General question on a motor mount (ESTES kit).....

[Re-Bar Ricky]

Hey all - I'm working on rebuilding my Estes Rock-IT kit and I'm using the original plans. For the motor mount, it says to build it so it looks like this -



My question, and it's more for satisfying my own curiosity - why would they have the motor mount built in this way? What I'm focusing on is the position of the two large centering rings. Usually one ring goes towards the front, by the engine hook retainer. The other one usually goes by the end of the hook or the end of the motor mount tube. Anyone know why they would have wanted this large space from the end to the first centering ring? There's no TTW fins or anything. The first one flew just fine so I was just curious....thanks...

 

[dr wogz]

does it have a tail-cone: or some other 'thing' that goes in afterwards?

the other thought, is that the lower one clears the motor retainer clip / is done so that it won't get glued / be hard to open & closed..

As with a lot of design & engineering, one person does it one way, another does it another way. both work, yet both are slightly different..

 

[Re-Bar Ricky]

No tail cone or anything. Just a wide open space.

 

[OzHybrid]

I'd say booster stage.
Took the design from something that had a booster and forgot to update it? It just risks extra damage to the tube end on landing with no ring support. If you're not going to use it for a booster, fit a ring in there. Make sure the hook slot still allows the motor hook to have enough spring to be able to fit the motor.

 

[samb]

Yeah I'd call that an area of potential weakness on that model. The unsupported aft end of the airframe could sustain more than the usual ding and dents in the course of an otherwise normal recovery. I'd be inclined to add a ring with a notch for the motor hook to support that area.

[edit] Good call RSA !

 

[bjphoenix]

Put the second ring towards the back where you think it would go. Put a notch in the second ring to allow the motor hook to be able to move how much it needs to move.

 

[Re-Bar Ricky]

I'm a step ahead.....already did what you folks had mentioned. I set up the rings like I normally would, and I did notch out a spot for the engine hook to be lifted up without damaging it. Gut instinct works most of the time.....

 

[jqavins]

Five of one, half dozen of the other. It won't make much difference, but I agree you made the right call for what little difference it does make.