Mini Playboy (oz13218)

About this Plan

Mini Playboy. Radio control 1/2A Texaco model, for Cox .049 power.

The original Playboy Senior (oz7835) was first kitted by Cleveland in 1939. This here is a reduced scale version for 1/2A Texaco RC.

Update 13/10/2021: Added airfoil coordinates, thanks to MartinHübner.

Update 24/1/2026: Added article in English, thanks to Jim.

Quote: "Mary, I really liked this design so I spent the time translating the German article into English. Please post so others can have more insight to this great design. Jim"

Quote: "The Mini-Playboy. Vintage Playboy Senior for 1/2A Texaco. By J Pipek.

The Playboy Senior was one of the most successful and famous model aircraft designs of the 1930s in the USA. Even today, vintage aircraft enthusiasts are captivated by the elegant lines and excellent flight characteristics of this model. It's no coincidence that the Playboy Senior regularly appears in the top ranks of SAM competitions. Our plan author J Pipek is very familiar with the Playboy.

My first Playboy Senior was also the most 'true to scale': built exactly according to original plans, with a wingspan of 80 in, or 2032 mm, and equipped with the equally original OHLSSON 60 engine. What a model! Majestic in the air, with its rumbling old-school gasoline engine, the Playboy also brought me several victories in SAM competitions. Besides this large Playboy Senior, two other versions already existed back then: the Playboy Junior (1372 mm wingspan) and the Playboy Baby (838 mm wingspan). In the 1940s, the models were offered as kits by Cleveland Model & Supply Co. Plans are still available today.

I was repeatedly asked by fellow model aircraft enthusiasts for construction plans for the Playboys, especially the smaller version, which was in high demand. I considered drawing up a new design based on the original plans. There were two reasons for this: Firstly, the old plans are based on technologies that are now obsolete; this is certainly a matter of debate, and the purists among the vintage aircraft enthusiasts insist on adopting everything in its original form. However, with a few adjustments to modern materials, one can greatly simplify the process without compromising the model's appearance or flight characteristics.

The second reason for a new design was the special vintage aircraft competition class 1/2-A Texaco, in which I wanted to participate with a small Playboy. The model for this class had to be carefully considered, as the decisive factor was the uniformly prescribed engine, the COX .49 Texaco (0.8 cc) and a tank with a capacity of 8 cc.

The small Playboys are very well suited for this discipline and are also successful in the USA, provided the weight distribution problem is solved: The original had a short nose because the engines at the time were quite heavy. The COX, on the other hand, is extremely lightweight, so you inevitably end up with a very tail-heavy model unless you manage to save a significant amount of weight in the rear fuselage and tail section. For this reason, it seemed advantageous to me to modify the fuselage for lightweight construction and the installation of a modern radio control system. After all, you can save many grams with lightweight balsa wood and cyanoacrylate glue.

Otherwise, however, I retained all the design features of the original; the model presented here, with a wingspan of 1255 mm, is therefore a fairly faithful, scaled-down replica of the Playboy Senior.

As soon as my Mini-Playboy was finished, I got the competition version of the COX .049 and was delighted with the beautiful weather on the day of the maiden flight. As a propeller, I mounted the relatively large propeller recommended by the manufacturer, COX 7 x 3.5.

The beautiful weather offered even better thermals, and soon my Mini-Playboy was almost out of sight. And because the COX engine has no throttle control, it just kept running and running and running - and I was fighting against the thermals at full throttle! In steep turns, I tried at least not to climb any higher. Eventually, however, the fuel ran out, and even a thermal doesn't last forever; in short, the Mini-Playboy was saved, landed safely, and I was thoroughly sweaty, of course, solely because of the hot weather. After this exciting experience, the model received a second elevator (for weight reasons, the first version only had one half of the horizontal stabilizer equipped with a control surface), and the control throws were increased.

General Construction Details: We already have to accommodate some ballast in the form of the RC system; therefore, it's crucial to avoid adding any further ballast. The lighter we build, especially in the tail section, the less lead ballast will be needed later. Due to the load-bearing horizontal stabilizer profile, the center of gravity is located relatively far aft, at approximately 50% of the wing chord. We must therefore position all the heavy components of the RC system forward of this point. The building materials: balsa, pine, plywood – the usual stuff. We begin with the fuselage.

Fuselage: On the plan, the two identical side sections are assembled from 4x4 mm strips. (Pin template, the plan protected by clear plastic film). The two sides are then connected with 4x4 mm cross braces, paying attention to right angles. Now the 2x3 mm form strips are glued on at the top and bottom, which are sanded down to 2x2 mm towards the rear of the fuselage. From 3 mm plywood, we cut out the motor bulkhead No. 1 and bulkhead No. 2..."

Supplementary file notes

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Article (en).

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