Finished the Beech so I started on a BUSA Sopwith Pup build yesterday. It is 1/6th scale, and has a 53 inch wingspan so it should fit in the car without having to take it apart. The wings are built in 3 sections, right, left ,and middle and then joined. I built the right wing last night and the left and the middle today and then joined them. BUSA makes great kits, although sometimes a bit of thinking is needed to understand what they are trying to say. I go by Glenns moto, you can always do something with balsa, so if I mess something up, I can fix it. But so far I think it is looking good, and the bottom wing is identical to the top, only a bit longer, so I will tacale that tomorrow.
Rob,
So the balsa delivery truck pulled up to your front door!. :)
re: your comment "BUSA makes great kits, although sometimes a bit of thinking is needed to understand what they are trying to say"
They have sure come a long way. I have only built one balsa USA kit and that was in about 1990. It was the Moonraker 52" span low wing .45 IC size sport/pattern plane. It was a box of balsa and a type-written one page instruction sheet that essentially said:
"Thank you for buying our kit. Put all the balsa pieces together properly, add the covering, add engine, radio and fuel. Happy flying"
After the truth in advertising requirement they should have called it a 200 piece flyable balsa puzzle. ;D
Keep building. It's going to look great. 8)
Frank
Photo is of the BalsaUSA Moonraker (not mine)
Finished the bottom wing yesterday. I find it somewhat unusual that the top and bottom wings of the Sopwith Pup were identical in chord and length. Tail feathers are next up. I will give them a go today I think.
you are motoring! Great work!
Once you get to the fuse, you should try to think of a way to install the batteries? I like what Jack Higgins did with his Norsman, it was a slotted nose cone, it basically removed the motor and ESC and then you twisted it on and locked it in place, it allowed for ease of battery install. The only risk was that the system was live until you unplugged the battery.
Thanks for the suggestion Greg. And thanks for the advice on the colour scheme earlier. I will be flying it on 2 - 4s 2200s. There are a couple of build threads on the plane and in one case the guy build a box behind the firewall and mounted the batteries vertically, right behind the firewall, accesed through a hatch on the bottom of the fuse. I have ordered an arming switch for the plane as I always hate arming a plane up side down. The kit allows for the firewall to be placed where needed to a degree, depending on the motor. I will move it as far forward as possible to help with balancing it. I worked for a couple of hours to construct the horizontal stab. Not too much work as there are a couple of good ball games on that need to be watched. I had a minor incident. I use the backing of monocote to cover the plans to protect them and make sure parts don't stick. I didn't notice that there was an area where there was none of the backing and managed to glue the stab to the plans. Not a big deal but required a fair bit of sanding to get the paper off the stab. Elevators tomorrow.
Rob, I saw another build where the guy basically cut the cowl in half, upper and lower. He made a ply former, on both halves, then added magnets and a dowel to lock it in place. The bottom one is fixed 100% to the plane. You basically just lift the cowl off and insert the batteries (Boxes made that they sit in. A 4S will fit fine. You could use a G60 or G46 for the application. I will see if I have any Sopwith type accessories at home.
Another thing I would do is make covers for the servos, I think the plans have them hanging out the bottom of the wing. Looks a bit nasty (Just ref the one I picked up last year)
The horizontal tailplane and elevators are finished, hinged and sanded. Vertical fin and rudder are finished. I will start the fuse probably tomorrow. This kit was produced 10 years ago or more and electric power then is not what it is now. The box says can be built either for gas or electric but they give no instructions of where to put the batteries. Greg's idea above is one solution. Alternately a hatch can be fashioned in the bottom of the plane and the batteries sit vertically behind the firewall. That of course means the plane has to be turned upside down to put them in and take them out. When Glenn built his 1/4 scale version he put a hatch in the side, and I could try the same thing. The real plane did have an inspection plate just behind the cowling.
What model will you be building next week? ;)
He's motoring!!!!
I built the fuse half yesterday, and joined them this morning. Then went flying for a couple of hours. Came home and back to work. Mounted the wing and drilled and tapped holes for wing bolts. Then the fun started. First make sure both wings at the tips are equal distance of the building board. Had to shim 1/32 of an inch to achieve it. Then trying to get the proper lower wing incidence. A frustrating hour and a half spent taking the wing on and off, sanding trying to get what the plans called for. In the end I got it but it was a bit of a tedious job, and the electric screwdriver I was using slipped off the bolt and put a hole in the sheeting of the bottom wing. I couldn't resist putting all the parts together. Then I ran around my work room making airplane sounds for 10 minutes.
Rob,
Looks like a Guillow's stick and tissue model on steroids.
re: your "Then I ran around my work room making airplane sounds for 10 minutes."
You showed such restraint. Only 10 minutes. I sure hope no-one heard/saw you or you would end up in a special ward. ;)
Frank
I woke up this morning, after mounting the bottom wing last night, thinking something wasn't right. The incidence was off and the wing was not as far forward as it should have been in the saddles. Spent about 2 hours correcting it. Now I think it is good. (long, boring story). After lunch I got to start working on the fuse again. Finished the ply deck and installed the stringers for the rear deck behind the cockpit. Tomorrow servos go in.
I decided I would like to build the plane with a tail skid that was sprung, rather than the metal fixed one that came with the kit. The skid of course in burried in the tail after the covering is applied and is not easily accesable so I wanted to make it as foolproof as possible.
I cut out a skid and cheek block using light ply for the skid.
I then built a small bulkhead to attach the spring I was using to attach to.
I was intalling it when I happened to tork the skid, breaking it in half. I had used light ply, not thinking that it is pretty weak stuff. lucky it happend now as it would have been a bit of a bitch to replace after covering.
I remade a skid of 3/32 aircraft grade ply and replaced the broken one.
The last picture is the final configuration with the skid stained.
The setup works well, at least on the building bench.
I am using pull/pull for the elevators and rudder. I installed tubes to guide the cables, and to make installing them after the plane is covered easier. It will also make it easier to replace a cable if it needs to be.
Tomorrow the top wind instalation and all the fuss it take to get the proper incidence, but using the jig I built today, it seems like it is going to be ok.
I suggest that you make the horizontal stab bolt on. Reason is that you can access the mechanism if it fails to do repairs. It happens.
I spent this morning working on the cabane struts. A jig is assembled and then everything is soldered while the upper end is attached to the jig and the lower ends are inserted into the fuse. Worked quite well affter an early bit of mixup with the two different sized struts on each side.
I want to be able to remove the tail feather so I can get inside if I want to. After talking with Greg Cadez I decided to use his idea, instead of something a bit more complicated I had in mind. I have created basswood hard points that will have blind nuts inserted from the bottom, and then bolts will hold the stab down on them.
Now the fight trying to get both wings parallel and lined up.
Going to watch football, enough for today.
A little more work on the Pup. It was suggested I make the tailfeathers removable. Greg Cadez suggested something simpler that I had planned and it seemed like a good idea. The tail is held down to the fuse with 4 bolts going into blind nuts imbedded into hardwood braces that are expoxied to the fuse stringers. I thought I had it lined up pretty well, but when I did up the forth cap screw and measured the leading edge of the stab was 1/8th of and inch closer on one side to the main spar than the other. A shim of 1/64th ply brought it square again.
The batteries will go ahead of the forward wing sadle bulkhead, just behine the front mounting block for the landing gear. I built a hatch out of 3/32nd ply and fit it in place. Have to figure out how to secure it, but I am leaning to a something simple like a cap screw or rotating latch. Supposed to be a snow day tomorrow so I will have the whole day to frustrate myself building!
Impressive! Nice work!
Today I finishing the battery hatch. I installed a sliding latch that is expoxied to the bottom of the hatch. the front end of the hatch has a lip install that hooks under the landing gear mount.
Then I turned my attention to the elevators. I constucted contol horns out of plywood as I did not want to use the nylon ones supplied with the kit, just to give the plane a bit more of a scale look. I am using a pull/pull system and I always thing it looks hinky to go to all the trouble of pull/pull on a scale model and then use nylon control horns. Saying that I may use them on the ailerons as they are on the bottom of the lower wing and not very visible and pull/pull on ailerons seems like a lot of work. Anyway, after several attempts at making the horn with the same rake and arm length for both arms, and then having to do it again, I feel they are pretty good. They system works well and all the contol wires stay the same tension through full movement of the elevators so i guess it is about right.
I also got the servo doors made and the mounting in the wing to hold the doors.
Only had a couple of hours to work today. I spent time making sure everything was as true as my ability allows, and I think, while not perfect, close enough. Then came the main struts. The struts are lamiated basswood that are cut to length and fit into the anchors that were previously glued into the wings. I reasoned that if they were the same length (the front struts were longer than the back by a little,) that when connected everything should line up, and it pretty much did. Needed to finesse a few things to get everything right but it is pretty close now. The main struts have wire bracing that had to be cut to length. The plans called for them to be bent and cemented into the struts but I did not like that idea much so I soldered the ends to washers that the bold holding the strut to the mount passes through. Again, I made 2 identical rods ( and again the front and back varied but they line up well. I should be getting the motor next week which will allow me to install the firewall and the cowl cheeks and cowl.
Rob,
Looking great. Keep going.
re: your "I spent time making sure everything was as true as my ability allows, and I think, while not perfect, close enough."
That's why our transmitters have trim levers. ;)
One day closer to spring!
Frank
Had a good day in the shop today. Funny I find some days are great and some you just wish you had never decided to work on the model that day. Anyway, installed the hardpoints in the ailerons and hinged them. The aileron hindges are inserted near the top of the surfaces but in and inverted V fashion, the pivot point of the hinge being at the upper wing and fuse surface. Worked well and pretty easy to get right. I built a control arm for the rudder and glued it in place. It is a piece of 3/32 ply and I used a protractor to draw it and then a band saw to cut it out. Why this did not occur to me with the elevator contol horns I haven't the foggiest. The plans call for a simple but joint where the fin meets the horizontal stab. I did not like that idea much so I cut the lower stringer of the fin after installing a sister beam and made a tongue out of laminated hard 3/32 (the fin is 3/16th thick.) I then cut a slot in the stab to accomodate the fin. after it is covered it will be held to the bottom of the stab by cheeks made of triangle stock. Should make for a strong arangement in the unlikely event I ever nose the plane over, haha.
Finished the landing gear and installed the wheels. I made a set of main struts but after assembling everything I felt I could do a better job than I had done. I used some of the hardwood my late brother gave me when he realized he was not going to make it, Thanks Dave. I am now waiting for the motor as the last step of assembly before covering, and of course the covering itself, which Arden says should be here this weekend. I am going to use natural colour Oracote from Germany that is like Solartex used to be, as it gives a very authentic cloth like appearance. The cowl cheeks were finished last night and after covering the fuse they have aluminum sheet applied overtop. If the thing flies well I will order graphics for it and paint the top surfaces olive drab.
I did a bit of research and found that the real Pup had metal landing gear legs, not wood. I used metal foil to cover them and I am pleased with the result. I was going to use collets to hold the wheels on to the axels but decided to go with a different approach, much like I did on the Neuport 11 I built 5 years ago. I cut a piece of brass tubing to the proper length. Soldered a washer to the inboard end drilled a hole in the outboard end for a cotter pin. Then I sweat soldered the brass to the shortened landing gear axel and mounted the wheel using a cotter pin. Happy with the results.
I spent the afternoon covering the wires for the cabane struts. The plans had them just glued, but I did not like that idea so instead I hollowed out a space for the wires in a piece of 1/8the strip balsa using Duragrit bits in a dremel. The wire fits inside and then the strut is backed with 1/64 ply. then they were stained. Happy with the way they turned out. I decided I needed to make an instrument panel. I was able to find some instrument faces I downloaded and printed. The dash is 1/64th ply with a backing of 3/32 balsa. I sandwiched a sheet of clear acetate in between to simulate the glass over the instrument.
Love the dash, Rob. Nice work! :)
Thanks Simon. going to try and make bezels for the instruments today.
The Motor and ESC are installed. Motor is a 4250 500kv from HK and esc is 80 amp, which is probably overkill on a 4 s set up but it is what I had and I figured I could use the weight in the nose. The fuse forward section is covered with 008 aluminum. The kit only came with enought aluminum to do the cheeks but on the real plane the top of the fuse was covered in metal too, so that piece is aftermarket and lightly different in sheen. I figure that's ok as the real plane seems to have different coloured bits as well. I will use a 15.8 and as I said on 4 s this will give about 500 watts and plenty for this plane to fly scale with. I added bezels to the instruments. I had some plastic sticks left over from another build and formed them round around brass tubbing. Painted them and glued them to the dash. Happy with the effect.
Got back to work on the Pup after taking 3 weeks off on a holiday south. In the time I was away, the Oratex covering I ordered arrived. The stuff is very nice to work with. Sticks at low heat and shrinks well, and great on compound curves. I used all of a 5 meter roll of the stuff but am happy with the results. There is still a fair bit of work to finish up, little details mostly. The ailerons have to be connected top to bottom with pushrods, the Vickers machine gun kit installed. A spreader bar for the gear, probably should be ready to fly if I put another full days work into it. Without batteries it weighs 5 pounds 4 ounces, so I expect flying weight will be about 6 pounds. I will wait to see if and how well it flies before painting the top of the wings and fuse olive drab, and ordering graphics from Callie. The radial engine is thanks to Dave Kates who prinited it for me. It fit the cowling exactly and I think finishes the plane. I am pretty sure (because I spent hours getting it right) that the incidence is correct and everything lines up pretty well and square, so it should be a good flying plane with a low wing loading.
Awesome!
That's it! I am going to have to pull the Saito Nitro Motor from Mine and convert it! Where did you put the batts again? Also did you adjust the firewall to fit the ep motor? I was going to Jam one 4S, 4000 into the cavity just before the landing gear.
Beautiful build Rob!