Importing and modifying a new mini excavator from China

[ptsg]

I know what you mean by the bonded washers. I have seen them, but did not know the name, Dowty. The one above uses a separate washer and O-ring, however. Are the adapters specced differently, O-ring vs. Dowty washer?

I don't think so. The metric adapters just use the face to seal against the face of the port, while the ORB fittings have a slight chamfer for the o-ring to seat in.

 

[Fixastuff]

I saw my first Chinese mini go by on a trailer yesterday. Glad I don’t do homeowner work anymore, guessing it’ll be a race to the bottom of pricing scale. lol.

 

[jaylast]

Hehehe ^^^

Iirc the fittings on my adjuster valve were referred to as 'orb', but also as 'npt'!
Iirc it was npt I used in the end- haven't needed any o ring face seal / orb fittings yet.

Nice buy DOH, and HCS with the EM 15- Yes Leking has claimed them in the past - you could search thread for 'leking' and my posts should return.
Most needed mod for mine was strengthen rear track frames/tails and change foot pedals to levers

Brief overview vids on my utube of the mods


Anxious to see how you make out with the crossover port mod Dave. I guess one could also be used for thumb to make it weaker than curl function. The expensive machines have that, but I haven't minded thumb/curl at equal pressures

 

[dfkrug]

Anxious to see how you make out with the crossover port mod Dave. I guess one could also be used for thumb to make it weaker than curl function. The expensive machines have that, but I haven't minded thumb/curl at equal pressures

You don't really need to add work-port RVs to your thumb circuit, as long as you follow some basic practices, incl using cyls of the same ID, using hi-quality cyls that can handle 3000-3500psi, and design your thumb in a way that it does not get excessive leverage from the bucket.

I have posted my DIY hyd thumbs on TBN, and I have never had a problem. I also never shared pins between thumb and bucket. Once you've gone hydraulic, you can never go back.

 

[HCS-II]

Hehehe ^^^

Iirc the fittings on my adjuster valve were referred to as 'orb', but also as 'npt'!
Iirc it was npt I used in the end- haven't needed any o ring face seal / orb fittings yet.

Nice buy DOH, and HCS with the EM 15- Yes Leking has claimed them in the past - you could search thread for 'leking' and my posts should return.
Most needed mod for mine was strengthen rear track frames/tails and change foot pedals to levers

Brief overview vids on my utube of the mods


Anxious to see how you make out with the crossover port mod Dave. I guess one could also be used for thumb to make it weaker than curl function. The expensive machines have that, but I haven't minded thumb/curl at equal pressures

Sorry, do you have a link to your YouTube videos? Would be interested to see pedals to lever mod.

My EM15 has cross braces to the track motors to prevent them twisting. I can post pictures if you want. It also doesn't have a bell-shaped turret like the LeKing KV13Plus, which had me doubting it being from LeKing.

Weird thing about the EM15 is that it uses M27x1.5 DKOL fittings for the return lines. M27 doesn't seem to be common in the DIN Light sizes which normally jumps from M26 to M30. I found out when I speced and ordered parts for a hyd. cooler and filter. Will post pictures when I install.

 

[dfkrug]

Weird thing about the EM15 is that it uses M27x1.5 DKOL fittings for the return lines. M27 doesn't seem to be common in the DIN Light sizes which normally jumps from M26 to M30

Good observation.

My Kioti tractor uses M27-1.5 metric O-ring port fittings, too. Definitely NOT DIN 2353 tube fittings or dual-purpose.

I will bet that M27 fittings are pretty common on valve bodies.

 

[JohnnyB24]

I just joined the forum. I just picked up a Miva VA15 which looks like the Diggit EM15 to me. Paid $6700 with a hydraulic thumb and a 24in tilting bucket. I am working on adapting and mounting the thumb as it was for a different brand, it says LANTY on it.
I'm mostly just trying to figure out how it's put together and how the hydraulics work but I did make a new cover for the unit that lets you open the side door without removing bolts. Not perfect but better than stock.

I changed the hydraulic fluid and did find a return line filter inside the reservoir but cant find a part number or a replacement. The fitting is 1in NPT fitting. Do you think this filter is adequate or should I try to add an external one.
There is an external filter for the pilot circuits but I don't know what a PN for that filer is either. It has a suction screen in the fluid reservoir as well.

 

[dfkrug]

I'm mostly just trying to figure out how it's put together and how the hydraulics work but I did make a new cover for the unit that lets you open the side door without removing bolts. Not perfect but better than stock.

I changed the hydraulic fluid and did find a return line filter inside the reservoir but cant find a part number or a replacement. The fitting is 1in NPT fitting. Do you think this filter is adequate or should I try to add an external one.
There is an external filter for the pilot circuits but I don't know what a PN for that filer is either. It has a suction screen in the fluid reservoir as well.

Welcome aboard, JOHNNYB.

You are doing the right thing: open it up and figure out what you have.

The return filter you found is probably inadequate. You really need a 10-micron filter, which is widely available and pretty inexpensive. Zinga is often the maker of the spin-on cartridge, and you should get a spare or 2. I posted my installation above, in the early part of this long thread. Glad they have a return filter on the pilot circuit. I have seen some pix of that, but my friend's EM15 does not have one. Can you get a photo?

 

[JohnnyB24]

All the hydraulics on this machine are metric sizes, and proved one of the bigger
challenges of this project. I got the adapters I needed from our friends at Discount
Hydraulic Hose in PA, but they were spendy, and one I could not find at all. I had
to make the adapter for the small hose that provided flow from the AUX circuit on the
dipper.

Standard-length new SAE hoses worked fine for me, so I did not have to have any
custom hoses made. The cost of adapters was higher than the whole filtration system.

Welcome aboard, JOHNNYB.

You are doing the right thing: open it up and figure out what you have.

The return filter you found is probably inadequate. You really need a 10-micron filter, which is widely available and pretty inexpensive. Zinga is often the maker of the spin-on cartridge, and you should get a spare or 2. I posted my installation above, in the early part of this long thread. Glad they have a return filter on the pilot circuit. I have seen some pix of that, but my friend's EM15 does not have one. Can you get a photo?

Thanks dfkrug. Great thread, I have started reading every post since the beginning and I'm about half way through and I have already learned a lot!
I think my pilot circuit filter is on the pressure side and I took a few pics but I have not opened that up yet.

I read in an earlier post that you had a lower volume pump you were going to try on your machine, did you ever try it? I love my new machine but even with the pilot controls, it seems to have way to much flow making it much more jerky than it needs to be. And why would they put on a 2 stage pump with a single output? The pump switching stages during operation can't be good for smoothness and control. It may also make it harder to reduce flow by simply throttling down.

I would love to try a new pump with about 1/2 the flow as the one I have now. In an earlier post you estimated current output at around 6 GPM I believe? I would prefer slower and smoother to the way it operates now, WAY too fast for my taste. I want it to be a more relaxing experience and stress the machine less, I am in no rush.

As a reference, I have had an old 1948 Ford 8n with a Sherman backhoe for over 30 years and that has a single stage, lower flow pump. It moves much slower but it's quite smooth and still has plenty of power. That think has dug A LOT of dirt over the years! I know much of that smoothness comes from the heavier weight, but it's still much smoother than my Miva.

I plan to add a new external return line filter next time I change fluid. I'll run the machine with the rear door off and take frequent breaks to help with the cooling.

Any thoughts you have would be appreciated!

John

 

[dfkrug]

I think my pilot circuit filter is on the pressure side and I took a few pics but I have not opened that up yet.

Yeah, that filter is in the return part of the circuit, draining to tank. That is good, but what is the spec on it, and how do you find replacements for it? At least they addressed this critical need. I would change to a known and serviceable 10u filter setup like what I did above.

Thx for posting the filter pix. I will check again the local EM15 to see if it has this somewhat hidden filter.