Hey Nonie,
The coaches here can give you more detailed advice, but this is what I have to say:
1. Flight Log and information about your plane. Many people come in here and ask questions without providing any data or images from the plane, which makes it hard for us to help you. If you could take pictures of each of your planes we could better diagnose any potential irregularities. Also, provide a Flight Log (and make one if you haven't already). There are a lot of parameters that you should record, so here is mine if you want to copy it:
https://docs.google.com/spreadsheets/d/ ... sp=sharing
Also, provide videos of your flights. If you don't want everyone to see them, you can PM them to the coaches and they can tell you what to change.
I'm missing a couple of things myself:
Torque before/after launch, because my partner is the one with the torque meter and he has not gotten it to work yet. This is one of the most important things to keep track of, going hand in hand with the number of winds per flight. In short, torque determines how high your plane will go and how many winds your rubber bands can take.
Reliable CG placement: Record your center of gravity (with the unwound rubber band on the plane) before each flight. You can use a pencil to measure it: just slide it under the wing and move the plane back and forth until it balances. You can use other objects too, including your finger, the tip of a knife, etc. I don't like using my finger because the margin of error is a bit too much - the wider/narrower the object is, the more/less accurate your measurement will be. I also recommend marking cm increments on the top of your wing post (the piece of balsa you rest on the pencil) so that it is easier to record your CG. It is measured in cm from the trailing edge (TE) or the wing. I'm not a very good follower of these rules because I test before school starts and find the CG without markings is a painstaking process that I do not have the time for between flights, but I will once I make my own markings.
Include these in your log, as well as everything I have in mine.
2.
Plane #1: Should be fixable once you record everything
Plane #2: Remove the kevlar and truss to put on the rubber bands (and the propeller, if you have to). I like to use an x-acto knife to cut the glue joints. Anything similar, like a pocketknife, could work too. You can also use acetone to soften them up. It's worth the hassle to have an easily adjustable wing mount.
Plane #3: Again, can be improved once you record everything.
3. Concerning erratic flights:
This may be due to external factors acting upon the plane. Are there any air currents from open doors, an HVAC system, or people moving near the plane? All of these could cause the plane to wobble a bit. After launching my plane, I don't move until the plane is well above my head and on the other side of the gym. Does the issue occur in a certain location in the venue? If not, then it's probably a trim issue. Your plane going straight sounds like you have little to no stab (horizontal stabilizer) tilt. It's the main trim factor affecting turns in the cruise/descent stage of your flight. Record stab tilt in your log (It's labeled HS tilt in Plane Information for mine). Increasing it will result in tighter turns during the cruise/descent stage.
Hopefully this helps, the coaches and more experienced flyers will be able to confirm/deny my suggestions and provide more information.
Edit: All the parameters you need can be found in the flights at the bottom of the log (you need to scroll down). My earlier iterations of the flight log are on the same spreadsheet and do not contain the accuracy, technique, or parameters that I have in my later flights.