PML Quasar Build Help

[Rob Campbell]

This past weekend, I picked up a PML Quasar kit from Chris Short at the monthly SEARS launch. I didn't realize it's a 2.5 inch diameter rocket with a 54mm motor mount.

I opened the kit today to start the build and realized the kit and the instructions don't match. Like many PML kits, the instructions call for passing the shock cord anchor under a notch in the upper centering ring and securing it to the side of the motor mound rube by saturating it with epoxy and gluing about 4 inches to the tube. I did this on my Tethys with no issues.

The issue the issue I ran into is given the length of the root edge of the fins if I epoxy the middle CR in place, it's very close to the upper CR to provide for gluing 4 inches to the side of the motor tube. My question is, should I cut a piece out of the middle CR or look at an alternative method to attach the shock cord tether?

 

[tsmith1315]

How close together are they?

 

[Rob Campbell]

How close together are they?

About an inch and a half, maybe 2 inches.

 

[tsmith1315]

The first one… well, only one I did that way I wrapped tight with a solid layer of nylon cord (1-2mm) with epoxy. Done in one session. I’d never seen it done and wasn’t sure how it would hold up.

Later RUD of the can showed that it was a very stout anchor. I wouldn’t hesitate to repeat that for a 2” section, on a rocket that size, but I might add a second layer. Hence not cutting the middle CR.

 

[loopy]

I see no issues with shaving a groove into the center CR for the cord and build it that way, personally.

 

[Donnager]

I'd either shave a groove in the second, or tie the tether in a loop below the top ring, with a slip knot or something similar.

I'd probably do the latter, and then coat/smooth the tie/knots with epoxy.

And then not worry about it.

Be sure if there are fins that go in that area, that you leave clearance for them, or you locate the knot so that it isn't an issue.