The DG 650 is an indoor, lighter than air, radio controlled, rigid airship. If you'd like to build one you should first understand what it takes. What it takes.
Being rigid, it cannot be folded up and stored like a blimp or deflated balloon. If you have a storage problem, consider this. Further, if you want to take it anywhere, plan on building a box or something big enough to transport it. They are fragile to some extent. There is also a space commitment. See Transport and Storage for a discussion on this topic.
The DG 650 plans are based on a 13.5 foot long, 26 in. diameter fuselage. The plans are not specific about what size you have to build though. It is not difficult to build as small as 9 feet in length by sacrificing payload and range, or as large as 16 feet, based on the plans. The plans consist of 32 CAD drawings and a 22 page builders manual. Click Order information for how to obtain a set of plans.
Smaller than 9 feet and you will really have to struggle with the limitations of ultra lightweight components, any larger and you will run into structural rigidity problems.
The shape of the DG-650 is similar to LZ-2, having a constant circular section for most of the length, with a rounded nose and tapered tail section. The tail is cruciform with a steerable rudder. It is powered by four geared electric motors driving 3.5 inch diameter propellers. It is very maneuverable and a semi seasoned R/C pilot will be able to dock to within a few inches after just a few flights. The motors are fully throttleable forward and reverse.
Unlike most R/C building, RC dirigibles are not a crash and rebuild sport. The DG-650 has been flying for more than four years. The flight qualities are superb and quite different than blimps. Certainly they are nothing like an airplane or helicopter!
Some leading particulars about the DG 650 as I have built it:
Length 13.5 feet (4.1 meters)
Diameter 26 inch (.66 meter)
Volume 37 cu ft (1.07 cu m.)
Gross weight empty 650 grams
Payload (demonstrated) 110 grams
Motors 4 geared electric 3400 prop RPM CW / 3400 prop RPM CCW
Cover 0.001" alum mylar
Lofting medium Helium
Battery 350 mAh 3.6 Volt Battery
Max Speed 5 MPH
Flight duration :15 min - ? longer than you want to
Radio 5 chan. (Four channels used)
Pulse width Modulating Speed controllers West Coast Blimps and Electronics.
With average building skills the DG can be built in about 2-3 weeks.
How does it fly? Well... It can be parallel parked. It's not a blimp. It flies very purposefully. You can establish a deck angle on climb out using dynamic lift and a thrust component. This maximizes the dynamic lift of the body. It is very stable in cruise. It is not as maneuverable as a blimp, due to its size. I admit the vertical fins could be smaller. Sometimes I fly without the upper vertical stabilizer. It will complete a 180 degree turn at cruise with a 30-40 foot diameter circle.
The second most fun you can have indoors!