School me on hydraulic components

[JDH429]

I hate to sound like the kid who wonders into the middle of the movie and asks what's going on but... I'm very interested in building an excavator. Its what has drawn me to this forum. I've been doing all the research and am unsure about what avenue to take.. Im new to rc Construction and esp hydraulically powered. One direction to go is to purchase a Rtr like the rc4wd 4200xl. I can learn the ins and outs and what makes one run. I've heard both sides of the story on this unit.. So im aware its not the greatest but i simply cant justify spending the money that the main stream units cost. One plus is its affordable and would be a cheaper way to get acquainted with this type of machine. There are some pretty convincing YouTube vids on this digger recently that Digginwithmartin has posted that make it sound like this machine has come a long way and the bugs have been worked out.
The other ave. is to just start from scratch, buy a Bruder, prototype, work out the system and go from there replicating and fabbing metal parts based on that model. However I have no experience with the hydr systems or who and what is the right choice. Actually I wouldn't mind if someone could chime in and explain the hydraulic system components that go into an excavator. What radio equipment is typically used as well. I've seen the guys who machine their own valve blocks and pumps and that simply awesome and my hats off to them but I'm not quite there yet. I am fully capable of machining and fabricating the majority of a machine tho and look forward to the build, but a Rtr for a few hundred more than what I may end up spending to fully equip a home brewed model isn't terrible either. I hate to sound like I'm asking for the short quick answer from people who have spent countless hrs building their own machines and figuring out the problems alone. I guess if I go the build from scratch way I want to make sure I completely understand what is needed and how it all works first. So I know a Pump is needed, a valve block, cylinders is needed but what else and what specifically should I be looking at if there is a best route to take as far as brands and methods. I just dont feel like i know enough to start and want to get to that point asap. Thank you for taking the time to explain things that may seem elementary to you but for a new guy believe me it's overwhelming.

[Lil Giants]

Seeings how you so politely & exquisitely ask for info with such clarity, I don't mind the time it takes to answer your questions the best I can. ;)

You pretty much said it all already: pump - filter - valve - cyls - that's it. :)

If you're basing your build off a Bruder 320, then the Leimbach hyd system should be adequate for your flow & power needs.

Shop here http://www.ttm-shop.de they'll ship your goodies inside of a week if they're in stock (99% yes they are). This is another vendor for Leimbach product http://www.der-getriebedoktor.de/shop2/artikelauswahl.php?kid=3100 for great service & fast shipping. Tell them what you're doing, they'll hook you up with all the right parts (you can come here with your list quote & we'll look it over to see if anything is missing).

http://img.photobucket.com/albums/v150/protrker/hoebrokenpieces.jpg

http://img.photobucket.com/albums/v150/protrker/dozergutted.jpg

[JDH429]

Ahh! Lil Giants comes through again. Thank you sir, I know it's not fun helping the little people but we sure appreciate it. Ok cool, that's a big help to know what dealer and parts the experienced builders use. I'd like to build something sturdy and strong and of course with good quality internals. I'll shoot them an email and explain my project and hopefully like you said they can just give me a shopping list consisting of everything I need.

What radio would you recommend? Id like to have a few channels open for extra control of accessories later if i decide to.

Did you not comment on the 4200 for a reason or? thanks for posting the pics of the exploded view of your Wedico, thats encouraging, lol. Thank you again

[JDH429]

Oh and when I said I couldn't "justify" spending the money I wasn't insinuating anything like its crazy to do so.... I simply meant its just not an option for me. :)

[Lil Giants]

Both those pics above are of Stahl models, 1st excavator, 2nd dozer, to show you the internals.

I see you mention you had researched the 4200, I've made some comments on this forum & others... none of it good news... I got one of the 1st ones just to satisfy my curiosity & the hyds/electronics were junk right out of box.. I didn't get much run time before it quit - permanently! :( I'm gonna use Leimbach hyds & other electrical to get it working well again soon. ;)

I like the Spektrum DX18 specifically for excavators, mainly b/c of the rotary proportional slider on each side of the radio to operate the tracks. You use the AR8000 rx which is good up to 9chs, then another device that plugs into the rx called X-Plus gives you the other 9chs... I haven't gone beyond needing 9chs. ;) It has 50 model memory, tx binds with all the other smaller ch rx's (maybe not the DX5 :confused:) so you don't need to buy the more expensive AR8000 rx if you're only needing 6chs or less on other models.

[JDH429]

Excuse my ignorance... I have read some of your posts on the 4200 and thought maybe there have been some updates or improvements noted since they first came out...Maybe the poor quality has pementatly stained its reputation...youd think whoever was trying to sell it would be promoting and or getting involved with the community to fix that...
Anyway thank you for the radio suggestion. Im a fan of the Spektrum radios and have a few but nothing as sophisticated as the sytems your using. This will all be a big learning process.
One more question is about the Slew Gear Ring? Is this usually a custom built part? Ive seen the servo operated gear box and actually hav the same one that CDM used here on his build

http://i.imgur.com/HsOukKr.jpg

But the contact ring for the track motor is what im wondering about...or is there a kit that some one sells already? Id like the swing to be somewhat quiet and powerful to be able to shove material across the ground on the swing without an issue. Get back to me when you have time. Gonna email http://www.der-getriebedoktor.de/shop2/artikelauswahl.php?kid=3100 shortly.
thanks again

[Lil Giants]

Gear Doc could get you Leimbach's bearing'd center pivot as well & Leimbach does have an endless spin kit to mate with it too.. but I hear it's quite pricey!

Other ppl make their own from scratch, including the endless spin for track drive power... have you looked RCP57's Volvo hoe build? That's a 98% scratchbuild that's near the same size as my Vario.. lots of innovation to be seen there. ;)
http://www.rctruckandconstruction.com/showthread.php?t=3135

I realize you're anxious to get going on making something now, but the constr forum is full of extraordinary ideas with many links to parts & pictures of how ppl did it for themselves... far too much info that I can't remember it all, but I know it's there. I guess it depends on what your ratio is of bought vs built it myself? I'm the "buy it now" builder so I get it working asap. ;)

As for the hk hoe... there have been some who have noted that their model has worked perfectly from the day they 1st turned it on, and they have the later 1.5v version with the 4th valve to relieve the pressure in the hyd system when there is no valve movement.. perhaps their expectations of how it should work is much lower too. And there have been others too with the 1.5v that have commented their model has ran erractic.. it seems in my mind's eye that it's a crap shoot what you're gonna get, and being they are half the price of the others, ppl will keep taking that risk & deal with the problems as they arise.

[JDH429]

Gonna take a look at that link and continue my research. Yes i want to start something soon but i need to figure out what i need to know first. Your help has been invaluable, really appreciate your time. Let me ask this for the **** of it, what in your opinion is the excavator to "buy it now " if money isn't an issue? The vario and stahl seem to be most mentioned in your posts. Thanks again, Jason

[Lil Giants]

I already have it with my JD850 & won't be replacing it... perhaps forever, just rebuild what needs to be.. when it needs it. :cool:

However, I was just talking with Frank of Fumotec (the designer/fabricator of the Vario hoe), this is what he told me in an email a few days ago..

"Bauma Fair / Show in Munich it´s the world's biggest show for construction machines and equipment. There on the Komatsu both should my latest upgraded wheelloader the WA500-7 and the brandnew excavator PC 490-10 be ready. This whill be a hard work to get both models finshed."

The show is probably later April :confused:. All the models I have seen of Frank's creation have been solid, durable, well engineered... maybe less so on the perfect scale detail, but the core is there to build on, and the modeler who cares about scale perfection (not me :D) can add their own details to dress it up. The pics of the tracks that Kalle posted in my thread are designed specifically for this excavator... which is why they may not be an exact transfer to the Vario model.

That'll give you plenty of time to read the forum threads before that 490-10 makes it's day view. :)

You're welcome... this is what forums are for, information trading to grow the hobby bigger and better with each new year. :)

[JDH429]

Wow, that's exciting news. I'd be very interested to hear more about those models. I don't want to sound too naive but your JD 850 is made by Stahl right? B/c vario makes one too? Just a bit confused.. Can't tell differences between manufacturers yet? You had suggested Vario for an option before and just wondered if the 850 is made by both company's why you picked one over the other... I'm mesmerized by it in your vids. Super badass.
So I got a response from the German dealer in regards to the Leimbach conversion parts for a bruder. Kit consists of 4 cylinders, all parts are leimbach except servos are Futabas. price is 1200.00 us plus shipping. System runs at 145 psi.

Bruder excavator.

This set contains:
12mm cylinder
pump
control valve
Servos for control valves
T-connectors
hoses
securing sleeves
hydraulic oil

This set is designed for Bruder excavators.

This set is not available from stock and will be ordered for you.
eimbach

Do you think this is a good setup for a machine that may possibly be built from 18 ga steel.? What mean is I'm thinking of replicating the 320 on sheet metal and possibly adding an inch or 2 to the reach. Will this hydraulic set up have an issue with the weight? I have no frame of reference having never operated a similar unit with that pressure. I wouldn't want to build the model to find out its underpowered or suffers under load. I want to be able to dig solid ground. Ya know?

[Lil Giants]

Klaus Leimbach http://www.leimbach-modellbau.de/ built the hydraulic systems & miscellaneous other parts and Harald Stahl http://www.stahl-modellbau.de/udp-005.html who milled the bodies, those two guys started together back in the 80's to produce RTR models for the average rc hobbyist unable to do so for himself. Harald Stahl died of a blood disorder @age 60 in Spring 2009, his son Lars took over & ran his father's side of the business into the ground by the Fall of 2011!

Klaus Leimbach also builds hydraulics for Wedico since early 2000's, and as well as for the general population that wants hydraulic components for their own scratchbuilds... so despite his partner's kid running half the business to bankruptcy, Leimbach carries on doing his own thing with his son. I don't know, nor have I heard if Leimbach continues to make any of the Stahl body kits.

Vario Earth-Movers http://www.vario-earthmovers.com/ is a subsiduary co of Vario Helicopters. Frank Preisendoerfer is an employee of Vario Helicopters, who had an interest in constr equip modeling too and the JD850 I have is his creation that the company he works for produced & marketed the model for him. (I don't recall exactly what yr it came out 08 or 09, I got mine in the Fall of '10 and built it over the winter)

My JD850 is 14th scale, but with a simple body change (provided by Vario product option) - it can be a 12scale JD450. John Deere track hoes sold in North America are actually made by Hitachi ---> different color & graphics. Hitachi 870 in 14th scale, Hitachi 470 in 12th scale = 4 different choices in one model. Pretty clever, eh?! :)

Since the Vario track hoe, Frank has established his own model company (and still works for Vario Helicopters too) called http://www.fumotec.de/ with a Bell 50 & Bell 40 ADT, Bell 4206 4x4 tractor, Komatsu WA500-6 wheel loader, Ponsee timber harvestor and soon to be released Komatsu PC 490 track hoe.

Per your order quote?
14mm bore would be much better power without sacrificing too much in flow, maybe even 16mm, considering the difference in weight of 2mm aluminum vs 18 guage steel. 145psi (10bar factory setting) -> in my little Stahl excavators with 14mm cyls I turned my press up to 15 - 16bar (over 200psi) without any harm in the short term (couple hundred hrs use).

Be able to dig hard ground with your home brew 320?... not likely, not really. I guess it depends on what type of ground you're referring to? :confused:

My JD850 with a gvw of 80lbs, 21mm bores with a working press over 400psi doesn't dig hard ground by the bucket full with each stroke... more like it peels off 1/4" slivers at a time in moist virgin clay loam soil. A ripper helps alot, but I don't rip very deep in one pass, it takes several to get that 4 inch tooth sunk to ground level. Well, you see how it is in my videos with it.

[JDH429]

Joe, what a great thread this is turning into. For some reason i thought you had ordered your JD850 from Stahl..when you had received the broken arm and were misssing parts. So its actually a Vario. I guess the Son of Stahl, Lars, had some BIG shoes to fill. I hope he can get that business straightened out but in the meantime Looks like Fumotec is taking the reins. What do you think the reason is for Fumotec to produce the Komatsu PC490(1/14 scale?) being it looks like a smaller model than the Hitachi 870? Is it maybe a new start for the new company? Its more comparable to the hitachi 470 i guess, a smaller unit. Either way it sounds like a great company worth watching. And do you know will Fumotec produce the JD850 or a similar sized model like yours or is that going to be owned by Vario from now on?

Ok so taking your advise on the cylinder size, i understand the home brew wouldnt be digging hard ground but im interested in building something that can dig dirt, not load mulch or plastic pellets?...:rolleyes: Ill see what options there are on the cylinder sizes. If upgrading to a larger bore will affect flow, i imagine the pump may need to be larger too or speed may suffer if i understand the mechanics correctly.

I think i may just start saving for a machine. And save my build for something less complicated on the hydraulics side. I dont know which way to go yet. Your JD 850 is incredible :eek: and like you said youll never need another. Its the heart of your operation.

Ive always been one to stop and listen to my peers and the wealth of knowledge they have to offer. Your help is greatly appreciated and i consider your time valuable and there for a real privilege. thank you, jason

[Lil Giants]

So you do have a 1st name :p... Hello Jason

Young Mr Stahl make a comeback...? I doubt it! It's 1.5yrs already & nothing. There's several constr model companies within Germany that have surfaced in the last 5 yrs, several more within the European Union, plus worldwide... unless Mr Leimbach is a gambling man and throws young Mr Stahl a branch... even then, the kid has already blown his ol man's reputation to smithereens!!! Too bad... the models were very functional, durable and reasonably priced. :rolleyes:

I don't know any specifics of Fumotec's 490 hoe, guess we're gonna have to wait till the unvieling at the Bauma show, whenever that is. The Vario hoe, I would assume Frank sold the cad files & copyright to that model to Vario and is maybe making a little from royalities. :confused: Afterall Vario is producing & marketing it on their own dime & reputation.

Given that I know that you know nothing of this pricey hobby, other than written words on the net, nor would I assume if you have the abilities to tackle such an unknown project for yourself, only you can decide whether to buy or build... and there's alot of variables to consider to get it working right the 1st time without any waste.

Personally, I've found it much cheaper & far more enjoyable to buy some one else's proven work vs me risking the cost of figuring it out for myself for the 1st time, and then I can grow from that 1st hand experience and change whatever so it works to my liking. :)

All these guys that do build their own, you never hear what $ investment they have in tools & machinery or how much sh*t they broke or material wasted during the learning curve.... and I'm sure for them it's less about the potential cost savings & moreso the challenge of "I did it myself", is what matters most.

[RCP57]

All these guys that do build their own, you never hear what $ investment they have in tools & machinery or how much sh*t they broke during the learning curve.... and I'm sure for them it's less about the potential cost savings & moreso the challenge of "I did it myself", is what matters most.


Hahaha!... yep:cool:! Well said Joe.

[cdm]

All these guys that do build their own, you never hear what $ investment they have in tools & machinery or how much sh*t they broke during the learning curve.... and I'm sure for them it's less about the potential cost savings & moreso the challenge of "I did it myself", is what matters most.


Hahaha!... yep:cool:! Well said Joe.

im already past what the HK hoe delivered would have cost me.

i tried to itemize once on another project and stopped at 2k. it was a simple truck build.... :(

since then i no longer even look. i need it, i buy it. as much fun as buying something built is, figuring it out yourself is a whole other dimmension of fun. sadly i also learned the hard way that there isn't really any way to deal with metal without a cnc.. you can emulate things (what i am doing) but really, you need it if you want to have realistic metal work. some people can do great things with a manual 2d vertical mill but you can only do so much even with years of skills on one.

i love joes summary above of the stahl and leim brands. and i can now say from personal experience that these are obsolete and inadequate. fortunately there are now better options, although much less popularized. if i had known from the get go, i wouldnt have bothered with lame.

[JDH429]

Thanks for the help and information Joe and CDM. I definitely have a better understanding of these machines now. Greatly appreciated!

[rson123]

Indeed, I learned a lot from this thread too, thanks for sharing!

[liftmys10]

Good history info post #11