Uhm, i didnt used tweakscale or other mods i just used stock parts and used the offset mode (2) while building. I attached the engines on an octaconal strut which is placed under the last fuel tank. So i made a new version which is even MUCH smaller but with the same parts as my old model. Actually there are 10 liquid tanks "compressed" into one tank (via the offset mode). The ion tank isnt missing its in the pod . Basicly its a two stage rocket: first stage: ion tank + engine and the unmanned pod second stage: liquid tanks (10) + engines new Height: 1.0m