Importing and modifying a new mini excavator from China

[D'oh]

Ok, why does 1 Pump have a Double Stack?

Ok, I get that it would have twice the Flow up to 13.5hp. But what would it drive? The Track Motors separately? Track Motors and Aux Bank? Why only 1 line?

 

[Rich B1]

I don’t think that is a double pump but rather an unloading pump, like a log splitter. A crude form of variable flow hydraulics.

 

[ArlyA]

I'd guess it is a pump per track. Pisten Bullys have a pump for each track plus more. The last bully I operated had 5.

 

[ptsg]

Ok, why does 1 Pump have a Double Stack?

View attachment 804655
View attachment 804657
Ok, I get that it would have twice the Flow up to 13.5hp. But what would it drive? The Track Motors separately? Track Motors and Aux Bank? Why only 1 line?

The bottom picture is a tandem pump. They share the suction side, hence why you only see 3 lines.

Having a tandem pump allows them to use two separate control valves and split all the functions between the two pumps. With one pump, everything is ran off a single pump, which makes it difficult to run various functions at the same time.

 

[D'oh]

The bottom picture is a tandem pump. They share the suction side, hence why you only see 3 lines.

Having a tandem pump allows them to use two separate control valves and split all the functions between the two pumps. With one pump, everything is ran off a single pump, which makes it difficult to run various functions at the same time.

I could see the SUction being a part of the Housing, that make sense. The Control Valve bank is where I was confused. thinking the Track Motors and Aux have the little control sticks, but I thought they were still tied into the main Valve Bank Like Fredrick's previous picture

 

[ptsg]

I could see the SUction being a part of the Housing, that make sense. The Control Valve bank is where I was confused. thinking the Track Motors and Aux have the little control sticks, but I thought they were still tied into the main Valve Bank Like Fredrick's previous picture

View attachment 804692

On some excavators they use a single sectional valve bank. However they can configure it to have two inputs (one from each pump) which then combine flows and return through a common section in the middle of the valve bank.

 

[Fredrik]

As far as i can tell on my mini everything goes through the valve block .

Is there a way to increase the RV pressure on these mini's ? I've looked and can't find it. I know I should know this but.........

 

[D'oh]

As far as i can tell on my mini everything goes through the valve block .

Is there away to increase the RV pressure on these mini's ? I've looked and can't find it.

I doubt that the extra pump will add pressure, just flow. However the only time I find mine laking is traveling. If I try to swing while moving, it's priority is the travel motors.

 

[dfkrug]

As far as i can tell on my mini everything goes through the valve block .

Is there a way to increase the RV pressure on these mini's ? I've looked and can't find it. I know I should know this but.........

Interesting pump. i was gonna ask, but you beat me to it.

Follow the two small outlet hoses to see where they connect. If BOTH go to the valve stack, then they must be joined first. As to why, I do not know...maybe your factory ran out of the right pumps? If it IS a log splitter pump like Rich describes (2 chambers with RV between), then some
performance tests are in order.

I do have an extra new 8-spool valve stack, and I have taken it apart to see how it is built. I also made the AUX control spring-centered, rather than detented, since I use a hyd thumb. Auger users may prefer detented.

As for the relief valve, I linked a Utube vid on how to test and adjust that. My XN08 was nuts-on, but the ones from Ouke were way low. Here it is again for those who don't want to wade back thru the whole thread:

 

[Fredrik]

dfkrug said "As for the relief valve, I linked a Utube vid on how to test and adjust that."

Thanks ,I'll check it out and let you know.

 

[Fredrik]

Had a couple hours to fab my oil cooler . Still needs to be painted, assembled and installed.

 

[dfkrug]

Where are you going to install the new oil cooler?

You know, no one is obligated to keep the sheet metal shell on the house. There are some versions of these 1-t minis made that have open houses. That way, the gas engines can breathe and run cooler.

 

[Fredrik]

Where are you going to install the new oil cooler?

Oil cooler is mounted behind the seat . Only place there was room really. Hopefully will have pics some time later today to show my progress.

Still cutting openings to let the heat out but wanting to leave enough structure to keep it rigid.


Has any one added more weight to the A** of a mini so you can dig better with the hoe perpendicular to the tracks?

 

[dfkrug]

Has any one added more weight to the A** of a mini so you can dig better with the hoe perpendicular to the tracks?

Most of the current crop of Chinese 1-tons have gone to an external cast counterweight of about 100#. My early unit has the 3 internal plates, weighing 75# total. No reason you could not have both.

BTW, a local friend just won another 1-ton mini-X at the monthly Sacramento auction. He is the guy I partnered with on the 6 black units in the container. The auction had 48 excavators, more than half of which were unused Chinese minis. I will post more on that one after it gets picked up.

 

[Fredrik]

Most of the current crop of Chinese 1-tons have gone to an external cast counterweight of about 100#. My early unit has the 3 internal plates, weighing 75# total. No reason you could not have both.

Thanks dfkrug, I didn't know if maybe the under carriage or slew bearings would be in danger of early wear out.

 

[Fredrik]

I've got some pics of what has been done so far.
First up is oil filter.

 

[Fredrik]

New oil cooler.

 

[Fredrik]

The small fans put out 300 cfm combined and only draw 1.5 amps combined.

 

[Fredrik]

make sure to prime all your new oil filled stuff.

 

[Fredrik]

Here is the old suction line. Way over spec. Was able to reuse the old fittings , but it took some careful cut off wheel work.
Look at the cross section of " THAT! " hose . Hit it a couple times with an 8 # sledge and it kept its

original shape. Only way to cut it was with a grinder cut off wheel.