The original kit didn't have an engine block. I added one, slid down from the top. A glue fillet was added from the top with a long rounded end dowel.
The top centering ring was glued 1/16" from the top.
The instructions have you start gluing the motor tubes at the right side of the engine hook.
With nine tubes total, that leaves one tube centered directly opposite the engine hook. I was concerned if I didn't start in the right place, the tubes may not end up with even spacing on either side of the engine hook.
The seams on the BT-3s were filled with CWF and a shot of filler/primer before gluing onto the mount. It would be impossible to fill the seams after assembly.
I started the first tube directly opposite the engine hook.
With the back end tube ends even, the ends of the small tubes didn't rest against the centering ring. It's probably okay, they will be glued on securely enough. The mount will be recessed inside the main BT-60 tube so the slight open gap against the ring won't be seen.
The other tubes were glued on side by side.
Notice the pencil marks on the back edge of the BT-3 tubes. Each tube was set on dry, pencil marks were made where the contact points and glue line will be.
Those pencil marks were extended down the tubes. A controlled line of glue was applied. It doesn't take much glue as I didn't was excess glue bubbles to show between the tubes.
Though it’s probably a thoroughly bad idea and I don’t think reliable ignition is feasible but how awesome would this model look coming off the pad with ten MicroMaxx motors surrounding the central primary motor? Are non-ejection
ReplyDeletecharge MicroMaxx motors even made?
MicroMaxx NE (no ejection)
ReplyDeletehttps://www.questaerospace.com/Micro_Maxx_Engine_NE_6_pk/p4193205_16860070.aspx
Openroad and Christopher,
DeleteQuest (and other vendors) have a MicroMaxx "No Ejection" motor available. But... these are meant for staging, as booster engines. The ejection charges are removed at Quest. The short 3/4 second delay charge is still there.
The front wall of propellant/delay still breaks through the front to ignite the second stage. These would have to eject (nine small engines raining down) or the gasses vented somehow.
The only way to make this work is if these MMX engines were "plugged" (epoxy?) with no chance of the forward propellant wall breaking through.
When you see a model with lots of small open tubes out the back, most rocketeers would think of a cluster. MicroMaxx engines are slow to ignite, remember bare nichrome wire igniters.
I did try a MMX two engine cluster Dueces Wild once. Only one engine ignited and that was with a 12 volt club system.