Importing and modifying a new mini excavator from China

[dfkrug]

Could you turn camera on and slide it under the digger and then wiggle the house? Or use a selfie-stick?

I would be impressed if the hoses allowed the movement we see.

Very interesting, must be a recessed bolt in there. Or a set screw up above the gear?

I will figure out a way to get a better vid.

I think what we see in the photos is the shaft of the motor above the pinion gear, so no room for set screws.

In this photo, you can see how the motor is mounted inside the house. There is a square weldment that limits the movement of the motor if it comes loose. Not only did they use double-nutted bolts here, but they mostly seem to be grade 12.9. They did not seem to cut too many corners here. Other makers, maybe not.

Accessing the heads of those motor bolts for removal will be difficult.

 

[jaylast]

Both are certainly possible. I suspect the mesh is the likely culprit. I have considered removing the swing motor and enlarging the mounting holes so there would be a little adjustment possible. Then push the motor a little closer to the ring gear to remove the slack. As the weather here improves, I will be more involved with some repairs.

I also think slop in the keyway of the pinion gear may be the issue.

I took my house motor off months ago and video'd that the slop was internal (posted here and also found on my chan). Zero perceptible play in ring/gear mesh or gear/keyway/shaft. All internal to motor.

Slop in motor (and boom/dipper) have grown after >35 gal gas hard use. So now having a new spare motor eventually I'll swap in fresh and fully disassemble old to see more precisely what is likely just poor tolerances internally.
The fact swing function runs full pressure on these if fun but they take wear fast (esp under abuse like using as a battering ram lol).
Also soon time to add oil cooler and fan, and attempt to take up the little slop that's also developed at the dipper and arm joints. I got pins but missed getting the corresponding (removable?) bushings these apparently use at all pivots.

Your first image looks interesting to me.
Is your digger electric?
Mine is, and this side almost looks identical. The potentiometer is for the electric motor for the hydraulic pump; while the lever is for lowering the blade, and widening the track. All same colour, position and form.

Could you please share an image of the control/display panel and mention what the gauges are showing? Thanks.

Uh, no not electric, sorry I've no idea what you are on about!
I literally have zero gauges, potentiometers, or even 'control' panel. Not even an hour meter bud!
Congrats on the E-digger, perhaps ours are similar base machines - it would be fairly simple to substitute one power plant for another in this case and with any of these machines.
When I checked prices they were a bit too steep for an 'E' setup, but would (and could) fairly easily convert after sourcing a good motor and motor controller setup (assume they are using 3 phase sensored DC motors).
Electric can be really great in the right situations, best things generally are the huge torque and low noise imo.

 

[JamesTheNextDoor]

Most of the swing slope on my mini-X was due to the keyway. This photo was taken before installing the cushion valve. When I replaced the broken pinion, I installed a new keyway. Of course, there was almost no slope. However, a month later, it reverted back to its previous state.

My conclusion was that stress was concentrating on the keyway, causing deformation. So, I eventually installed the cushion valve...

The red liquid in the picture is Loctite Threadlocker, which was of course of no use. Instead of Threadlocker, applying retaining compound used for cylindrical fitting parts could be a solution. I've already purchased Loctite 638. However, what concerns me is that instead of the keyway, another part might break, such as the shaft of the swing motor. So, I haven't tried it yet. After installing the cushion valve, I didn't worry much about the swing slope. I plan to try it out when I have to work on the swing motor someday.

 

[dfkrug]

I took my house motor off months ago and video'd that the slop was internal (posted here and also found on my chan). Zero perceptible play in ring/gear mesh or gear/keyway/shaft. All internal to motor.

Yes, I remember your posts. I really want to see the internals of your motor. I assume it is a BM1-200. Is it made by Hydro Man, like mine? What did you have to pay for it, total?

I wonder if your keyway is also like the unusual one shown by JAMES above.

How tough was it to remove the motor bolts?

Since the house rotation is somewhat jerky, it is often hard to avoid hammering action against an immovable object. That's one of the reasons I want my cushion valves installed soon.

 

[dfkrug]

I got pins but missed getting the corresponding (removable?) bushings these apparently use at all pivots.

I buy plain bearing inserts by size, shipped directly from China or a US bearing vendor on the E. coast. You can probably get hundreds of hours on these machines before needing to replace them, if everything is kept greased.

 

[jaylast]

BMR-315 is what they used in these. I can tell you everything definitely cost more than double their quoted price by the time all said/done for this import. What a freaking fiasco. Somehow the stupid importer got away with 'DDP' and I was still left with another 10% charge for last transit. Even if using an on shore company I think they will take no responsibility for a mistake on their end. Including extra charges (or much bigger issues like 'lost' or damaged cargo.)
Seems to be a reason alibaba uses third party for the acutal importation . . . They also want no responsibility for the shipping fuckery that goes on.

Bolts/ motor came out and went back just fine. Key/ keyway appear same.
You have not replaced any inserts yet? IIRC you said <100hr on yours.

Mine look kinda soft like brass - not ridiculously worn but joints aren't near as tight as new. Inserts prob softer than the pins. Would prefer to use whatever manufacturer used but might check generic bushings/inserts thanks. Tolerances have to be kinda tight ID and OD

 

[MaxG]

Uh, no not electric, sorry I've no idea what you are on about!

You have this potentiometer next to the ignition key. What is it for?

 

[jaylast]

That's not any picture of mine. No I def don't have any poteniometer on the machine. Highest tech thing is a solenoid lockout for pilot control down on the main valve body

 

[MaxG]

That's not any picture of mine. No I def don't have any potentiometer on the machine. Highest tech thing is a solenoid lockout for pilot control down on the main valve body

OK then... The whole arrangement looks eerily similar to mine... where this potentiometer controls the speed of the electric motor.
The lever on the left (in the image) adjusts the track width and moves the blade.
What is weird in the picture, is the 'engine start' button at the end.
The yellow is the same on mine, and the metal is bent at the same location.
Anyway, thanks for the reply, well never know

 

[NorthShoreDave]

If you haven't installed the extension for hydro tank, could you possibly get the dimensions for me? I bought an AGT L12 last week delivered in Ohio. A few days later I lost all hydraulic pressure when going down the ramp on my trailer. Hyd fluid was full, so I looked at the suction line on the tank. It is on the end at the lowest point possible. looks like a design flaw, and your post confirmed it. Thanks.

I just purchased an L12 and am having the same hydro issue(loss of power on steep grades). The seller did give me a piece of pipe as a fix but no directions. Did you do the mod on your L12?? Thank you