This video shows how to cut slots and tabs in Depron using a hotwire and guides. These are the horizontal and vertical stabilizers for the Jupiter Duck. My thinking is that the slots and tabs will add strength to the joint between the stabilizers.
When I cut out the stabilizers I added tabs and slots to make a stronger joint. The bevel on both the elevator and rudder were cut with a hotwire and guides that I made from yardsticks. I shot some video of that process but I haven’t processed that yet. Since Depron has no paper backing to use as a hinge, I needed to get something. A couple of the manufacturers use a 3M product called Blenderm for electric hinge material. So that is what I used. I usually pin the surfaces down when applying the hinge tape. It just makes it easier to apply. Still using those red balsa building pins.
One of the problems with working with foam is making the control surface bevels. Most builders that I have seen on the Internet just use a sharp knife, either x-acto or utility knife; the kind with the break off blades. I have been having good luck using a hotwire to cut foam so I thought that I would try cutting the bevels with hotwire. I made a few hotwire guides from wooden yardsticks that I bought at Ace Hardware for 99¢. The wood is clean and straight. For the Jupiter Duck I made three. One for the elevator, one for the rudder, and one for the bottom of the vertical stabilizer. They are cut at a 45° angle. The original plans for the Duck don’t show tabs and slots for the stabilizers glue joint, but I decided to add them for strength since my Duck is going to be a 200% version. I’ll probably also add bamboo skewers to strengthen the stabilizers. In the pics below I showed the plan template in the yardstick guide to give an idea of what the relationship between them looks like. I have a couple videos in the works to actually demonstrate the process. Stay tuned.
The Jupiter Duck has 8 degrees of dihedral for each wing panel. On the plans it shows the midrib tilted 8 degrees during construction. With the rib tilted there will be a small gap where the rib doesn’t touch the wing surface. So I came up with a way to make a good gluing arrangement. I made a 3 layer midrib, then created a guide from wooden yardsticks such that the midrib is held at the 8 degree angle. If I would have just cut the angle into a single rib, there wouldn’t be much rib left. Probably could have used just 2 ribs. That would have worked fine. Next time. The first picture on the right below shows the part that holds the rib. I used double sided crafters’s tape for that. Then I used a hotwire to cut the angle. Worked great. Took a little experimenting to get here.
I have a Jeep that I take off roading 2-3 times a year. Bought this one just over a year ago. Every so often I do an upgrade. This time it was new alloy wheels. Bought the wheels from Quadratec and had them installed along with new tires at Discount Tire. A link to the Hardrock Wheels at Quadratec is HERE.
Why didn’t I think of this before? Up until now I have been using a plastic drug store protractor to measure various angles on model planes. On the Jupiter Duck it’s 8° dihedral each wing panel, 5° right motor thrust, 4° motor up thrust. You get the idea. This one is available at Amazon. To view it click HERE.
The top panel of the Jupiter Duck powerpod needs to have a double bevel where the back part meets the wing. The sander table is set to 135˚ to do this. I marked the angle from the plans and just held the Depron at that angle. I used a Logan Hole Cutter to make a hole in the wing to allow the motor wires to pass through to the fuselage. Then I glued the powerpod and pinned it to the wing. I let it set overnight. Then I pinned the back end of the top panel to the powerpod. The Depron doesn’t flex very easily so I decided to glue it in two steps. First the part where it meets the wing dihedral. Let that dry overnight. Then glue the front part. I don’t have a picture of that yet. Going well so far. Started work on the horizontal and vertical stabilizers. Should have some pics in a few days.
The Jupiter Duck in it’s original design has a 25″ wingspan. I decided to double that to 50″. So the question came up about what motor / ESC combo to use. The wing without the power pod weighs just under 4 oz. So it’s going to be a light weight. The 200% Ducks that I found on the Internet did not have any information about power. So I decided to try a Park 400 motor. The recommendation is to use a 10-20 am ESC. The Park 400 comes with 3.5 mm bullet connectors while the 10 amp Eflite ESC comes with 2 mm connectors. Now what? As it turned out after a fair amount of internet snooping around I discovered 3.5 mm female to 2 mm male bullet adapters. Bought the last two on Amazon. Almost every 10-20 amp ESC that I found had 2 mm connectors. Just seems like the Park 400 should come with the same size connectors as most recommended ESCs. My 2nd grade teacher, Mrs. Schnitzer, used to say that solving problems make you smarter. They do. Embrace them.
Nearing completion of the powerpod for the Duck. In the pictures below you will see the Logan Hole Cutter that I used to make a hole for the motor wires to pass through. The top view shows the 4˚ right thrust in the firewall. The battery is used for photo purposed to keep the pod from tipping forward. I used blind nuts or t-nuts to help mount the motor. What you don’t see is the bottom of the pod side panels cut at an 8˚ angle to fit for better gluing on the wing. I used a Hot Wire Foam Factory Table to cut the angle. Worked really well. Next time I’ll take some pics.
Thinking ahead to a time when I may need to retrieve the Jupiter Duck from the pond. Love the Internet. I stumbled across this airboat made from Coroplast; simple, cheap. Looks like a fun build. Here is the link to the article on R/C Universe.