Playmate Junior (oz12971)

About this Plan

Playmate Junior. Radio control sport model for electric power.

For the original 50 inch Playmate design see Playmate (oz7594). This here is a later, reduced scale version for geared DC-5 motor.

Direct submission to Outerzone.

Update 21/04/2021: Added article, thanks to Pit.

Quote: "About 16 years ago, I designed and published a plan for a low-wing, 3-channel model I called the 'Playmate'. Many modelers enjoyed this design and built it from both plans and kits. As I became more involved with the RC electric micro-flight movement, I began to look for a model that I could scale down.

The more I examined the possibilities, the more the Playmate looked like the top candidate. Of course, this concept of a model of a model is old news to the free-flight fellows who already enjoy flying older models in similar sizes.

It was important that my miniature be as small as I could make it but still have full 3-channel control. While completing other projects, I had identified the drive motor, batteries and RC gear that would be most suitable for such a venture. With 64 square inches of wing area and a weight of 2 ounces, the Playmate Jr may not be the smallest RC model, but it does have the smooth, friendly handling of the larger original. It is also the most agile miniature model I have ever built.

Although the Playmate Jr is small and light, it's a poor candidate for confined indoor areas such as a standard gymnasium. Equipped as shown, its speed ranges from 12 to 22mph. Owing to its speed and responsiveness, it is best flown outdoors. It can handle a reasonable breeze and be flown in the smallest of outdoor areas.

Let's talk a little about the equip-ment. The Sky Hooks & Rigging receiver is the smallest I have found, and it's downright reliable. The very early WES-Technik kit servos are small, light and very reliable. I chose a DC5-2.4 drive motor for its very high efficiency. The Playmate Jr. requires only a 5-cell Ni-Cd battery to provide more than ample motor power, and I decided on a 4.2:1 gear ratio to drive a 5.75-inch-diameter propeller.

I initially set aside an FMA Mini 5 ESC because it was a tad bulky, but after I had removed its thick shrink-sleeve and swapped its wires for wires of a more suitable diameter (bye-bye warranty!), I had a 1-gram ESC that was plenty small enough.

I built the airframe in the lightest way I could devise without sacrificing durability. I chose what seemed to be the lightest covering—Campbells Custom Kits' Esaki Japanese tissue. Available from hobby stores in several colors, it can handle moderately rough treatment. Sprayed with a coat of clear lacquer, it worked out very nicely.

The basic fuselage is a 1/32-inch balsa shell; a soft balsa block forms the top deck; and the tail sur-faces are simply 1/32-inch balsa sheet. There are a couple of options for covering this model:

1. Cover everything with the tissue, and coat it with clear lacquer. This produces a bright, tough model that is very light.

2. Cover the wing and tail with colored tissue, and lightly spray the fuselage with a color coat.

I chose the second method, and I have achieved very pleasing results using automotive touchup spray paint. For the clear finish, I use Krylon Crystal Clear spray lacquer, which is readily available and is entirely compatible with Krylon paints and other touchup paints.

Now, since this is a model of a model. I whittled a little pilot out of very light balsa and added a mock engine - also balsa. This little bit of foolishness added only about 1 gram to the overall weight, and judging from comments made by other modelers, it was time well spent.

If you want to build a Playmate Jr, you should have some experience working with small parts and controlling weight. If you have worked with small free-flight models, so much the better. You should also be adept at picking the lightest balsa sheets. I benefit from a pair of reading glasses, and I occasionally need to use tweezers (the double dose of patience goes without saying!).

If you make substitutions, please keep an eye on the weight A 2-ounce RC model is not really that difficult to produce, but you do have to challenge every extra gram. If you intend to do any serious work with micro models, I strongly suggest that you invest in a decent weighing scale. I use a simple, scientific, mechanical, triple-beam scale, but almost any good scale will do the job.

Instead of giving you a detailed explanation of the construction, I'll assume a little experience on your part and touch only on a few areas that are the most important..."

Update 14/4/2023: Added complete article, thanks to theshadow.

Supplementary file notes

Article.

Corrections?

Did we get something wrong with these details about this plan (especially the datafile)? That happens sometimes. You can help us fix it.
Add a correction