Estes Citation Patriot 3" Upscale.

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DeltaVee

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So not far away, is a library makerspace with a superb, high precision laser cutter. I upgraded my Great Goblin to plywood parts. With the introduction of the GG and the 3" Der Big Red Max, I thought it'd be excellent to do 3", mostly pro-series parts, and cut the fins/rings myself. I should have shot the parts prior to commencing construction but alas... the motor mount is glued in complete with slotted rings to receive the slotted fins... And a nice ejection baffle built into the tube coupler. The overall airframe length is 33" once it's glued together. My good friend Frank donated the nosecone to my cause and here it is as of right now:

upscalepatriot3in.jpg

The lower airframe is 11.5" long, the main 3" psII airframe being 21.5" long. Of course I could have gotten a 34" long tube from BMS but I have many psII 3" tubes lying about! I had hoped that Estes might get around to offering this as a kit (I suppose an F15 *might* be able to launch this if you went with balsa and cardboard for the rings) but figured it was unlikely any time soon.

I also recently purchased the 4" dia Mega Red Max nose cone which is still for sale... and I understand that it should work well with LOC 4" tubing! BTW the upper ejection baffle plate was sourced from Launch Lab.
 
Fins are TTW, so they transfer almost all the thrust from the MMT to the airframe. Centering rings are mostly just to keep things aligned while the glue dries.

Just nest two BT-20 MMTs alongside each fin so they're glued to the main MMT and the fin. Skip the aft bulkhead, it really doesn't do anything. Leaving the space open vents whatever comes out the top of whatever 18mm motors you fly with, so you can run pretty much any motor, including whatever's cheapest or on clearance somewhere.

For motor retention, you can embed a short piece of threaded rod in the aft part of each fin tab, just far enough out to clear a 1.25-in aft closure on a composite. A flange nut or washer and nut on the end of the three rods will retain any 29mm motor as well as the cluster supplements, if you're running them.

If you have six supplemental mounts, you can always run two, three, four, or no additional motors, depending on what kind of performance you want or need. Maximum flexibility.
 
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Fins are TTW, so they transfer almost all the thrust from the MMT to the airframe. Centering rings are mostly just to keep things aligned while the glue dries.

Just nest two BT-20 MMTs alongside each fin so they're glued to the main MMT and the fin. Skip the aft bulkhead, it really doesn't do anything. Leaving the space open vents whatever comes out the top of whatever 18mm motors you fly with, so you can run pretty much any motor, including whatever's cheapest or on clearance somewhere.

For motor retention, you can embed a short piece of threaded rod in the aft part of each fin tab, just far enough out to clear a 1.25-in aft closure on a composite. A flange nut or washer and nut on the end of the three rods will retain any 29mm motor as well as the cluster supplements, if you're running them.

If you have six supplemental mounts, you can always run two, three, four, or no additional motors, depending on what kind of performance you want or need. Maximum flexibility. Heck, there's probably room in there for nine if you want to get crazy, but that might kinda restrict the ejection charge venting a touch.
All darn good ideas, I must say! But I love working that laser cutter too! It's the BOMB!
 
Leaving the space open vents whatever comes out the top of whatever 18mm motors you fly with, so you can run pretty much any motor, including whatever's cheapest or on clearance somewhere.
This does require being absolutely certain the center motor lights, unless one is running electronic ejection. (I know you know this, just mentioning it for the benefit of those new to mixed clusters.)
 
This does require being absolutely certain the center motor lights, unless one is running electronic ejection. (I know you know this, just mentioning it for the benefit of those new to mixed clusters.)
With my plan of stocking up on F15-4 bulk packs on Black Friday, I have build outlines around wasting the central ejection charge, too.
 
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