I found that a quick filament controlling strap could be easily made by sticking two pieces of blue painter's tape together, along with a light weight (I used a single stick of heavy duty staples I had on my table at that moment.). It works very well and keeps the filament feeding nicely for hours without a problem.
Hi Don. Glad its working out. To fix the filament jumping off (when the spool is new) you can try printing the new filament spool rollers on the download site. Since the spool rolls on bearings (standard 608 bearings from any skate shop) this means the spool turns much slower and reduces that problem. We also flip the spool around so it actually feeds down from back towards the front. After these changes it rarely pops off now.