Strong 1kg Spool Holder

This is an update of the 1kg Spool Holder for he UP printer, here:
thingiverse.com/thing:20898
On the original the weight of the spool could cause the upright to bend slightly. So I've shortened the barrel by 5mm because the spool tended to drift out, increasing the twisting of the upright. I've also strengthened the upright by adding 3 ribs. Finally I made the barrel solid so I could print it raftless and supportless.