ok guys,

getting ready to start building my 3rd kit. I'm progressively getting better and better, but this 3rd kit is more about doing it right, instead of just trying to get it done....make any sense? I'd like to hear how you guys make sure everything it square and plumb? what tools?

say for instance setting the wing ribs to the spars.... do you just use one triangle, or 1 on each side? seems like a beefy triangle with a wide base, 1 on each side of the rib would work well.

some suggestions please!

thanks,
Dan

On the wing rib thing. If you have a square on the one side , the other side would be square also. A good straight edge (at least 30"), a couple of different size triangle squares, assorted size clamps, some pins, & above all else, A FLAT SURFACE to build on. A good straight plane will sure make flying it easier. Just don't get carried away getting everything "perfect", as it sure can take some fun out of the build. Good Luck

house of balsa used to have a tool for that purpose enlarge it and make it out of ply for larger ribs, i remove the removeable part from an adustable t square alsoit is heavy and has a wide base.

The absolutely most basic way to build true is to start with a perfectly flat building table. Everything else follows from there.

The thing is, it really wouldn't matter if a rib is tilted a degree or two. The wing will still build fine and fly fine. I never use rib alignment triangles and all my wings come out fine. It's easy to eyeball a 90 degree to the table, zap it with Cyano, and it's done. I've build entire half-wings in an hour that way with no problems.
But if the building table is twisted in any way, then that twist will be built into the wing permanently since it's that flat reference that establishes the "trueness" of the wing itself.

The same thing goes for the fuse. If the fuse is built with a slight twist because of the table not being perfectly flat, then that twist will be built into the fuse so that the tail section might be off from the nose orientation. Even a little bit off here will affect the flying characteristics of the plane.

To get a perfectly flat building surface, I started with a large, steel top workbench such as this:
http://www.grainger.com/Grainger/items/7D179?Pid=search

After I set it up where I want it, I sight along the surface to make sure each corner is square to the others (trust me, you're eyes are good enough to do that accurately). I shim under whatever leg I need to in order to get it true, and being steel, I know it won't change from it's "true" condition.
Then I cut a piece of high quality plywood to go on top of the steel, and then I cut a piece of sheetrock to go on the ply for a surface to pin to.

Sounds like a lot of work, I know, but imagine yourself down the line after building maybe 10 planes and how you'd feel if every one of them gave you trimming problems due to twisted structures.

Highflight,
That is a great loing table. I use a folding table with a door and a piece of sheet insulation on top to pin to. I think probably the most important thing is to have a little patients and read the instructions very carefully. Experience goes a long way too. I am building my 5th kit and it is still not perfect, but is much much better than the first. My first the horz stab was built with the leading edge too high. The plane would fly with a nose down attitude. You can imagine what the ground handling was like. Especially on take off.
Goodluck with your build zipandsplat
Alan

For positioning the ribs I use several of these jigs: http://www3.towerhobbies.com/cgi-bin...&I=LXM406&P=ML
For building board I use this: http://www3.towerhobbies.com/cgi-bin...?&I=LL7354&P=1
or even better this one: http://www3.towerhobbies.com/cgi-bin...?&I=LL7355&P=1
just couldnt find ceiling tiles near me.

I'm starting to use the GP wing jig. Works Very well. This insures a perfectly straight wing.

For the fuselage, RCM has an article on how to make a wing jig, AND the fuse jig. The fuse jig will help ensure the fuse is straight, and the horizontal will build perpendicular to the fuse.

It takes a little work to set up, but it also saves work, headaches, and frustrations in the long run when it pulls together correctly the first time.

Even though I have built off a flat table for years, my preference is in the use of these jigs.

Look into this. It's worth the time.

Brian

For wing ribs I use a squared hard wood block. I line the rib up press it against the block to hold it plum, make sure the le and te are perfect then I zap it with a bit of thin ca, double check it and then hit it with enough thin ca to hold. I also make every cut/stringer/shear plate is a perfect fit with no gaps. Having no gaps in any place is the trick to a strong plane that will stay plumb through the tourture these planes go through.

I also use multiple incidence meters, various squares, various levels and of course a plumbed work table...

Dan,
Like Highflight I install ribs by eyeball. I have a flat, and LEVEL, table. With the level table you can use a carpenter's level and plumb bob to help with alignment. I also use lots of centerlines and cordlines on parts. Straightedges are useful too. I use steel and aluminum angle irons to hold parts in place and straight while glue dries.
Chuck

Thanks for all the replies guys. I have basically been using a triangle, which sounds suffice...sometimes the perfectionist in me makes it hard to get anything done!
Dan

I go by eye.

What comes in handy some times is a triangel wiht the 90 corner notched. It comes in hand for aligning the horzontial and vertical stablizers. You can get some cheep sets a the office supply stores. They are very accurate, but just not very durable.

for small pices, dig out your credit card, It is as square as you need to be.

I started making the self jiging wings and that all but eliminates the square rib issue, but and it's a big but, you can still get the wing built with a bow lookind down on the wing. A fence on your bench would prevent this.

THe 30" straight edge is really needed. I go to the local hardware stores, and search through their cheep door sills. You have to check closely and a lot of time, they are bent. The work well as they taper down to about 3/32 on the edge and make long cuts a breeze. You can get them in 36" lengths and if possible find a 48" one. You will need to drill out the screw holes as they are usuly punched in and the flashing will cut up your wood, Drillabout 3/8" and that will remove enough that the piece will lay flat with out any interference from the holes.

A door makes a good bench top, if you can, get a flat solid core, and get one 36" wide. If you can find one, you can lay it on saw horses if you are tight on space. and lean it o the wall when not in use. A good solid core will not twist. and it is heavy enough that it will stay put on saw horses with out scrws or clamps. You can lay a piece of dry wall on that for a pinning surface. Use some packing tape around the edges to keep the dry wall from rubbing off onto eveything.

Don

For wing ribs I cheat. I use the same steel blocks I use to square up stuff on the mill. That's pretty much overkill but it's handy for me and they don't move around much as they are heavy. Any triangle/square you can fit there works ok. A flat table is a good starting point.

omg yes I forgot, a number of straight edges (36" and 48" and I also have an 8 foot one for thos looong jobs lol) I find the straight edge very handy for perfectly lining up the spars in wings... and other odds and ends...

Have you looked into a magnetic building table? Most people who go that route find that the quality of their builds is improved, to say nothing of the ease of construction.

I second the magnetic system as an alternative, it works great. Read all about it here:

http://www.airfieldmodels.com/inform...oard/index.htm

Dan,

This is for after you have finished your perfectly straight wing, stab and fuse:

http://www.robart.com/how_to/how_to.aspx

You can find all you need to know at the website pointed by ppkk above.
Just like you, his creator is a perfectionist about building model airplanes.
Check his many how-to articles there.

I think one of the most effective ways to build straight is to focus on what is critical. As builds get increasingly complex you will be forced into making a few trade-offs. Knowing how each inaccuracy effects flight performance will get you consistently nice flying planes without unnecessary tedium. For example, gluing two wing panels together with a two degree angle between their chord lines is a minor disaster but a bulkhead that's five degrees off square in the fuse is just cosmetic and isn't worth fixing.

Hi, Do you self a BIG favor and buy the GP building board.The big one is 18X48, I have had mine for almost twenty years and is still dead flat! It's made of 3/4 balsa blocks all glued togeather.You'll be glad you did buy it Best investment I've made in this hobby.That and LOTS of clamps.LOL

Go to your big box store and buy some 1" aluminum angle stock. Cut them in 1" lengths, and drill a small hole in one side. Then use a push pin to hold the angle metal to the work surface, and against the rib or former. They won't move because of the push pin, and the angle will remain at 90 degrees.

Bill, Waco Brother #1