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Jun 12, 2015, 05:52 PM
titoplane
Thread OP
Discussion

BMJR Sioux build


Hello Guys
I decided to do a build of the BMJR Sioux, After taking a good look at the plans and reading of the assembly instructions I have a good Idea of what I`m going to do. I will make the plane a 3 channel with Rudder ,elevator and throttle. I will give the engine 2 degrees of right thrust. I`m not going to use the wing platform and will reinforce that area to have access to radio and gas tank also will be able to move battery and receiver for a good center of gravity. I will be using a Cox surestart engine with the carb sold by Cox international. Covering will be plastic film in some aereas and paint in others.
I liked that all the parts came in sealed plastic bags But when I started the build I realized that I was missing the firewall doubler and landing gear doubler. This parts are 1/16 of an inch and have to be laminated to be strong enough. I called BMJR and they are sending the missing plywood parts In the mean time I decided to make the doublers out of 1/16 ply I had. I laminated the parts with Devcon 30 minute epoxy.
The fuse sides are spliced as they came from BMJR I guess the laser cutter he has can`t cut it in one piece. I glued the pieces together with Titebond. I`m not going with the airfoil elevator,so I used my Exacto knife and cut the slot straight on the bottom and glued the piece to the top to have a straight slot for the elevator. I made the hole in the Landing gear doubler 3/4 of an inch longer for better access to the gas tank,I want to be able to take it out without having to do surgery.
I `m going to be using a Cox Surestart.049 and to mount it to the firewall I made aluminum standoffs And I will be using 2-56 allen screws with blind nuts. I took the engine backplate off to place the needle valve up with an inverted engine. Took out the needle valve and turned in the lathe to make it thinner and I bent the tip. I`m going to be placing photos but It will not be a step by step thing. Here are some pics.
Juan
Last edited by titoplane; Jun 14, 2015 at 06:45 PM.
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Jun 13, 2015, 08:23 AM
Hey, watch this!
Raymond-leflyr's Avatar

Decisions, decisions


I've been "eyeing" the Sioux for a long time - but I was dithering between glow and electric power (yes, I know - so Sioux me). I'm gonna watch your project and see if it tilts the scales for me.
Jun 13, 2015, 11:38 AM
Rudders are overrated
The_LeadingEdge's Avatar
Quote:
Originally Posted by raymond-leflyr
yes, i know - so sioux me
puns!
Jun 13, 2015, 11:38 AM
Rudders are overrated
The_LeadingEdge's Avatar
I like those standoffs, they make a nice mounting system. Did you make them yourself?
Jun 13, 2015, 01:39 PM
titoplane
Thread OP
Hello Guys
I made the engine stand off from 1/4 inch 6061 round aluminum in my lathe the are 7/16 inch tall. I wanted to move the engine away from the firewall because I will be using a carburetor. I worked on the plane last night and glued the sides to all the bulkheads with CA and the gear bulkhead and firewall with 30 min epoxy. I assembled it in a jig I have for building fuses and wings. I wanted to make sure I have a straight fuse. I haven`t glued the top side of the fuse because I want to star installing the servos and want to build a tin gas tank and fit it to the nose. I like to make things removable in case of a problem,I hate doing surgery on airplanes. I glued a piece of 1/8 x 1/4 balsa to the fuse top to reinforce the area that is going to be the wing saddle since I will not be using the wing platform. I want access to the insides of the fuse. Today I will work on the tail feathers will post more pics when I`m done.
Jun 14, 2015, 08:18 AM
Registered User
Attached are photos of the Sioux I built from plans given to me by Joe Wagner. I was not satisfied with the original setup using a single channel pulse system and a DC Dart diesel. I installed a Cox .049 but it had too much power. Now set up as 3 channel electric it flies easily. I would lighten it and power it with a throttle sleeve PeeWee .020 if I build another.
Jun 14, 2015, 08:29 AM
EB-66C Team Member
xplaneguy's Avatar
And it was a fun model to fly!

Thanks LittleRock!
Jun 14, 2015, 12:09 PM
titoplane
Thread OP
Hello guys
LittleRock thanks for posting those beautiful Sioux pictures, I saved them in my computer. When I was googleing for Sioux pics there not many to look at and get ideas. I worked a little bit on my plane and took F-1 and laminated it with 1/64 ply on both sides to be able to sand it to an arch shape to have access behind the firewall for a gas tank. I saw on the internet a beautiful red Sioux and noticed that it had a full depth rudder, I took a look at my plan and modified it for it. I chopped 1.5 inches from the back of the fuse,but before doing that I glued a 1/16 ich wedge tail post to keep it aligned. I decide to work on the elevator but when I got the parts together there was a bow in the gap so I proceeded to true both parts. I have a 2 inch x 17 inch aluminum angle with sandpaper on one wall (100 grit) and masking tape covering the other inside angle that I use to true parts I`m going to join. The elevator is 3/32 and kind of hard to hold and sand so I placed 3M double sided tape on 3 of my fingertips and had no problem sliding the balsa until it was true. Then I glued both elevator halves and placed some weights on it to keep it flat until the titebond cures. As weights I use 2 liter windex refill bottles full of water. I made a Servo mount with provision for a switch and is already glued in place. thanks for your replys.
Juan
Jun 16, 2015, 12:28 AM
titoplane
Thread OP
Hello Guys
I did a little work on the Siuox tail feathers today. I made a new rudder because I didn`t like the wood that I got from the kit. I went to the hobby shop and bought some 3/32 balsa. The elevator wood looked fine but I cut the tips to place some cross grain wood to prevent warping with age. I sanded the leading edge on the elevator and rudder with a sanding form I made to have a nice round shape.The sanding form I made makes sanding the edges a piece of cake. I made it out of a 3/16 center with two 1/8 inch wood on the sides then I cut a 3/8 inch strip of 400 grit sanding paper,which I form into a U shape using a round piece of wire. I place it in the slot on the form and then I place a couple of layers of masking tape on the inside of the slot to keep balsa part centered and to avoid sanding a step on the part. I always make sanding forms to make life easier. I also made a wire joiner for the elevators since I don`t like to use a wooden dowel because is easy to break the balsa to the dowel joint. Here are some pics.
Juan
Jun 16, 2015, 02:54 AM
Nitro User
1/2A Nut's Avatar
Looking good Juan!
Jun 16, 2015, 03:57 AM
Registered User
Paul_BB's Avatar
Nice!
Jun 17, 2015, 04:32 PM
EB-66C Team Member
xplaneguy's Avatar
Beautiful work Juan! I'm looking forward to seeing your 1/2A Sioux fly.
Jun 17, 2015, 07:20 PM
titoplane
Thread OP
Hello Guys
Thanks Xplaneguy I will try to get photos of the first flight. I haven`t done much lately due to having to do things around the house plus appointments at the VA. I `m getting ready to work on the wings but before I start assembly I read the instructions to be sure I`m building it according to the kit instructions but at times I do things my way. I made a stack off all the ribs that could be seen thru the covering (w3) and sanded the burn mark left by the laser cutter. I might use a transparent film for covering the wing and didn`t want to see the dark area left by the cut. W2 and W1 are going to be under 1/16 inch balsa so I didn`t touch them.I used two short pieces of balsa plus needle pins to keep them aligned and went at it. The trailing edges are rectangular pieces that have to be shaped to a taper,no easy matter. My idea which I have used successfully in other instances is to take a piece of 3/8 inch plywood and place 4 strips of 3M double sided tape at the edge of the plywood. Then I stick the trailing edge over the tape flush with the edge of the plywood and start block sanding at an angle until I have a close approximation of what the instruction says to do. I then remove the trailing edge very gently by pulling on the tape until the balsa is free of the plywood,since we have been applying pressure to the balsa while sanding some times the tape sticks real good to the balsa, then I remove the pieces of tape individually. Here are some photos of the procedure.
Juan
Jun 18, 2015, 02:55 AM
Registered User
I have BMJR Super Sniffer kit. I have a bunch of Cox engines but most likely go electic. Bl motor/ esc/ li-pos to hard to resist.
Jun 18, 2015, 01:36 PM
titoplane
Thread OP
Hello Guys
I worked in one of the wings last night and today I`m sanding the leading edge to cover the top of the wing with 1/16 balsa. I weighted some of the balsa and it was a little heavy so I took some balsa from my stash that was ligther and replaced it. I placed the wing in the 3/8 piece of plywood I use for sanding and held the wing in place as I did with the trailing edge with some strips of 3M double sided tape. then I placed some 3M blue masking tape over the ribs about 1/32 from the leading edge stick. I use the masking tape to protect the ribs from the sanding bar with 100 grit sandpaper and as a guide for my sanding. Once I get the leading edge stick close to the shape needed I use a sanding block with 400 grit to finish. By using the tape I can tell if I`m sanding at the right angle. If I see I`m close to getting thru the masking tape I flip it 180 degrees and stick it again for fine sanding. Here are some pics.
Juan


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