Jammed AT 29/360 case liner

[Mr G]

Putting together an Aerotech I200W reload and after loading in the grains, placing the forward seal ring and gasket on the end and greasing the black plastic liner per instructions, it stuck about 2 inches in. It took a dowel and a vice to knock the liner back out. After taking everything apart and cleaning it off, the liner by itself was inserted to see if it was the cause of the issue. Sure enough, it would bind up - but only from one end. When I turned it around, it slid in fine for about half the liner distance and then began to get tight.

Anyone have this problem before? Are Aerotech liners inconsistent in outside diameter? The grains slid in fine and there were no burrs or other protrusions. I even sanded down the sticking end a little to see if that helped, but it did not make any appreciable difference in the fit.

I thought I'd check here to see if this is a known issue before I contacted the factory. Anyone been down this road?

 

[jimzcatz]

Sand the liners to fit, happens all the time. I even have to peel paper from grains regularly.

 

[Handeman]

I've only had the problem with Aerotech phenolic lines in my Dr Rocket 38/480 case. It doesn't happen very often, but if a certain friend is at the launch, I borrow his AT case and the same liner will slip right into that case. I believe it has to do with tolerances of both the case and the liners. If it is tight and you can't borrow a different case it fits in, do as Jim says, sand it down until it fits. I usually use 180 grit because it cuts fast and doesn't leave too rough of surface.

 

[Mr G]

The liner that got stuck in the second 29/360 case fit easily in the first case. So it wasn't an issue with the liner. From the serial number nomenclature, it appears the second case was manufactured April 2009 and the first case six months later in October. The anodizing is darker on the second case so maybe is was produced from another vendor who used different tolerances? I would like to think something this critical would be carefully measured and inspected so this kind of problem would not be foisted on the end user who wouldn't necessarily know what to do.

Not much to do about it as there is no longer a manufacturer of this particular product. Thanks for the sanity check guys - sanding the liner it will be.

 

[Kruegon]

I had to peel a liner just last weekend. G77 in an AT case. Wasnt a big deal. It wouldn't go in but about 1/2 an inch. I peeled one layer off and it fit perfectly. No issues in flight or cleaning. Not the first I have heard either. Peeling a layer is actually instructed by AeroTech.