improve spray table wheels

[LukasFreeze]

The spray table should be rolled in and out of the building with ease. Some small wheels were attached in a first attempt, but don't do the trick :-(

We could either attach bigger/better wheels on each leg (would need a brake, too!) or go with a wheelbarrel-like design using a single large wheel:

(handles are optional, I hope the idea becomes clear 😆)

[Titan-OX]

I'd do to medium wheels. Around ø120mm.

Also the locking mechanism for the flaps is weak. So maybe a hinge at the top as well with a removable pin (on a string or semi captive) would do the trick

[Johannes09]

Ich habe den Tisch neue Räder verpasst. Zum bewegen muss der Tisch auf der einen Seite hochgehoben werden.