twn

Now on with setting the incidence of the lower wing and setting it level and removing any twists in the lower wing that may or may not be there and finally using some micro balloons and epoxy and saran wrap to make some nice fitting wing saddles…

In the end yes there was a minor twist in the left lower wing. Once I got the saddles working with the wing level and with the incidence set to zero I threw on some incidence metteres, threw some heat at the wing panel and twisted out the small warp ( it was warped about .5 degrees at the tip. She is straight now.

Once I get the fusalage/saddle sides sanded I post some pics of that...

Revy

My Feedback: (1)

LOL Haven't given up, but your doin' such a good job on that one!

twn

It takes time. After you get a few kits under yer belt you will excel... Learn new tricks and old ones!

Biggest thing is probably having a good solid work surface that is perfectly level with no droups. Use lots of straight edges, levels & measuring devices and the one tool you want to have (actually get yerself 3 or 4 of them) is an incidence meter. I can't live without at least 2. On my work surface (2*4, 3' by 7' bench with 3/4 mdf) I just throw a sheet of 1/2" drywall on it and pin to that. They are very flat and the pins hold very well. You can even glue pieces of scrap wood to it to hold stuff yer gona sand like control surfaces. When it gets too used just throw it to the dump and get a new one for $10!!

twn

Set up the bottom wing to the fuselage with the proper incidence and set it level. I just used some small scrap balsa on the saddle surface to get the incidence right and sanded where it was needed. This is a great time to remove and warps in the bottom wing. Once the saddle is setup right thro yer incidence meters out at the wing tips and check for warps. Apply some high heat to the leading part of the wing and twist against the warp and hold until cool. Works great. If you have to do this, recheck the saddle again for correct incidence and level. Rework if needed. Fixing the warps will be much easier if you do it before you build the turtle deck as you need the fuselage strongly held level.

With the epoxy & micro balloons you throw some saran wrap on the wing so the epoxy doesn’t stick to it, make sure it is tightly held down, then mix up some 30 minute epoxy. I like to take my finger and put a small amount without micro balloons on the wing saddle first, nut much but it will soak in to the saddle better and will bond the balloon mixture better. Then mix in as many micro balloons as the epoxy will soak up. It will be very thick. Be care full not to mix too much as the epoxy will kick faster! Then put a think gob of it over the mating surface that you just put epoxy onto. And throw the wing on and tighten it down. Wait about 45 minutes for it to start to kick. Pull the wing off. The saran wrap will stick to the epoxy so carefully remove it from the wing as you pull the wing off. Then remove the saran wrap. Take an exacto and carefully cut the extra epoxy/micro balloons off from the edges. Once cured, about 6 hours later, sand flat… makes a perfect look every time. I learned this trick from somebody here on rcu but I don’t remember who. Often I use some balsrite to get the covering to stick to the epoxied saddle. This also made a very nicely sealed leading edge of wing to fuselage. Should keep the fuel out!

I like the Great Planes 30 minute epoxy. It separates from saran wrap very nicely. Also if you do this micro baloon trick be sure to use 30 minute epoxy or it will harded too fast.

I re-enforced the firewall with tristock as the manual says. I added some extra for good measure. The stuff is very light and worth it to add in. Especially with a larger engine it will keep the vibration lower. Rory says that a lot of stress is passed into the top of the fuselage through the stringers and balsa… The stronger firewall and extra tristock will definitely help here. I will also wrap some 1” 1.5 oz fiberglass tape around the edge of the firewall.

You can also see the tank tray mount and dry fit of the tank. Next step will be to do the turtle deck and cabanes. Unfortunately I can’t find and heavier aluminum. I was going to do the lower cabane mod and side mount the cabans but nobody has any ½” by 3mm aluminum in our area, not even machine shops… lol So I will be using the kit stuff.

EscapeFlyer

My Feedback: (1)

I always thought a fairing on the bottom wing would look really nice on this biplane.

Just an opinion.

Brian

Revy

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That is an issue for me right now. Room is limited. My table (not ideal anyway) is tore down and requires re-setting up. So everything is put aside for the moment.[&o]

twn

A fairing, interesting. Do you mean something like what is on the inner te of a funtana?

EscapeFlyer

My Feedback: (1)

twn

Not exactly.

I'm thinking more on the lines of a faring starting around the thickest part of the wing having it's widest point at the TE and brought back to the fuse, and into the fuse.

I saw this in some coverage of an event in a Model Aviation magazine awhile back. I'll see if I can find it. The Ultimate was covered in the flag pattern. It sticks in my memory because it was the most amazing Ultimate I've ever seen.

I'll see if I can find the pictures on line anywhere.

Brian

twn

More progress!

I wet the turtle deck on both sides and got really flexable and then I bent the turtle deck first around and old hand railing. I let it sit for a few hours while I went looking for a smaller dowel and I found the perfect fit, the center of my xmas tree. [X(]Yikes don’t tell my other half!! [X(] I re-wet the turtle deck and clamped around the dowel and left it for 24 hours. Made a nice tight turn all the way down. I added some strips of balsa to the fin and stab so the turtle deck could fully adhere. I used gumby glue (gorilla) it was my first time ever to use this stuff. Wow is it ever strong. I got a bit too much on it so I got some sanding to do…

Tomorrow I’ll complete the fuselage!

twn

A few more pics...

Revy

My Feedback: (1)

This thing is gonna be niiiice![8D]

twn

More progress…

Completion of the turtle deck filling sanding. I had a bit of sanding of the gumby glue. This glue sands VERY nicely! Easily fixed. I don’t use the balsa like filler. I have had many bad experiences with the mud like stuff. Blemishes, air pockets that rise up under the covering when the heat gun is used and ruin a good job etc.. I mix a whole lot of micro balloons with the epoxy to make it light and very workable, yet strong and stands up to heat. I used some masking tape to keep the sander from sanding unwanted areas like the stab.

twn

Some more!

Front deck sheeting… I changed the two outer 3/16 stringers for ¼ for added strength. The kit supplied 3/16 was very spongee. A word of warning, with the front sheeting, be sure to really wet it good and tape it down in place prior to gluing and let it sit for a bit, a few hours to hold the shape and the proceed with gluing it to the base of the fuselage and then wet it again and glue it to the first stringer. I used a combination of gumby glue and ca. I also had to pin the center section, elastic band it and wrap string round the fuselage a number of times so it would hold its shape because as the wood swells when wet causing unwanted lumps. The string, rubber bands and pins totally held it. Dried nicely.

Unfortunately I still can’t find any ½” by 3mm aluminum so the side mounted cabane mod is out for now.[&o]

As you can see the epoxy/micro balloon trick in the wing saddles looks great! I did a quick mock up. I couldn’t resist. It’s starting to take shape!! I also couldn’t resist. That spe26 would definitely fit. Its pretty temping!! But I think I’m gona stick with the 120ax. More power and 6 oz lighter. Seriously with the spe26 in one hand and the os 120ax in the other, it is really hard to feel the difference in weight. They feel so close!!

twn

I drilled the bolt mount in the top wing to attach to the cabanes. Pretty simple… I used my drill press o get nice 90 degree holes. I used my dremel to center pre-drill through the epoxy so the drill bit doesn’t slide off center. I used a smaller drill bit than the 4-40 bolt to keep the bolt firmly in place. I was just going to epoxy the bolt in and cover over the top so they won’t be seen but in the end I have decided to leave them open for easy change out. I can now complete the top wing and fiberglass the center join. I will use 2” tape for the top wing and zpoxy again.

twn

I have mounted the 120ax and set the proper down thrust (0 degrees) and right thrust (2 degrees) I actually took the right thrust to 2.5 degrees because of the larger engine. I will play with this later when I’m dialing in the plane’s cg. I found that I had to move the motor slightly up from where the plans show it mounted in order to match up to the cowl. It was down a good 1/4" and looked terrible. I know the engine is sitting 1/8” above the thrust line we will see how she flies. I’m in the process of cutting holes in the cowl for the engine/muffler. Unfortunaly it looks like the muffler will still stick out a bit. Oh well.

Revy

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Looking good, man.[8D]

daveopam

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You are doing fine without my help, but..... I think I would flatten out the stock ALUM wing mount and use it as a spacer on top of the cabanes. It would add a little strength and make the wing the right height for the struts. Speaking of struts. If you have not finished yours. the ARF has a little better looking set up. If you are interested I will post a few pics. It would be a little more work, but that doesn't seem to bother you.

David

twn

yes please post your strut pics. I will be doing them very soon. Thanks again!

What I was going to do with the cabanes is use some nylon to make 2 spacers with the right height/angle. I was thinking of using the kit top wing mount in that fashion, however the one in my kit is steel, not aluminum...

twn

Here are some pics of the cowl with the muffler on. Pretty much finished. I was hoping the muffler would be inside the cowl. No luck. Oh well…

twn

Here are some pics of the final sanding and filling on the wings before I fiber tape the top wing join and do the 30 degree double bevel on the ailerons/wings. For the top wing I’ll just use some 2 inch tape so the feathering of the edge is easier… 2 inches should be more than enough strength!

I used some firm 1/16 balsa to fill the low spots and epoxy/micro balloon to smooth out the smaller imperfections.

daveopam

My Feedback: (9)

I'll get you the pics Tom. How they work is the strut slides over the top of the rib tabs instead of sitting next to them. You would need to round out your ply struts so they fit over the tabs before you build the balsa around them. Should not be that hard. I should be able to get the pics this evening.

david

twn

I don't know, my tabs are pretty wide. 1/16 aircraft grade ply laminated on both sides for strength... They are a bit more than 1/4" wide. That would leave no meat for the 4-40 bolts to grab to on the struts? Definately a good idea and would hide the ugly honkin tabs. I'm just not sure how to put the strength back in after removing enough material to hide them?

daveopam

My Feedback: (9)

You would need to add some extra balsa around the top and bottom of the struts, and use a thicker balsa strip up the center. Once sanded it should still look OK. Another thought, you could recess the tabs into one side of the struts instead of going around the tabs? This would require less building up of the struts. It would also be a cleaner look than the stock set up.

David

daveopam

My Feedback: (9)

Here's the pics. Since your ribs are so thick the recess idea sounds better all the time. This way might make them a little bulky. Either way would be an improvement IMHO. David

twn

I thought that I’d share how I do center lines for hinging and beveling. I use to use one of those stupid twist jobs that “auto find” center for you but I found that they would dig a deep grove and cause the ca hinge possible flex where you don’t want it.

I find absolute center with a fine rule and push a pin into it. I do this about every 11”. I hold a 12” ruler against the pins to draw a line with a soft very fine mechanical pencil I use the smallest dubro t pin but they are usually thicker than the pencil lead so I will flip the ruler to the opposite site and draw again. This makes the line thicker but center is more precise. I then proceed to start the hinge slot with a number 11 exacto and then finish up by using the gp hinge slotting tool (motorized) I push the blades inside the slot about a millimeter ro 2 and then turn the machine on and go the rest of the way through. I don’t run the machine when I’m pulling the blades out. Sometimes it will chew the entrance wider if I keep it running. If I’m putting pinned hinges in I do all of the slots with the thin blades and then I switch to the fat blades and push the blades in just a little and then run the machine and never pull the machine out while it is running. This leaves a very tight entrance to the slot and it keeps the pinned part of the hinges very solid.

For beveling I just mark it and push a pin in on the mark, hold the ruler against the pins and draw the line across and then I use the razor planer to get it close to the line and then finish up with the sanding tool. For double bevels on 60 size planes the wing bevel I mark it at 4mm and the aileron bevel I mark it at 3mm. This gave me 50 degrees of travel and leaves more surface on the aileron.