n00bs Gonna Build a Carden

[gareth.ky]

Thats a good tip! How is that stuff about peeling off the T-bar?

Anything you can do to make the sanding easier will pay for itself almost immediately. I used to think the T-bars were expensive. Now I would say you should have this as a start:
12" on 150 grit
24" on 150 grit
24" on 220 grit
36" on 220 grit

The 24" is the size I use the most. Smaller sizes are useful when you want to sand a smaller area. Larger sizes are good for big sheeted surfaces. Past 220 grit its probably better to stick the paper to a foam block. You are looking to smooth the surface at that point not shape it. 400 grit is my next step up. I'll do a pass with that and maybe some 600 before covering.

I'm finding that I put hanger rash on everything so I am holding off on the finish sanding until after all the work is done. All the nicks and digs are my fault. One of the biggest culprits was the T-bars. I was using the 3M Spray Mount adhesive and the ends of the paper would peel up. If you don't notice it will put some serious scratches in the surface. Now that I'm using 3M 77 thats happening a lot less.

I just seem to drop, scratch and nick everything at least once. Guess I'm just clumsy. I have a big cotton towel that I put all the parts on now. This cut down on the amount of dents in parts from grit on the table.

[mark786]

You have to try the roll stuff. Doesn't peel back but when you are ready to take it off it doesn't leave much to clean. I use to use 77 but had to always use adhesive remover to keep the build up down.
I think you will find that your final sanding will be good with 400. It will leave it as smooth as a babes butt. I agree with your other grits, that is about all I use is 220 and 150. You can take alot of material off with 150 grit.
Mark

[gareth.ky]

I haven't done a big write up on this phase of the project yet. I'm not really happy with the way it all went. Not that the results are bad, just that it didn't go smoothly and there were some mistakes made.

Speaking with Walt over in the ML 300 build thread he shared how he cuts his surfaces on a band saw. Thats the way to do it, everything else is less accurate and more work. I didn't have a bandsaw but I wouldn't approach this task again without one.

Part of me wants to do another kit just so I can apply everything I am learning building this one.

[why_fly_high]

Dude, I'll send you a kit with my bandsaw and we're set. I'll have to figure out which 40%er to send you.

Dan

[gareth.ky]

I should have borrowed your bandsaw!

I have a couple of parts where the center line of the bevel is not in the center line of the surface. I can't really figure out how this happened?!?! So on those parts the surface is is offset from the airfoil. In some places by more than the sheeting thickness.


AeroFAIL!

Hard to see but there is about 0 gap between the aileron and the wing. Everything thats sticking up is above the wing.

I've pretty much decided to do these over. 1 elevator and both ailerons are affected. The Rudder and 1 elevator are pretty nice.

The elevators are not exactly identical. At the root one is about 1/8" longer than the other. I don't know HOW that happened either. I had the parts in the shuck and over the plans when I marked them. The longer of the two also happens to be the one that came out pretty well.



I don't like having some 1/2 baked shido on my airplane.

[Neil4]

so you are going to get a new elevator half and wing panel and do it over again?

[Simpleton]

You can hit the glued on sand paper with a heat gun and it really speeds up the peeling off process, and comes off cleaner than just peeling it off at ambient temp.

[SunDevilPilot1]

Sandpaper Tip:

I buy standard 3M sandpaper but attach it to my sanding bar with carpet tape. incredibly strong tape that generally comes off without leaving it's "sticky" behind. A little "goo gone" will clean the bar in short order if needed.

SunDevilPilot

[gareth.ky]

	Quote: Originally Posted by Neil4
	so you are going to get a new elevator half and wing panel and do it over again?

no no, nothing that drastic! Just cut off the bevel material and do it again. This time with a bandsaw.

[Neil4]

oh ok. Good luck.

[FlyguyXII]

Are you planning on lightening up the tail of the airplane any? I see that you lightend the belly pan and turtle deck. Im following this thread very closely because i am seriously thinking of doing the same thing next year for my 85.

[FlyguyXII]

subscribed

[gareth.ky]

	Quote: Originally Posted by FlyguyXII
	Are you planning on lightening up the tail of the airplane any? I see that you lightened the belly pan and turtle deck. I'm following this thread very closely because i am seriously thinking of doing the same thing next year for my 85.

If it doesn't balance once its all put together I might have to do something. The tail surfaces weigh nearly 9 oz. I think maybe 2oz of that could be removed to make balance. I have a carbon tail tube thats going to be at least 3/4 oz lighter than stock the alu tube. I got the spinner and got the full backplate for it. Hopefully all the little things will add up.

Right now I'm working on a few things around the house and my shop so not much is getting done. It's so close to being fully assembled but things keep getting in the way. I'm getting things ordered in the meantime, like the spinner, prop, servos, fuel system etc. Almost all of the hardware is here already.

[FlyguyXII]

What is you goal weight?

[gareth.ky]

I'll be happy if its around 25 pounds.