aymodeler

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Construction of the fuse top continues with the installation of the stringers and the razorback spine. All very straightforward with no real surprises. I have spliced the extenders on to the end of the tail section of the precut skins, soaked them down with Windex, and formed them around some aluminum ducting to set in a curve. I was tempted to glue them in place today, but decided to give up and save some fun for next time.

Just to drive myself crazy, I have been keeping a log of the hours spent working on this project. Total since October 1st 2011: 53 man-hours (I never claimed to be fast!).

raptureboy

Hey Ay, glad to see you are back. I am hooking mine up like connor did and I will use a brass tube flattend at each end then drilled to receive the wires. You could use 2 std horns back to back and then screw them together or they make a special control horn for pull pull but it looks ugly to me more suited for the 3d types. It not that hard to do it this way, I inserted a piece of steel pushrod to make the tube solid and the it will be epoxyed into a slot on the rudder.

raptureboy

Here are some pics of the wing and gear mods, not exactly the kind of thing a first time builder might want to tackle but worth the effort to have the gear fit all the way into ithe wing. I have a picture ofthe full scale wing that shows the spar placement and there were 4 spars in it. Also some shots of the contol linkages again, the blue rod is sullivan golden rod to contol the elevator. Also a picture of the dle 20 I will use for power. I am sold on these engines, this is my 3rd one and I will put one in my new p-40 also, they are great and for the money can't be beat! 15 min on 10 oz of gas at wot.

raptureboy

Oh this picture thing drives me nuts![:@]

raptureboy

Now for a little eye candy this is a p-47 N from warbirds over Delaware this summer, note the sguared off wing tips of the N variation . A great event if you get the chance to go, it's in July.

aymodeler

My Feedback: (3)

Great shots! Your technique for attaching the cables at the rudder does look very straightforward and much cleaner than the standard control horns. Ithink I will give that a try.

It appears as though the cables spread out from the center-line as they move forward (i.e.; the control arm length at the servo will be longer than at the rudder), is that correct? I have been reading up on pull-pull systems and a lot of pundits claim that this is not desirable. I suspect that most of these posts are geared more toward the 3-D types which have much larger control surface travel and much higher loads than we will be seeing. Do you expect to see any slack in the opposite cable? Do you have any concerns about flutter at all?

Also, I was wondering if you could post a photo of your elevator hinges (you mentioned in your PM that you used three per side)? Sorry to be nagging at you with so many questions. Ireally do appreciate the help though!!!

Your wing mods look great. I am not there yet, but will be referencing them closely when Ido (you can bet I will be pestering you for more photos too!!!). I've heard about Wings Over Delaware but have not made it there yet. It's definitely on my to-do list (assuming my travel schedule ever lets up).

Thanks again for all your help!!!

Al

raptureboy

Ask away! I'm no expert but I do read RCU I only have one plane right now that uses pull pull and the hook up is about the same. There are many opinions about the subject as you have found out. What I see, and experience is that closer in on the surface horn and farther out on the servo horn provides more control throw. You can reduce or increase throw by adjusting either one or both connections. You will see some slack in the opposite cable from the direction of pull but not much if you get them adjusted right. I will try to add more detail on the gear change and the spar modifications ie: measurements, materials, etc.. later. To me experimenting is all about learning new things and seeing what works and does not. Since this is my 2nd p-47 I want to try and go to the next level. I haven't added the 3rd hinge yet but it will be just like the others.

raptureboy

Hey AY are you out there? I have been busy working on my wings and got them glues together and now I'm preparing to start the sheeting. Pictures to follow soon.

aymodeler

My Feedback: (3)

I'm still here, but have not been able to spend any time in the workshop lately (been back on the road again)

Looking forward to seeing your pictures - I live vicariously through all those with lives under there own control!

raptureboy

LOL Yeh I'm not so sure of that! I had all the best intentions to get up early today and spend the day working on the plane, but instead I had to take down the Christmas tree and clean up that mess and then snow blow the driveway and do the laundry [:'(] by then it was 2pm and I didn't get much done tonight. I have the sheeting all glued up and ready to install and I see that 30"is not long enough to go from the center out to the end. It just makes it to the tip rib #13 a little short still. I don't know why they just didn't provide 36" pieces. I decided to go with 3/32" sheeting instead of 1/16" beacuse the last one I built I kept putting cracks and holes in the sheeting because of being so thin, especially after sanding. I stayed with the 1/16 on the flaps and ailerons to stay light on the controls, and I wiill just taper the sheeting into them later. Changing the gear location and all the extra work involved in adding new spars really added to the time. I quit keeping track but I bet I have 25-30 hrs so far into the wings alone. The learning curve[] Are you in sales, that keeps you traveling so much? I picked up a couple of ARF's over the holidays a Greatplanes PT-17 and the Top Flight P-40, I know this kit is going to be taking some time and I hope to have it all done by the end of this summer. I'll post some pictures as soon as I get some tings worth posting. I like your blog that's really professional looking. Hope you get to have some down time soon.

aymodeler

My Feedback: (3)

Thanks for the compliment on the blog. WordPress makes it easy, not much skill there

Actually I'm in IT. I'm heading up a project to deploy a complex business system (SAP) at sister division at the company I work for, so I'm spending a lot of time on site there. The project is scheduled to run through mid-summer, so I don't expect to get too much building (or flying) until the later half of the year []

How much weight do you think going to 3/32 balsa will add? I've heard others suggest the same, but since I plan to glass the plane I wasn't sure if the 3/32 would be overkill and I am getting concerned about weight.

raptureboy

The weight of 3/32 is about twice that of the 1/16 per sheet. 23g vs 12g. Times that over 16 sheets and you have added about 6oz. I may only do it on the bottom sheets, my last one came in around 13# and flew fine with a 26cc gas engine. Sorry to here you have to be on the road so much[] it really disrupts your family life and fun time. Hope you finish early

raptureboy

Here are some wing pics. Gluing this all up was a real pain. You definitly want to make sure you have everything set up and dry fitted before you mix your epoxy, and don't mix more than about 1/2oz at a time of 30 min or it will kick off in about 15 min. In changing the wheel locations I should have waited on cutting out the original main spar until I had it all joined together because when you cut W1 to insert the dihedral brace you end up with the center being all floppy. I used the dihedral brace as a template to cut new ones for the rear spar and then reduced them down in width to account for the thinner section of the wing. After I had it all glued together I used poly-urethane glue as fillets around some key areas. I spray a little water on the areas I want to glue, then add a thin bead and then it foams up and man it is glued but good!

raptureboy

Some more

raptureboy

Well I ‘m typing this again because of the stupid time out problems with this server/site. I made some progress the last 2 weeks on getting the wing sheeted and the aileron linkage issues resolved. I persisted in working out using the single servo and bellcranks as called for in the original plans and after much deliberating and just plain screwing around, success! I hope someone gains from all my pain! I installed some rails in the center bay and turned the servo sideways to mount. I opted for the Dubro duel ball link connector instead of the stock one. Using Sullivan golden rod to make the connection instead of the steel pushrod, I flipped the bellcrank around so it connects from the bottom. Hopefully the pictures explain it better.

raptureboy

One other thing I want to note, is that leaving the bellcrank assemblies loose instead of gluing them in early like they have you do in the instructions makes it a lot easier to hook up the linkages. Here are a couple of pictures showing the fillets made using the poly-u glue, not as pretty as epoxy and micro balloons but it works great. The little circuit board thingy you see is my servo tester; you use this to setup and test your servos without having to hook up your radio. A great device and one of those things that once you have one you wonder how you got along with out it.





http://www.york-electronics.com/

raptureboy

I think the 3/32 sheeting is the way to go, certainly for the bottom of the wing it really makes things stiffen up and smoothes out any irregularities in the ribs underneath. I will share my method of attaching the sheeting here. After fitting the leading edge pieces in, I spray the top surface with a light mist of water and ammonia and then place it on the wing and then weight it with sandbags. After it dries it takes the shape of the wing better and is easier to glue down. Next I use regular wood glue on all the tops of the ribs up to about the last ¼� of the leading and trailing edges of the sheeting except for the tip rib #13. I apply thick or med CA to the tip rib and along the leading edge of the sheeting and along the top of the spar where the sheeting is spliced. Lay your sheeting up against the leading edge and pin it down (don’t dawdle here, make sure you have your pins ready.CA waits for no one [>:]) while holding up the trailing edge with your other hand. Once the leading edge is bonded you can then begin laying down the trailing edge, working from the center of the sheet out towards the tip and center of the wing. Wet the sheeting a little more out at the tios if needed to get it to conform to the ribs. Put some weight on the middle of the sheeting and allow it to dry. I find this helps by allowing the sheeting to span over any small areas of the rib that may be low from sanding a little too much and saves a whole lot of pinning. One other thing, the sheets are 30" long and the instructions say to let it hang off the tips a 1/4" or so, good luck with that. The last 2 pics show how short you end up, they should have used 36" sheets some of my sheets were only 29-7/8" long and I just made it onto the ribs.(see the pencil tip)

aymodeler

My Feedback: (3)

Great stuff! I'm really itching to get back into my workshop.

raptureboy

Hey man glad to see your checking in. I'm starting to feel like I'm taking over here. I hope you get some down time again. I'm starting to feel like I'm remodeling homes again, every time I open up a wall I find another can of worms but it's a good learning experience and the next step to building a full out scale beast. I have my eye on a Brian Taylor Spitfire build someday, maybe I'll win that contest I entered on FlyRc.com for a set of plans and all the stuff needed to build it

bigtim

My Feedback: (13)

I think going with the 3/32 sheeting is the way to go, when I did mine I used the sheets that came with the kit, firstly they had really bad edges so I needed to true them up with a strait edge gluing them together wouldn't have been pretty with the finished edges they had out of the box .

then when I finally got to sheeting the wing after getting the skin down I had a really bad case of warping between the wing ribs,looked like a WWI biplane,and I only really noticed the ripples after I glassed the wing, fortunately it was only on the leading edge back to the forward spar on the top of the wing.

I ended up using a light weight auto body glazing putty and a old credit card to smooth out the edge,lots of filling and back sanding went into getting the LE right for painting,knowing what I know now I would have scrapped the 1/16 wood and gone with the thicker sheeting,since I added the extra weight in filler any ways, here is a photo pre glassing and the ripples are hard to see,and after paint and in the sun the paint prep took some serious elbow grease to get it right

aymodeler

My Feedback: (3)

Thanks for the encouragement raptureboy, I knew when I started this project off that it would be a long slow process.

I think I'm sold on 3/32 for the wing sheeting. bigtim's is the third recommendation for that I've come across. I am still a bit nervous about weight though ...

aymodeler

My Feedback: (3)

Well I finally got a chance to get back into my shop and make a bit more progress. Last weekend, I had an hour to sneak into my shop, and I thought that would be enough time to get the lower sheeting glued up. Fortunately, I decided to use Titebond aliphatic resin instead of CA. I got the sheeting partway glued down but was really struggling to keep it from buckling. I was totally dissatisfied with how it looked, so I pulled it off, wiped off the glue with a damp rag and decided to leave this for when I wouldn’t feel rushed.

I had a bit more time today, so I took another go at it, again using Titebond. This time, everything went smoothly and I got both lower sheeting pieces glued down. After the glue set up, I went back and started to trim back the sheeting near the stabilizer saddles. Once again I started to feel like I was rushing things, so I decided to call it a night and leave this fussy step for the morning.

raptureboy

Glad to see you made it back to the shop. I know what you mean about rushing it and then wishing you had waited. Smart move to wait until you have more time. I have made a little more progres myself, I will post some pics of my work soon

raptureboy

Here are some pics of the retract air lines and also my aileron servo hook up. On the far right you can see that I used thicker blocks for the aileron hinges as I will be using the robart hinges. I had to run the nyrod sheathing through the gear well area and I will try to hide it later perhaps as a hydraulic line or something.

raptureboy

This site really stinks. I have been trying to post 2 lousy pictures since last night and it still times out.[:@]