T E A M
have been flying parkjets for years and its time for a change. Seeing the dlgs at the NTU aerofest 2012 fly like paper dragon flies, i simply want to get my hands on one. Take a quick look at some dlgs availble on the market and wow, they are NOT cheap! Bo bian, i dunwan to make my wallet cry, haha....so build my own~ did some research on the best airfoil to use and selected the HM51. The wings are bluefoam cut along a template with a hotwire cutter
the leading edge is a balsa square stick carved and sanded to shape. The strength of the wing and the solid launch peg comes from a 6mm carbon tube that runs through the entire wing (protrudes out on the side where the launch peg will be) for a real solid launch, i drill a hole through the carbon tube and the launch peg is stuck into the hole and secured with epoxy. The wing's leading edge is den covered with fiberglass, so is the center portion( where the two wing halves comes together ).
Next is to install the ailerons. The balsa ailerons are airfoiled to match the wing's profile.
Ok, now the part where weight saving is really critical....the tail assembly. too heavy means need to add weights to the nose..not something i wanna do....the boom is also 6mm carbon tube. for the tail surfaces i use 3mm balsa, keep it simple. simple = light weight. to install the vert stab, i use 3mm carbon strip on both sides and insert(epoxy) into the tube(boom).
for the elevator, i use a pull spring setup. the mounting pylon is carved out from balsa.
the horizontal stab is epoxied into place and the string for pull spring is pulled through the boom.
The entire tail assembly is only 20g! pretty darn good!
I painted the wing's top with black, bottom red stripes to be highly visible in the air.
Now all thats left is the pod....i use 3mm balsa for this. it is a simple box construction with the front and back soaked in hot water to soften for bending into final shape. Its carved and sanded to shape and covered with monokote.
the hatch is held on with a screw. Since the bottom half of the vert stab will be in contact with the ground quite often and i dont want it getting wet...answer to that, monokote
Now its just assembling all the major parts toghther
the biggest problem i have with this build, how to squeeze everything into the pod =]
One week of building later~ DLG finally completed!
the leading edge is a balsa square stick carved and sanded to shape. The strength of the wing and the solid launch peg comes from a 6mm carbon tube that runs through the entire wing (protrudes out on the side where the launch peg will be) for a real solid launch, i drill a hole through the carbon tube and the launch peg is stuck into the hole and secured with epoxy. The wing's leading edge is den covered with fiberglass, so is the center portion( where the two wing halves comes together ).
Next is to install the ailerons. The balsa ailerons are airfoiled to match the wing's profile.
Ok, now the part where weight saving is really critical....the tail assembly. too heavy means need to add weights to the nose..not something i wanna do....the boom is also 6mm carbon tube. for the tail surfaces i use 3mm balsa, keep it simple. simple = light weight. to install the vert stab, i use 3mm carbon strip on both sides and insert(epoxy) into the tube(boom).
for the elevator, i use a pull spring setup. the mounting pylon is carved out from balsa.
the horizontal stab is epoxied into place and the string for pull spring is pulled through the boom.
The entire tail assembly is only 20g! pretty darn good!
I painted the wing's top with black, bottom red stripes to be highly visible in the air.
Now all thats left is the pod....i use 3mm balsa for this. it is a simple box construction with the front and back soaked in hot water to soften for bending into final shape. Its carved and sanded to shape and covered with monokote.
the hatch is held on with a screw. Since the bottom half of the vert stab will be in contact with the ground quite often and i dont want it getting wet...answer to that, monokote
Now its just assembling all the major parts toghther
the biggest problem i have with this build, how to squeeze everything into the pod =]
One week of building later~ DLG finally completed!
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