SEMROC Marauder Build

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RocketsNorth

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I've had some welcome downtime from work since the start of 2010 which has allowed me time to get at the collection of kits I've collected and not had time to open.
I was very anxious to get at the Marauder kit because this is the first 2 stager I've attempted and I'm looking forward to getting it finished and into the air.

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The one thing I found with this kit that I had not found with the other SEMROC kits I've assembled previously was that everything seemed tight and sanding was required to make the centering rings and coupler fit onto the engine tube.

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So more sanding of the centering rings and the inside of the booster body tube and attaching the shrouds the booster was basically complete.

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And then Disaster Strikes :shock:
After putting the engine mount into the sustainer and allowing the glue to dry I realized that coupler for the booster and the sustainer would not mate properly because I had not tried a dry fit before gluing the mount into the sustainer.

I'm now waiting to receiver the replacement parts from SEMROC to complete the build.

I must say, that the Sales team at SEMROC are awesome and very helpful.

I'll continue the thread once the new parts arrive.
 
Rule of thumb: Always test fit parts BEFORE gluing.


That looks like a nice kit, I've been eyeing it myself, so I'll be keeping an eye on this thread... :cyclops:
 
The one thing I found with this kit that I had not found with the other SEMROC kits I've assembled previously was that everything seemed tight and sanding was required to make the centering rings and coupler fit onto the engine tube.

I found the same held true for the Semroc Thunderstrike I completed last week. The Laser X I am currently working on has thus far, not required any extra sanding. I am looking forward to following your project, I have a Quest Navaho I am working on, but I was looking at purchasing a Marauder here in the not too distant future..
 
I found the same held true for the Semroc Thunderstrike I completed last week. The Laser X I am currently working on has thus far, not required any extra sanding. I am looking forward to following your project, I have a Quest Navaho I am working on, but I was looking at purchasing a Marauder here in the not too distant future..

Hey Steve I too am building a Thunderstrike - just got the first coat of primer on it this evening - and I didn't have any issues with fit on her. :confused2:
 
:Before I continue, I have give a really big thanks to the folks at SEMROC CS, as promised they sent me the set of tubes, rings, etc to continue this build. Awesome, awesome, awesome service :clap:
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So learning from my last mistake, the first thing I did was to pull out the engine tubes and the coupler and spent about 45 minutes sanding the outside of the tubes and inside of the coupler with 320 & 400 grit paper test fitting every few minutes.
Once satisfied, I set the centering rings and coupler on the engine tubes and marked the positions of each as indicated in the instructions.
All pictures from here out are set with the booster to the left and the sustainer to the right.
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Next I dry fit the centering rings and coupler.
A mark at 1/16" was paced on the bottom ring of the booster - this is the final position of the end of the booster BT and is VERY important i have learned.

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Next I slide the booster BT on and aligned to the mark on the bottom ring.
I marked the coupler where the top of the booster BT ended. I did this because it dawned on me that the BT's for the booster and sustainer needed to butt together in the final assembly. According to the instructions the bottom of the sustainer's BT final placement must be even with the bottom of its engine mount, so by marking the coupler I would know it the sustainer engine tube was seated far enough into the coupler for the BT's to butt together.

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Once satisfied that I had everything properly aligned and not overlooked anything, the centering rings and coupler were glued in place and allowed to dry. Then the booster BT was glued in place aligning to the mark on the bottom in the centering ring and allowed to dry.

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Hey Steve I too am building a Thunderstrike - just got the first coat of primer on it this evening - and I didn't have any issues with fit on her. :confused2:

I should clarify my comment a little more. The fit was only a little tight and required a little sanding. Perhaps mine was just one of those "one in a few". Otherwise, it was a nice build and finished into a nice looking rocket. I shot the white on last weekend and am waiting for it to cure-out. Hopefully I can shoot the next color this weekend.
 
it was a nice build and finished into a nice looking rocket. I shot the white on last weekend and am waiting for it to cure-out. Hopefully I can shoot the next color this weekend.

Hi Steve;
You're gonna post some pix when she's finished, right?
I would love to see your work.

Dean
 
Over the weekend I gathered the courage to glue the sustainer motor mount in. To this I used the old Estes technique, cutting a piece of scrap balsa and marking the centering ring measurement onto the stick, then slathering glue around the inside of the BT at the appropriate distance then sliding the mount into the tube.
After a couple of hours I marked the lines for the fins and LL and glued the fis into place.
Tonight I did the fillets. Next is final sanding and begin the priming.
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