Building the MPM Hansa-Brandenburg W.29
By Shane Weier
I thought I'd post a few comments on the MPM W.29 kit which has just started its journey across my work top.
I've previously posted on this subject noting that it seems one of the best WW1 kits I've seen in 1/72, and I still think it's excellent value. But there are a couple of changes that really must be made to capture the look of the original.
The wing should have dihedral in the inner portion and a kink at the point where the struts join beneath the wing, so that the outer panels are very nearly flat. I cured mine by the technique used in vacforms to induce dihedral. First, I removed the ailerons, then with a razor saw slit the underside of the wing almost through parallel to the rib stations. Pull the tip down to close the gap and run a little CyA into the slit and the job is done.
The ailerons also lack the characteristic washout at the tips. This is simple to add by slightly heating the part and twisting the trailing edge at the tip upwards. The balance portion of the aileron should stay parallel with the inboard edge of the part, so there is a fairly sharp kink at the hinge line (See photo 46 in Datafile)
In plan view, the wing leading edge should be a straight line, but they curve slightly forward at the tip. It's scarcely noticeable unless you place a straightedge on it, but the truly dedicated (lunatic) will try to reduce the LE at the tip slightly to improve this.
I refined the tip (aileron balance) of the aileron, which is rather thick compared to the photos, cleaned up the remaining edges and cleaned up the wings.
Also cleaned up and mated the float parts. They go together well, detail is a little different from the Stair plans but not enough to bother me (I wonder why we always assume the plan draughtsman is right and the toolmaker is wrong ?)
Time elapsed - about 1 hour total.
So far, enjoyable, and the changes made come under the classification of minor tweaking. If MPM would only produce the model in 1:48 as well I'd be a very happy little vegemite
MPM provides a floor, two seats, control column (choice of plastic or etched wheel), etched rudder pedal and choice of plastic firewall or etched brass and film.
I cleaned up the interior and decided that with no top wing to hide matters, and two holes to view through, I'd better do something to improve matters. An hour with 10 x 10 thou and 10 x 20 thou strip and a few fragments of 5 thou card, added a reasonable facsimile of the interior seen in the Datafile.
BEWARE. The floor will not fit properly using the tabs on the fuselage interior. They are not at the same level, and induce a vertiginous cant if left alone. Also, the floor is too wide and needs some material removed from both sides to fit.
Since I'm a pedant, and don't believe the seats sat on grey plastic cylinders, I removed the cylinders from the floor and replaced the forward one with a scratchbuilt fuel tank. The rear seat hinges upwards at the rear of the observers cockpit. I made a new one and "hinged" it from a new structural crossmember. (The seats aren't bad, and I'll use the front one, but the picture of a licence built Finnish machine shows a canvas bucket which I enjoyed copying.)
There is also a tank (fuel? water? The drawings show the filler, but the model doesn't have one) behind the top of the pilots seat. Again, a quick scratch job adds to the busy look.
Two questions for those with the Datafile.
In the interior photos there's what Rimmel calls a "sprung foot step flap" near the pilots left elbow. This does not appear on the outside on Stairs drawings, nor as far as my doggy eyes can tell, on any of the photos. Maybe it's a Finnish modification. Does anyone have any evidence the German machines had this step. BTW I don't mean the step beside the Observers cockpit, which IS shown.
Question two. Rimmel reports the instrument panel and firewall as dark mahogany and the cockpit as light grey. There is little tonal difference in the front cockpit. Any guesses on the estent of bare wood? (the photos shouldn't be as difficult to interpret as contemporary ones)
I now have the interior complete. A couple more warnings are in order. On my sample the pilots seat is slightly too wide for the interior. To some extent I'd anticipated this. When I added stringer detail to the sidewall I first scraped the walls down considerably both to get a smooth surface and to make room for the 10thou detail. I also thinned the seat back and sides to near transparency in order to get a nearer scale seat back. Just the same, it interfered with the sidewall detail, which had to have some localised work to make everything fit.
Instrument panel/firewall is easy. I chose the etched brass version, and used tiny fragments of prepainted decal sheet to "paint" the instruments/controls/data plate rather than trust my shaky hands. Unmentioned (IIRC) in the instructions are several tiny holes/slots in the plate which need even tinier switches in them. I used minute bits of brass shim and fine copper electrical wire.
The engine bearer "platform" is also slightly too wide, and as with the cockpit, the locating tabs are somewhat offset, though not as bad. I found that it will be possible to glue the halves together and slide in the engine from the front before adding the radiator part, which will ease sanding the join between the halves by keeping the fragile engine out of the way.
At this point I need to correct a correction I made in an earlier part. The engine support part had been modified for width, and the tabs on the fuselage modified to allow it to sit horizontally above the lower of the two. BUT when I slipped the engine in, it immediately becomes obvious that the even the lower pair of tabs are much too high. The true position for the panel seems to be below the lower ones. I fudged it by triming about 2mm off the bottom of the engine, and since it can't be seen it doesn't matter, but the experience reminded me how necessary it is to repeatedly dry fit everything.
I offset the elevators and thinned the trailing edges. This is the usual pain in the rear because of the difficulty of keeping the indentations along the rear consistent, but pays dividends in the final finish. Incidentally, I chose the later style small tailplane, but the chord at the centre is about 10 thou shorter than the slot in the fuselage top. Just room for a card shim, or a wipe of putty.
So - almost ready to join the halves. Given that I had some slight problems with all the interior being a little wide, I may have been better off laminating a 5 thou shim along the fuselage edges.
At first glance the engine is terrible. I started to prepare a scratchbuilt one, but fortunately came to my senses and decided to have a close look at the kit part to decide if it's salvageable. I think it is useable, but the flash is fairly awful. I removed all the detail above the cylinder head and will use all the area below - block, cylinders, manifolds, ancillary gear - with scratchbuilt piping and cylinder head detail. I justify this because it's only 1/72 after all, and the gear inside the panels will be almost invisible, while the cylinder heads are right out there with the viewers beady eyes !!
However, I chose to use the brass firewall/instrument panel, and despite the engraved position in the fuselage interior it's still markedly too wide to fit. I engraved the marked positions to several times the original depth before the fuselage would close.
When it did close it became clear that the engine panels are canted inboard to a greater degree than they should be, so that the fit to the radiator would become problematical. I added a shim of 5 thou card between the fuselage halves forward of the cockpit which eliminates this slight distortion (and incidentally also eases fitting of the firewall).
Got everything nicely glued, seams sanded and polished out and look inside to admire the cockpit - and notice that the process has shaken loose the petite rudder bar. Aaaargh!. Happily, I had replaced the control column (which is way too thick and clunky) with a piece of fine brass rod. It was possible to bend it back, shake the rudder bar out, hold it on a piece of brass rod with blue tack and manouver and glue it back via the gap between steering wheel and cockpit coaming. Moral: Be careful because the fuselage interior is just wider than the bar and the area of glue is tiny.
Just in time for adding the wings !
First up, the wings have tabs presumably at the position where the spars run, since some of the float spars share the same mounting holes on the fuselage. The tabs are in the same position on each wing - but the slots in the fuselage are not. I filled ALL the slots, cut off all the tabs, and added two brass rod "spars" to strengthen the joint.
The wings wouldn't look right, no matter what. I traced this to there being far too great a sweepback on the wings. According to the datafile, this is about 4 degrees, mine were nearer double that. You can improve matters by carefully sanding the inboard end of the wing so that the leading edge is shortened while the trailing edge is not, but I don't recommend completely correcting the angle, so it will be obvious that the ribs now have an angle of 4 degrees to the fuselage, instead of parallel. I halved the difference, built a complicated jig to hold everything in alignment and glued the wings on.
That left me pondering whether the supplied hex would sufficiently confuse the eye to hide the minor outline errors. While doing so, and idly perusing the decals I note that:
a) mine are impeccably registered, perfectly printed, and match two colours of the A/G decals precisely
b) the hex is printed in shapes to fit the various surfaces, with plenty of extra to allow easy trimming. I notice that they have correctly printed the hexes chordwise (wings) spanwise (ailerons), lengthwise (floats, if you need it) and fuselage. Neat. Full marks to MPM for capturing this detail.
Thats where I know stand folks. Still enjoying the model. I'd like to point out again that the changes I've made are scarcely obligatory, except where being able to close the fuselage is concerned, so if you buy one and don't make the same alterations (or different ones) - good for you.
I eventually decided to use the kit engine. As usual it's slightly under size (to allow for fuselage sides which are significantly and inevitably over scale thickness), and seriously flash encrusted. It helps to have a good photo of a Benz III to know what to leave, and the W.29 datafile does not oblige. There is a good one in the W.12 Datafile though if you can get access to that.
I simply cleaned up the cylinder heads to leave a narrow rocker arm on top of each, and filed and scraped around the pushrods to improve the definition. Painted up, and with little of it in view it's simply not worth bothering with spark plugs and wiring which is not visible - for once I checked before doing it. IF I build another, I'll make new and individual rocker arms and springs - when hell freezes over.
The radiator on mine was too narrow by a little. Some sanding of the forward engine panels neatened things up without making the shape visibly different from any photo. Charles has just pointed out to me that there are several variations on the radiator style - but since I have no idea which variant is fitted to the machine I'm building, the kit one will suffice.
I spent some time masking, then an undercoat to reveal the usual building flaws. For once, no centre line seams (those will not appear until after the last topcoat of course), but some moulding flaws which I'd missed in preparation. A couple of little "lumps and bumps" appear on the wing surfaces, and are simple to remove. I also found a number of what looked like hairline cracks in the plastic of the fuselage, repaired by running a bead of cyA in and polishing almost immediately after it dried. I can't recall anything there at first inspection, so maybe I clamped things too tightly and did it myself.
I've chosen an aircraft which is arguably in the "sea green" colour noted by Rimmell. This is shown in the top profile of the Datafile rear cover, and I suspect that any Australian told that the sea ever appears that colour would laugh in ones face. Nevertheless, I've mixed my own shade using RLM02 (of that other conflict) and a touch of brighter green. Undersurfaces are Clear Doped Linen, wings needed painting in the recommended humbrol shade to provide the third colour of the hex cam, and the floats are dark brown in preparation for a dark "wood" finish.
At the conclusion of the last episode, I was about to apply the hex decals to the kit. I can report that they all went on perfectly well, though you should be warned that the decals are both tough and thin and need care. Use plenty of water underneath, position as closely as possible to the final position and only then slide off the backing paper direct to the model surface. Make sure the paper is in contact with the model, as these decals have a tendency to slide right around the paper edge onto the undersides.
Although mildly awkward to use, the results were superb. I never used any softening agent, but the decals conform tightly and have proven very robust against my clumsy handling.
National markings etc. came from a mix of kit decals, Americals and some laser printed aircraft numbers for the plane I'd decided to build. I had more trouble with the kit crosses than the hex, but only because the cross shape is harder to get off the paper without edging under at some point. I ended up with a minor blemish which I fixed at paint touchup time.
Struts are a nightmare in the making. The MPM ones are brittle and not accurate in length or shape. Notably the "V" shaped struts which attach to the fuselage lower longerons and the centre of the float cross struts are too narrow by far to sit as intended. It may be possible to open them up somewhat, but that will make them shorter still and they are already too short.
I made a jig, manufactured the front and rear "M" shapes, built another jig and used that to connect floats, "M" and fuselage, then added the six wing support and the fore and aft bracing strut one at a time. I used Contrail struts which (perhaps because of their lack of rigidity) popped in quite nicely and when finished give a strong structure with a good scale appearance.
Only the details left. I used the kit elevator horns, but cut the rudder horn away from its etched "wire" and used just the horn. These look fine with monofilament control lines.
The steps and grab handles from the kit etch work nicely too, and add that touch of fine detail which is critical in fooling the observer into believing you're a better modeller than in reality.
I used the observers gun, but it needed a LOT of refinement, adding a scratch built mount from brass shim and rod, an ammo reel from disks punched from styrene sheet with the trusty Waldron, and a brace for the ammo reel from ceramic wire rigging material. My model represents one of the radio fitted machines so I needed just one (starboard) Spandau which was done with an Eduard etched gun. This adds a great deal to the look of the nose.
Only seat belts (front only, I am ambivalent about whether the kit style belts were used by observers) and the windscreen (an easy to trim vac, though a tad thick) and then a little engine detailing to finish.
I replaced the too thick and clunky exhausts with new ones from styrene rod, the coolant pipe from copper wire (rather than the unconvincing flat, etched part) and all was done.
Nice kit, damn fine decals (if touchy to apply) of a spectacular looking plane. The only critical outline error is the outer panels of the wings which really must be turned down or the kit looks nothing like the real plane. Otherwise, any problems are typical minor fit difficulties inherent in shorter run kits, or due to the relative crudity of the detailing parts - and perversely this added to my pleasure by giving me more to do than just slam it together.
That's all folks. I hope all of you who haven't bought one of these kits thinks about doing so. MPM deserve a boost for producing *any* WW1 subject, and this one is - in Australia - $10 cheaper than the Pegasus and definitely not $10 less in quality.