AT liner problem

I am trying to load a Aerotech I 218 R into a Rousetech 38/360 case. I have used this case four times before with I 218R and I 161 W with no problems. The case was perfectly cleaned after last use. There is no discoloration on case. Fore and aft closures screw right in place. When I went to put the liner in it was tighter than normal. So I pulled it back out and put a light coat of lithium grease on the liner and tried again. (I never used grease before) I got it about half way in and it stopped. So I placed it on the table and pushed it harder it moved about a 1/4" more and will not go in any further. Now I can not get it out (without ruining it) I even tried putting a spent CTI 38 mm cartridge in the case and pushing it out . I won"t budge. The strange thing is that the liner that is sticking out of the case slides right in to my Rousetech 38/720 case.

If the liner is too big for the case, a peel of the outer layer of the liner is in order. Only peel the outer layer, then re-insert until it slides into the case easily. Repeat if necessary. Been doing that for years with AT reloads.....

This is an occasional problem with the paper (not phenolic) Aerotech liners. Apparently there is some overlap between the maximum OD tolerance of the liner and the minimum ID tolerance of some cases. Possibly exacerbated by the liner swelling due to humid storage conditions.

The remedy that suggested by the Aerotech rep who I talked to is to carefully peel the outer glossy paper layer off of the liner, then grease it thoroughly before installing. I've had to do this a handful of times, and haven't had any problems with it.

I have heard of doing that. But I can not get the liner out without destroying it.
And why does it slide into my 38/720 case with no problem? And can I get a liner from Aerotech? (I would'nt want to pay hazmat to return the reload to them.)

You can but paper liners from AT

I would call them and see if they would be willing to send you one for your problem, if not they are for sale on the RCS Products page

jim fustini said:

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I have heard of doing that. But I can not get the liner out without destroying it.

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Try heating the case up with a hair dryer or heat gun while pulling the liner.

And why does it slide into my 38/720 case with no problem?

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Apparently, your 38/720 case has a slightly larger ID. Manufacturing tolerances and all that. The only way to be sure would be to make actual measurements using a telescope bore gage and a micrometer.

And can I get a liner from Aerotech? (I would'nt want to pay hazmat to return the reload to them.)

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Call them up, and I'm sure they will work something out. They do sell the paper liner tubes separately on their RCS rocket motor parts page:

https://www.rocketmotorparts.com/products.html#paperliners

Jim,

Try heating up the case then using your spent motor push the liner out. You may have to alternate between heating and cooling. I had this happen with the liner for a J180.

Thanks Bob, I will try the heat gun.
And I will order a liner if I mess this one up getting it out.

Rocketlady said:

Jim,

Try heating up the case then using your spent motor push the liner out. You may have to alternate between heating and cooling. I had this happen with the liner for a J180.

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Hi Kathy,
I am going to try that. I just strange that this is the first time it happened after using it four times. And I never had any problems with any other AT reloads. Will you be at MIS this Saturday?

The heating/cooling did it. Thank you.

Glad everything worked out.

Like the others have said, paper liners sometimes are a very tight fit and removing the top layer of paper from the tube alleviates this problem.

I flew an I218R myself this past weekend and I didn't have any issues getting the liner in or out.

I will also say that from experience that sometimes the phenolic liners fit too tightly and sanding is the only way to remedy this issue short of contacting AT and requesting a new liner.

I was going to say, it isn't just the paper liners that are a problem. Most AT paper liners I've had an issue with are reloads for the 24/40 and 29/40-120 cases. I did have an issue with the phenolic liner of the first I1299N I flew. Had to sand that a lot to fit the case.

I always have trouble with the 38/480 reloads. I always build them at home where I can use a couple of seconds of light sanding on the belt sander to make for an easy fit.

terryg said:

I always have trouble with the 38/480 reloads. I always build them at home where I can use a couple of seconds of light sanding on the belt sander to make for an easy fit.

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Have you ever taken a measurement of the ID on your 38/480 case?