Importing and modifying a new mini excavator from China

[jaylast]

Agree ^^ Maybe baffle in tank or something? Plumb in and tee a 2nd outlet? Same thing might help the supposed problem with the Agro L12 hydro tank.

dfkrug I finally got 'something' from them about diggit/leking 'YLYX' pump.
9.2ml total displacement (6+3.2)

Considering turning up the cutoff from high to low flow, and turning up stack pressure too. Same or better travel speed would be the goal. With same or better multifunction flow. And more power in curl, boom lift, and travel.
The current transition from slow to fast movement seems to be the jerky part. And the only really challenging function is boom up/down. Considering finding max flow/pressure and then perhaps running a flow control on each hose of boom function.
I almost want to try a 14 or 16gpm 2 stage pump to see how much more fast it operates (and if it is that much more jerky . . . ) The engine seems to have more than enough HP to operate up towards double the flow at full pressure also.

Honestly the entire current system is probably just way better suited to lower rpm more torque diesel.

 

[dfkrug]

I finally got 'something' from them about diggit/leking 'YLYX' pump.
9.2ml total displacement (6+3.2)

Interesting. Did you get any explanation of all the pressure #s on the maker plate? I see 13MPa (1900psi), which I guess is the system RV setting. Seems low, while the 20 and 25MPa #s are crazy high (2900-3600psi).

If you have a 2-stage pump, you should have access to the full 9.2cc pump volume at lower pressures, but if you have a large pump with flow divider as I saw on the Diggit EM15 here, you would not. And I did not sense a flow rate change when operating the EM15 to relief.

 

[jaylast]

Here's goog translate:

CBL-ES06/FS03 two-stage pump technical parameters
1. Displacement: front pump 6ml/r, rear pump displacement 3.2ml/r.
2. The opening pressure of the relief valve is 13MPa. When the system pressure is lower than 13MPa, the front pump and the rear pump supply oil at the same time, and the displacement at this time is 9.2ml/r. When the system pressure is greater than 13MPa, the relief valve opens and the 3.2ml/r rear pump supplies oil. 6ml/r front pump circulation.
3. The rated pressure of the rear pump is 20MPa, and the maximum pressure is 25MPa.
4- Maximum speed 3600r/min. Right rotation.
Yantai Liyouxin Hydraulic Technology Co., Ltd. Technical Quality Department

Compared to two stage pumps on amazon etc, the rv setting (which I still assume is adjustable) is already like 2-3x higher, while the total flow/displace is kinda lowish.
Perhaps after playing with settings it'd be fun to try a 14 or 16 gallon two stage with similar total pressure and similar rv setting capability
If I had a single pump I might wanna try an amazon two stage for < 200$ also. My travel controls aren't pilot and they do fine with the dual flow/speed.

I think a pressure gauge and adapter(s) is prob a good investment for adjustments and eventual troubleshooting

 

[dfkrug]

CBL-ES06/FS03 two-stage pump technical parameters
1. Displacement: front pump 6ml/r, rear pump displacement 3.2ml/r.
2. The opening pressure of the relief valve is 13MPa. When the system pressure is lower than 13MPa, the front pump and the rear pump supply oil at the same time, and the displacement at this time is 9.2ml/r. When the system pressure is greater than 13MPa, the relief valve opens and the 3.2ml/r rear pump supplies oil. 6ml/r front pump circulation.
3. The rated pressure of the rear pump is 20MPa, and the maximum pressure is 25MPa.

OK, I see. The 20 and 25MPa specs are just the ratings of the pump. RV for the system will still be about 2400-2500psi. And the 1900psi for the 2nd stage cutoff makes sense, too.

You should not do anything until you get a gauge and adapter to test and adjust the system RV. I suspect it is set low, and possibly close to the 1900psi setting, which is not what you want.

 

[Rich B1]

I added hinges to the rear cover yesterday to make engine access vastly better. Also a pic of the hydraulic filter I had previously added. With the rear cover hinged, I can move the filter further to the rear.

 

[dfkrug]

I added hinges to the rear cover yesterday to make engine access vastly better. Also a pic of the hydraulic filter I had previously added. With the rear cover hinged, I can move the filter further to the rear.

Good mods, Rich. Have you checked RV pressure yet?

 

[Rich B1]

No I haven’t checked the RV yet. The pump has a 90° elbow on it, need to get thread size and order another one to see if I can thread it for a test port or get a T and adapters for a test port at the pump.

I am making a bracket to install a cylinder on the grapple. Going to add quick connects to the boom so may use a test port there as an alternate.

It isn’t hurting for power, so checking the RV hasn’t been a priority.

 

[dfkrug]

I am making a bracket to install a cylinder on the grapple. Going to add quick connects to the boom so may use a test port there as an alternate.

You should get some metric O-ring plugs and adapters anyway.

Just attach gauge at AUX hose on dipper. remove the plugs to determine what size it is. I have seen 2 sizes, both metric O-ring, used there.

If you saw my vids, you saw the grapple in action. It is junk, IMO, cuz the pivots are not greaseable. It also operates off a mechanical linkage, not hydraulic. Not completely useless, but hydraulic would be way better, and the plumbing is already there.

 

[Rich B1]

I do need to get some metric caps and plugs. My first foray into getting metric fittings did not go smoothly. So ended up getting only what I needed. Next order will have a bit more on it.

The lack of grease fittings on the grapple is a concern. Have an idea to try, but not sure it will work yet. The actual grapple on the machine I got is fairly robust, but the available positions with the supplied link are limited at best.

 

[jaylast]

DIN 2353 mostly on mine so far. Has the o-ring and steeper interior chamfer. (compared to din 7631)
2353 m16-1.5 dia/thread (L10) at boom - converting to m14 (L08) for attachments.

Will also have to get adapters to sae for future mods and something to attach pressure gauge.

VEVOR 60MPa Hydraulic Pressure Test Kit Diagnostic 3 Gauge 6 Couplings Excavator | eBay

Why Choose VEVOR?. VEVOR Hydraulic Pressure Test Kit 5 Hoses 5 Gauges 13 Couplings 14 Connectors. VEVOR 60 Ton Hydraulic Cylinder Ram Hollow Jack Single Acting 2" 50mm Stroke. Our straight hydraulic pressure testing set includes three pressure gauges, and three connect tubes, six couplings.

www.ebay.com

I don't think a single fitting will work haha.

Discount hydraulic (as mentioned) has been a great source. And possibly more expensive Brennan Brennan Hydraulic Fittings and Adapters Is a great resource they spell out the threads/fittings well.