Interchangable Motor mounts????

[William]

YEA I was just reading, a post were a couple peaple built the big burtha with interchangable motor mounts, and i think that is a great idea, for alot of rockets that i plan to build, like i am starting to build the estes Phoenix, and i would love to build it with A interchangable motor mount, But i have know idea how this works. is ther any one out there with the plans on how to build interchangable motor mounts so I can adapt this to alot of the rockets i build, thanks

 

[Elapid]

with an interchangeable MMT.
also a Goblin upscale, Mosquito Upscale, FatBoy, and Super Big Bertha...

i made the MMTs inside couplers that are 4" long. a short section of coupler acts as a thrust ring, and a hardwood dowel mounted in the MMT allows it to be secured in the rocket by a single screw.

good luck!

 

[wwattles]

Funny you should mention doing it in an Estes Phoenix, as a couple of us have done just that! A search in here for Frankenphoenix will show my version of it. I basically did the same thing that Elapid did, but I friction fit the centering ring.

Here are a couple pics from some of my previous posts.pic 1
pic 2

A few things to watch out for:

1) Phoenix needs a LOT of noseweight when you start clustering it. CP is naturally a fair distance forward, and the clusters make it a lot less stable without extra weight.
2) If you keep the motor exhaust end as far forward as the original design, you run a strong risk of scorching the inside of your centering ring tube. Coat it with some foil tape, and replace it as necessary.


Hope your project turns out well. We want to see pics of a happy you with a victorious Phoenix!

WW

 

[OKTurbo]

I did a plug-n-play motor mount on my BT80 der Red Max project. It will take several different motor combos.

Here is the original thread with build details...
https://www.rocketryforum.com/showthread.php?s=&threadid=7882

 

[Bill]

Originally posted by william
But i have know idea how this works. is ther any one out there with the plans on how to build interchangable motor mounts so I can adapt this to alot of the rockets i build, thanks

Doug Sams is the first person I know to do this. He has an excellent page about it at https://home.flash.net/~samily/better-bertha.


Bill

 

[Micromeister]

The Quickest and easiest way is to make a slide in motor adaptor and/or spent motor casing stop to take up the room above the standard 2.75" long D motors if you build the base motor mount to fit the Longer E9's.
Basic construction is a Bt-20 body tube 2.75" long with 3 - AR-2050 centering rings and a standard estes type motor hook.
Build the adaptor to fit the existing base motor mount with the 3rd centering ring retained by the kit stock motor hook. If the base motor mount is set up for E9's you'll need to cut a spent D motor casing off to take up the space above the adaptor mount. I carry a couple cut spacers, an 18mm and 13mm motor mount adaptors in my range box. If I want to fly a model on a smaller motor I can slip in an appropriate adaptor and away we go
Friction fitting is doable but a bit more of a pain, still using the third ring as the outside stop ring. To go from single motors to clusters is another consturction method but isn't that difficult to do if planned before the model is built.

Motor mount adaptors have been around almost as long as I have. My Old Estes 1/100th Saturn-V Kit came with a single D13 or 3 C6 changable motor mount set up. I've been using 24mm-18mm and 18mm - 13mm motor adaptors since the early 70's good grief!!! What's old is new again... Bell bottoms are coming back also
hope this helps