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Old 10-14-2005, 08:40 PM
  #51  
bubbagates
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Default RE: Pay It Forward Build Thread!! Sig LT-40 build

Ok everyone, with Ken's permission and a little thought of my own I've come up with an idea.

Now I understand that designing a trim scheme from the ground up takes time and effort and I felt we needed to go one step further so along with the graphics Ken is going top provide to the winner of the trim scheme contest, I'm going to purchase a Hangar 9 Twist which will be sent to the winner. This plane is a nice second plane with the rates kept low and can do nice 3D if you want it to.

Now if you do not prefer the Twist, I'm sure it will be no problem to send the winner the cash equivalent. Now I'm gonna be a little cheap here. The plane is $99.99 on Horizon's web site but if you prefer the cash then I will send $80.00. I would prefer to send the cash if the winner so choses to a Paypal account.

The decision of the judges (SeeBee1 and his daughters) are final.

So lets start getting to work on the schemes folks

ORIGINAL: RCKen

When I first said I would do this build we (seebee1) and I didn't really have a covering design in mind. I was going to work up something when I got closer. But after some PM'ing back and forth during the day today we have come up with a different idea. We've decided to let you all, the RCU community, design the covering for Seebee. Remember that this plane is being built for him and his daughter, here is what Seebee posted about it earlier in the thread

She likes everything little girls like barbies, dolls, butterflys, Disney princess, ect..... fav colores are purple & pink I cant think of anything more to put down right now!!!! She would be happy with just about anything. Feel free to ask any questions that you might have and I can ask her.

Thanks Jim
So Bubbagates and myself are going to run a little contest here to try and come up with the design for the plane that we are building for him. Motivation for the design should come from Seebee's daughter, and as he said above please feel free to ask him any questions you might have for her. While this is going to be a friendly contest, there are a few "ground rules" that we need to go by. They are
1. All colors used need to be those available from the line of [link=http://www2.towerhobbies.com/cgi-bin/wti0091p?&C=QAA&V=TOP]Monokote [/link] .
2. No matter what color or design that is used please make sure you include the "Pay It Forward" and the "Navy Seebees" logos that I have included here.
3. While not mandatory we encourage the use of logos for other products used on this plane. These include Sig (LT-40), Futaba (Skysport 4 channel radio), Webra (.50 2-stroke motor), Top Flight monokote, Master Airscrew, Dubro, Tower Hobbies, and of course RC Universe. If you cannot find a good working copy of any of these logos please let me know and I'll get you copies of what you need.

So there you go. Nothing too fancy. What does the "winner" get?? Why the satisfaction of helping your fellow man or course!!! Actually, since Pay It Forward is pretty poor all around there isn't too much we can give, but I will put together a package of high quality vinyl graphics for the winner. I'll include the following:
2 ea, 4" RCU logos (your choice of color)
4 ea, 2" RCU logos (your choice of color)
2 ea, 3" Pay it Forward logo
4 ea, 2" Pay it Forward logo
6 each, pilot's name graphics (i.e. Pilot: John Doe) (your choice of color)
I'll see if we can't come up with a few more graphics to throw into the prize.

I'm included in this post a 3 view of the Sig LT-40 for you to use to design the covering scheme. I have a larger version of this file available on one of my servers:
[link=http://www.rcgraphicszone.com/rcstuff/LT-40_seebee1_large.jpg]Sig LT-40 3 view drawing[/link] . I've also included a copy of the PIF logo and a Navy Seebee logo for you to use.

Ok, I think that is it for now. If you have any questions about the design make sure you ask Seebee about it. Also, I'll be more than happy to answer any questions that I can.

That's it for now

Ken
Old 10-14-2005, 08:48 PM
  #52  
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Default RE: Pay It Forward Build Thread!! Sig LT-40 build

[sm=thumbup.gif][sm=thumbup.gif]

Ken
Old 10-14-2005, 11:51 PM
  #53  
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Default RE: Pay It Forward Build Thread!! Sig LT-40 build

In the previous post I layed down the bottom main spar as well as the bottom rear spar. In the next steps I'm going to start laying out the ribs as well as the shear web. I can hear some of you right now asking, what is a shear web. Forgive me here if don't get the exact “word for word definition†of what shear webs are, but I'll sure do my best to get what they do correct. Shear webs basically give the wing a lot of strength. The “backbone†of the wing is the spar that runs the length of the wing, but it doesn't have any strength if the wing is flexed up or down. This is where the shear web comes into play. It will give the wing strength in the up and down direction. Shear webs are just plain wood, usually balsa, but it's very important that they be placed with the grain running perpendicular to the spars. In this case that means the grain will run “up and downâ€. See the diagram below for a little visual aid on this. Shear webs are attached between the 2 spars (top and bottom), and have the grain of the wood running perpendicular to the spars. When shear webs are glued in the don't necessarily need to be glued to the ribs on each side, but THEY MUST BE GLUED TO THE SPARS ON TOP AND BOTTOM. I know that sounds weird that they don't have to be glued on the sides, but remember that we are going for strength up and down. Now with that said, I do glue it to the ribs on each side. Every little bit helps, but as said above it won't hurt if you don't get it glued. See first diagram for an example of how shear webbing can be attached. It can be attached to the outside of the spars, and glued to the front or back of the spar. As I said above, it doesn't have to be glued on the sides to each rib, but IMHO it's better if you glue it to the ribs. The other way to attach shear webbing is to glue it in between the spars, forming an “I-Beamâ€. Both ways of building shear webbing will work. If asked for my opinion I'll tell you that gluing to the outside of the spars is definitely easier to build. On this LT-40 it calls for the shear webbing to be built in between the spars, as an “I-Beamâ€. Since the shear webbing is precut I don't see any reason to do it differently than the instructions call for.

I've learned a few things the hard way as I built kits in the past. One of those things that I learned the hard way is to test fit. I just started applying glue to parts and slapping them in place. If you can't already see the problem with that I'll tell you what it is. Not all parts fit correctly right out of the box. Sig makes wonderful kits that have great quality in their cut parts, but even those need to be test fit when you build. If you just start slapping parts on, you're going to end up with a mess of a plane. Trust me on this one, learn from my experiences. The biggest parts you going to need to test is the ribs, and how they sit on the spars. Since this is a flat bottom wing, and we are building on a flat building surface, we want to keep the bottom flat. And this can be our “point of referenceâ€. You want all the ribs to sit flat on the floor when they are in place on spars and in the notch on the trailing edge. In the case of the W2 and W3 rib it will rest flat on the balsa sheeting built earlier in the build. As you can see in the second picture, there is a gap between the bottom of the rib and the sheeting. In order to close that gap we'll need to make the “notch†in the rib deeper, so that the rib will sit lower on the spar and the rib will be flush with the sheeting. Use your x-acto knife to trim material away from the top of the notch in the rib, see picture 4. When you are trimming away trim it A LITTLE BIT AT A TIME, and check often to see if you have it correct. Remember, you can always keep trimming but it's almost impossible to replace the wood. Once you it correct the rib will sit flush on the sheeting, or flat on the building board for ribs W4 and W5. If you have a gap between the top of the spar and the notch in the rib, see picture 6, you will need to sand a little bit off of the bottom of the rib. Use a sanding block to remove a little bit of material at a time. You want to use the sanding block so that you keep the bottom of the rib flat. Just like before, remove a little bit at time and check your progress often.

Ok, I'm going to wrap up this post now and for the next post I'll start putting the ribs in.

Pictures
1. Example of shear webbing, and where it adds strength
2. Difference in shear webbing mounting
3. Improper fit of W3 rib. Bottom of the rib not firmly against bottom sheeting.
4. Area needed to trim in order the adjust the fit of rib on the spars
5. Completed adjustment. Rib sitting firmly on the bottom sheeting.
6. Another improper fitting rib. Notch in rib does not touch the top of the spar.
7. Sand the bottom of the rib to adjust the fit of the rib on the spar.


Until next time

Ken
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Old 10-15-2005, 09:56 PM
  #54  
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Default RE: Pay It Forward Build Thread!! Sig LT-40 build

Wow, it's easy to get behind in the posts. So far I've got a good portion of the left wing built but I haven't shown you all anything yet. So it's time to correct that. I'll run through the steps as they are laid out in the instructions. As I proceed with this build this may be the way it goes. I may go a bit without any build posts, and then I'll post a large number in a row. As I said before, each post will be limited the the number of pictures I can post at one time.

As we get ready to lay out the ribs I want to retype a note that is printed in the instructions:

Note: It is possible for plan paper to shrink or expand slightly with humidity changes. If it has, this is where you will notice it! You may find that the rib notches in the trailing edge do no exactly match the rib location on the plan. Nonetheless, they should be very close, not off by more than the thickness of a rib. A slight difference is nothing to worry about! The machine-cut notches in the trailing edge are correct, and you should build your wing according to them. To install a wing rib in the steps coming up, simply put the rear end of the rib in the notch, and then align the rest of the rib parallel with the rib lines on the plans. Do not alter the notches in the trailing edge!
There is a very good reason why I wanted to re-type this warning from the instructions. A lot of the time new builders will look at the plans and consider them “gospelâ€, and in some cases that can be bad. In this case, if you line up the ribs with the plans there is a very good chance that your wing will turn out warped or crooked. In this case use the trailing edge(TE) as a starting point, and then layout your ribs using the TE as guide. As you lay out each rib make sure that the distance between the ribs stays constant all the way through the length of the rib. Although the instructions didn't mention this in advance, there is a very good guide that you can use that will simplify laying out the ribs. The shear webs. All of the wing bays, with the exception of the last two outer bays, have shear webbing between each rib. Since this is the case you can glue the shear web to an installed rib, put the end of the rib in the notch in the TE, and then set the rib on the rear and main spar correctly by seating the rib firmly against the installed shear web. Don't worry if this sounds confusing. It will all become clearer as we start laying out the wing, also you can refer to the pictures to see what I am talking about. But what I am saying is that sometimes you have to use the plans a guide instead of “gospel†in laying out what you are building. Reading the instructions and looking at the plans before starting to build will usually help you realize that you may have to “fudge†from the plans a bit to get a good build.

There are 5 different ribs that will be used on the wing, W1-W5, so we will want to make sure that we have the in the proper order before we start setting the ribs. W1 is the root rib, meaning that it is the very center rib. W1 (root rib) of each wing panel will be butted up against each other. Then moving from the center of the wing panel the next ribs in order will be W2, W3, and W4. Then from that point to the outside of the wing all the ribs will be identical, being the W5 rib. It needs to be noted that ribs W2 and W3 are a little smaller than the rest of the ribs. This is because they will have balsa sheeting over them when the wing it constructed. What I like to do at this point is pull out all of the ribs I will need for this wing panel, and then lay them out in the order they will be in on the wing (see picture #1)

Ok, let's start laying out the ribs. The instructions tell us to set ribs W2 and W3 first. Since the notch in the TE didn't line up exactly with the plans, and taking into account the note from the instructions I posted above, I chose to start with the W3 rib. The reason why I wanted to start with this rib is because we have already laid out the sheeting that will cover W3 and W2, and since this sheeting covered the printed plan below there was no reference point for me to put down the W2 rib. Whereas if I put down the W3 rib first I could then use that as reference for placing the W2 rib. The best reference point that I can recommend is the actual line for the root rib (will be the far right side of the wing). I guess you could have done the same thing and place the W2 rib first, but I don't think it would really matter. So whichever way works best for you I'd say go for it.

Picture #2 shows a test fit of the rib over the already applied sheeting. As I said in my previous post, you want to make sure the fit is tight here. Another quick note, glue cannot fill a gap, Any gap you have where parts join will weaken the overall structure of the wing, so you want to try and get your parts as tight fitting as you can. When you are test fitting the part you will want to mark it's final location because we will need to remove the part to apply glue (this won't aply if you are using CA. You can just leave it in place). Since I have to wait for glue to dry I prefer to do several parts at once, and then wait for the glue to dry. In this case I want to glue in W3 and W2 and the same time so I can weight them down while they dry. With W3 dry fit in place measure the distance on the TE between the notches for W3 and W2. Move up to the rear spar and mark the same distance, and do the same thing on the main spar. This will give you the location for the W2 rib. As with the W3 rib you will want to test fit the rib to ensure a tight fit on the spars and the sheeting. When you are satisfied with the fit mark the location for the W2 also. Once you are satisfied with the fit of the W3 and W2 rib apply a bead of glue along it's edge (picture #5) and put it in place on the location marks you made. Once the glue was applied and both ribs are placed in location I double checked the alignment for both ribs. Satisfied that both ribs are in place I put a sheet of scrap balsa wood on top of the ribs, then placed a couple of weight bags to hold the ribs in position while the glue dried. I wanted them to have some weight so the joint with the sheeting was a tight bond.

Since this is where I stopped for the evening while I was building I will wrap up this post so I can it up on RCU. As soon as this is posted I will start writing up the next posts. Like I said at the start, I have a lot to write up.

On the next post I'll work on spacing the ribs and shear webs on the spars.

Pictures
1. Laying out all ribs in the order they will be installed
2. Test fitting rib W3 to ensure a tight fit on the spar and with the balsa sheeting already in place.
3. Another shot of test fitting.
4. A 3rd shot of the test fit.
5. Applying a bead of glue on the rib before setting it in place.
6. Using weight bags to hold the ribs W3 and W2 in place while the glue dries.


Until next time

Ken
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Old 10-16-2005, 07:48 AM
  #55  
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Default RE: Pay It Forward Build Thread!! Sig LT-40 build

Alright, here we go with the next steps. As I said in my last post, I've already got most of the wing built but I need to catch up on the paperwork!!! So far we have the bottom main and rear spars, the trailing edge (TE), the bottom sheeting, and ribs W2 and W3 in place. Now it's time to start setting the rest of the ribs. Although it sounds like a lot of work, the rest of the ribs don't really take that much time. If you are building along it should take less than an evening to get the rest of the ribs in place. The biggest key here is to practice how to set the rib. We are going to use the shear webbing (since they are precut to size) and a ruler to place the ribs. If you were lucky and the notches in your TE match your plans (see the note in my last post) it will be a piece of cake for you to set all the ribs, but for the rest of us we need to set the ribs using the notches in the TE as a guide. Ok, let's get going on these.

The next rib out from W3 is going to be W4, so make sure that you have the correct rib to go in place here. Once the W4 rib is set then all the ribs from there out to the end of the wing will be all W5. As I place these ribs I'm going to do it 2 different ways in order to show both ways of setting ribs. For W4 and the first W5 rib I'm going to measure the distance for each rib. First measure the distance from W3 to W4 at the notch on the TE (picture #2), make sure your measurement is accurate. Remember what I said going into this thread “Measure twice, cut onceâ€. Yeah, yeah, yeah, I can hear you now, “We're not cutting, we're glueing!!†You know what I mean!!!! Picture #3 shows transferring the measurement to the rear spar, you'll do the same thing on the main spar too. Test fit the rib in place where it will sit on the spars. You might ask why we are test fitting it since it won't be glued to sheeting like it was for W2 and W3. Simple. You will need to check the fit on the how it sits on the ribs.

Remember, each bad fitting joint will weaken the wing. But if you take time to ensure all joints fit tightly you'll be rewarded with a very strong wing. I'll let you in on a little secret — The difference between and average builder and an expert builder is simply attention to detail. Not rushing through your build and paying attention to things like these joints goes a long way to making an expert builder.

Back to the build. If the rib doesn't fit tight against the board AND the top of the spars, then take a few minutes to adjust the way it fits. Once you are happy you're ready to glue the W4 rib in place. Unlike the W2 and W3 ribs, we are going to put glue only at the notches for the spars and the back end of the rib where it will attach to the TE. Set the rib in place and double check your measurements to ensure the rib is in the correct place. Use 2 sets of the 90° brackets I discussed earlier to make sure the rib is perpendicular to the building board. It would also be a good idea to double check with a square to ensure the rib is correct (picture #7). Also, before your glue sets we are going to double check with the SW2 shear web. It should fit snugly between W3 and W4. If it does fit snug then you are good, if not adjust the position of the rib.

Why did I measure the ribs in the first place when it would have been easier to just use the shear webbing to place the ribs? Remember, my main goal for this thread is as a teaching tool for others out there thinking about building a plane. Buy showing different procedures I can hopefully help others out there see ways of doing things in there builds. Although I am building an LT-40, a lot of these procedures will be used as you build other types of planes.

I want to stop here for a moment and point something out in particular to this build. When we built the main spar we used a spar doubler on the inner portion of the spar in order give it added strength. The end of that spar doubler will be at the inside edge of rib W5 (see pictures 9,10, and 11). What should be done here is to cut the spar doubler to length to fit. Once you have your measurements for placing the rib use a straight edge razor blade and very very carefully cut through the spar doubler (be careful to not cut into the spar below it) and remove the extra spar doubler. The rib needs to be fitted tightly against the spar doubler, as this gives extra strength to the wing. Once you have it properly trimmed you can now glue in the first W5 rib using the same procedures for placing and double checking your rib that you did for the W4 rib.

We now have ribs W2, W3, W4, and the first W5 rib in place. This is shown in picture #12.

Pictures
1. Ribs W2 and W3 in place, ready to start placing the remaining ribs
2. Measuring the distance between ribs by checking the distance between notches on the trailing edge
3. Transferring the measurement to the rear and main spars
4. Double checking the distance between ribs at the leading edge of the ribs.
5.Ribs W4 and W5 in place.
6. Between ribs W3 and W4 before shear webbing
7. Using the shear webs to double check the distance between ribs.
8. Checking to ensure the ribs are perpendicular to the spars
9. Showing position where spar doubler should end
10. Another view of spar doubler end
11. One more view. Important that spar double butting up tight with rib W5 for strength
12. View of ribs W2-first W5 in place.



Until next time

Ken
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Old 10-16-2005, 07:52 AM
  #56  
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Default RE: Pay It Forward Build Thread!! Sig LT-40 build

Boy Ken,

Looks good. I know you did the build last nght, but you did the post this AM and probably with only one cup of coffee.

Looking better and better, SeeBee1 is gonna love this
Old 10-16-2005, 12:11 PM
  #57  
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Default RE: Pay It Forward Build Thread!! Sig LT-40 build

Ken does that ever look cluttered with all the magnets. The build looks great and yesterday i went out to my father in laws farm because he said he had a sheet of metal that was 2' by 4.5' that he said i could have for a building table. I took three different levels and moved them all around to see if the surface was perfectly flat. Lucky me it was except for about 4 inches on one end. So a little torching and some grinding later viola!! a building table that i can use magnets on. Any place that i can buy just magnets that you know of ken that work good for modeling. Thanks

Flyboy76

p.s. i pity the fool that tries to steal my table hee hee it weighs about 250 lbs with the legs welded on.
Old 10-16-2005, 12:40 PM
  #58  
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Default RE: Pay It Forward Build Thread!! Sig LT-40 build

Flyboy,
Yeah, now that you mention it I guess it is cluttered. I really hadn't thought about it much. The amount of magnets I use it different for each build.

Good luck on your set up

Ken
Old 10-16-2005, 02:49 PM
  #59  
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Default RE: Pay It Forward Build Thread!! Sig LT-40 build

What a busy guy you are! Is Lawton in some special time zone that recieves 48 hrs in a day? Looking good, your magnet system still amazes me!


Mark
Old 10-16-2005, 10:42 PM
  #60  
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Default RE: Pay It Forward Build Thread!! Sig LT-40 build

I got a question. Or rather a problem. PHOTO 1: Although the plans do not call for beveling of the wing tip bottom where it meets the rib, should I to make the ends meet better? PHOTO 2: How do I fill in this huge gap at the L.E end of the wing tip plate? The plans say there are gaps but I never expected this big!!! Tip not glued in yet by-the-way .

P.S: I love this thread - getting better and better. Can not wait to see more [sm=thumbup.gif]
Old 10-16-2005, 10:49 PM
  #61  
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Default RE: Pay It Forward Build Thread!! Sig LT-40 build

Tigerdude,
Ok, as far as the bottom of the wing. Yes you do want to "bevel" it off. Remember, this is a flat bottom wing and they way you have it will leave a "bump" in the covering at the wingtip. You want a nice flat transition into the wing tip.

As for the gap, it's hard for me to tell from you pictures. If you can wait until tomorrow I'll have the wing panel on my build off the table where I can do the wing tip also. I should be able to get you an answer as soon as I can see how it all goes together. Sorry that I can't be any more help right now.

Ken
Old 10-16-2005, 10:54 PM
  #62  
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Default RE: Pay It Forward Build Thread!! Sig LT-40 build

Thank you so much, I can wait - I have plenty more to do, such as start the right wing panel!!!

You being the professional you are, I am sure you will know what to do, I am not worried . Wish some day I could be as good as you and the other members here - but I don't know [sm=bananahead.gif]
Old 10-16-2005, 10:59 PM
  #63  
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Default RE: Pay It Forward Build Thread!! Sig LT-40 build

Tigerdude,
you'll get there. Just takes practice.

Ken
Old 10-17-2005, 11:30 AM
  #64  
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Default RE: Pay It Forward Build Thread!! Sig LT-40 build


ORIGINAL: elenasgrumpy

What a busy guy you are! Is Lawton in some special time zone that recieves 48 hrs in a day? Looking good, your magnet system still amazes me!


Mark
48 hours? Man, I wish days were that short!!!!

Sometimes I wish I had that much time to try and get things done. But I'd rather be busy than sitting around bored all the time.

This may sound silly, but the magnetic system really is way cool. It still amazes me too. I don't know how I ever built without it. I just can't find enough words to encourage others to consider setting up a system like this. There has a been a lot of comments made to me about the system since I started this build, but I do want to make sure that I give the credit back to RCU member Caffeenman. He's the one that documented the instructions that I used to set up my system.

Ken
Old 10-17-2005, 01:06 PM
  #65  
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Default RE: Pay It Forward Build Thread!! Sig LT-40 build

I guess I owe everybody a little apology. The “real world†stepped up and stopped my from posting the rest of my progress. First off, I had a really good day at the flying field. The weather was just about perfect, so of course I had to stay out and get in some extra flying. Then after I got home a couple of problems at one of my clients kept me working for the rest of the day, and into the night too. So I wasn't able to back on here to finish catching up posting the build. So, let me take a bit of time and finish catching up my postings to where the build is at.

In my last post I described setting the ribs by using a ruler to measure the distance between the notches on the Trailing Edge (TE), and marking that same distance on the 2 spars. Now we'll talk about the easier way of doing, and that is using the shear webbing to space our ribs. Even though I showed both ways of placing your ribs, this is probably the best way of doing this. This is because you want a tight fit of your shear webbing between each rib. Even when doing very accurate measuring it's possible to be just a bit off when marking. We're all human, so it's possible to be a bit off. By using the shear webbing to place the ribs we can ensure a tight fit between the ribs because we will be gluing the ribs in place by butting them against the shear web. We should have the first W5 rib in place so far. Before we start placing the remaining ribs, let's take a few minutes to catch up and place the shear webbing between the ribs that we have in place already. On the main spar we are going to place a SW-2 shear web between ribs W3 and W4, and on the rear spar a SW-3 shear web will be places. Apply glue to the sides and the bottom of the shear web and put it in place between the ribs.

NOTE: Since the shear webbing is an important structural component of the wing you want to make sure there is a very good joint here. This is no place to skimp on glue. I recommend going along the bottom of the shear web where it sits on the spar and put in a fillet of glue along the length of the web, with fillet meaning putting a bead of glue into that joint (if you are using CA for your build you will want to use medium or thick CA to do the fillet). I can't stress enough the importance of having a good joint with the shear webbing. Also, remember from our discussion of shear webbing in previous posts, the important joints are the top and bottom joints where it joins with the upper and lower spars. I do however recommend that you also make a good joint on both sides of the webbing where it meets the ribs.

Now place the shear webbing between W4 and the first W5 rib. You will use another SW-2 on the main spar, and a SW-3 on the rear spar. Gluing it in place will be identical to the first one that we did. Once we have that we are now “caught up “ with the ribs that we have in place. Now we will use the shear webbing to place the next ribs. It's a pretty simple procedure to do them. Even though it's easy, I try to pay extra attention on tasks like this because it's the easy tasks that I get sloppy and make mistakes. Starting at the W5 rib that is in place put a SW-1 shear web on the main spar and a SW-3 shear web on the rear spar. With these in place you can now set the next W5 rib. Of course we should dry fit everything before actually using glue. (“Measure twice, glue onceâ€). The last SW-1 shear webs that will be put in place will be in the 3rd bay from the end of the wing (2 open bays with no webbing), and the last SW-3 shear web that will be in place will be the 4th open bay (3 open bays with no webbing) (see picture #8). Once we get down to the last shear web we are back to measuring the distance for placing the ribs. As you place the ribs in place make sure that you keep using the 90° brackets on each rib to keep it perpendicular, you can see these brackets in us in pictures 4,5,6,7,8,9, and 10. It doesn't hurt to check each rib with a square also as you install the ribs. Trust me, it's a lot easier to double check everything as you build than it is to un-do a mistake (voice of experience talking here!!!! ).

Once you have the last W5 rib set this is a great time to take a break. I said, take a break. Yep, put your feet up and relax for awhile. Why so pushy? Because it's really easy to get moving too quickly. Once you get into a groove it's easy to “get addicted†to progress, you want to finish more. This is when huge mistakes start happening. I like to take a break every half hour or so, and I try to not work late into the night, because mistakes happen when I get tired. And besides, it's time to let all the glue to dry on all of the ribs before we place the top spars and the leading edge. Pictures 9 and 10 show where we are at right now.

So let's take a break for now.


Pictures
1.Getting ready to place shear webbing.
2. Shear webbing SW-3 in place on rear spar.
3. Showing shear webbing on the main spar.
4. Shear webbing SW-1 in place on main spar
5. Another shot of SW-1
6. A set of ribs with shear webbing in place between them.
7. Shear webbing in place and ready to place the next rib.
8. Locations of final shear webbing.
9. A shot of all ribs in place.
10. Final ribs in place.

Until next time

Ken
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Old 10-17-2005, 01:58 PM
  #66  
MinnFlyer
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Default RE: Pay It Forward Build Thread!! Sig LT-40 build

Possible color scheme?
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Old 10-17-2005, 02:06 PM
  #67  
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Default RE: Pay It Forward Build Thread!! Sig LT-40 build

Mike,
Kewl!!!!!!!!!!!! I like it!!!!! Let's see what Seebee thinks.

Come on everybody. Let's see your ideas here. As you can see by what Minnflyer has done, there isn't really any limits on the covering design. So have some fun with it. And remember, the winner will get a new plane out of it!!!

Ken
Old 10-17-2005, 02:35 PM
  #68  
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Default RE: Pay It Forward Build Thread!! Sig LT-40 build

ORIGINAL: MinnFlyer

Possible color scheme?
Uh oh, the god of photoshop is at work. Looks good Mike...
Old 10-17-2005, 06:24 PM
  #69  
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Default RE: Pay It Forward Build Thread!! Sig LT-40 build

Now that the glue has had a chance to dry, we can work on the leading edge, the top main spar, and the rear main spar.

As we get ready to put the main and rear spar in place we need to take a minute and take a look at how the parts fit together. This goes back to discussion on the shears webs, and also what I talked about with gaps. Any gaps between parts will make a weak joint, and since the shear web gives our wing strength we want to install the top spars so there is no gap between the top of the shear web and bottom of the spar.

If you look at picture # 1 you can see the the top of the shear web sits lower than the notch in the rib, this will result in a weak joint when we put the spar in place. To correct this we need to take a little bit of wood from the bottom of the notch in the rib. Picture # 2 shows using an X-acto knife to carve off the wood. Just like everything else, do a little bit at a time. Picture #3 shows another great tool that will come in handy in a lot of places. It's a nail file that you can pick up in the beauty department at Wal-mart, picture #4 shows using the file to file down the notch level with the top of the shear web. Picture #5 shows the notch even with the shear web now, and a test fit of the spar in picture #6 shows that we have a good tight fit between the spar and the shear web. This is exactly what we are trying to get, this will give you very strong joint. At this point don't worry if they don't match up exactly, as a little difference can be taken care of with some sanding later. Please note in picture #7 the 3 inner ribs do not extend all the way to the top of the spar. This is because there will be sheeting installed on top of these ribs. For now we need to focus on the joint between the spars and the shear web. Picture # 8 shows the test fit of the top main spar, and #9 shows a test fit of the top rear spar.

The instructions tell us to compare the leading edge to the cross section on the plans to see the proper alignment of the leading edge. If you look at picture #10 you will notice that the leading edge is not a symmetrical piece, so it's important that you get the proper alignment for this part. I've marked the part with an arrow in order to show which way is up. Picture #11 shows a test fit of the leading edge.


Pictures
1. Difference between the top of the shear webbing and the bottom of the spar notch in the ribs.
2. Using an X-acto knife to remove wood from the notch.
3. Cheap nail file can be found at Wal-mart.
4. Using the file to sand the notch in the rib
5. Bottom of the notch now is even with the top of the shear web.
6. Test fit of the spar shows a tight fit between the shear web and the spar.
7. First 3 ribs sit lower than the top of the spar. This is to install sheeting.
8. Test fit of the top main spar.
9. Test fit of the top rear spar.
10. Marking the leading edge with the proper alignment
11. Test fitting the leading edge.


Until next time

Ken
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Old 10-17-2005, 06:48 PM
  #70  
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Default RE: Pay It Forward Build Thread!! Sig LT-40 build

Now that we're satisfied with the fit of the top main spar, the top rear spar, and the leading edge it's time to go ahead and glue them in place.

(NOTE: If you are using CA you will need to use thick CA to glue the spars in place. This will give you enough time to apply the CA and still get the spar in place.)

Picture #1,#2, and #3 show applying a bead of glue to the notches and top of the shear web. Just like gluing in the shear web to the bottom spar you don't want to skimp with glue here, we want this to be a strong joint. Once you have the glue in place go ahead and put the top main spar in place. You will need to put weight on the spar to hold it in place while the glue dries. Picture # 4 shows holding the spar in place. I've used the fixtures from my building system to hold it down, you can use anything that will safely hold it in place. Now do the same with the top rear spar. Picture #5 shows the spar being held in place with weight bags (I did not have enough fixtures of the size needed to hold both spars at the same time ). Before gluing the leading edge in place I marked the location of the ribs while I was test fitting it in place. I apply the glue to the marks that I made and put the leading edge in place. Picture #7 and #8 shows the fixtures I used to hold the leading edge in place while the glue dries. Once the glue is dry you can now remove the wing panel from the building board.

Ok, now we are caught up with the posts now. This evening I will be removing the wing panel from the board and I plane on addressing Tigerdude's problem with the wing tip.


Pictures
1. Applying glue to the notches in the ribs and the top of the shear web.
2. Applying glue to the notches in the ribs and the top of the shear web.
3. Applying glue to the notches in the ribs and the top of the shear web.
4. Holding down the top main spar while the glue dries.
5. Holding down the top rear spar while the glue dries.
6. Applying glue to the leading edge.
7. Holding the leading edge in place while the glue dries.
8. Another angle of the leading edge.

Until next time

Ken
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Old 10-17-2005, 06:55 PM
  #71  
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Default RE: Pay It Forward Build Thread!! Sig LT-40 build

outstanding work Ken. Wanna build one for me?
Old 10-17-2005, 07:25 PM
  #72  
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Default RE: Pay It Forward Build Thread!! Sig LT-40 build

Mike, Nice color scheme! How are you doing that?

tsands I too would like to send him a 4* sixty, & have it come back as an ARF!

Looks good Ken, yep I'm back but ouch!.[sm=frown.gif]

Mark
Old 10-17-2005, 08:00 PM
  #73  
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Default RE: Pay It Forward Build Thread!! Sig LT-40 build

Hey guys,
You bet. I love to build. I'll figure out a way to get you all taken care of. Just have to stay home from work is all!! Just don't tell the boss that I'm home building a plane. shhhhhhhh. It's a secret! oh yeah, we own the business. rats!!!!!


Ken
Old 10-17-2005, 08:36 PM
  #74  
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Default RE: Pay It Forward Build Thread!! Sig LT-40 build

ARF????? I want mine RTF!!!!!
Old 10-17-2005, 08:44 PM
  #75  
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Default RE: Pay It Forward Build Thread!! Sig LT-40 build


ORIGINAL: elenasgrumpy

Mike, Nice color scheme! How are you doing that?

tsands I too would like to send him a 4* sixty, & have it come back as an ARF!

Looks good Ken, yep I'm back but ouch!.[sm=frown.gif]

Mark
Mike's considered the god of Photoshop here on RCU. I wouold not be afraid to bet he did it with that


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