Need help selecting motors

[boatgeek]

I'm finishing up this year's major project (final sand and paint this week!), so I'm starting to think about next year's project. I want to build a scale-ish Falcon Heavy with drop-off side boosters. By scale-ish, I mean that it should look like the real thing from 10-20 feet away, but doesn't need all of the pipes/landing legs/gingerbread etc. that the real deal has. Nose cone/payload shroud will be 3-D printed, so it should be sorta real-looking. Here are my constraints:

* Probably minimum diameter, although I would consider 24mm or 29mm in 38mm tubes
* Minimum tube size 24mm, maximum 38mm. I don't have space to go bigger, much as I might like to build a 98mm beast!
* I would like "real-looking" motor effects, white to orange flame, white to gray smoke. CTI white or IMax are in that range, but other choices are welcome. On the other hand, there might be a good reason to use a different motor, so I don't want to box myself in.
* Able to fly as a cluster with powered side boosters or just a powered center core
* If the side boosters are powered, they should drop off after burnout. Otherwise, they'll stay attached.
* If side boosters are powered, I would like them to burn out well before the center core.
* I have CTI cases (several 29mm 1 and 3-grain, 38mm 2, 5, and 6-grain with some spacers), so I would prefer to stick with those or go single-use.
* Usual rules for cluster safety apply--the center core has to be able to lift the whole package safely without the side boosters
* I am open to airstart side boosters or cluster ignition on the pad. I have an Eggtimer Quantum that can theoretically at least do airstarts.
* Ideally, I'd like to keep the whole shooting match below 8,000 feet for ease of recovery, tracking, and not having to go to the away cell.
* I'd like powered boosters to come off well within visual range so I don't need more trackers. I have one tracker that can be used on the core.

A couple of thoughts:
all 29mm: F59 side boosters, H87 core. I don't know if this would have enough thrust to get off the pad on the center core alone
29mm + 38mm: F59 side boosters, H110 or I175 core

What do you all think? Do you have other advice?

 

[markkoelsch]

Kevin Trojanowski did a large rocket (delta ?) with powered, drop off boosters. He used drilled nylon screws with an ematch and black powder to release the boosters. From what I recall about the other hardware to attach the boosters you might want to go a little bigger.

 

[boatgeek]

Kevin Trojanowski did a large rocket (delta ?) with powered, drop off boosters. He used drilled nylon screws with an ematch and black powder to release the boosters. From what I recall about the other hardware to attach the boosters you might want to go a little bigger.

I was hoping to make the boosters small enough that they could be held up with a burn string in case of non-firing side boosters and that they could then drag separate after burnout. That is one of the many challenges to sort out going forward.