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-   -   Jim Pepino's YMF-5 Waco (https://www.rcuniverse.com/forum/scratch-building-aircraft-design-3d-cad-174/3938241-jim-pepinos-ymf-5-waco.html)

WacoNut 11-14-2008 06:24 AM

RE: Jim Pepino's YMF-5 Waco
 


ORIGINAL: Big_Bird

I forgot.

Anthony, isn't yours about due for a maiden flight? What's the hold up?
Spring:D
I still need to do the instrument panels and a couple little odds and ends, I am in no hurry to get it into the air before spring. I will put it into the air before my 33% but I expect to have both ready to fly before the weather breaks.
I do want to try those flat spins for sure, sounds like a very fun flying plane.
Anthony

hopkimf 11-15-2008 11:00 AM

RE: Jim Pepino's YMF-5 Waco
 
Guys,

I finished the ailerons and realized my two panels of Sig ribbed material are not enough and need splicing, as Big-Bird mentioned earlier. I was wondering if there is another source where I could get long enough pieces? If not, i'll order more and splice. Not a big issue.

On the top wing-cabane connection mentioned above, I like the idea of adjustment, but opted for the simple approach. I made a locating fixture for four pads and welded them to the cabane wires. My checks indicated it assembles without any shimming. I was also concerned about trying to tap the music wire without softening it. My home heat treatment - annealing- has never worked well for me.

Thanks.

Big_Bird 11-15-2008 11:40 AM

RE: Jim Pepino's YMF-5 Waco
 
Mike,

If you cut carefully, like in the peak of one of the ribs, the splice is almost undetectable. Also, if you make the splice in the curved part near the wing tip there is plenty of surplus material to do this. Like Anthony, I'm pretty picky but I'm very satisfied at how my splice job worked out. I don't know of a source other than Sig for the material.

Now for a laugh from you northern guys. Brrrrr, It has gotten chilly here. 45 degrees last night and 34 predicted for tonight. I'm living too far north.

Got to head for the Decathlon factory. I didn't get the day off.

WacoNut 11-15-2008 12:18 PM

RE: Jim Pepino's YMF-5 Waco
 
Ken,
I hate you[:@] Raining and cold here today and it is supposed to change to flurries later.

I spliced my pieces near the tip also and sanded the edges good at the splice and added a little spot putty, the splice is all but invisible.
Anthony

hopkimf 11-15-2008 06:59 PM

RE: Jim Pepino's YMF-5 Waco
 
Ken & Anthony,

Good advice. I'll splice it thru a rib near the outer end.

It's 38 F here with much worse to follow. We lived in OK some years ago and it got cold with snow and ice, like here. But in OK it was gone in a day. I golfed one year on New Years at 55 F. And spring came in Feb, not May. When we moved back up north, we just hated it. So we're in the process of locating a warm, sunny spot to rent for maybe a month in Jan-Feb time frame.

Thanks again,
Mike H

hopkimf 11-17-2008 05:16 PM

RE: Jim Pepino's YMF-5 Waco
 
Guys,

I went to SIG website to get the ribbed aileron covering and found out they no longer offer it. So I asked them for a retailer that might still have some. No help. They referred me here to RC Universe. Any ideas?

Thanks,
Mike H

WacoNut 11-17-2008 06:14 PM

RE: Jim Pepino's YMF-5 Waco
 
Ouch,
The only other option I know of it to buy some plastistrut angle pieces and glue them down individually on the aileron.
Anthony

Big_Bird 11-17-2008 07:06 PM

RE: Jim Pepino's YMF-5 Waco
 
Glad I bought the material when I did.

You can also buy some thin styrene sheet to cover the ailerons before you start CAing down all of those little strips. By doing this you can get the exact scale number rib-lets. Once you get the technique down it will probably go pretty fast. Getting over the shock of having to do it is probably the hard part.

hopkimf 11-17-2008 07:52 PM

RE: Jim Pepino's YMF-5 Waco
 
Guys,

Way back I bought two pieces, so I have enough for the top I think. Maybe I can use your ideas somehow and make up the bottom side myself.

Thanks.

Big_Bird 11-17-2008 09:18 PM

RE: Jim Pepino's YMF-5 Waco
 
After you get the top side done, take a photo and paste it on the bottom side. Nobody will ever know.:):D

skylarkmk1 11-18-2008 12:19 AM

RE: Jim Pepino's YMF-5 Waco
 
Mike,

There are only 272 corrugations on the 4 ailerons:), 34 per side x 2 sides x 4 ailerons. If you need close-ups of the Standard Waco Aluminum Ailerons, contact me via PM or e-mail. I have a bunch of pictures that show the location and spacing of the corrugations (offset from the ends), height, width, rivet pattern for the siffeners inside the ailerons, the control horn (ball end style) mounting and more.

hopkimf 11-18-2008 07:41 PM

RE: Jim Pepino's YMF-5 Waco
 
Big_Bird,

I might just do that. But seriously, how about using one of the Sig panels as a mold. Maybe I could dump a thin layer of some goop in there and come up with something that works. But what goop? Finishing resin? Can't remember what it's called? Just thinking. And then how about getting it to release? Or Maybe I could cut a bunch of slots in a piece of wood and find some real thin aluminum sheet and hammer it into the slots? Just dreaming.

Skylarkmk1,

I'm not trying to do an exact scale job. Thanks for the info, but the SIG type stuff is good enough for me in terms of spacing, etc.



Big_Bird 11-18-2008 11:24 PM

RE: Jim Pepino's YMF-5 Waco
 
Mike,

I was kidding. Take a look at this site. http://www.evergreenscalemodels.com/

Tower Hobbies carries Evergreen. Take a look at this. http://www3.towerhobbies.com/cgi-bin...&I=LXF835&P=SM

skylarkmk1 11-19-2008 02:03 AM

RE: Jim Pepino's YMF-5 Waco
 
Mike,

I understand completely and was just letting you know what to look forward to if you went all out. :)

The grooved wood and hammered aluminum have been tried and rejected, the aluminum curled too much and distorted from straight. Roof Flashing is way too thick, nearly full scale in thickness. See the Waco YMF thread in Vintage and Antiques (check the index on page 1, or post 3808).

Making a mold from the SIG panels is one way to go. Take a look at the Aluminilite site http://www.alumilite.com/ for some ideas. I would think a silicon mold of the panels would work. Secure the Panel to a piece of plate glass, seal the edges, make your mold box and pour the silicon for the mold. This way you can use the flat surface of the mold formed from the glass to help control the thickness of the new panel. Once cured, remove the mold from the glass and clean. You can then use the mold with the pattern up to let gravity help form the new part.

A layer of light fiberglass (.5 or .75 oz fiberglass or the equal in carbon fiber) with epoxy over the mold treated with mold release should work for the new panels. The epoxy (with a little colloidal silica or milled fiberglass to thicken and reinforce) will form the corrugations with the fiberglass as the flat sections and to reinforce the whole panel. Apply the mold release, paint a little thickened epoxy in the grooves, lay a pre wet strip of fiberglass over the mold and squeegee off any excess (use the edges of the mold as a guide). A slightly rough bottom surface should be no problem. If the weave is showing on the top side when pulled from the mold, primer will fill it pretty fast. Just keep it thin to look scale and the weight down.

Their Aluminilite Casting Resin may work if glued to a sturdy sub structure. The casting resin is a little lighter than the epoxy BUT only has a 3 minute open time so you would have to work fast while the epoxy (I like West Systems) has a much longer working time.

Another way to go is to use a fiberglass plate from a place like CST - The Composites Store http://www.cstsales.com/ The Plate is available in thickness from .010 to .060 and estimated weight of about 43 grams per sq. foot to 238 grams per sq ft. Pour the epoxy into the mold and place the section of pre epoxied plate into the epoxy, work out any bubbles and let set. It would be more consistent in thickness than the first method.

hopkimf 11-19-2008 09:14 AM

RE: Jim Pepino's YMF-5 Waco
 
Big-Bird and skylarkmk1,

I'm going to take a look at both ideas. Not sure if I'm good enough to pull off the mold (no pun intended), but I'll study the references.

Thanks,
Mike H

RICKSTUBBZ 11-19-2008 09:47 AM

RE: Jim Pepino's YMF-5 Waco
 


ORIGINAL: hopkimf

Guys,

Way back I bought two pieces, so I have enough for the top I think. Maybe I can use your ideas somehow and make up the bottom side myself.

Thanks.
Mike,

I remember Anthony writing that he bought wheel pants and cowl from Barth (I think). I wonder if they have aileron corrugations?

Big_Bird 11-19-2008 10:24 AM

RE: Jim Pepino's YMF-5 Waco
 
Anthony,

Did corrugations come with your AMR Waco?

WacoNut 11-19-2008 09:12 PM

RE: Jim Pepino's YMF-5 Waco
 
No it didn't, I am still trying not to think about that:D
I am not sure about Barth, I only asked about the cowl and pants. I am sure I will do a home brew on the AMR.
Anthony

Big_Bird 11-19-2008 11:17 PM

RE: Jim Pepino's YMF-5 Waco
 
"No it didn't, I am still trying not to think about that."




Shudder

Ask Michel if he has any ideas on the corrugations.

WacoNut 11-20-2008 08:10 PM

RE: Jim Pepino's YMF-5 Waco
 
I will give Michel and Dany a shout soon and ask them,
I am off to spend the day scouting for deer tomorrow, one of my favorite spots borders a State Forest and the hills are huge, it taked me 45 minutes to climb the hill and reach my spot. I just can't seem to climb that hill like I used too. The next couple of weeks will be consumed with scouting and hunting. Once hunting season is over and I have recovered I will get back at the Waco full bore.
Anthony

hopkimf 11-23-2008 11:03 AM

RE: Jim Pepino's YMF-5 Waco
 
The Waco is getting to me. On the ailerons, I sanded them with a radius on the TE. Then I cut a piece of ribbed stock and realized it would not conform to my sanded-in radius. Should have left it sharp. Then I told myself I didn't need the ribs and covered the ailerons. After finishing, I changed my mind. Now I need to strip them, square the edges and add a new TE piece and sand to size. Or, is it possible to make that stuff conform? It didn't seem like it wanted to (I'm referring to Sig. Didn't get any Evergreen yet). Big-Bird, I did read your post on the subject, but it doesn't look like it will work for me. Anybody else out there that "steps in it" like I do?

On the LG sheeting, I have plywood supplied by kit cutter. I could flare it out, and did review some posts, but wondering about an easier approach. I went through the pains of fiberglass etc. on wing saddle, but don't want to do it here.


Thanks,
Mike H

WacoNut 11-23-2008 11:14 AM

RE: Jim Pepino's YMF-5 Waco
 
On the ailerons you need to keep them square and tapered down as sharp as possibe,
You can try sanding it back then glue a new piece of balsa back on and sand it down again. On the landing gear fairings I filled in between the wires with blasa and gave it a layer of 2oz glass cloth. I know you didn't want to hear that but that is how I handled the problem. I feel your pain;) You are almost there don't let it get to you now!!!
Anthony

hopkimf 11-23-2008 06:39 PM

RE: Jim Pepino's YMF-5 Waco
 
Thanks WacoNut,

I'll take your advice on ailerons. I'll probably work up a flared out top.
Mike H

hopkimf 11-27-2008 09:23 PM

RE: Jim Pepino's YMF-5 Waco
 
Guys,

I reviewed the threads on windshields and decided to try something different. I got some brass strips and silver soldered a frame together. One for the center section and two for the side wings (rear cockpit only). I'll cut clear plastic and attach to inside. This approach was was easily done (except for the blobs of solder on inside to be filed off), and I thought easier than the fiberglass over the windshield, etc. The reason for going this way was the sum total of my previous experience where I just cut and bent some windshield material and more or less glued it in place. Nothing ever looked good or straight. This time I'll use the profile gage to nibble out the underside and make it lay down as it should. I know this is a mundane detail that any scale modeler goes through, but it's the first time I've tried to do it sorta right.

I have a Bob Dively Stearman waiting when this one is done. The Stearman is a full kit, so it should be a bit cleaner to build than this one. I know this is the wrong place to ask, but the Stearman calls for a 3.8-4.2 engine. I have two G-62s, one for the Waco and another. I don't want to buy a bigger one. They weigh about the same. Can I "underpower" the Stearman and get away with it?

Thanks,
Mike H

WacoNut 11-28-2008 12:46 PM

RE: Jim Pepino's YMF-5 Waco
 
Mike,
The Stearman should be OK on a G-62 if you keep the weght down, I would look at putting some lightening holes where you can. I have a Ziroli 87" (22.5%) Stearman framed up and it is condiderably lighter than my Pepino Waco. I have the Robart struts on this plane as well. Keep the tail light and you should be fine.
Post some pics of your windshield, don't keep all that hard work to yourself.
Anthony


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