Importing and modifying a new mini excavator from China

[Fredrik]

So, naturally I contacted Jiahe.

I smell a mini in TimberFarms future.

 

[dfkrug]

Virtually all these machines come from Shandong province, tho it is difficult to tell who the factories are and who is just a reseller.

The Diggit has one of those bizarre hyd pumps that looks like it has 3 chambers, but only one inlet and one outlet. This machine divides the flow for the servo controls at the main valve stack.

 

[dfkrug]

The 2 arm consoles house 2-spool hyd valves, connected up with 1/4-inch hoses.

 

[dfkrug]

You can see above that fueling up the Briggs engine requires removing the small or large plate under the seat. I suppose leaving either open would just roast the operator.

 

[D'oh]

Virtually all these machines come from Shandong province, tho it is difficult to tell who the factories are and who is just a reseller.

The Diggit has one of those bizarre hyd pumps that looks like it has 3 chambers, but only one inlet and one outlet. This machine divides the flow for the servo controls at the main valve stack.
View attachment 808172

I noticed the Pump on the Digger also, however unlike the other picture, only a single line out?

And pretty tight in the Digger

 

[Rich B1]

That pump really looks like it has an unloaded in it. The hex sticking out of the middle is likely the unloaded valves.

Getting pilot (servo) pressure from the main valve isn’t unusual, they use a pressure reducing valve for the pilot. But it is odd in likely an open center system, unless they have a priority flow divider as part of the valve inlet.

 

[pmsmechanic]

New oil cooler.View attachment 805399View attachment 805400

Just a note on this installation. The outlet line should be looped over the top of the cooler. Or the inlet and outlet mounted to one side with the outlet on top. Otherwise the oil takes the path of least resistance and possibly the cooler never runs full of oil.

 

[TimberFarm]

I smell a mini in TimberFarms future.

Absolutely!

 

[dfkrug]

That pump really looks like it has an unloaded in it. The hex sticking out of the middle is likely the unloaded valves.

Yes, it looks like the pump may have an RV on the center section (unloader valve). I should have taken it off to see what it is.

In operation of the excavator, I was looking for signs of a 2-stage pump with internal RV. Could not detect that it behaved like it had one. I would have expected that the flow rate would have been higher when moving a given cylinder until it met resistance. Then it would slow down. I did not experience that behavior.

I did notice that the machine exhibited signs of low main RV setting, which I adjusted. Pix are next.

 

[dfkrug]

I opened up the Diggit EM15 and here are some more pix.

The main stack valve looks like others on these 1-ton-ish machines. It has 8 spools, with 4 of them actuated by servos. Wheel motors, blade, and AUX are direct-acting, with the boom, dipper, bkt and house pivot all handled by the arm-rest servo valve joysticks. AUX and blade are operated by foot pedals.

A hydraulic accumulator is used with the pilot circuit to maintain control in all conditions.

As for the sheet metal on the house, workmanship is disappointing. One of the side panels is hinged, but it can't be opened until another panel is removed. Panel removals are necessary to get at the battery. Overall internal accessibility is not bad, however. No need to remove ROPS or console, as with many other machines.