What size charge wells?

I ordered a GiantLeap Vertical Assault. I plan to build it as it comes out of the box, except I'm adding a swivel.

For DD, does anyone know what size charge wells I should get? It's a 3" diameter rocket, but I don't have it yet, so I don't know any other dimensions. Thanks for any advice.

Figure out what size charge you need for the rocket, then use the appropriate size wells.

I would think 1.5-2 grams is at the top end of need, but only you know at this point how many shear-pins [2-256 are about 24lb break strength @] being used, how long cords are and the internal volume being pressurized.

Well, that's the problem. I probably won't see the kit for two or three weeks, so I don't know any of the answers to those questions. Will I need shear pins at all? How long are the cords? How long are the parachute bays? Won't know till I see it.

I was hoping that someone who has one might chime in with some advice so that I can get a jump on ordering my DD system.

You can calculate out the size of the ejection charge roughly online, most online calcs tend to be fairly energetic so this should be reasonably safe. Check the manual for payload bay sizing.

A 2cc charge well (or in my case, centrifuge vial) will hold about 1.8g of powder, a little bit of wadding, and the ematch. This ratio seems to scale quite well in my experience.

I fly a K-ARLISS that is pretty much an all fiberglass version of the Vertical Assault. (We blow the main at the top, then deploy a payload with them, ~9K on a K550.) The largest charge I ever use is 1.5 grams, with two 2-56 nylon shear pins. It hasn't failed yet, with 20+ flights over several years.

I like the little centrifuge vials myself, but the bulkhead mounted charge wells will certainly work, if that's the style you like. Just be sure to pack some dog barf in there to hold the charge packed around the initiator.