18mm motor adapter

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Screaminhelo

Screaminhelo

Shade Tree Rocket Surgeon
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I can't find the reference that I remember so I figured I'd run this by the forum.

I am planning on making some 18mm adapters for a 24mm mount and I remember seeing a reference that was 2 pieces of tube with a block in 1 end of each and a couple of centering rings that simply slid in place of a 24mm motor and used the existing retainer. I thought that I saw it on the Apogee site but I can't find it now. Does anyone recall this? It seems pretty simple and I'll likely go ahead with it, even if I can't find the reference but it would be nice to see if I am forgetting something.
 
I posted a couple of pic here for a 24 to 29mm adapter. Same principle but use 18mm tube and 24mm centering rings. The washer keeps the adapter from spitting out through the center of the retainer

https://www.rocketryforum.com/showpost.php?p=651967

You could also make something like these:

ImageUploadedByRocketry Forum1408504483.060636.jpg

Hope this helps
 
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The easiest cheapest adapter is a spent 24mm motor IE, a "mini" will fit in a C, A "C" will fit in a "D". Tape thrust rings and friction fit, you are all set!!
 
Free, yes (while the reusable Estes adapters are about $2 each - the price is for a set of three). But easier - no. All you have to do is drop the 18mm motor in one half of the adapter and then close it up with the other half, and insert in your motor mount as if it were a 24x70mm motor. After the flight, pull it out, open it up and toss the spent motor. It's then ready for another.

When using the next size up spent motor as an adapter you have to knock the nozzle out and often clean up the rest of the bore, then fight to get the motor you want to adapt into it. Afterward the whole assembly must be tossed (or fought with to get apart), so you need another larger spent motor to adapt the next smaller one. The old casing method is also heavier at the wrong end of the rocket....

That said, I've done it that way and I know it works. But now I use the Estes 18-24 adapters and also the 13-18 adapters. Much faster/easier and always on hand in my field box.
 
jimzcatz said:
My idea is free!! I am sure you cane come up with a spent motor,plus they are thick walled.
Click to expand...

Although extremely thrifty, this may not be the best idea. Thick walled means heavy... not the best thing when you are adapting down to motors with a mostly 4oz. maximum liftoff weight....

I thought I too remembered seeing an Apogee video.. but maybe it was this issue of their newsletter some years ago on a "clipless" adapter.

https://www.apogeerockets.com/downloads/Newsletter227.pdf

Jerome :)
 
BEC said:
Free, yes (while the reusable Estes adapters are about $2 each - the price is for a set of three). But easier - no. All you have to do is drop the 18mm motor in one half of the adapter and then close it up with the other half, and insert in your motor mount as if it were a 24x70mm motor. After the flight, pull it out, open it up and toss the spent motor. It's then ready for another.

When using the next size up spent motor as an adapter you have to knock the nozzle out and often clean up the rest of the bore, then fight to get the motor you want to adapt into it. Afterward the whole assembly must be tossed (or fought with to get apart), so you need another larger spent motor to adapt the next smaller one. The old casing method is also heavier at the wrong end of the rocket....

That said, I've done it that way and I know it works. But now I use the Estes 18-24 adapters and also the 13-18 adapters. Much faster/easier and always on hand in my field box.
Click to expand...

You are seriously over thinking this. While I admit to absolutely no experience with the Estes adapters, I didn't know how cheap and easy they are to use. About the spent motors, I use mine over and over. You don't have to remove the nozzle, just enlarge the hole for ejection. Makes a great motor block. If you have to force the motors in and out you haven't cleaned the adapter enough. With all that said, I bow to the ease and cost of the Estes system . Thanks for the info.
 
jimzcatz said:
You are seriously over thinking this. While I admit to absolutely no experience with the Estes adapters, I didn't know how cheap and easy they are to use. About the spent motors, I use mine over and over. You don't have to remove the nozzle, just enlarge the hole for ejection. Makes a great motor block. If you have to force the motors in and out you haven't cleaned the adapter enough. With all that said, I bow to the ease and cost of the Estes system . Thanks for the info.
Click to expand...

Jim:
While using Spent motor casings is the Cheapest way to adapt 13 to 18 and 18 to 24mm BP motors they also add a good amount of unnecessary mass that can be almost as easily avoided by buying or Making from our own scrap these little motor adaptor mounts that are reusable and much lighter:) I've been using the same two 24-18 adaptors since the early 90's still working just fine today.
Both Idea are perfectly fine.. but spent casing do cost a bit of altitude and are a bit harder to secure in the model. Giving all the Options to the OP is what this forum is all about. He/She can make up their own mind which way best suits their flying;)

24mm to 18mm motor adapters-sm_3-ring_02-10-90.JPG
 
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Micromeister said:
Jim:
While using Spent motor casings is the Cheapest way to adapt 13 to 18 and 18 to 24mm BP motors they also add a good amount of unnecessary mass that can be almost as easily avoided by buying or Making from our own scrap these little motor adaptor mounts that are reusable and much lighter:) I've been using the same two 24-18 adaptors since the early 90's still working just fine today.
Both Idea are perfectly fine.. but spent casing do cost a bit of altitude and are a bit harder to secure in the model. Giving all the Options to the OP is what this forum is all about. He/She can make up their own mind which way best suits their flying;)
Click to expand...


Agreed on all parts!
 
Microomeister- You hit the nail on the head my friend! I knew that even if no one had the reference that I was looking for, there would be lots of 'this is how I do it' offered. One way or another, I knew a solution would present its self.

They spent motor casing is one that I will remember for when I forget the adapter.

I do like the Estes product, but my LHS only has 13-18 adapters. I know that I can order them, but I have a bug to build it. My idea is similar but the adapter will be 2 short tubes instead of splitting down the length. When the parts arrive, I'll document the process and post it for critique/inspiration.

Thanks for all of the replies. If someone has any more ideas, I am here to learn.

edit
Jerome- I somehow missed your post, that is exactly what I am looking for!
 
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