Moska MB bis (oz16671)

About this Plan

Moska MB bis. Radio control scale model. Wingspan 30 in, for electric power with GWS IPS geared motor.

Quote: "Moska MB bis. A 30 inch span scale model designed by Peter Rake, the prototype model being built and described by Pat Lynch.

Peter Rake's little Moska couldn't get much simpler - which is exactly what I wanted when I asked him if he had any VERY simple designs that needed building. Why? I recently moved to a new city and felt I needed a change from moving, renovating, redecorating and generally being domesticated. My temporary workshop was slowly filled with stuff that hadn't anywhere to go just yet, and the little remaining space didn't suit my three or four bigger building jobs, so here we are - an IPS-size titch of a model - a Russian Moska.

The plans were acquired as pdf files and tile-printed onto A4 sheets, stuck together and the parts sections cut away and stuck to balsa, spruce and ply with a water-soluble glue stick and cut out as required. A light mist of water softens the glue and the paper can be peeled off after cutting. No real need for laser-cut bits, there are only a few of them!

Building: The little Moska's fuselage is fairly straightforward. The two sides are framed up from 3/32 sq spruce for the longerons with balsa uprights and crosspieces and some balsa sheet parts at the front and rear. I built the two sides on top of each other complete with the vertical wing supports from 3/32 spruce. After sanding smooth, the sides were joined with the tailskid plate at the back and a central former just aft of the cockpit. The fuselage was then pinned to the plan on its side (the sides are totally straight) and the various crosspieces were added making sure everything stayed square. Medium CA was the glue of choice.

Some sheeting at the tail end, plus the front formers and UC mounting plates gets the basic fuselage almost done - just some rounded formers on the top of the fuselage, and a piece of light 1 mm balsa sheet sprayed with water and CA'ed in place using clamps and tape to hold the curve. The upper spruce longerons were slightly chamfered to get a neat finish at the edges.

Next, the internal woodwork was done. Servo rails, rigging blood fixing blocks and the motor mounting plate and IPS motor 'stick'. The motor plate is offset to achieve the required 2° down angle. Then a major brain-fade - I marked the IPS mounting stick with the fuselage pinned over the plan - upside down! After gluing the stick firmly in place it was of course giving me 2° of LEFT thrust - could make for interesting take-offs! Make sure the motor stick gives a little RIGHT thrust.

A piece of 1/16 sheet was fitted over the area in front of the cockpit waiting to be blended with the cowl to made later...

Tail bits: The tail outlines are all of 1/32 x 3/32 balsa strip soaked in soapy water (the soap aids absorption), carefully bent around 3mm Depron forms and allowed to dry. Small scraps of balsa were pinned up against the wood which was allowed to dry naturally. The strips were then removed, glued together with white PVA. and re-pinned to dry.

An elevator spar of hard 3/32 balsa, plus ribs of soft balsa, were added to the tail parts and everything rough-sanded to an even 3/32 thickness. The rudders had a 1 mm hole drilled for the CF shaft - I used a drill press to get it accurate

but with care, a pin vice would have done. The elevator was mounted to the fuselage rear with two 1/8 x 3/8 tabs of Mylar hinge material. Nothing glued yet of course

WINGS The wing ribs (not many of them) were cut using the printed cut-file and sanded as a stack to get them all the same and then glued to the 1/4 x 3/32 hard balsa spars. The TE was cut from some medium 3/32 sheet, notched, and glued in place followed by the LE from some 1/8 strip. Laminated wing tips were formed from three strips of 1/16 x 1/8 soft balsa strip, soaked and pinned to shape on the plan. After gluing the tip laminations in place, small blocks of shaped soft balsa were added at the root leading edges and the whole lot rough sanded..."

Moska from R/C Model Flyer July 2019.

Direct submission to Outerzone.

Note see 2013 prototype build thread by Pat Lynch, along with lots of great build pics on RCGroups at: https://www.rcgroups.com/forums/showthread.php?1969505-Peter-Rake-s-IPS-Moska

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