From 1974 to 1987 I went through a few pattern planes. A Vertigo with a ST blue head 60, Atlanta with an HP61 Gold Cup, Vega 40 size with an HP 40, A UFO with a Rossi 60, a couple Kaos 60s The Hippo Tipo I now still have, A Saturn with a Rossi all these were piped and there's a few more that I'd have to get the pictures out on to identify. There's a pattern meet coming up up here in Upstate Ny. I'm wondering if the Classic craze has hit the Syracuse area yet. There's also one at Blue Swan airport in Athens, Pa this summer or there used to be which isn't far from here. Looks like I need to show up at these memory makers. I'll bet it'll be as much fun or maybe more fun then it was back then. Used to be the highlight of my summers.

Today I received my wing cores and they are not damaged. Maybe tomorrow I can at least lay out for the spars and retracts and servos. I plan to take my time because I have difficulty getting the sides and floor of the pockets for the retracts flat and even. If someone knows some secrects please divulge them. If the surface is rough and uneven it will take more epoxy. I am planning on using manilla folder material to line the wheel wells and servo pocket. Any better thoughts there?
Go ahead and jump right in Doxilla. Any comments are appreciated.
Jim

Jim,

I've never used "paper" as a lining/building material on the exterior of a model like this. I suppose that if you finish it properly, it ought to hold up but it wouldn't be my material of choice. 1/16" balsa wrapped around a paint can makes for a nice and round wheel well (2.5" ID) in the wing for the 2.25" main wheels.

As far as getting a smooth surface to the foam in preparation for wood application (either 1/16" balsa wells or 1/64" ply), use fine sandpaper on a "dowel" that fits into the well. If the "dowel" is a touch larger than 2.5" in OD, not a big deal - your wells will just be slightly larger. Likewise for the side walls where the retract body is installed - bond some adhesive sand paper to a flat piece of hard wood or a plastic spatula and use this to smooth the bay out. With that done, you can then "sheet" the bay - it will be much easier.

As far as sheeting the cores - I use laminating epoxy but I believe I'd be happy with PU glue as well once I figured out its nuances. What I hesitate a little with PU glue is that it requires attention when drying to make sure it doesn't "invade" areas where you don't want glue (e.g., in your retract mount holes). PU glue expands and "foams" when activating so this is the only disadvantage that comes to mind with PU. Of course, this also results in a very good bond between sheeting and foam. Whatever glue you use, what is important is that you sand your cores smooth - being careful not to alter the airfoil and sand in flat spots - evidently. The smoothed out core will increase the surface area of adhesion and prevent "pools" of adhesive in the "beads" of the foam (even closed cell foam has them).

Use laminating epoxy or PU - take your pick. Either way, you need very little glue. Hope this helps.

David.

I get no response from Eureka. The weather up there has
been very bad this spring. I ordered a Pole Star around the
middle of April and haven't seen it yet but my card has been
charged on April 15.
Ralph

Try him on his cell phone. (479-239-4427 or 479-239-5539) His residence was in an area where he had no way to get out because of the floods in Ak. He has relocated since and is in the process of setting up shop again. I just received a parcel from him yesterday. He is now at a higher elevation with a larger shop. Jim

Between yesterday and today I managed to get the wheel wells and retract mounts opened up and sanded flush. I have one wing ready to install the carbon fiber spars but when I cut the spars I had a mind lapse and only cut two and as we all know four are required. I will try to cut two more tomorrow.
Does someone have a picture of how robart wire main struts are installed? Can I rotate the strut so that the coil of the spring just clears the air cylinder? Its just been too long to remember.
I will make a template so that after the wing is sheeted I will know where the wheel wells and servo mounts are to make it easier to locate. That is for later.
I would have never thought of using sandpaper to smooth out the retract area without comments from David. Thanks.
Jim

I managed to find some time after dinner and cut the carbon fiber spars. While the saw was out I also cut them to length. This stuff is extrememly difficult to cut, I found that only a carbide blade or an abrasive wheel is the only thing that works. The tool steel blade did not like cutting this stuff at all.
I have ordered some laminating epoxy and it should arrive soon. I would like to be in a positon to be able to laminate the wing cores when it arrives. That means I must get the spars epoxied in place and lightly sand the cores as recommended by David.
More tomorrow since the world did not end as predicted.
Jim

Spars are epoxied in place as is the retract blocks. Also installed a servo rail in each wing.
I started joining the planking for the wings and found that each piece of sheeting needed to be trimmed to be straight. While cutting those straight I had a thought from the past. I remembered that we used to put dowels (1/4 inch dia.) through the retract mount and into the foam for additional support for the gears. Good thing I remembered, so I accomplished that task today also.
All four wing skins are joined and sanded and it looks like the lamination might be next.
I answered my own question about the location of the axle for the retract. I have that resolved.
Wound up ordering an extensoin for the Macs pipe so the the round part of the header clears the fuselage in the front. This tells me that the nose width is too wide but its going to stay like that.
Pictures attached of the wing assembly prior to planking.

Jim

Jim,

looking good. Before you go ahead and sheet the cores, you might want to take care of the wood sheeting of the retract and servo wells. You can do it after the fact too but it tends to be easier to do before.

David.

David,
I did weigh that out and my thoughts are that if I fill in the wells I might have a difficult time feeding the servo wires and air plumbing in place. Just my thoughts.
My llaminating epoxy will be by end of week and then I can laminate the cores. I now know that my "77" spray is acceptable to foam but I am going to stick with the laminating epoxy thinned with alcohal and put on with a piece of foam as a brush.
Jim

Jim,

for the servo leads and air plumbing, what you typically do is produce a duct in the top of the wing. It can be a rectangular duct simply sanded into the core with a piece of CF (like the ones you have as spars) with sand paper on each side and bottom or you can use a piece of balsa. Alternatively, you can just make a cylindrical duct in the upper part of the core below the upper surface using sharpened brass tube. The former is a little easier but both are not that difficult. If you sand the duct into the top of the wing, you can then apply a thin piece of 1/16" balsa between the opening side walls so the sheeting has a surface to adhere to.

Once your ducts are made, you can run thread from the servo wells to the center of the panels to make it easier to route servo lead extensions and/or plumbing. Often the plumbing for the retracts is easier to pull from the center of the base of the retract well just underneath the sheeting. You make the duct and then once the base is sheeted, you can make a small hole in the sheet to pass the tube. The servo leads are often closer to the LE of the wing so you can pass them along a separate duct.

In my Tipo wing, I made arrangements to pass both servo leads and electrical connections to the retracts (they are electric Multicons) along the same path but either setup works. If you like, and you use cylindrical holes in the core, you can even line these with rolled up paper or a cardboard rocket tube. It makes passing the leads a tad easier but its not necessary. I use rolled up paper when making circular holes in the core.

Another good tool to pass leads/tubes is chain link from the hardware store. It is heavy so it naturally "falls" into the holes and "ducts" from one end to the other allowing you to tape your leads or tubes to it and then pull them in place. I would recommend that you install both your extensions and tubes prior to joining the panels but it can also be done afterward - your choice.

David.

David,
What was I thinking? I later thought that if I had to replace the servo or its lead I would have a problem the way I was going. So with that thought aside the wheel well walls and floors are in. Not as pretty as yours but they are in. Picture attached.
I am still waiting for the lamination epoxy. Not much more activity until it arrives. I might smooth out the engine cowling inside and put some protective coating inside once it is smoothed out.
Jim

If its any easier i bought 2 airframes for restoration off the bay, both where excellently packaged, one arrived with the wing broke in 3 places and the second had its back broken in several places. Both by the same delivery company, called complained they said they would refund me the cost of the models in auction but not there true value. both models where not available on the market like i explained but they said if they payed out the would come collect them.

Enjoying the thread and keep up the good work, all ic an say is ur a brave man with all the sanding and shaping thats to be done.

Sir Crashallot,

I am one of those who fly to build. I am 70 years old and have been in the model airplane building mode since I was about 7 years old. Some build to fly but that is not me. The carving, shanding, shaping and fitting of the wood together is in fact a challange and keeps me busy since I am retired. The real builders find time to get the job done.
I am not as quick as I once was but the enjoyment is still there for me. I have folks ask me how an airplane can last for up to and past 10 years and still look good. My answer is good engineering and workmanship along with good maintenance.
Folks in our club have problems with their planes and some absolutely do not believe in balancing propellars or spinners as an example. They just want to fly their ARF's but that is not my cup of tea.
Jim

It's Friday and the wing panels are laminated. Just waiting for the epoxy to take set. Sometime tomorrow I will be able to start trimming off the excess planking and sanding flush. I started with a foam brush which started to come off of the handle and wound up using a piece of foam to finish off the spreading of the epoxy. I thinned the epoxy with 91 percent alcohol to be sure not to get it too thich which relates to more weight. After trimming and sanding the planking flush, I will weigh each panel and report the weight and add a picture.
Jim

Jim,

24 oz or under is the target - tips & chin included. Mine came out at exactly that but I hadn't hollowed out the tips when I weighed it - maybe an ounce less once hollowed.

BTW, the ZAP finishing resin doesn't need to be thinned. If you thin it too much, you can end up with a very mild epoxy mix which is ok for glassing but might be questionable when sheeting. In order to avoid applying too much epoxy, the trick is to lift the sheeting to the light until you see a sheen. If it's glossy, you have too much. I just pour it on and use a CC to spread it out. Most of the glue ends back in the container as I scoop it back up with the card. I find the sponge just soaks it up and cuts into your work time - as you know, one has to work fast.

When you sand the sheeting, do so with both wings in their shucks and stacked. It is the easiest way to produce two identical halves. Just watch your sandbar to make sure you don't add further taper or "arcing" to the sides.


David.

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Well sir i hope when i am your age that i am as good a craftsman as yourself. im mearly 24 25 this june and been building and flying since i was 11. I have bought arf models but never again and thats all il say about them. I really do perfer being creative and either scratch designing or building from plans and kits. Im rebuilding a 1/5th mustang over in crash and rebuild on here, that was an arf, dont know the manufacturer... but the fiberglass fuselage is a right old mess, most of it is down to poor lamination ect.from the rear of the wing to the tail there are no formers!! but yeah you probably read enough comments from people on here about how poor the quality is on them. I will keep an eye on this thread and hopefully il learn a few things, as my dad always told me sit watch and listen very carefully... so thats what am guna do.

David,
I did thin it out a bit, but I applied it to both surfaces and it seemed to want to adhere well. It is under compression at the moment and will sit until at least 1300 hours tomorrow. The instructions said that it could be thinned with 91 alcohol, so that is what I did. Sure hope it was not a mistake at this point in the build. Tomorrow will tell the story for sure.
I am using three cinder blocks sitting on top of the shucks with both wings in the same stack. Later tomorrow I will post my results.
I finally ordered and 11 ounce Hayes tank and might have to modify my front motor mount in order to get it where I think I want it to go. Should have had the tank on hand before I installed the front mount. Live and learn.
Jim

Sounds good Jim.

Build on!

David.

I dug the Hippo Tipo out of it's 25 year hiding place today and low and behold the G series radio equipment was still in it. I even found the Gold transmitter. So I snapped a few pictures of it in my studio. Too close in here but you get the idea. You can see where the paint is pealing off the fuselage. It's dirty and has cobwebs but it's structurally sound and the Rossi while sticky still turns over. Check it out.[img][/img]

Here's another Hipo Tipo. And Jim, I just found this thread. You are getting some great advice from guys that have helped me many times. Good looking work so far.

David,

that's a sweet looking T825. It needs to be polished up and made flight line ready for some serious flyby's!

What' it got for engine and gear? It'd be interesting to see some pics of the radio install, tank, etc - might assist Jim.

David.

Well, today another hickup.
I have removed the wings from the laminating process and trimmed and sandes all of the edges and sanded in the dihedral. I was about to epoxy the leading and trailing stock in place and found that the airfoil or wing thickness at the center of the wing was thicker than that in the plan. I did not want to laminate material to the stock that I had on hand for the leading and trailing edges, so I have ordered the proper sizes from the Balsa Store that will fit.
The flight surfaces have been lightly sanded to contour, without any flat spots and just sitting in the shucks for now.
The wing cores with skins and landing gear blocks with the walls and floors in place have a weight of: L/W 10 and 3/8 ounces and R/W 10 and 1/3 ounces. Not too much more to report.
Jim

David,
Very pretty airplane and gread coloc scheme. What distinguishes a Hippo Tipo from a Tipo? Is it the same size airplane or larger. What are you powered with?
I have not seen a Tipo I did not like either.
Jim