Aerotech K1103X with plugged forward closure no anchor

[mpitfield]

I am just assembling an Aerotech K1103X motor, and the instructions do not deal with a plugged forward closure. Do I assemble it as per the instructions, treating the delay grain like a smoke grain, no drill out for time adjusting and obviously leave out the BP? If so, what about the forward delay spacer, will it fit, I am also inclined to grease the forward closure. One other thing I noticed is that the forward closures advertised for sale these days are standard and plugged but threaded? I was going to use my non-threaded, any reason why I shouldn't? I do have the plugged threaded as well, so it's no issue to just use it.

 

[tbonerocketeer]

I am just assembling an Aerotech K1103X motor, and the instructions do not deal with a plugged forward closure. Do I assemble it as per the instructions, treating the delay grain like a smoke grain, no drill out for time adjusting and obviously leave out the BP? If so, what about the forward delay spacer, will it fit, I am also inclined to grease the forward closure. One other thing I noticed is that the forward closures advertised for sale these days are standard and plugged but threaded? I was going to use my non-threaded, any reason why I shouldn't? I do have the plugged threaded as well, so it's no issue to just use it.

Just build like normal, no drilling.you will still use the forward spacer in the same spot.

 

[mpitfield]

Thx Chris. It would be nice if they just included that part in the instructions.

 

[mikec]

AFAIK there's never any assembly difference between a non-plugged closure and the equivalent plugged closure, except you can't put BP in a plugged closure since there's no place for it to go.

 

[woferry]

AFAIK there's never any assembly difference between a non-plugged closure and the equivalent plugged closure, except you can't put BP in a plugged closure since there's no place for it to go.

Not true for some AT 38mm plugged closures, they have a lip at the top that prevents the normal flat washer or delay O-ring from being used. But that's the only difference I've seen. I realize we're talking 54mm in the case of the K1103X.

 

[Flyfalcons]

Just flew a K1103X in a 54/1706 with plugged closure last weekend. What a great motor! Took my 5.5", 16.5lb rocket to 3536'. I thought it would be more of a lob but that motor pushed it with real authority. Yes, be sure to install the forward delay assembly as usual.

 

[DavidMcCann]

I've flown a K805G and K1100T with plugged, non threaded forward closures and built as normal, omitting BP.

 

[mikec]

Not true for some AT 38mm plugged closures, they have a lip at the top that prevents the normal flat washer or delay O-ring from being used.

Really? Which one? There are five 38mm forward closures on the current AT price list (floating, plugged, plugged/threaded, and endburn-style plugged/threaded) and of course the classic non-floating forward closure that no longer seems to be on the price list, and I would expect all of these to be assembly-compatible except the endburn style. Of course there have been a lot of variations in hardware over the years.

 

[mpitfield]

Just flew a K1103X in a 54/1706 with plugged closure last weekend. What a great motor! Took my 5.5", 16.5lb rocket to 3536'. I thought it would be more of a lob but that motor pushed it with real authority. Yes, be sure to install the forward delay assembly as usual.

Well, it lite without issue. Great motor, actually a really nice motor and a must launch again. It pushed my 3" Darkstar (13.4lbs) to 8,270' AGL..." with real authority"!

 

[plugger]

IIRC there are two types of plugged forward closures in 54mm. One is "half height" from a delay grain height perspective, the other is a "full height". Years and years ago we had a guy come from NSW to attempt his L2 at our annual big event. He soon realised his chosen reload delay was half height and yet he had a full height forward closure. He made up the difference by stacking Australian 20 cent pieces in the forward closure above the delay. It worked a treat.

 

[mikec]

IIRC there are two types of plugged forward closures in 54mm.

Yes, standard and extended. The extended is used for various long-burn motors like J90W, J135W, K185W, as called out in the instructions. K1103 uses standard.