Grumman TBM/TBF Avenger page 1 2 3 4 5 6 7 8
Scratchbuilding the retracts

Retracts is a theme where you can spend multiple evenings on discussions while changing nothing. There are some good retract producers in Germany and they build reliable retracts, but before charging s.b. of them you have to be aware that this will cost effords in enabling him and money too for his services. So what - when I have the oportunities to help myself with constructing in CAD, milling in a turning lathe and a milling machine combined with a little experience in metal works either?


I turned on my CAD and constructed the main retracts. Forgive me, but I won´t show all of the details I constructed.:

The tail retract was next to be constructed. Both kind of retracts will be pneumatically driven by self constructed cylinders and will each lock in their endpositions to guarantee a savely working landing gear for the Avenger.

Then I usesd the milling machine to produce the parts of the tail retract. On the right side you see the first parts I produced..

Assembling the parts for a cylinder has something of a "LEGO playing" feeling for grownups. For Airpressure-equipment I use FESTO-couplers with 3mm hoses. These parts are small-industry standard in Germany, reliable, easyly available and affordable as well.

First time putting the cam into it´s place. Here will be your new job!

First part of assembly finished. All parts glued together and airtight and - it works!

These two blocks will become the cams for the main gear.
I put them into the milling machine
and drilled the central whole into them.

In this whole the screw for the maingear will fit.
Right side: drilling wholes into the bracket.

Milling the chunk and drilling the closure

Drilling some wholes into the closure
and watching how it fits when I put the parts together for the first time..

This screw will hold the main gear.
Look inside the retract mechanics.

stay tuned!
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Stand 06/2010