High Level Design
The overall dimensions of the ALCM are 14', 9" by a wingspan of 9' 6" - so the half scale version is about 7', 5" and a wingspan of about 5'.
There are two basic ways (okay, there are probably more, but two for me), to build this fuselage. One, is build a plug and do a fiberglass shell - super lightweight and lots of room inside, but on the con side - everything internal is completely custom - bulkheads, center rings for motor mounts, etc. - still probably the lightest approach. The other way is a bulkhead/foam approach - similar in some ways to what I did with the Nike Hercules sustainer, but in a more profound way. Either approach requires custom bulkheads (that fuselage demands it). The plug and shell approach is going to demand a perfect plug to get the sides perfect - so you have to model the bulk of the fuselage either way. Because of this, I have decided on a bulkhead and foam approach, with a carbon fiber and fiber glass covering - a bit heavier, but I can control a lot more about the profile of the thing. This approach also allows me to use off the shelf stuff for MMT (75mm), center rings (birch), motor retention (Aeropack) and recovery (various).
The bulkheads have to be perfectly identical for this to work out. Because of this, I am CNC'ing all the fuselage bulkheads. I will use my personal CNC (Shark HD500) for some prototype work but will likely use a fulfillment shop like SendCutSend for the final parts. The fins will also be CNC'd. I'm still studying the wings, but thinking they have to be 3/8" Carbon Fiber that's CNC'd. Very little hand cutting on this model or the shape warps.
The spine of the rocket will be a 6" Blue Tube that I will section into about 3' pieces to allow for modeling of the aft and mid-portion of the fuselage, using a coupler that will glue the two parts together. The key to this project will be absolutely identical bulkheads that are lightweight, aligned perfectly and not too far apart to keep the continuous surface from breaking down. It's looking like I will have a bulkhead every 6" of so with foam sandwiched between.
It's impossible to model this fuselage with something like OpenRocket, but I can do some approximation to work the wings, 3 fins and bulkhead weights in to get an idea of what it will weigh and where the CP and CG will be. Additionally, as I mentioned previously, the wing unit will be removable to fly with or without them. The wings are a huge drag factor - losing almost 450 feet in altitude when they are attached. Let's face it, there's a lot of drag with the entire fuselage - the air inlet the polygonal fuselage, the change up of the fuselage after the inlet, etc.
This isn't the end-all-be-all design, so don't get overly excited. It's a placeholder to understand some basic dynamics of the model.