Having seen the video of Gordon's 4 ton stone, yesterday, I realised that it fell quite a bit faster than when I modelled it. This worried me a little, so I went through the model and found a bug that was reducing the effect of gravity (pity I can't patent the bug as a new invention). Anyway, I've fixed the bug and there is now an update for the model. You can download it as a zip file, in which case you need to unzip it to C:\\Program Files\\Stoned, or you can download the exe file directly to the same folder without unzipping, take your pick:

http://www.swifttools.com/Update.zip
http://www.swifttools.com/Stoned.exe

In either case you will be asked if you want to overwrite the exisiting file. You should click "yes".

If you haven't yet downloaded the full package, I have updated that too and it's available via:

http://www.swifttools.com/Stoned.zip

Both the height of the tower and the offset can now be reduced quite a bit. This also reduces the loading on the A-frame, which the program also now displays as requested by Gordon.