Which hyd excavator pump/setup for a newbie

[Mike205]

Hi, I'm looking to purchase my first hydraulic setup.
Sorry for the long post it's been a long time coming.
This is after trying my luck with screw drives and the bruder cat, these attempts ended with disappointment having experienced non stop servo creep with diy rotational servos and sticking cylinders a real hair puller !
My current workhorse is the Bruder schaeff which is much more functional than pretty, works ok, using mini servos using pushrods. Every attempt I have made with the undercarriage has ended up with tracks that just have to look at a small stone and they fall off
The reason I am writing this post is I have been looking at the website for around a year and have tried every alternative to hydraulics because of the expense involved, and lack of knowledge. Also I think not enough info supplied on the German websites.

I need a system for a 1:14 size machine to begin with I am only intending to move/dig soft material so a Bruder cat to start me off, now
down to business, I don't want to spend £1000 on a system that isn't going to grow with me. Is 12 bar going to cope with a fully metal arm, and perhaps a move up to 1:12 scale. At roughly the same price, the premacon jung pumps have 600ml and 900ml capacity and upto 45 bar, as opposed to the leimbach pumps which go up to 380 or 450ml and 10-16 bar if I am correct.

Would the premacon pump for 900ml work in a Bruder cat 1:14 or would it be too large or powerful and would it work at 10-16 bar, if so I would not need to upgrade later, or would a 12 bar pump be all I am likely to need for an all metal arm 1:14 or 1:12 machine ?
Thanks for any input

[Lil Giants]

Every hydraulic system comes with a prv (pressure relief valve) so you can set the psi to whatever you want, be sure you get a guage too.

If you think you build bigger models in the future, then the Premacon hydraulic package would be the better choice... the Premacon package will need about twice the space as the Leimbach & may not fit in the confines of a Bruder model with all the other electronics, batts, ect.

Messing with a plastic Bruder model, 10Bar is plenty strong for it & you'll need to make more than just the arm from metal if you if you last more than a few hrs.

[FlyingBeagle]

If I was converting a bruder I would probably buy one of these kits. Even knowing that I was going to move up to a better piece of equipment someday, I would just plan to sell my converted excavator and recover some of my original investment. I personally dont have any experience with these systems, but I know there are a number of folks on the forums that have had these systems and as far as I can recall they have been relatively happy with them. Obviously it is no premacon or vario setup, but from what I understand they are not junk either.

http://www.magomhrc.com/en/cat-320/2...kit-for-x.html

Its an option worth looking in to.

[Mike205]

Thanks guys for the benefit of your experience and advice.

I suppose if I were being sensible i think I should start with a Bruder cat 320 as it would mean starting with the more reasonably priced hyd set-up and base model and also it being easier to source the metal upgrade parts and would be a fairly quick build and then I could see just how much I will like hydraulic models.

On the flip side however, and there just always has to be one, if I were to build a model slightly bigger than the bruder to accommodate some Premacon hydraulics, I would be avoiding the need to source another whole set of expensive hydraulics if I feel the urge to build a bit bigger. However myself not being a skilled craftsmen such as some of you guys clearly are, I would find it harder/longer and more expensive to build or source quality metal parts.

At the moment I only feel the need to have a desktop type environment for my models as that is the way I like to view them at work as opposed to looking down over them. So I really shouldn't need a big machine, however the bigger the machine the better as they look more realistic, and nicer I think to see working.

One day I will have it in my mind to buy Leimbachs Bruder cat complete conversion kit in which the brushed motor takes it to around 10 bar for around €930 if I wanted more > 16 bar I would have to invest another €200 on top of that .

The next day i'm thinking Premacons individual bits with a brushless motor as standard and upto 45 bar or so potential.

If only there was a small motor-pump set-up with upto say 22 bar that would be ideal, but to my limited knowledge I have yet to find one.

With regards to the Magom hrc kit, the only thing that puts me off their kit is the sound of their pump or motor, don't know which part is making quite a loud noise, judging from what I have seen on YouTube.
I personally don't mind paying double or more for a quieter setup, but that's just my opinion.

My dilemma at the moment reminds me of the problem I had when choosing an electric helicopter, do I go for the 450 size (cheap parts when you crash), or the 500 size (more expensive parts, but it's bigger size means more stability so less likely to crash) in theory. Ended up buying both in the end.

Decisions, decisions......

P.s does anybody know what ml pump is included with the Leimbach bruder conversion kit ie 200, 380, or 450. ( I e-mailed them but they responded "it's a complete kit") ?
Anybody bought their conversion kit, if so could you post and let me know what you thought of it,
Thanks again guys.

[Lil Giants]

I've been using Leimbach hyd systems for yrs & they're great for small scale models using 12-14mm bore pistons with 2mm ID plumbing for reasonably quick cycle times.

The 200 pump will be the mini with a brushless motor that is used primarily to operate their trk crane, not meant for long continuous operation.

The 450 pump was originally for their telescope cylinders & the brushed motor was bi-directional. Is it now mono directional for use with valves? I don't know.

The 380 pump, I knew as a 350ml/min pump, but maybe the 380 version is with the brushless motor on it running at 8000rpm, instead of the 6000rpm brushed motor. A faster turning pump, you'll just wear it out quicker if left running all the time. Todays more sophisticated radios with channel mixing, you can limit the wear & heat build up by making the pump activate only when necessary... makes your run times last longer too.

[Mike205]

Just been informed by Der Getriebedoktor, the supplied pump with their Bruder cat 320 conversion is the 380 ml pump. The same or similar to the Wedico Cat 345d I believe, runs at 12 bar on the brushed motor. Could somebody in the know inform me what the ml figure means in pump terms. Is it the capacity of the oil tank, or the ml pumped per minute.
Does it mean the 380 would be able to supply more / bigger cylinders than say the 200 size , but at the same pressure ?
Thanks

[cosworth34677]

Originally Posted by Mike205

Thanks guys for the benefit of your experience and advice.

I suppose if I were being sensible i think I should start with a Bruder cat 320 as it would mean starting with the more reasonably priced hyd set-up and base model and also it being easier to source the metal upgrade parts and would be a fairly quick build and then I could see just how much I will like hydraulic models.

On the flip side however, and there just always has to be one, if I were to build a model slightly bigger than the bruder to accommodate some Premacon hydraulics, I would be avoiding the need to source another whole set of expensive hydraulics if I feel the urge to build a bit bigger. However myself not being a skilled craftsmen such as some of you guys clearly are, I would find it harder/longer and more expensive to build or source quality metal parts.

At the moment I only feel the need to have a desktop type environment for my models as that is the way I like to view them at work as opposed to looking down over them. So I really shouldn't need a big machine, however the bigger the machine the better as they look more realistic, and nicer I think to see working.

One day I will have it in my mind to buy Leimbachs Bruder cat complete conversion kit in which the brushed motor takes it to around 10 bar for around €930 if I wanted more > 16 bar I would have to invest another €200 on top of that .

The next day i'm thinking Premacons individual bits with a brushless motor as standard and upto 45 bar or so potential.



With regards to the Magom hrc kit, the only thing that puts me off their kit is the sound of their pump or motor, don't know which part is making quite a loud noise, judging from what I have seen on YouTube.
I personally don't mind paying double or more for a quieter setup, but that's just my opinion.



Thanks again guys.

i think its the motor and what you put it in, i use there pump in my dump truck
tipper trailer and excavator. and the two dumpers are not to loud they are no louder then the truck pulling/ or driving them. but the excavator!!! that thing is pretty loud. so i think its all the plastic that acts like a drum

[Lil Giants]

The 380 is the maximum ml per minute the pump is capable of producing at a specific speed... Leimbach's supplied brushless motor. Leimbach's chosen brushed motor would be 350ml per minute.

[Actros4160]

Mike205

More volume means faster movements. Yes, you can increase pressure but you wear the pump out quicker. A volume of 380ml for all movements on one go are not enough, I believe. The Wedico Cat345 I have has the same pump at fixed pressure of 12bar(175psi). One movement at the time is fine. If you move the bucket and stick and the same time you can see how slow the movements are. If the bucket is full and you pick up the arm which has 2 cylinders you can see it even better. If you are not to worried about that you will be fine.

Personally I would choose the Jung pump IPZ1-7 which will be done in the near future.

http://www.jung-fluid.de/standard-ri...-ipz-1-hr.html

Regards,
Bernd

[Mike205]

Have ordered the liembach bruder cat hydraulic kit, it should arrive in a few days
Being a complete kit helped me to decide which to get, no need to worry about which connectors to get and so forth.
A bit concerned now by the previous post saying the 380ml pump won't be enough to move all parts at the same time when loaded, if this is the case. I will see if maybe one of the brushless motors and esc I have lying around from my airplane days will work with the pump to increase the rpm and I will try to implement the mixing on the radio to increase the life of the pump.

If during the time I have the set-up the pump fails, I would probably invest in the Jung pump as recommended by Actros 4160.
Hopefully the valve block, cylinders, hoses and connectors would all be compatible with the Jung pump as long as the pressure level is kept within their limits
Thanks guys

[Lil Giants]

You can move all three cyls at once, it's just that it slows down the speed of the stroke which each valve activated in series.

What size pistons did you get?

Here's a video of mine showing the speed of the hydraulic movements, the pump is powered by a brushed motor @6000rpm.
https://www.youtube.com/watch?v=mddf_4Qwmoo

[Mike205]

Thanks Lil Giants for posting that video, that speed looks ok for me, and could always be increased by replacing the brushed motor with a brushless one I guess.
The website says the 'piston diameter is 12mm' and the 'outside diameter is 16.5mm'. This is all I have to go on till there get here I'm afraid.
Thanks

[avel]

Not sure if this has been posted before but here is a calculator for how much strength a certain hydraulic setup will have.

http://www.baumhydraulics.com/calculators/cyl_calc.htm

[Lil Giants]

The diameter you have is the same as the excav in the video. That excav is quicker than earlier Stahl hoes I had b/c it's using 2mm plumbing, the earlier ones were 1,5mm ID. That extra 0,5mm in dia made a notable difference in cycle speed.

Increasing the pressure will make it flow faster too forcing the oil through the lines quicker. But if you are putting this into a plastic Bruder model, the arm/pivot points will break.

My 850 uses a 0,3ml/revolution Jung pump and it's capable of 1200ml/min. The cyl bores are 20mm (boom/bucket) & 22mm (stick), all four cyls filling from the bottom of cyl at once makes the overall speed quite slow with 2,5mm ID hoses.

Premacon's 944 excav uses a Jung pump, maybe the 0,3/rev with I'm assuming 14mm bores, the cyls move way too quick making the model unrealistically fast & the operators spill dirt everywhere, hit the trks, ect. Proper radio programming could prevent a lot of that with much finer control on the tx sticks.

[Actros4160]

Mike,

if you decide to go with the Jung pump make sure you get a pressure relieve valve with it. You can set the pressure to your need.
I hope will help you and have fun with your bruder conversion.

Bernd

[Mike205]

Hi,

Got me the kit, postage was real fast, it was posted from Germany on Friday and delivered Tuesday to Uk😀
Everything beautifully machined, a shame the instructions are only in German.
Next task in hand is to make a replacement metal arm for the cat, as my original was pretty badly cut up and weakened due to making space to fit servos inside for my screw drives.

Its a shame i don't have the equipment and especially the talent that you guys have when it comes to quality builds, i'll just have to see if i can pull it off.