CMR Models - Pfalz Dr.I: Model Review by Andy White

1/72 kit: Pfalz DR.1
Czech Master Resin (Model No.CMR-5082)

Model built & reviewed by: Andy White

Background History

Little information seems to have been written about this second most famous German triplane. However, its performance was far superior to the better-known Fokker Dreidecker. In late 1917, both the "Red Baron" Manfred von Richthofen and Tutschek flight-tested the Pfalz Dreidecker, serial number 3050/17, at the Pfalz factory in Speyer, on the Rhine in Germany. See: Triplane Madness: Pfalz Dr.I 3050/17. Apparently von Richthofen was very impressed with the qualities of the type. For example, the Pfalz Dreidecker could easily out-climb its Fokker counterpart.

The Pfalz Dr.1 was armed with two Spandau synchronised 7.92mm machine guns, firing through the propeller arc and had a maximum top speed of 201kph - compared to only 185kph of the Fokker DR.I.

How many were actually built and saw service is debatable. Some figures give as little as ten to fifteen aircraft, whereas others point to the fact that production serial numbers seen applied to Pfalz Dreideckers serving with Jasta 73 include 221/17 and 222/17.

Siemens-Halske SH.III 160PS Rotary Engine
The aircraft was powered by the Siemens-Halske SH.III 160PS rotary engine. This powerful unit was unusual for a Rotary design. Normally, the crankshaft remained stationary and the cylinders rotated around it - while attached directly to the propeller. As the power of Rotary engines increases during WWI, the method of harnessing this power resulted in bigger propellers and higher ground clearance of the airframe. A disadvantage of this design was that the enormous torque-effect of the rotating cylinders and propeller caused handling problems. With the Siemens-Halske SH.III 160PS, a novel approach was to make a Rotary engine whose crankshaft and pistons rotated in the opposite direction, so reducing the torque-effect from the cylinders and propeller.

Most Rotary engines rotated at about 1,200 to 1,500rpm, whereas the Siemens-Halske SH.III 160PS rotated at only 900rpm. However due to the opposite rotation of the crankshaft, this gave a virtual engine speed of 1,800rpm. A side effect of the slower propeller speed was that for the extra power developed, the engine ran hotter, causing cylinder cooling problems - hence the very open-fronted cowling design fitted to the Pfalz DR.I.

'CMR Models' Pfalz Dr.I Kit

It had been over twenty years since I'd built and finished a scale model aircraft. In fact this model was a complete departure from my usual era of aviation - Post-War British Military Aircraft. However, having as yet never attempted a 'Resin' model, I thought this would prove an interesting example to start with. Czech Master Resin's (CMR Models) re-released Pfalz Dr.I [CMR-5082] is in fact based on their original model first manufactured some twenty years ago, but brought up to date with modern vacuum casting in PUR material, new instruction sheets, a decal sheet and "Pfalz-Flugeugwerke G.m.b.H" scale drawings.

The moulded parts were held in heat-sealed pockets of a plastic bag, making it easy to check them over while still safely packaged. The parts were very crisply cast with fine detail and not a single air hole - something that I had heard can often be found with resin models. Of the major parts, most items were easily removed from their casting blocks - having very fine connecting runners. Only the two fuselage halves had large moulding blocks, which required removal. At this point I encountered my first problem:
— The Tailskid: This is finely moulded to the port side fuselage half, but had broken away with the edge of the moulding flash. Though unfortunate, this was easily remedied by replacing the whole skid with a length of brass rod (see later).

The Build

From this point all initial work centred on cleaning off moulding flash and dry fitting parts, before attempting any assembly. All parts fitted together well, with no distortion to the fuselage halves or wings.

Once satisfied, I washed everything in a bath of liquid detergent, to remove any trace of mould-release agent that would affect the paint adherence to the surface.

My next decision was what aircraft to make. The two schemes supplied in the model are of 'Aluminium-doped' [or Pfalz 'Silbergrau'] Dr.I 3050/17, plus 222/17 of Jasta 73. However partly due to the "Pfalz-Flugeugwerke G.m.b.H" scale drawings supplied - and the fact Misterkit's Pfalz 'Silbergrau' acrylic paint was out of stock - I decided to build the original prototype Dreidecker airframe, in varnished plywood monocoque and clear-doped linen flying surfaces. See The Elusive Pfalz Dr.I

This necessitated the removal of the machine guns and in-fill of the top forward fuselage, along with the addition of small scoops on either side of the fuselage (below the middle wing), plus two tiny metal access panels just behind the cowling. The cowling, though crisply moulded, did however lack certain details:
— Cowling Stiffeners
— A small raised plate on the port side
— Three large 'Ventilation Slots' on the lower edge
All items clearly shown on the "Pfalz-Flugeugwerke G.m.b.H" scale drawings - the 'Cowling Stiffeners' were made from fine copper electrical wire; the small plate from sheet styrene and the three 'Ventilation Slots' cut by hand. Also you are required to scratch-build a shaft to mount the engine, cowling and propeller on - I used brass rod.

I also decided to give the model more 'life' by offsetting the rudder and ailerons. A light score along the aileron hinge lines, followed by light pressure, partly split the seam - without completely breaking off the aileron in my fingers! A quick wipe of Cyanoacrylate down this seam set them at the desired angles.

The Cockpit: Personally, I wouldn't advise fitting the seat and control column directly onto the cockpit floor, as show on the assembly diagram. Glue the floor to one side of the fuselage, as well as the instrument panel and paint the detail. Once the fuselage is assembled, sanded, painted, etc., then the control column can be glued in place with the help of a pair of tweezers. The seat can be guided into place with a cocktail stick with a spot of putty on the tip - this is the easiest way I found to get the seat in the exact centre of the leather cockpit edging ring.

The Fuselage and Lower Wings: Generally the main parts fitted together cleanly - especially the upper joint of the fuselage halves. The lower surfaces joint needed a thin wipe of filler. I used the superfine, white grade of 'Milliput®' for this, as well as filling the area where the two machine guns had been left off. This easily sands to a remarkably fine finish, with no visible 'edge' to the filler. I tested the surface finish with a thin coat of acrylic paint, to look for any remaining blemishes, prior to the final painting. Once ok, this was removed and the whole fuselage de-greased with a wipe of thinners.

The Axle: According to the "Pfalz-Flugeugwerke G.m.b.H" scale drawings, this should in fact be made up of a central bar with tapered ends between the undercarriage legs - not three parallel rods as supplied in the model. This I made from a main axle of brass rod, covered by a length of plastic tube. Once glued, I carefully added the tapers to either end of the tube before painting.

The Tailskid: This I mentioned earlier had broken off the fuselage side it was moulded to. This in fact was a bonus because, by having to replace it, I could drill up through the underside if the fuselage and insert a short length of brass rod right up inside. There is absolutely no way that this can now be accidentally broken off by heavy-handedness! I cut the shoe off the bottom of the original resin tailskid and glued it to the end of the new brass version. A quick coat of etch primer to the exposed brass and enamel or acrylic paints will adhere perfectly.

Painting
As you can see, the majority of parts were painted prior to final assembly - even the rudder and tailplane, partly because of the difficulty in painting the control horns once assembled to the rear fuselage. I used a mixture of enamels and acrylics, as they were the colours I had to hand.

The Colours: These were based on the information written on the "Pfalz-Flugeugwerke G.m.b.H" scale drawing and the black and white image of the 'Prototype' airframe on the Sanke Card. See The Elusive Pfalz Dr.I
— For the Fabric-Covered Surfaces I used: Misterkit Acrylic German Clear Doped Linen [GC-10]
— Plywood Monocoque: A hand-mixed enamel Dark Beech colour
— Wing Struts, Undercarriage, Control Horns, etc: A hand-mixed enamel Dark Hardwood colour
— Propeller: Two-tone enamel Hardwood ply-effect
— Engine: Xtracolor Burnt Steel [X508]; Tyre Black [X505] & a Rusty-Brown for the Exhausts
— Pushrods, Cowling & Heat Shielding: Xtracolor: Natural Steel [X502]
— Wheels: Humbrol Satin Dark Sea Grey [164] and Xtracolor Tyre Black [X505]
— TOPCOAT: Xtracolor Semi-Gloss Satin Varnish [XDSS]

I decided to hand paint the model, as I wanted to achieve a slight grain-effect on the Plywood Monocoque. By thinly applying the colour by brush, the original resin of the model could offer slight shading. The Wing Struts were left unpainted until the wings had been completely assembled. This was fortunate as the centre struts needed to be shortened by about 0.5mm to get the wings set correctly. Many model makers swear by Future (Klear) floor polish as a topcoat to protect decals, but to me it leaves a very unnatural 'High-Gloss' finish - especially when they apply it over the fabric-covered surfaces!

Finishing

The Decals: I was surprised how fine these were, plus the quality of the minute lettering - things have come along way from the old days of Airfix and Frog decals of my youth! The CMR decals I found easiest to move and locate in position on the model's surfaces with the aid of a small paintbrush. No solvents were needed and because I had coated the model with semi-gloss varnish, the tiny transparent film edge of the decals proved to be almost totally invisible.
— Note: There is a slight error on the decal sheet in that one pair of Maltese Crosses are oversized. Though the fuselage and upper wing decals (1) are 8.0mm, the underwing and rudder should be only 7.0mm - the rudder decal (2) has been produced at 8.0mm also. Simple solution - apply underwing 7.0mm cross decals (3) to the rudder, then trim 0.5mm off each limb of decal (2) and apply to the underwing surface (instead of the rudder). This way the slightly thicker limbs of this cross will be totally unnoticeable.

The Windscreen: This had to be scratch-built from acetate. However the assembly instruction sheet showed a rectangular 'Slab' for the screen - this is not the case. By checking the supplied scale drawings, it can be seen that this is not only semi-circular in shape, but also curved in profile. I found a very simple solution to this:
— I used the acetate pack from a Supermarket Bacon Rasher container! Don't laugh, the reinforced structure impressed into the sides of the vacuum-moulded tray, provided a variety of curved surfaces, which could be easily cut to the shape required. This was finally stuck to the fuselage in front of the cockpit with white PVA glue - as this dries transparent.

The Rigging: This was an absolute nightmare and I will have to find a better method for next time. I had originally wanted to use the ultra-fine lycra stretch cord supplied for this very purpose (out of stock at my distributors), however I started looking at WWI modelling articles on the web. Some modellers said they had used 0.005" (0.127mm) Stainless Steel wire - yeah right, where am I going to find that! - Others had used 0.005" (0.127mm) and 0.010" (0.254mm) monofilament fishing line. So I finally found some black nylon 'invisible' sewing thread, which is about 0.005-inches diameter. Difficulty sticking it, trying to hold it while it set and pulling it so that it was straight when finished ............ aaah!
— My advice? Do your research and thoroughly practice first on some scrap material before attempting to rig a WWI aircraft you've just finished building.

Conclusion

Overall, this is a relatively simple resin model to build, which makes up into an interesting example of World War One 'Triplane' technology - and a change from the usual Fokker Dreidecker. The most time consuming part being to rig the model (and my complete lack of experience in this field!), but this shouldn't put off the first-time resin modeller, as the model still looks nice even in the 'un-rigged' state.

Would I build it again? The simple answer is YES. Ok I had to dust off the cobwebs from my many years of modelling neglect and some things I would do slightly differently with hindsight. However for me, the most useful thing was the inclusion of the "Pfalz-Flugeugwerke G.m.b.H" scale drawings. These enabled me to look further into the model, showing how easily an unusual example could be quickly reproduced from the production model supplied by CMR Models.

I am now debating about a stable-mate, which in the future is most likely to be Pfalz Dr.I 221/17 of Jasta 73, fitted with the production cut-away lower cowling and enlarged ailerons - described on the "Pfalz-Flugeugwerke G.m.b.H" scale drawings - but that's for another time.