Posts: 14714
Joined: 7/10/2002 From: Lawton, OK, USA Status: offline
Ok, I promised it and here it is. This is my build thread showcasing the build of a basic trainer type airplane. I have been considering doing a build thread of a trainer for about 6 months now in order to show a lot of new pilots that it's not as difficult to build a kit as they may think. A recent request in the Pay It Forward thread , http://www.rcuniverse.com/forum/fb.asp?m=3381064 , was for to help get a family into the RC hobby. I offered to build a plane if a kit was provided. This was the perfect opportunity for me to do this build thread. So I'm going to kill two birds with one stone here.
When I was asked which trainer kit to purchase for this build it was almost a no-brainer on the answer, the Sig LT-40. First of all, this is a very good flying trainer. It's a little bit bigger than other 40 size trainers which makes it a little bit more stable in the air and also makes it easier to see. The second reason for choosing this plane is that it is easily the most complete trainer kit on the market today. Anybody who has ever built a kit knows that you always have to read the “required to finish” list on any kit you buy. The Sig kit has everything you need to build this plane except for the covering material, glue, and building tools. There is no other trainer kit on the market that is this complete that I am aware of.
This build thread will cover everything from when I open the box starting this build all they way through the maiden flight of the plane. I plan on building this plane as close to the instructions as I can. If I make any changes from what the plans instruct I will document exactly what I am doing differently, and why I am doing it differently. I've been in the RC hobby for almost 10 years now and I have been building for 8 years. During this build I encourage comments and questions from everybody out there, because the RCU audience is why I am doing this thread.
Since this is going to be a construction article as well a forum for questions I will be taking lots of pictures as we go, and I'll post as many of those pictures as I can. If there is something you don't understand please feel free to ask me about it and I'll try post additional pictures to help explain it. Or if there is something that want to see that I haven't provided a picture of please let me know.
I will be building in the exact order of the instruction manual provided with the kit. On a lot of kits that I build I sometimes will vary the building sequence, but I want to do it in order here to help cut down on any confusion.
Ok, here we go. The first pictures posted here are of my working area, the magnetic fixtures I use to build with, the required shot of the unopened kit box, and first opening of the box.
Pictures 1. The "Box" picture. Unopened box. 2. Instruction manual removed from box.
Until next time
Ken
< Message edited by RCKen -- 10/10/2005 3:55:29 AM >
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The take off is optional, but the landing is MANDATORY!! AMA # 712539 www.gettingairborne.com Moderator- Beginner''s, Sport Flying, Off-Topic, & AMA Discussions RCU Community Moderator
Posts: 14714
Joined: 7/10/2002 From: Lawton, OK, USA Status: offline
Post #2 A lot of people that I have met think that they need a shop full of expensive tools to build a kit. This really isn't true. Having a lot of tools sometimes makes things a bit easier, but you don't “have” to have them to get the plane built.
Here is a list of tools that you'll need (most of this list is from the LT-40 instruction manual): - Building board. 12” x 36” minimum size. There have been lots of discussions on RCU about the best building boards to use. You can do search on RCU and you'll definitely dig up plenty of suggestions. The most important thing that you are looking for in a building board is that it is FLAT. Some people will confuse flat with level and spend lots of time making sure that the board is exactly level with the floor, but this doesn't do anything, you can have a board that is level and not be flat. The best way to tell if your board is flat is to get a 36”-48” metal straight edge and lay this on it's edge across the board from different directions. There should be no gaps between the board and the straight edge. A board that isn't flat will build warps into your wing and fuselage assemblies. So you want to spend a little time getting a flat board.
A good source for a flat surface is to go to your local Lowe's/Home Depot/Lumber store and get a 2'x6' hollow core door. They aren't very expensive to start with, but if you ask the store if there are any that are damaged you might save a few bucks. Usually the damage will be cosmetic and won't affect the door for use as a building surface. Before I went to a magnetic building system I would push the pins directly into the door, but it can be hard to push them in for some, so you may want to get something to put on top of the door to push pins into. Acoustic ceiling tiles (turn them over and they are flat without the holes in them) and sheet rock are two things that work really well for this.
-Plan covering material. You want this to cover the plans with. Since you will build directly on top of the plans you will need to cover them to keep glue and epoxy from getting on them. A lot of people use wax paper, but I prefer plastic sheeting. Look for 3 or 4 mil poly-vinyl sheeting in the painting department at Wal-Mart or Lowe's. A roll will last for several years.
-T-pins. -Masking tape -Rubber bands. #32 and/or #64 -Scissors -Ruler. Preferably a metal edged ruler. This will give you a good straight edge that you can use to cut with. You don't want to cut using an x-acto knife and plastic ruler. -Pencil -Modeling knife. An X-acto #11 knife. IMHO you just can't have enough of these. -Razor Saw. This is probably one of the best “must have” tools out there -Single edge razor blades. You can't have enough of these either. If you buy them at Lowe's/Home depot you can get a box of 100 and save some money. -Triangle. -Assorted Screwdrivers -Pliers. Regular and needle-nose. -Drill. And a few assorted drill bits. -Covering Iron -Sandpaper. 80, 220, 320 grit. You can use scraps of lumber as sanding blocks instead of spending money on aluminum sanding blocks.
A few of the “nice to have” tools are a heat gun, and Hobbico slot machine (for cutting hinge slots) but you can live without them.
Ok, before we officially get going here I do want to point out one big difference in they way I build as opposed to others in the hobby. Most builders will have a board that they build on where they can use pins pushed into the board to hold the parts in place as they build. I used this method up until about a year ago and then I converted to using a magnetic building system. For instructions on building a magnetic system please reference, Magnetic building system at www.airfieldmodels.com . My building table consists of a 24”x72” sheet of 18 gauge steel which is placed on a hollow core door. The door is what makes the building surface completely flat while this steel is used for the magnetic building fixtures. The difference between methods I will use and those used using pins aren't enough to really make a huge difference.
The other difference you will notice in the way I build is that I don't use the CA adhesives that are popular these days. I use Elmer's Carpenter's Glue (another good brand to use is Titebond II) for building. For steps in this kit like installing the CA hinges I will use CA, but for the main build I will use Elmer's and epoxy for the build. I used to use CA when I build, but I made the decision to switch to wood glue about 2 years ago. My main reason for switching was the fumes, they can be very harsh on your eyes, nose,and lungs and I just got tired of the discomfort. When you build with CA your parts have to be positioned correctly when you apply the CA, otherwise your part is stuck where it is out of place. With wood glue you have time to get your parts positioned correctly before the glue starts setting. Also, CA will make the wood it is applied to very hard and when you start sanding it can be difficult to get a good finish. The surrounding wood will sand away quicker than the wood with CA applied to it. With wood glues, the glued joint will sand just like the wood itself.
Pictures 1. Magnetic building system fixtures 2. Magnetic building system 3. Magnetic building system 4. The very "basic" tools
Until next time
Ken
< Message edited by RCKen -- 10/10/2005 6:20:48 AM >
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The take off is optional, but the landing is MANDATORY!! AMA # 712539 www.gettingairborne.com Moderator- Beginner''s, Sport Flying, Off-Topic, & AMA Discussions RCU Community Moderator
Posts: 14714
Joined: 7/10/2002 From: Lawton, OK, USA Status: offline
First step, place the box on your work area and make sure you have plenty of room. Open the box and remove the instruction manual and the plan sheets. At this point, CLOSE THE BOX BACK UP. I know, I know, you're all excited about the brand new kit you just got home with and this is going to be hard to do, but you need to do it. Leave everything in the box (except the instructions and plans) for now.
READ THE INSTRUCTIONS COMPLETELY.
There isn't a better way of saying it than that, but read the instructions. Yes, it is dull reading but this is probably the most important thing you can to do help ensure successful build. I can't count how many times I have seen somebody open the box, the manual, and a bottle of glue and start building the plane, and yes the results will show (anybody remember Chad? Opps, did I say that out loud). Sometimes instruction manuals will have steps that aren't quite clear about a step, but in later steps it will become clear as to why something needs to be done a certain way. Also, as you read you may find that there are things you want to be aware of when you get to a step, this is the time to start making notes in the instruction manual. Also, as you read the manual cross reference to the plans. The plans will help you understand things in the instructions. The manual and the plans should be used hand in hand. Don't pick up any wood, glue, or a knife until you COMPLETELY understand every step in the manual.
Now, on to the next step. Re-read the manual. Arrrggghhhhh. I hear you all groaning out there. I'm just trying to point out how important this is. This is probably the most important thing you can do to help ensure a successful build, understanding what you are going to be doing. I usually read the instructions 3 times before I start the build. Then as I build I will re-read the step I am getting ready to do, this will refresh in my mind what I need to do and let me make notice of any notes or special instructions I may have made when I was reading them initially.
Pictures 1. Opened box. 2. Instruction manual removed.
Until next time
Ken
< Message edited by RCKen -- 10/10/2005 4:06:39 AM >
_____________________________
The take off is optional, but the landing is MANDATORY!! AMA # 712539 www.gettingairborne.com Moderator- Beginner''s, Sport Flying, Off-Topic, & AMA Discussions RCU Community Moderator
Posts: 14714
Joined: 7/10/2002 From: Lawton, OK, USA Status: offline
Now we get to finally dig into the box!!! Yippee!!! Make sure you have enough clear area to take everything out of the box. What we are going for here to lay out everything and inventory it all to make sure we have everything, also want to make sure that nothing is damaged. We're not going to cut out anything at this time, just label everything and inventory it. Sig does a great job on their instruction manuals in the fact that they will include a key to all the die-cut and laser cut part sheets (see first picture) which will help you identify and label everything.
Anybody who has ever built a kit has at one point or another used the wrong stick of wood. A lot of times kits will have two different sticks with the same dimensions but different lengths. The longer sticks are usually needed for crucial items (like spars) so you can't splice a piece together, so if you use the stick in the wrong place you're going to be making a trip to your LHS to get a new one (yes, I have done this too!!!). Here's what I do, measure and label ALL of your sticks (and flat wood too, if included with kit). Measure carefully because it's easy to mix up sizes that are close, for example 5/16” and 3/8”. When you have to cut a length off of one of these sticks always cut off of the opposite end where you marked your measurements, that way you'll still know what size the stick it.
When you have all the sticks labeled, start to inventory them. Check off the parts on the included parts list (page 3 of the manual). After you have the sticks inventoried then you can do the die and laser cut sheets, and then the parts in the bags. Try to keep them neat as you inventory, because we are going to sort them out and separate them according to where you are a going to use them. As you inventory the parts make sure that every part is labeled with the part number on it.
One important thing you want to do at this time is look for damaged parts. As you can see in my pictures, there is a “groove” in one of the ailerons. This can easily be fixed by filling in the groove with balsa filler, but not all damage can be fixed. If you find damaged parts, as well as missing parts, you need to contact either where you purchased the kit or call the manufacturer and arrange for replacement. I've dealt with Sig before and they are really great about taking care of problems.
Pictures 1. All wood, parts, and plans removed from box. 2. Manual showing parts location on part sheets. 3. All sticks layed out to getting ready to label. 4. Sticks layed out to label and parts list in manual 5. Measuring sticks. 6. All stick sizes labeled and checked off in manual parts list. 7. Misc. parts labeled. 8. Hardware inventory and seperation into containers. 9. All parts checked off list. 10. Damage to aileron.
Until next time
Ken
< Message edited by RCKen -- 10/10/2005 3:34:28 PM >
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The take off is optional, but the landing is MANDATORY!! AMA # 712539 www.gettingairborne.com Moderator- Beginner''s, Sport Flying, Off-Topic, & AMA Discussions RCU Community Moderator
Posts: 14714
Joined: 7/10/2002 From: Lawton, OK, USA Status: offline
Once all the parts are labeled I like to separate them into the major assemblies (i.e. Wing, fuselage, tail, etc...). As you can see from the picture I use large zip lock bags to store the parts in. First separate all the die-cut parts from the sheets. Be really careful when you do this because sometimes the dies might not cut completely through the wood. First try to to slowly work the part back and forth to separate it from the sheet. If it still won't come out, use an X-acto knife to cut it out, and on the laser cut parts use your knife to cut the small “tabs” holding them in.
As I remove all the parts I will stack all them together until I am done removing them. Once I have them all out I will then separate them into groups. This on one thing that I like to do on every kit, and it's a good point to remember. DO NOT GO ANY FURTHER UNTIL YOU KNOW WERE EVERY PIECE GOES. This goes right along with the same reasoning as reading the instructions above. If you know where all the pieces go then you won't have any surprises when you start to build. Also, as I find where a part goes I get a better understanding on how to build each step.
Pictures 1. Gently push parts out of tree. 2. Work part back and forth to remove. 3. Cutting parts out if they can't be pushed out. 4. Cut tabs of laser cut parts to remove. 5. All ribs removed, sorted, and stacked together 6. Wing sheeting stacked together. 7. Fuselage parts 8. Hardware parts layed out to inventory 9. All parts needed for wing gathered together. 10. All parts for major assemblies bagged and labled.
Until next time
Ken
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The take off is optional, but the landing is MANDATORY!! AMA # 712539 www.gettingairborne.com Moderator- Beginner''s, Sport Flying, Off-Topic, & AMA Discussions RCU Community Moderator
Posts: 14714
Joined: 7/10/2002 From: Lawton, OK, USA Status: offline
Each die-cut piece that is removed may need to have a quick swipe with sand paper to smooth the edge. You don't want to hit it too hard and change the shape of the part, but just enough to take the rough edge off of it. Also, on the laser cut parts you want to remove the charred “black” edges. Same thing here. A quick swipe with sand paper will remove it. You can get the edges of all the parts now as you are separating them or you can wait until you get ready to use each part, it's your choice, but I prefer to do it all now.
Notice that there is a nice pile of “scrap” wood. This is all of the sheets that the parts came out of. Do not throw it away yet. This is a great source for scrap wood that you may need during the build. I've had to cut new pieces before (yep, I screwed up and broke a piece) while building, and you can usually cut new pieces from this scrap wood.
As you can see in my last picture, everything is separated out and ready to go.
All of the labeling, inventory, and separating took me about 2 hours to get done. Yes, it is a lot of extra time but I consider it time well spent. I'm now completely organized and ready for the build.
Pictures 1. Gently sand rough sides of die-cut parts 2. "Charred" edge of laser cut part. 3. Gently sand edge of laser cut part 4. "Clean" edge of laser cut part after "charring" sanded off. 5. All items checked of parts list. Everything is here!! 6. All parts separated, bagged, labeled, and ready to build 7. Scrap wood saved "Just in case"
Until next time
Ken
_____________________________
The take off is optional, but the landing is MANDATORY!! AMA # 712539 www.gettingairborne.com Moderator- Beginner''s, Sport Flying, Off-Topic, & AMA Discussions RCU Community Moderator
Posts: 14714
Joined: 7/10/2002 From: Lawton, OK, USA Status: offline
Ok, first change from the instructions. Well, not really a change. I think that Somegeek (or maybe Tigerdude) commented in his build about dihedral gauger. I just didn't like the look of it at all. On one side of the gauger is supposed to be a 90° angle to the bottom, and the other face is supposed to be used to set the dihedral angle of the wing. As you can see in my first picture that both sides of gauger have a “curve” in them. I just don't like the thought of using this to set the proper dihedral angle, so decided to go ahead and make a new one before I got going on the rest of the build.
Since there is a template printed in the instruction manual it's a fairly easy procedure to make a new one. I scanned the template into my computer. I printed out the scan to can compared it to the template in the manual to make sure it was the correct size. Once I was sure I saved the scan into a PDF file (PDF's are great for this sort of thing because it keeps the size correct no matter what computer or software is used to print it out). I've uploaded the PDF to one of my servers in case anybody else out there needs a copy of it.
When separating out parts, the inside of former F-4 is a perfect piece of scrap wood to make a new dihedral gauger from. Cut out the template you printed, making sure to it “oversize” leaving some extra paper around the template. The easiest way to make a new gauger is to attach the template to the wood. I use 3M 77 adhesive spray to attach it with. Spray a light coat on the wood and wait a few minutes for it to partially dry, then press the template onto the wood and then let it dry. I use my scroll saw to cut the new gauger, just cutting close to the line. If you don't have a scroll saw you can use a razor saw (I told you it was a must have too ) to cut it out with. Then you want to sand it down to the lines on the template, sanding down to “just touching” the printed line. Take your time and only sand a little bit at a time. Once you have the new gauger finished make sure you double check it with the template printed in the manual to make sure you have it correct.
Cool, looks like we're just about ready to actually start the build (whew, finally). The instruction manual tells you to cut the left wing panel plan from the plan sheets. I used to cut my plans, but I try not to do that anymore. If you can place you plans on the table without cutting them it would be best to do it that way. If you really think you need to cut your plans you can get a copy of them made first. Any Office Depot/Staples/Office Max should be able to make you a copy of your plans. Just make sure to check and ensure they did an accurate copy of them before you leave the store. Most copy center's will help you make sure. Now attach your the plan to the workbench with the left wing panel showing. Make sure you room on all sides to work with. Attach the plans with some scotch or masking tape, and then put a sheet of plan protector (wax paper or plastic sheet) over the plans. Make sure the planes are completely flattened out on the work bench.
Time to start building!!!
Pictures 1. Original dihedral gauge. Notice "curved" sides 2. Scrap wood from inside of former F4, good size to make new part 3. Verify that scrap wood is big enough to cut new part 4. Spray scrap wood with adhesive to apply dihedral gauge template. 5. New gauge comparing to original gauge 6. New gauge. Verified size with template in manual. Ready to go. 7. Left wing plan layed out on building board. Ready to start building!!
Until next time
Ken
_____________________________
The take off is optional, but the landing is MANDATORY!! AMA # 712539 www.gettingairborne.com Moderator- Beginner''s, Sport Flying, Off-Topic, & AMA Discussions RCU Community Moderator
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) to cut it out with. Then you want to sand it down to the lines on the template, sanding down to “just touching” the printed line. Take your time and only sand a little bit at a time. Once you have the new gauger finished make sure you double check it with the template printed in the manual to make sure you have it correct.