GoodWeld Lite allows you to weld hundreds if not, thousands of parts in 3 simple clicks! (make sure to group everything before use) You can get the model here: www.roblox.com/library/15416627598 or typing GoodWeld Lite in the toolbox. [make sure to turn on show unverified creators]
THE WELDS MIGHT AFFECT HINGES, AND OTHER CONSTRAINTS.
This model does not use the weld object, but the new WeldConstraint object.
[keep in mind this is only the first version of this plugin and stuff might break, report it in this post, or if you just have suggestions.]