D/E Motor Adapter

[noise]

Not sure this belongs in propulsion, but...

I want to make a motor mount similar to the one that comes with the Estes Big Daddy for another project.

Specifically I want it to be able to accommodate Estes E length motors, but also be able to use D length motors if I want by inserting the adapter ring (essentially just a long piece of engine block).

So my question is, where can I get a piece of engine block to the correct length, or alternately is there something else I could use?

 

[brianc]

Originally posted by noise
So my question is, where can I get a piece of engine block to the correct length, or alternately is there something else I could use?

Cut a section of an expended D or E motor case to the proper length. I usually peel
a layer or two of the outer paper to help with removal.

 

[noise]

Originally posted by brianc
Cut a section of an expended D or E motor case to the proper length. I usually peel
a layer or two of the outer paper to help with removal.

Excellent! Thanks!

 

[loopy]

And the length of that section would be 1 inch.

 

[powderburner]

If weight is a concern you can make your own spacer out of common materials.

Cut a one inch wide strip of cardboard and roll it into a cylinder. Line the inside of the BT50 MMT with a scrap of waxed paper and insert the rolled-up cardboard. Tack the edges of the roll with CA.

If your rocket was already stable with E motors then it should be OK to use a spacer cut from an old 24mm motor case. If the rocket was originally designed for D motors you might want to use something lighter (like a cardboard roll) for a spacer to avoid moving the c.g. too far aft.

 

[hokkyokusei]

Tube coupler of the required size will work too.

 

[KermieD]

Or don't bother with the block and use a tape ring around the motor to keep the D from pushing up into the rocket.

 

[maricopasem]

Originally posted by KermieD
Or don't bother with the block and use a tape ring around the motor to keep the D from pushing up into the rocket.

I second this suggestion. This technique has worked great for me.