Working on an osprey at the moment, are there any other ways to anchor kevlar cord without gluing it to the MMT? Smaller U-bolt or eye?
You still have to be careful though because you can't put a quick link on it
You mean you cannot use a quick link directly on the eye-bolt. But obviously you can use the quick-link to connect your harness to the other end of the Kevlar with the loop, which is what I do on my Darkstar, and if I ever finish my Pain Killer I will simply do the same thing. The point being that your completed assembly, as is and used as intended, is a possible solution for this build.
Reason for not wanting to glue harness to MM?
Got rockets 12yrs old with hundreds of flights and harness still fine.
So much simpler than fighting ill fitting hardware in tiny space.
I've never broke one, but have burnt one to a crisp when front closure blew off.
Just used small section of coupler to make new harness sandwich ....slide into airframe... down onto top of CR. & glue.
View attachment 320179 View attachment 320180
View attachment 320181
I suppose it would be quite simple to make it removable if one desired such.
Reason for not wanting to glue harness to MM?
Got rockets 12yrs old with hundreds of flights and harness still fine.
So much simpler than fighting ill fitting hardware in tiny space.
I've never broke one, but have burnt one to a crisp when front closure blew off.
Just used small section of coupler to make new harness sandwich ....slide into airframe... down onto top of CR. & glue.
View attachment 320179 View attachment 320180
View attachment 320181
I suppose it would be quite simple to make it removable if one desired such.
Maybe your hardware is ill fitting Jim,, I don't know..
Mine most definitely isn't...
When I make up a short attachment harness to a stainless welded polished eye,,
it fit's in this application like it was meant to be there,, perfectly...
( yes, you have to grind a sixteenth or so off both sides of the flat washer)..
My method is neat and clean and looks and works like it was manufactured to be...
If you like your glue method that's fine,, more power to ya..
I like every single aspect of my method better, bar none...
Teddy
I'm not as smart as Crazy Jim, but I figure there's no point in using an eyebolt if the body tube is too small for me to reach down in there and undo a quicklink or whatever. For me, this means the rocket has to be at least a stubby 4" rocket or larger. Everything else gets a Y harness against the motor mount tube.
I bent a piece of music wire to get down a body tube and through an eye deep in there
Reason for not wanting to glue harness to MM?
Got rockets 12yrs old with hundreds of flights and harness still fine.
So much simpler than fighting ill fitting hardware in tiny space.
I've never broke one, but have burnt one to a crisp when front closure blew off.
Just used small section of coupler to make new harness sandwich ....slide into airframe... down onto top of CR. & glue.
View attachment 320179 View attachment 320180
View attachment 320181
I suppose it would be quite simple to make it removable if one desired such.
With that in mind, I would like to pose a question to all. Maybe it could help both the OP and me with additional options. Do you think it would be possible to take CJ's concept, apply it to FG components, and possibly expand on it to make the assembly removable? I was thinking of using t-nuts so that I could slide the assembly into the airframe and hold it in place with 3 screws through the airframe which would give the option of removing it and plugging the mounting holes in the airframe when I wanted to use plugged motors. Are there any solid reasons that you could think of why this would not work?
Sounds like there are many paths to rocketry shock cord nirvana.
Follow the path with heart and makes you happy.
Teddy can you post a pic of your setup?
My reasoning for not gluing harness to MM during the build is because it is a 2.6" airframe and 54 mm MM. The CR is less than 5 mm thick.
Eyebolts can fit in tight spaces. You can use a shock cord anchor ahead of the motor or a threaded forward closure and connect right to the motor as well. Though that last option removes motor deployment as an option.
or a u bolt thru the top centering ring (offset so it wouldn't stop a motor tube from being passed by it)
I have used a U-bolt through the centering ring for 3" w/54mm mount. The only downside is that I cannot reach to replace the harness using this method.
got a picture of the u-bolt or where you got it?
With that in mind, I would like to pose a question to all. Maybe it could help both the OP and me with additional options. Do you think it would be possible to take CJ's concept, apply it to FG components, and possibly expand on it to make the assembly removable? I was thinking of using t-nuts so that I could slide the assembly into the airframe and hold it in place with 3 screws through the airframe which would give the option of removing it and plugging the mounting holes in the airframe when I wanted to use plugged motors. Are there any solid reasons that you could think of why this would not work?
Cheers,
Michael
View attachment 320178
I had Teddy @ one bad hawk, make me up several short pieces of Kevlar with a loop on one end, to attach to the recovery harness, and a stainless welded shut eye-bolt sewn into the other end. I use a double upped forward centering ring to anchor it to. I have this setup on two 3" rockets with a 54mm airframe, my 3" Darkstar and my 3" Pain Killer, that I really need to finish. Here are some pics of the Pain Killer, Darkstar is the same setup.
![]()
![]()
![]()
![]()
Thank you Michael..
This is exactly the reason I carry the 3/16" welded stainless eyes...
You still have to be careful though because you can't put a quick link on it..
If it's a 54mm mount in a 3" airframe then the link will stop the motor case from coming up past it...
.
Teddy
Yep,,
For sure..
There are two configurations this works great for..
A 54 in a 3"..
And a 38 in a 2.6"...
I'm not certain it will fit in a 38 in a 2.1"....
Teddy
Reason for not wanting to glue harness to MM?
Oh man,,
Thank you Tony,,
Tim,,
As soon as you posted that I emailed 2 people to give
to give me the measurement from the top CR to the top edge of the booster...
I was going to make 2 of them and take a pic to post,,
but neither of them got back to me yet...
Yep,, that's the idea Tony..
How do you like that set up ??
Teddy