I got a BT60 full size Omega some time ago and started building it today, I was so surprised with the problems I ran into.

The Sustainer fins root tabs are off set and only go in the sustainer one way. The Booster fin tabs are centered and the fin can be flipped in either direction.

In may case, both the booster tube (BT60) and the Sustainer tube fin slots are off by about 1/4". In other words, the fins align only about 1/4" over hang below the bottom of each tube.

The other problem, if I follow the instructions, the centering rings that engage the fins want work at the locations shown in the instructions, not even close. The centering rings with fin tabls go near the end of the motor tube tube, just over the end of the E engine hook is which is 3.75" long itself.

Using the booster for an example. It's body tube is 5" long. The fin slots are go up the tube from the aft end 2.75". The Engine hook by itself is 3.75", putting the aft Center ring with slots over 1" away from the fin tabs.

Same is true with the sustainer motor mount to.

Look at page 4 step 14 and notice that the forward centering ring with fin tab locks is about 3.50" back, with the engine hook flush with the bottom of the booster tube. The slot only goes to 2.75" max. The centering ring is over 1" to far up.


I can work all this out, just wondering if anyone else has built one of these and have run into these problems?

Attached Files

Omega.pdf (1.97 MB, 26 views)

__________________
=======================
If the Sky is the Limit, then,
why is there Footsteps on the Moon?
=======================

The way I look at it the fin slots in the centering ring are only so you can push the engine mount in place with the fins already glued in place. It basically provides clearance for the fin tabs. You push the engine mount in until the bottom ring touches the fin tabs.

__________________
www.BRSHobbies.com - Full line of model rocket products! Free shipping offer! No backorders or delays!

Ok, makes sense, guess I’m use to centering rings and through the wall fins working together.

Still leaves the fin slots at about 1/4” off.

Guess I’ll have to rework them and double check centering ring location before gluing them down.

Thanks!

__________________
=======================
If the Sky is the Limit, then,
why is there Footsteps on the Moon?
=======================

Another possible problem you may encounter (if this is the Semroc fullsized Omega) is with the "OMEGA" body tube decal. I found that it HAS to be coated with liquid decal film or the image will disintegrate in water. The fin decals are OK and I didn't have to coat them.

I don't know if all of the Omega body tube decals had this defect, but mine did.

__________________
Never trust an atom. They make up everything.

4 out of 3 people struggle with math.

Chemically, alcohol IS a solution.

NAR# 94042
SAM# 0078