Re: Building tips and hints
You can also use a label maker like a Brothers http://www.ptouchdirect.com/ set on a small font and then use Lowell's method of clear shrink wrapping. More expensive than making them on the computer at home but may be handy if you are wiring out at your hangar and don't have a computer or printer available or you have to make a change to your wiring system.
Our sponsor SteinAir carries several sizes of the clear shrink tubing if you have trouble finding it locally.
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Re: Building tips and hints - 'SafeClamps'
There has been some thread chatter lately on clamps potentially working loose. A fellow Avid builder got me into the habit of safe tying radiator, fuel and other 'critical' hose clamps. SafeClamps also reduce the inclination to automatically and unnecessarily tighten clamps; over-tightening of hose clamps is a common mistake that leads to premature failure. Extra work, but time well spent IMHO.
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Re: Building tips and hints
Other threads have covered fuel system testing, etc.; however, while building I wanted to get some idea how much fuel had to be in the wing tanks to supply the header tank with a measured amount of nose down.
Our front driveway is brick cobbles so it was a simple matter to pull some bricks, dig a hole for the nose gear, measure the deck angle then fill/drain/measure the tanks.
The attached photo is with a 10 degree nose down which resulted in a minimum of 6 gallons on each side for the fuel to be available to the header (That's on this particular series 7 trigear - sure it is different for other builds and models). In reality nobody is likely to hold that position in flight long enough to exhaust the header - but I wanted to have some facts to deal with. Found out it was basically proportional as the deck angle is reduced (3 gallons on each side at 5 degrees - perfectly level the unusable fuel in the wing tanks was less than a quart.
Sidebar suggestion - if you do this in town - probably a good idea to let the neighbors know first so it reduces the number of uninformed earthlings who might call up the local constable about the "small plane crash in someone's driveway" :o - don't ask me how I know this........
Dave S
KF7 Trigear
912ULS - Warp
Re: Building tips and hints
First thing I thought when I saw that picture is that somebody would call and report a crash.
I spent over 10 years on/off building my RV-4 and I'm sure the whole neighborhood thought I was a nut. I remember one Halloween when some little kid behind a Frankenstein mask asked: "are you the guy with the airplane in the garage?"
Re: Building tips and hints
This is valuable info. I suppose it is worse in the earlier models with the full aft localtion of the fuel tank port. It reminded me of the flight home from Homedale, I made several years ago in my IV when I opted to forgo the fuel stop in Winnemucca because of favorable tail winds and a bit of curiosity. I crossed the Sierras at 10,000 ft. and then proceeded to drop down to the 2300 ft. pattern altitude in the ramaining 25 minutes of flight. I used a 500 fpm descent as I liked the airspeed - all the time watching the fuel level in the vent line and the glass fuel filters. Eventually I saw the low fuel warning light come on as I unported both tanks. Reducing the descent took care of that, but it can be an issue and should be considered when long descents are planned on relatively low fuel levels.
Lowell
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Re: Building tips and hints
Hysol Application - All Models
There’s not much guidance in the instruction manual that came with my Model 7 SS for using Hysol. You are pretty much on your own after reading, “Bond the ribs to the spar.”
Making a nice fillet with Hysol is like trying to pinstripe with finger paint. Mistakes and smears show up as dark gray smudges on the light wood ribs and silver spar. Not pretty! I know it won’t show when the aircraft is covered, but l know it looks bad now. It’s one of those pesky pride of workmanship things.
I played with several different methods and got a lot of epoxy under my fingernails. It took a combination of methods to develop a suitable technique. A couple of modified syringes seems to be the best.
Because Hysol will barely flow through a 12 ml syringe tip, I drill out the tip to 1/8 inch. This allows the Hysol to flow much easier, particularly when it starts to thicken after 15 minutes or so.
At one time I used a Popsicle stick to load the application syringe. It was a bit messy.
Now, to load the application syringe I use another syringe that has the entire end cut off; not just the tip. The wide opening makes it easy to suck up a good load. Using the loading syringe I transfer the Hysol to the application syringe. Very little spill and clean up is easy with a rag and some denatured alcohol.
Now, with the application syringe loaded I can apply the Hysol without a lot of mess. When the parts are bonded or I run out of Hysol, I clean the syringes with denatured alcohol. I get multiple uses from syringes.
Using an application syringe with a 1/8 tip opening I can put the goo just where it needs to be or lay down a nice fillet.
Speaking of fillets… Mask off both sides of a rib on the spar or leading edge. Then use a plastic shield cut from a milk bottle to keep excess Hysol off the ribs. The shield should be cut with a radius about 1/8 inch larger than the spars. Hold the shield against the rib while you smear the goo. Retract the shield and remove the tape for a clean looking fillet. Wipe the shield with alcohol before doing the next rib.
Top photo shows modified application and loading syringes.
Bottom photo shows plastic milk jug fillet shield.
JP
Re: Building tips and hints
Need Lots of Clamps
I am finding that I need lots of clamps to do various jobs like: gluing wooden ribs to vertical & horizontal tail, apply rudder post fibreglass fairings, and applying door framing. I have 20 spring clamps and about a dozen mini quick grip bar clamps and have used nearly all of them on some of the above mentioned jobs. A few steel C-clamps are useful but not as necessary as the other type. I borrowed a bunch as well as bought more of my own and am glad I did. You can get by with lots fewer clamps, but must do things in multiple stages instead of all at once with one batch of epoxy.
Jim
Re: Building tips and hints
I like this baggie idea a lot, especially the part about doing one side of the rib at a time. It would allow for easy checking of rib positioning as the alignment marks will remain visible until the Hysol sets on the glued side. Nothing is more frustrating in the build than finding when mounting the flaperon brackets that one or more of the ribs drifted during the curing process.
Lowell
Re: Building tips and hints
Haven't done the wings, but on the tail I "tacked" the ribs in place using a small amount of hysol between tube and rib at the exact location of each rib. I then used tightly wrapped zip ties around the tubing to hold the ribs in place until set. I then came back later and did all the filets without having to worry about stuff shifting.