Importing and modifying a new mini excavator from China

[dfkrug]

Did the manufacturer provide hydraulic pump specifications? Max RPM's?,
gpm output graph across the RPM spectrum? Believe you shared pressure reading when your gauge was
connected to the aux. Circuit.

The only spec I got was for the relief setting on the stack valve. 2400psi, which I verified in the pressure
test. I always test pressures, esp on new equipment as it is often set incorrectly.

I have purchased new hyd pumps for tractors in the past, and this one seems to be a bit larger displacement
than what I normally buy. That is based on the width of the center section, an approximate guide to volume.
My estimate is 1/2 to 3/4 cubic inches. I suspect that the volume was chosen based upon an engine running
at somewhat less than 2500RPM.

Also discovered in my initial test of my new engine: my IN and OUT hoses were connected backwards at
the factory! I could have blown my stack valve. I do not know how this mistake could have been made
as the unit I purchased (originally intended for a volume customer in Slovakia) showed clear signs of
having an engine installed then removed. I guess it was not tested.

 

[Tags]

Nice job with all your upgrades. A fella near me is selling similar machines as well as wheel loaders. I looked at the excavators and ran one around about 6 months ago, just too much money for an off brand with no support. I could buy a good low hour name brand for the same price. I've attached the CL ad just for a comparison....

2�17 Mini Excavator X16 Financing Available - heavy equipment - by owner - sale

 

[dfkrug]

I looked at the excavators and ran one around about 6 months ago, just too much money for an off brand with no support. I could buy a good low hour name brand for the same price. I've attached the CL ad just for a comparison....

The XN16 is the next size up at Shandong Landworld, and features brand-name hydraulics and a Yanmar engine,
but no EPA certification, last I checked. They got them in under the radar, apparently.

I agree that for $18K, you have other options for a good used mini-X. I think they priced it a few $K high, and hope
they offer some kind of support.

Thanks for posting.

 

[Agvg]

The Chinese excavators I have seen is way to expensive, makes no economical sense to buy one, there may be a market for minis but in the popular 8t marked it's pointless.

 

[dfkrug]

The Chinese excavators I have seen is way to expensive, makes no economical sense to
buy one, there may be a market for minis but in the popular 8t marked it's pointless.

In the 8-ton range, there are many many choices. I do not know what you see in your area, but the
one Chinese brand I see on the left coast in the US is Sany. When I looked at their prices, they were
substantially less than the majors. I do not know how well they are supported, however. Sany does
not have anything as small as my 1-ton unit.

 

[Agvg]

They have tryed to sell Sany here to but those big brands holds they're value very well so that you save on buying you do loose much more when you are done with it.

 

[dfkrug]

When I bought my mini-X, I knew that I was going to have to install a new engine, and
maybe deal with other changes necessary to accommodate it.

But two major changes I did not expect: installing a pressure filtration system (above), and
upgrading the pin-greasing "features". The latter job took more time than the filtration system.

The XNO8 came without zerk fittings in a lot of places. Instead of zerks, many pivots used
flush-face needle-greaser fittings. Some were inaccessible, even with the provided needle-grease gun,
and others were installed in places that were subject to getting knocked off by dirt or rocks. I
assume that potential damage is why needle-grease fittings were used in vulnerable areas. My
first photo, which shows the house gears, also shows the dozer blade cylinder with w a flush-
face grease fitting on the cylinder clevis.

I changed them all to zerk fittings. To keep them from getting knocked off, I could just flip
a cylinder around and install a 90 or 45-deg zerk, in some cases. Needle-greasing is not going
to work as well as zerks, even when you have good access for the gun.

I removed some pins to flip some of the cylinders and discovered that the maker had gotten
paint inside the pin bosses, making them hard to remove/replace. The sleeve bearings
are replaceable, and some have nylon linings. I used a small drum sander to clean out the
excess paint.

In one photo, you can see how the house ring and pinion gears are lubed. Two hoses with
zerks on the ends were used.

 

[Agvg]

Suppose there are more covers around the gears?

 

[downsizingnow48]

Those flush fittings and the adapter do not look workable for sure.

I had to experiment a bit but now use this type of flush fitting (both threaded and tap-in). They need to be used with a matching Lincoln grease needle. With the correct needle, greasing is very easy, compared to standard zerks.

 

[ruffdog]

So they are using those anti friction bushings on the cyl rod ends? Where the grease supply is? Strange. If and when the bushing rotates, the grease stops.

 

[dfkrug]

If and when the bushing rotates, the grease stops.

Correct. The sleeve bearings are interference-fit, so probably will not rotate. Neglecting
a pin that does not take grease can eventually cause the sleeve to rotate, yes.

The best solution is to use a bored pin with protected zerk fitting in the end. My Bulgarian
backhoe has those.

 

[dfkrug]

With the correct needle, greasing is very easy, compared to standard zerks.

I do not have much experience using the needle grease fittings. We all have needle-grease ports on our
chainsaw bar sprockets, but I use oil there, not grease.

I want to use the same gun and grease for everything, and do not want to have a second gun full
of grease.

On the replacement cyls I bought, the grease fittings have the dished tops like yours. I do have
a needle grease fitting for my Lincoln electric grease gun....never used it.

 

[bindian]

Those flush fittings and the adapter do not look workable for sure.

I had to experiment a bit but now use this type of flush fitting (both threaded and tap-in). They need to be used with a matching Lincoln grease needle. With the correct needle, greasing is very easy, compared to standard zerks.

Never seen a flush fitting on heavy equipment. Only on our Boeing 737s. I hate them. They are a quick way to put grease in your eye, hair, or face. They don't lock on, so if there is hardened grease, you will squirt grease out at an angle, usually on yourself.
hugs, Brandi

 

[dfkrug]

Never seen a flush fitting on heavy equipment. Only on our Boeing 737s. I hate them.

That is interesting, Brandi. I realize that aviation is a different world. Why do you suppose flush-face
fittings are used there?

 

[dfkrug]

This is a spare bucket cylinder that I got with my shipment. Note the dished needle-grease
fitting. The other needle-grease fittings on my XN08 all had flush-face fittings. Maybe you
can position your grease gun at a slight angle with the dished fittings?

Anyway, this cylinder will go towards my custom hydraulic thumb, if I do not use a leftover
cyl from another project. At least I know the IDs are the same. i.e. the bucket cyl and
the thumb cyl will be matched.

Note that this cyl has paint on the replaceable sleeve bearing. It seems to be made of all-metal;
no nylon or Teflon coating. I will remove the paint before using.

 

[dfkrug]

Here is a strange thing I came across when analyzing my new machine: one of the bucket links
is not welded to its bosses. Its mirror-image on the other side is welded as you would expect. You
can see the latter in the 4th photo of post #67.

I sent the attached photo off to China with my question. Their response on the photo (in red), and email
made no sense to me.

I have since welded the bosses, but my paint job is not even close in color.

 

[downsizingnow48]

They must consider those to be collars, not bosses.

 

[dfkrug]

They must consider those to be collars, not bosses.

Look at the other side, Pat.

Regardless of what you call them, the links will wear out fast if allowed to rotate on their
respective pins. The bosses and bolts stop that rotation.

 

[downsizingnow48]

I agree completely on welded bosses a better way to go.

 

[bindian]

That is interesting, Brandi. I realize that aviation is a different world. Why do you suppose flush-face
fittings are used there?

Clearance issues. They are used where zerts would get knocked off. Like door hinges where the snubber or guide arm would hit the zerts when the door is closed and the parts nest on each other. Or flight controls where the part the fitting is on (in?) moves under another part.
hugs, Brandi