Boys and more of their toys: HARVee update
Posted: 2004-05-04 02:56pm
I don't know if anyone here has heard me bitch and moan about Arizona State's High-speed Autonomous Rotorcraft Vehicle (sorry about the truly asstastic website). Anyway, we're getting ready to attempt tethered hover in a few weeks, and it was realized that the computer case has cooling air intakes, but the fuselage did not. So I got the task of making a ram-air cooling system to get air to the computer so it doesn't melt in the damned Arizona sun.
Top view of HARVee - these pictures are pre-cooling air intake
So anyway, the ductwork. I hacked out a hole in front with a Dremel and epoxied a few pieces of basswood to hold the thing together.
Top view of the area of interest. Aluminum box is the computer case, the nose is to the left . Just visible is the edge of the cutout.
Foreward view. Visible is the ram-air intake and the computer in the rear. The guy who did the box is a EE, so notice the pain-in-the-ass design of the cooling air intakes into the computer box. Three long, narrow slots. Real fun to run ducts to those, as opposed to nice round holes.
Another shot of the computer air intakes and the nose intake. Visible through the bottom of the hole is the computer battery in the extreme nose. On top of the computer case is the 802.11b hub we're currently using for communications.
Blurry shot of the inside of the nose. Notice how little room there is to construct the foreward part of the duct. That battery must be removable.
So at this point, I had to construct a fixed duct and a removable part. I built the fixed part first out of cardboard and basswood. Note I had to go from a complex curved inlet to a rectangular hole in about 2-3" of fore-aft space. Compound curves in cardboard can bite me.
Fixed part of the inlet duct complete and epoxied in, pre-fiberglass.
Foreward view of the duct and fixed inlet. Inlet duct has been glassed in at this point. Foreward duct is essentially complete.
So, then it was time to built the removable duct. This promised to be a huge pain, because I had to route air into those little tiny narrow slots. The entire duct had to be easily removable and essentially airtight, and above all LIGHTWEIGHT.
Removable duct in progress. Cardboard construction, held together with wood glue (the electrical tape is to hold the thing together while the glue cures)
Duct complete. Big aluminum tube sticking out of the fuselage is the spar.
Duct complete.
The whole shebang: duct in place with computer. Visible through the aft access cover is the mount for the boom and the pitch fan motor.
I need to rebuilt the removable duct, and it's about 20% done. Being built in lightweight plastic sheet this time (the kind cheap three-ring binders are made of). This should be lighter, more airtight, and much more flexible. This will make installation easier: right now, getting the duct in and out really sucks.
Top view of HARVee - these pictures are pre-cooling air intake
So anyway, the ductwork. I hacked out a hole in front with a Dremel and epoxied a few pieces of basswood to hold the thing together.
Top view of the area of interest. Aluminum box is the computer case, the nose is to the left . Just visible is the edge of the cutout.
Foreward view. Visible is the ram-air intake and the computer in the rear. The guy who did the box is a EE, so notice the pain-in-the-ass design of the cooling air intakes into the computer box. Three long, narrow slots. Real fun to run ducts to those, as opposed to nice round holes.
Another shot of the computer air intakes and the nose intake. Visible through the bottom of the hole is the computer battery in the extreme nose. On top of the computer case is the 802.11b hub we're currently using for communications.
Blurry shot of the inside of the nose. Notice how little room there is to construct the foreward part of the duct. That battery must be removable.
So at this point, I had to construct a fixed duct and a removable part. I built the fixed part first out of cardboard and basswood. Note I had to go from a complex curved inlet to a rectangular hole in about 2-3" of fore-aft space. Compound curves in cardboard can bite me.
Fixed part of the inlet duct complete and epoxied in, pre-fiberglass.
Foreward view of the duct and fixed inlet. Inlet duct has been glassed in at this point. Foreward duct is essentially complete.
So, then it was time to built the removable duct. This promised to be a huge pain, because I had to route air into those little tiny narrow slots. The entire duct had to be easily removable and essentially airtight, and above all LIGHTWEIGHT.
Removable duct in progress. Cardboard construction, held together with wood glue (the electrical tape is to hold the thing together while the glue cures)
Duct complete. Big aluminum tube sticking out of the fuselage is the spar.
Duct complete.
The whole shebang: duct in place with computer. Visible through the aft access cover is the mount for the boom and the pitch fan motor.
I need to rebuilt the removable duct, and it's about 20% done. Being built in lightweight plastic sheet this time (the kind cheap three-ring binders are made of). This should be lighter, more airtight, and much more flexible. This will make installation easier: right now, getting the duct in and out really sucks.
