O&K Damitz RH6.6 Big OilPump 750ml

[SRS-RC]

Today i will show you an impression of the Damitz RH 6.6 with the bigger OilPump include.

You can drive more functions at the same time without loss...

I drive this excavator by my own and i´m very proud of it.

https://www.youtube.com/watch?v=sTU6S5bSSk4

[Lil Giants]

It definitely looks smoother to operate than a decade old Damitz model hoe with its then 380ml/min pump... is the new version pump a dual gear output similar to Leimbach's design or just a much thicker single gear?

How fast is the track speed now? It'd be neat to see a vid with the tracks travelling full speed + the boom/stick/bucket/rotation all in motion too... or a various periodic combination there of. :D :p

[SRS-RC]

It´s a bigger single gear.
It is not the biggest one, but the 750ml pump is enough for the RH6.6.

there is the opposite of the new and the old oil pump

https://www.youtube.com/watch?v=vvTiM6OSOD4

[liftmys10]

Huge difference in track speed

[SRS-RC]

you are so right, but think of the real speed! this isn´t a racing car ;)

[thetractorfan]

The bigger pump gives a better breakout force. You could probably dig through thick clay or even slightly frozen ground with this machine. Also, better pump gives more torque to the tracks so you can`t get stuck very easy. And you can do so much more if you have auxiliaries because Damitz has everything from orange peel grapples to clamshell buckets. so much better than other RC excavators.

[thetractorfan]

you are so right, but think of the real speed! this isn´t a racing car ;)

Speeding around the construction site is not a good idea anyways. Especially if it is a public construction site. Accidents happen with the slightest mistake. Just 1 foot of a fall off of formwork could snap a metal hydraulic hose or destroy the cab if the ground below is made of hard material. And, if you drive into a bulldozer or wham into a truck, you could face big expenses,( possibly legal), to replace the damaged vehicle. Not to mention, excavators don`t have brakes.

[trucker1970]

It´s a bigger single gear.
It is not the biggest one, but the 750ml pump is enough for the RH6.6.

there is the opposite of the new and the old oil pump

https://www.youtube.com/watch?v=vvTiM6OSOD4

Well thank you very much for this! I just got my Damitz here in the USA (I have to wonder if it is the only one in the USA) and my track speed out of the box was like the slow one in your video. I was hoping that the new ones had been upgraded to go a normal scale speed, but no.. it's just like the videos I've seen of other Damitz. I took it outside for it's first dig and my tracks wouldn't move. I honestly can't remember if they moved at all outside I'm pretty sure they did and then all of a sudden they didn't. I do know they were moving just before I took it outside I was using them on the concrete floor and although slow they were working. I don't know what happened but now I have a huge hydraulic leak around the slew area where the track lines are. I have less than an hour on this $8,000+ machine so I'm a bit disappointed. I bought the Damitz because I love the hydraulic slew and track motors just like the real machine. I'm really hoping I don't have to upgrade the pump to get my tracks to function like yours. Here is a video shortly after I installed my receiver and set up my radio. You can see the slow track movement. https://youtu.be/qZXiqKOUeP8

[Rimrock]

Well thank you very much for this! I just got my Damitz here in the USA (I have to wonder if it is the only one in the USA) and my track speed out of the box was like the slow one in your video. I was hoping that the new ones had been upgraded to go a normal scale speed, but no.. it's just like the videos I've seen of other Damitz. I took it outside for it's first dig and my tracks wouldn't move. I honestly can't remember if they moved at all outside I'm pretty sure they did and then all of a sudden they didn't. I do know they were moving just before I took it outside I was using them on the concrete floor and although slow they were working. I don't know what happened but now I have a huge hydraulic leak around the slew area where the track lines are. I have less than an hour on this $8,000+ machine so I'm a bit disappointed. I bought the Damitz because I love the hydraulic slew and track motors just like the real machine. I'm really hoping I don't have to upgrade the pump to get my tracks to function like yours. Here is a video shortly after I installed my receiver and set up my radio. You can see the slow track movement. https://youtu.be/qZXiqKOUeP8

If you are 'lucky' it's a leakage on one of the threaded hose fittings/hose connections. Would check them out first and possible tighten up. Loctite 542 on treads help, if tightening alone isn't enough. but be careful not tighten the fittings to much, can break off bolts. Otherwise it can be a leaking o-ring in the hydraulics going through the sleeve area, slip ring.
Damitz is for sure some fine machines. I'm personally not a huge fan of the hydraulic track motors, they're know to be a bit slow but with the upgraded pump seams to have a fine speed, the hydraulic slip ring makes things more complicated than with the standard solution of eletric track motors as Premacon and others uses. But it's naturally the most true to scale with hydraulic tracks)

[trucker1970]

perfect thanks for the quick reply I may try to get started on it tomorrow.What I'm not understanding is I've seen videos dating back nearly 10 years with slow tracks. If it's as simple as a bigger pump why have they not done this themselves?? I still love this machine I was surprised to find the body and cab was some type of molded materials and not metal to be honest. It's not a problem it looks fantastic, but unlike me it could stand to gain some weight 😂 at 10 kg it's a little lighter than I was expecting definitely makes for easy transport though. I was able to get it no waiting he had it in stock so that was nice. The Premacon I liked was double the price and who knows how long of a wait. Anyway... I'm grateful for this site I know there is a lot of shared information and much knowledge from people have been into this for a long time so I don't feel so alone when I run into problems like this. Thanks again.

Frank

[trucker1970]

I wonder should I try this one? http://www.magomhrc.com/en/123-hr7-hydraulic-pump

[liftmys10]

Frank, congrats on your awesome machine!
I would first find out which pump you exactly have already. Second, make sure the servo for the track were opening up the valve completely. I would check that out. Also make sure you are using the correct weight hydraulic fluid.

[Rimrock]

I wonder should I try this one? http://www.magomhrc.com/en/123-hr7-hydraulic-pump

Take my advice, that's not a setup one want in a high end machine.
The pump itself, HR7, is top notch, used by Premacon and others, but with Magoms setup there are taken some 'short cuts', in order to keep the price that low.
Better take a look at Premacon's setup with the HR7, 900ml. They got the motor and planetary gear-drive as it should be. An issue is size. Your machine is quite compact. most ideally would possible be the 750ml Damitz pump?

[trucker1970]

OK great I will take your advice. I'll post more when I dig into it and see what I have.

[liftmys10]

OK great I will take your advice. I'll post more when I dig into it and see what I have.

Honestly it looks like the boom and arm are moving plenty fast already. Which makes me think you already have the bigger pump and the issue is somewhere else?

[trucker1970]

Frank, congrats on your awesome machine!
I would first find out which pump you exactly have already. Second, make sure the servo for the track were opening up the valve completely. I would check that out. Also make sure you are using the correct weight hydraulic fluid.


Thank you! I am using the Scaleart oil the builder/modeller/whatever he is sent me and had in the machine. He sent me a new bottle. I have to assume he knows what he's doing. The Damitz has little tabs on top that makes it easy to see where the servo is at and they are both opening 100% I will check and see what the current pump is when I get time. Thanks

[trucker1970]

Honestly it looks like the boom and arm are moving plenty fast already. Which makes me think you already have the bigger pump and the issue is somewhere else?

hmmm ok could be 😐

[Tp_hofmann]

Whats your current status? A (german based) community is also in regular exchange on facebook, so you could subscribe and try to get some help through this channel as well.

Another option is to call damitz directly...

[trucker1970]

hey first off thanks for messaging and helping.

current status = I unplugged track servos so I don't accidentally open valves. I don't dare attempt to take this thing apart. It's too advanced and nice for a hack like me to touch. I have no clue why #1. the tracks were so slow because the pump handles all the other functions just fine. Speed on cylinders is good and swinging and lifting at the same time is not an issue. #2. why SOMETHING broke and the tracks don't move and it just dumps oil when a track valve is opened.

I am trying to get a hold of diggingwithmartin and see if he can help. He is only about 3 hours drive from me and he has done work for others before. As of right now that is my plan.

anyone wanna buy this thing?? hahaha

[Tp_hofmann]

As for #2: personally imwould try to find the root cause, otherwise you cant enjoy your excavator. I had bursted tubes in the past and its not a big deal to replace it. As for the tracks: did you check the servo movements? It could be very easily that they are limited in their movement, which would result in less pil arriving at your track motors.

Overall: the hydraulic tracks will never be like a "race car", however with your point they should be able to move your machine. Feel free to pm me separately.

Rgds,
Thomas

[trucker1970]

As for #2: personally imwould try to find the root cause, otherwise you cant enjoy your excavator. I had bursted tubes in the past and its not a big deal to replace it. As for the tracks: did you check the servo movements? It could be very easily that they are limited in their movement, which would result in less pil arriving at your track motors.

Overall: the hydraulic tracks will never be like a "race car", however with your point they should be able to move your machine. Feel free to pm me separately.

Rgds,
Thomas



Yes I am sure the servo is opening fully they have little "tabs" on top and it makes it very easy to see the movement and I adjusted the % on my radio so all servos were opening 100%. Also... a burst line inside the slewing area would make perfect sense for what is happening. The rate of hydraulic oil loss is extreme when I open a valve. The tracks were stuck and I kept working the controls when it occurred and I was outside in dark soil so I didn't notice the oil right away until my other movements stopped and I killed the pump immediately when that happened knowing I was losing oil. If this is going to happen again if I fix them and I can only use them in a dirt free area and have to worry about them binding and bursting a line if I use them then they aren't worth fixing. I'm just a little mad right now of course I want them working properly. I just don't feel like I did anything wrong for anything to break. I mean if I can't use the tracks in dirt what's the point. Thanks Thomas. I'll figure something out and PM if I need help/advice.

Regards,

Frank

[Tp_hofmann]

Frank - this really reads like a burst tube.

The fix is fast and as a machanic you get to know your baby even better. :)

Cheers,
Thomas