure but to honest I'm just happy to have it working at this point. I'm not sure what size pistons are in the Vario machines but these are 5/8 so when you open three valves at once it takes a lot of oil to fill all four cylinders. I figure with my KV, voltage, motor efficiency and power loss through the reduction it's turning less than 3K but I don't have a tach so...:confused:. I believe a bigger pump would have been better but I haven't experimented with different oils yet either. At present I'm running hydraulic oil which may be too thick? I've read that some guys use ATF but I've only tried that in the pump my father inlaw built so I don't know if it would improve my speed or not. I have the mixing set up now to be about 70% with one fuction and 100% with two or more.

Thanks for the input Joe, you have more experience running this stuff than anyone else(probably in the world) so it is interesting to hear your set ups.

Reg

Re: Volvo EC300D
 

Boom & bucket are 16mm & the stick is either 18 or 20mm.. a bit bigger than 5/8.

I use Esso Hydraul 50 (comparable to a 10W hyd oil).

I started out with an ATF in my home made post pounder and I had trouble with foaming (likely b/c of the high rate of discharge), so I switched to the Hydraul 50 & it cured that problem! Not sure how well it might work with this application? :confused: After running a 5amp charge, there is a wee bit of foaming in the tank, that's usually after ripping, maxing out the pressure relief for the entire charge!

Probably your pump rpm could be considerably lower (25%) than mine, which is why the hyd speed is notably slower. You could go to 4s lipo @16.8v and then limit the EPA %'s in the gear switch & mixes to get pump rpm up to 4000. Also limit the EPA in the swing & track motors if they're not rated for that high of voltage & to keep them at a favorable operating speed. ;)

I only know what I have used & your hyd system is quite similar to mine in almost every way. ;)

Cheers :)

Re: Volvo EC300D
 

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

Mike

Re: Volvo EC300D
 

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...:cool: