Hitachi ZAxis 135 excavator

[Beekster]

So, I got this kit from Hasegawa in 1/35 scale:


It's part of a series of construction equipment that they make, including a variant of this machine with two arms, a pavement roller, a Japanese agricultural combine, and a wheeled log loader.  The latter is on my acquisition list.  Hitachi excavators are sold in the US under their brand name and this one is also sold as a John Deere machine.  You know how when you buy a new car, suddenly you notice others just like it that you hadn't noticed before?  Works that way with models, too.  I've spotted at least three Hitachi excavators locally, including one of this exact machine, in recent weeks.

I had a couple of reasons for buying this kit.  One, I hoped it would solve some problems with my second Madill yarder project by way of perhaps copying some of the track parts.  No joy there.  Two, it did come with a grapple arm attachment that would be a good complement to the Madill yarders.  This week I decided to start playing with it.  Like any other Hasegawa kit, the fit is excellent.  I decided to start with the boom & grapple arm:








It goes together pretty easily with very little sanding & filling of seams required.  I did use my punch & die set to enhance the detail on the grapple arm; the molded discs didn't stand out enough so I added discs of .005" stock on top.  Not as easily seen are smaller but thicker discs which beef up the locations where the hydraulic cylinders pivot; I wanted some additional strength there.  Hasegawa does indulge in some strange engineering.  Notice that the hydraulic cylinders have a white seam around their circumference:  Hasegawa molded these parts as two halves this way, rather than as a longitudinal seam like a lot of gun barrels.  The fit is actually pretty good, and the most tedious part of working with these is scraping & sanding the mold seams and the seam created by the parts join.  There are two more cylinder assemblies to be made, for the boom elevation.  All this stuff is workable; the whole arm (mocked up here) will articulate and the claw rotates and the jaws open and close.

I will keep working on this a little in between vacation preparations which will increasingly dominate my schedule over the next week and a half, mostly getting the car cleaned & prepared for the road trip.

[JCON]

Fun kit!!!

[Beekster]

Aug 24, 2021 12:43:29 GMT -6 JCON said:

Fun kit!!!

It is, so far.  It has some other oddities; like axles at the pivot points which have keys on the ends and are supposed to be inserted and twisted a certain way to lock into place.  That only sort of works; so far I've trimmed each of them flush on the exposed end before fitting the end caps.  Everything still articulates just fine.  The crawler frame has little springs for the idler mounts so that it can be moved fore and and aft for establishing proper track tension.  The tracks are rubber-band type and mildly stretchy, so they ought to self-adjust.  Time will tell.

The cab will be the biggest challenge.  There's a lot going on in a small space; a lot of decals for various placards in there, and that huge greenhouse.  The transparent pieces are supposed to be sandwiched in between the inner & outer door panels and between the cab frame and the interior trim panels.  I suspect that I will have to paint parts on sprues and apply decals before assembling things together.

[JCON]

Sounds like a fun challenge!!!

[dogfish7 (R.I.P.)]

Nothing, the Beekster, can't handle.

[Beekster]

Aug 25, 2021 9:32:30 GMT -6 dogfish7 (R.I.P.) said:

Nothing, the Beekster, can't handle.

We'll see.  At least this thing is an OOB build, unlike the yarders.  I suspect part of getting stuck into this one is a bit of modeling therapy; just built and paint it.  This won't be the only such project.  I've got something of a war chest built up in my PayPal account, and when I'm back from vacation the log loader kit from this series will be purchased along with a couple of bulldozers, probably a MiniArt D7 and either the Meng D9 or the resin MMK D6K.  I'm still in the market for suitable parts to copy for the tracks & sprocket for the second yarder.

[Beekster]

Started working on the cab this morning. Not many parts; fit is excellent. But even Hasegawa can have an engineering oopsie now and then. Look at the piece on the right, and in close-up:




Hasegawa not only molded this panel hollow, it also failed to fill in the rest of the rubber boot around the control stick. I've looked at it with the seat in place, and the boot is going to be quite clearly visible. Maybe they thought the operator figure would totally obscure this: I don't know. I haven't built him and I don't know if I will use him. But most of this will be visible through the huge front window, so despite my intent of an OOB build has gone a bit sideways, and a fix is in process as you see. I'll sand down the plastic stock once the glue has set up, and use epoxy putty to make the missing portion of the rubber boot. Until I discovered this I thought I might be able to paint these parts tomorrow. Oh well.

That side panel on the left requires four instrument placards, and the smaller one on the right gets three. There's even one for the inside of the front transparent panel, which is funky. Never encountered decals for clear parts before.

[bravo1jon]

very cool. I have had my eye on this kit for awhile. Thank you for sharing the build. I am very happy to watch your build.

[dogfish7 (R.I.P.)]

Maybe, you can only look at it from the left side.

[Beekster]

Aug 26, 2021 8:01:19 GMT -6 dogfish7 (R.I.P.) said:

Maybe, you can only look at it from the left side.

No joy, Dogfish...I mocked it up, and the front portion of the inner face is visible through the front window opening.  Whatever; the fix is complete and I airbrushed color on these components this morning.  Color references are a weird mix of British BSC 381 call-outs and others like "German Gray".  The cab interior calls for a British modern aircraft color that's equivalent to 36440 Gull Gray; I've got 36414 Flint Gray on hand and that's what I used.  As for the "German Gray", the color photos on the box tell me that 36118 Gunship Gray looks pretty close so that's been sprayed on stuff too.  More of that to come; I stopped when the cup was empty and cleaned up but the cab & superstructure parts that will be used next all got covered.

[Beekster]

Another day, another engineering lapse. Behold the rotating base for the excavator, with a couple of parts added:


But turn it around, and we see this:




Yes, that's a gap there that ought not to be, and it won't be entirely obscured by other stuff in the end. Fortunately the fix is easy.



Some epoxy putty and a good squish with a flat piece of metal does the job. Of course, it has to set up now for 24 hours before I can do anything else with it, so I'll have to work on other parts of this. And run out to take photos. For the last couple of weeks, there's been a similarly sized Kobelco machine parked at a nearby road project, inside a fenced bioswale the city is building. It's got a very similar grapple claw, so I'm going to get some general reference photos. Never can have to many of those, can we?

[dogfish7 (R.I.P.)]

This thing is just full of gaps. TG for Putty!

[Beekster]

And here come more oddities from Hasegawa's kit engineers. This is the body of the excavator coming together. The dark gray parts are now glued to the base and the rest mocked up. Fit is excellent. Better than excellent for that light gray piece; that's just snapped in there.

That part has some decent detail of big hoses and gizmos, and you'd think that here's an opportunity for some careful detail painting. You would be wrong:



With the cover in place you can't see anything. I don't know if that panel is hinged, but probably not. I'll bet it's just plastic and held on with a few bolts on the real thing to make removal for maintenance as easy as possible. In the last photo, you can see some white stock filling the back of the dark grey parts on the front corner. I will fill in those orange panels the same way because it's easy to do and because I don't know how much of those inner surfaces will be visible once the whole boom assembly is put together. Gaps everywhere indeed! But at least they are mostly on inner surfaces.

All the orange parts will get a coat of light gray primer before paint to ensure that the orange is uniform, and that includes the boom and claw. I also need to ask the google what objects equate to 30 grams of ballast, which has to go in the back of the base panel.

[bravo1jon]

Great work so far and good fix on the gap. I'll know what to do now.

[Beekster]

Aug 28, 2021 13:21:07 GMT -6 bravo1jon said:

Great work so far and good fix on the gap. I'll know what to do now.

Thanks, Jon.  Really simple fixes, and even if it turns out that some aren't strictly necessary the time involved is minimal and I would rather indulge in a little sheet styrene overkill now than regret it later.

I pulled the trigger yesterday on the wheeled log loader, which (I hope) arrives as scheduled by next Thursday before we leave for our road trip.  I've been enjoying this machine, and the log loader fits in my forestry equipment theme.  I'm not so sure about the two-arm thing that uses this excavator frame, but the wheeled bucket loader would have possibilities.  I just discovered that Hasegawa has also released a version of the wheel loader kit with an angled snowplow blade.

[Beekster]

More mocking up on the body of the excavator. I need not have worried about filling in the backs of the orange pieces, but there's nothing wrong with a bit more structural solidity. You can see some of the required counterweight in the background, and some sheet stock at the back of the mount for the boom arm. Hydraulic hoses will thread through into that area, and this will block the view inside. It will all be black in there. You can see a gray unpainted side piece and a smaller top piece that covers the gap on top; it fits better than it looks in the photos. The instructions have you try to glue the sidewall to that top piece when you attach all the orange stuff. It's easier to use some angle stock on the inside for a better joint and attach it now, as I have done here.

[dogfish7 (R.I.P.)]

You'd think they would have used a clear engine cover, to show all the high details.

[Beekster]

Had the first annoying setback today while working on the little bulldozer blade arms. They have two attachments each for hydraulic hoses, and one of the teeny parts vanished escaped my fingers and went I know not where. Now I have to go to the hobby store, darn it! I can make replacement parts out of square stock drilled out for .016" brass wire, no big deal. But my old pin vises won't clamp tightly on my tiny drill bits, so I need to go shopping for another pin vise. The kit gives you a nice length of black hose, but I might look to replace that, too...it's really glossy, and a flat finish would look better. I probably have enough left over from plumbing the Madill yarder, but if not that's on the shopping list, too.

[dogfish7 (R.I.P.)]

If nothing else, it's a good excuse to go shopping.

[Beekster]

The blade assembly is coming together. I fabricated replacements for all four of the hydraulic hose mounts, since the kit parts were so fiddly and I feared that the tiny plastic pins would break anyway. Now I've got .016" brass rod in there, and the hose won't break off the pin. The whole mount might break off, but I'll worry about that if it happens.




My parts are somewhat overscale, but you'll never notice. Those raised rectangular flats on the hydraulic rams are mounting pads for guards which protect the hoses, and very little of the hose mounts will be seen in the end. I won't attach those (and the hoses) until this assembly is on for good and painted.

There's one other little thing that can be done to improve this assembly. The sliding portion of the hydraulic rams, which mount to the top of the mounting frames, are molded with a little raised line around their circumference. Left alone, this locks the blade in a horizontal position. Sanded away, the rams articulate properly and the blade can be raised.