Friday, October 12

Build Guide Pt I: Meng Models M911 C-HET & M747 Semi-Trailer (Trailer.)

Andy Moore has sent us his latest update of his latest build - the US M1911 C-HET Tractor and its accompanying Trailer the M747 Heavy Equipment Semi-Trailer in 35th scale from Meng Models. He has paused to give us a guide on how to get the most out of the trailer part of the build in today's update...

Build Guide: M911 C-HET & M747 Semi-Trailer
Manufacturer – Meng Models
Product Number – Stegosaurus Series SS-013
Scale - 1/35th 
Product Link & Distributors on the Meng Website
Price -  ¥20,000 - US$196 - £147 - €160 from Hobby Link Japan

Today - Build Guide Pt I: Meng Models M911 C-HET & M747 Semi-Trailer (Trailer.)
It's been a while since we looked through the box of Meng's new M911 C-HET truck and trailer, so it's high time we got the build underway. Today we're going to start off by looking at the M747 trailer which is essentially a kit in its own right. The first stage is the assembly of the chassis rails and cross members. Before that though, there are a few ejector pin marks that need dealing with. Surprisingly, these were on the outer side of the rails and, as such, would be visible on the finished build. For this, I used a homemade mix consisting of styrene off-cuts dissolved in Tamiya extra thin cement.
With the filling done, the build starts with the main frame that supports the suspension. This is straightforward enough, but you need to pay attention when attaching the shock absorbers as the unattached ends of these need to line up with the axles later on in the build. The attachment pegs do a reasonable job of aligning the shocks, but do a quick visual check after attaching them to make sure they're all roughly at the same angle.
This unit, together with the other cross members, are then slotted into holes in the sides of the main rails, resulting in a very sturdy box section frame. The easiest way to do this is to attach all the cross members to one side first then slot the other rail into place. Pay particular attention that all the cross members are installed the correct way round as some have attachment points for other components later in the build.
The next step is the addition of the lower chassis plate, which also incorporates the gooseneck at the trailer's front end. This part is very thin and flexible but, once attached to the chassis will actually increase the rigidity of the whole assembly.
Just to make sure though, I clamped the plate onto the chassis rails while the glue dried. You might also be able to see that, like the rails, the gooseneck on the chassis plate needed a few ejector pin marks filling. Some of these were subsequently covered up, but it's best to fill them anyway as you'd be kicking yourself at the end of the build if one was still visible.
The side frames on the gooseneck are next to be added, but some of the inside edges of these frames will be hard to reach with an airbrush once in place, so they got a quick coat of paint first. While I was at it, I sprayed the inside edges of the rest of the chassis, as once the main deck in added these areas will also be harder to access. As you can see, I'm going with the NATO green scheme, but I'll be giving it a twist as you'll see later in the build.
The main deck is next up and this simply slots into place on top of the chassis. The instructions have the deck being attached at the same time as the upper frame on the gooseneck, but in my case, I'd added the frame part first (because I don't always pay attention to instructions). That meant I needed to angle the front of the deck slightly to allow it to slot under the bottom of the gooseneck frame. Apart from that, it fitted without a hitch.
With the main deck in place, the trailer finally starts to look the part. It's surprising how many parts go into the construction just to get to this stage, and there's still a fair amount left to add.
Many of those remaining parts go into the construction of the axles and suspension, of which there are two types on the M747. The two forward axles are mounted on a simple swing arm, while the rear two are independent and feature vinyl gaiters to replicate the air suspension system. Those rear axles are made up from two halves which are then mounted to a two-part A-frame.
Those axle halves have very prominent raised plugs left by the mould ejector pins and they will need to be carefully removed not only to allow the parts to go together, but also to allow the metal axle bar to pass cleanly through the centre. Back in the in-box review, I'd mentioned that I couldn't find any mention of the included metal axles in the instructions, however, on reading them more carefully, they are indeed shown, albeit in a blink-and-you'll-miss-it reference.
Once the axles are built up, and so long as you've fully removed those ejector pin plugs, the metal bars should slide cleanly through the axles. Simply space the bar so there's an equal amount sticking out from either end.
When attaching the rear axle A-frames to the chassis you need to insert the vinyl gaiters, which in theory should mount onto the studs on the underside of the chassis. On mine, they didn't want to press down onto those studs, as the A-frames seemed to be sitting very slightly too far forward for them to line up correctly.
With a little pressure they did push down onto the studs and I'll be able to superglue them in position later on. For now, though I'll leave them loose to give me some adjustment when adding the wheels to ensure all eight pairs of wheels touch the ground.
The forward axles are much simpler, attaching to a pair of swing arms which in turn mount to the chassis underside. As with the rear axles, I gave these a preliminary coat of paint in case any areas proved hard to access later on.
Also getting a coat of paint before installation were the trailer's air tanks. These require some very fine, and rather fragile, pipes adding which, once the tanks are attached, need to line up with connection points on the inner sides of the chassis rails. Due to the delicacy and lack of any degree of adjustment of the styrene pipes, I decided to replace most of them with copper wire. The wire would not only be stronger, but could also be bent to meet up with the chassis connectors if required.
Once the tanks were in place on the chassis, I did need to slightly tweak the line of the pipes which wouldn't have been possible had I used the rigid styrene parts.
Among the various on-board tools on the M747 are a couple of long wooden planks strapped to the rear of the gooseneck frame. The supplied parts have a reasonable wood-grain texture and the retaining brackets are moulded in place. Although they look okay, I wanted to have something more realistic on this build, so I swapped the plastic parts for two lengths of balsa strip. I added some wear to the wood, particularly on the ends of the planks, and used strips of thin styrene for the brackets. These later had bolt heads added from a Meng accessory set.
The two rear loading ramps can either be posed up or down. If you have them up, Meng has supplied the retaining chains as moulded parts. While they don't look quite as realistic actual chain, they should look fine once painted up.
The last parts to add are the support legs at the front of the trailer. These use photo etched brackets into which the legs clip via the small pins moulded onto their ends. While this works well enough, you do need to slightly spread the PE brackets apart to clip the legs into place, and additionally, I wanted to keep the legs separate for painting, so a little modification was called for.
This was done by cutting the pins from the ends of the legs and drilling holes where the pins had been. That allowed me to pass a styrene rod through the brackets and the holes in the legs to hold the legs in place. Once the parts are painted, the rod can be glued into the holes in the legs while still being able to rotate in the PE brackets.
I'll also be using wire pins for the foot and the front section of the support leg (temporary ones seen here), meaning I can easily switch between a leg up or legs down stance depending on whether or not the trailer is hooked up to the truck.
And that's where we'll leave the trailer for today; fully built up and ready for the main paint coats. That will be coming up soon on TMN so stay tuned.
Andy Moore

Thanks to MENG for supplying this trailer and truck for Andy to review and to build for you - with more of this as it is completed in the next few weeks...