Ted:

I can't help you much with the bottom of the nose cone, but if you look at the Carlisle patent it shows a view of the engine mount. If my memory serves me correctly, in the Carlisle mMArk 1 the motor mount was made from metal and the drawing seems to support the case for an "doughnut hole" type of motor mount where the motor is more or less pressed and squeezed into place in the donut hole itself. I would make a SWAG that Orvillse kept this motor mount for his Mark 2 and just used hardwood instead of metal.

You have to remember that intially the Mark 1 and Mark 2 only used Carlisle hand made motors from his arbor press. He didn't use a metal sleeve surrounding the motor so under pressure the paper casing would "bulge" out slightly. Vern estes when he was doing his iinitial motor testing on his pre-Mabel hydraulic press, which allowed Vern much higher press presures than Carlisles hand operated arbor press, also discovered the tendency of the paper casing to bulge under pressure, and he solved it by using a metal sleeve round the paper caisng, thus containing any tendency to bulge.

I have a Sept 1958 Aerobee-Hi build artcile and there is no mention on how the motor is retained within the model.

In a "build" article from Jan 1960 on the MMI Arcon , it states "In the original kit, a plastic "COLLAR" (My emphasis) is cemented inside the rocket body, against which the solid-propellant engine is fitted". On the 1st firing, the motor ejected instead of the nose cone being fired free. Checking with the manufacturer we (were instructed) to slip a rubber band around the motor and it then stayed in the rocket body and fired off the nose cone so the parachute came free and lowered the unti to the earth. Rubber bands are now used instead of the plastic collar. "

The way I interpret the above was that they used a simple plastic colarr or ring to friction fit the motors into. This obviously is not a real good solution, so they used a simple rubber band to provide a even better friction fit. I guess they had not invented the use of masking tape yet.

I'm sure there are some people reading this that probably have an unbuilt MMI Aerobee-Hi or Arcon stashed away that they could look at and provide pics of the collars or motor mounts used. Or perhaps paper instructions in the kit?

hth

ted: pm me offline ?

terry dean
nar 16158

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"Old Rocketeer's don't die; they just go OOP".....unless you 3D print them.