Go job, I like it!!! If there is a plan to put four SRB"s on the real one, I bet a model with four SRB's would fly without fins, especialy if the rocket where lengthened a little. I've done it lots of times.
Nope, there won't be any four SRB boosters using shuttle size solid rockets out of KSC... I know I've seen proposals for them several times, even pics of 3 SRB proposals, but none of them are realistic... total pie in the sky thinking...
When Ares V was still being developed, it went from 4 segment shuttle type boosters to 5 segment Ares I type SRM boosters... the weight of the two additional segments is quite substantial. Ares I problems pushed more of the lunar stack mission weight onto the Ares V, which needed additional performance to lift the additional mass... so the SRB's were increased on Ares V to 5.5 segment boosters (each segment is made up of two smaller segments, joined together at the factory in Utah after the propellant is cast into them, then these joined segments are shipped individually to Florida by rail and stored in bunkers at CCAFS, and moved over to the VAB at KSC for assembly into the shuttle or rocket stack-- these segments are joined together at the "field joints" between the segments-- the other joints are locked together at the factory. The 5.5 segment boosters would have added an additional "half segment" to the top of the booster for additional thrust over the standard Ares I type five-segment boosters). The addition of an extra "full segment" mass (two half segments, one on each of the two Ares V boosters) plus the additional mass of the Ares V's larger planned 10 meter (33 foot diameter) core (versus the SLS "shuttle size" 8.4 meter (27.5 foot) core) and six RS-68 engines was enough to max out the weight that the VAB floor, crawler, and crawlerway could support... plus the additional mass of the launch platform. It was also rapidly approaching the limits of the pads themselves and what they could support. There was even talk of going to SIX segment boosters for Ares V since more performance was needed, but it was completely unfeasible, without COMPLETELY reworking the VAB floor, crawlers, crawlerways, and pads that would support the massive stack during assembly, movement out to the launch pads, and hold them for launching... which would have been prohibitively expensive and was a non-starter.
The Russian Buran shuttle launcher, the Energia rocket, used four boosters, but the Russians use LIQUID rocket boosters, not solid rocket boosters, and unlike solid boosters liquids are moved to the pad EMPTY of propellant and fueled at the pad, whereas the solid boosters are moved fully fueled from the VAB, making them EXTREMELY heavy. Therefore NO more than 2 SRB's (at least when we're talking about large SRBs like the 146 inch diameter shuttle-size SRBs) can be supported with the infrastructure at KSC. Liquid rocket boosters would be a totally different story, just as with the Russian Energia.
Now, there were also proposals for Saturn V variants back in the late 60's that would have added four solid rocket boosters to the sides of the Saturn V. These proposals, however, would have had the Saturn V stacked on the MLP in the VAB as was normally done, and then moved to the pad via crawler. Then the crawler would have brought in a new piece of equipment that would have sat on the pad, equipped with cranes and equipment to stack and attach the solid rockets to the sides of the Saturn V as it sat on the pad... the solid rockets themselves would have been moved out to the pad via the crawler one at a time (or in segments, depending on the solid rocket design). Therefore the crawlers and crawlerways and VAB floors would never have had to bear the full weight of such a massive stack of solid rockets and the core Saturn V. (the pads would have had to been beefed up, however, as well as the new solid stacking facility built to be transported to the pad via the crawler, and hauled away by the crawler before launch after attaching the solid boosters to the Saturn V.)
For these reasons, any "four SRB" proposals are pure fantasy, at least for NASA rockets out of KSC...
As for adding more SRBs to the Dr. Zooch SLS kit and it being stable without the flame fins, in a word-- DON'T. It won't be stable. The Dr. Zooch kits using flame fin units are designed specifically to use the flame fins as instructed to remain stable and fly stably.
Later! OL JR
