AT K560 propellant tight in phenolic liner

[Steven88]

Hello. Yesterday I loaded up an AT K560 into the phenolic liner and the propellant fits very tightly into the liner. It took me pressing my hand down with substantial weight to get both propellents to slide into the liner even after sanding the edge of the cardboard a bit. The further in they got the more friction obviously so it got harder to do. Will this cause an issue or a Cato if the propellant can’t freely up and down slide in the liner? I’ve heard before that it should be slightly loose. I opened another box of K560 propellant and it is looser.

 

[Handeman]

As long as it's positioned correctly in the liner, it shouldn't be an issues. Some motors require the grains be glued into the liner.

You can peel the glassine layer off the outside of the grains if you want them to fit loser.

 

[mikec]

It's fine as long as they're positioned correctly. Sometimes it's necessary to peel a layer of paper off the grains, or sand them, to get them into the liner.

 

[jimzcatz]

I have actually had to slice the grains lengthwise with a razor and peel the casting tube down to when it turns brown. This is very common with Aerotech reloads. Never any issues with my method. I have also had to put the black liners on a belt sander to get them to fit in a case!!

 

[mikec]

If you think you have it bad, I'm putting together an M685 with six grains that all have to be glued together and aligned, and they were all way too tight also. Be nice if these tolerance issues could be addressed, I remember when the grains were actually loose in the liner as intended.

 

[loopy]

If you think you have it bad, I'm putting together an M685 with six grains that all have to be glued together and aligned, and they were all way too tight also. Be nice if these tolerance issues could be addressed, I remember when the grains were actually loose in the liner as intended.

Tolerances coupled with conditions like temperature and relative humidity...it's not all just tolerances. there are lots of factors at play. Sometimes we just have to peel paper.