lamarkeiko

My Feedback: (1)

I have a Knockabout that I picked up at an estate sale a couple years ago. It had nice fiberglass floats, which is what mostly interested me in buying. I am in the process of recovering, repairing and refurbishing. Attached is a photo of it as purchased. It came with no landing gear except a very crudely built tailwheel. A year ago I did fly it one time by attaching some extra landing gear that I had. Got one good flight, but upon landing, the gear I attached to the bottom plate in front of the wing just came off, tearing the plate it was attached to with it. It was really one of my smoother landings, so at that point I figured the plane needed refurbishing. The covering was in poor condition. The ca hinges were wrinkled and comming out in places. So I have totally stripped all the covering from body & wings. Once the covering was removed, signs of past repair were apparent, and the fact that the covering was not original. The wings have the blocks and holes where the main landing gear was attached, which is how I plan on attaching new gear, since I have some that fit very well.
Now I finally come to a question I would like some advice on. The ailerons are operated by one servo and torque rods. It would be very simple for me at this point to refurbish and fit with two aileron servos. Is there any good reason not to do this? One more question is on the cowl. The plane has a very lightweight fiberglass cowl with some points where there is some cracking. I was considering mixing up some epoxy, adding milled fiberglass, then thinning with alcohol enough to be able to paint a coat on the inside of the cowl to strengthen it. Has anyone done this before. Thanks for any help.

LamarACH=CONFIG]2062049[/IMG]

jimmy7432

Sorry I don't have an answer for your questions but I am doing a rebuild myself and was wondering how you are going to replace the CA hinges. I am going to recover my plane as well and was trying to figure out how to take the control surfaces off and then reattach them. The only thing I could think of was to reposition the hinges as not to fall where the old hinges were glued in place.

donnyman

Hello
The technique of beefing up your cowl. Glass fiber wont work as well as sheet glass. be sure to clean the cowl well, lay the sheet glass over the hole and only use enough resin to fill the weave of the cloth any more is dead weight with no added strength. fill the holes with the milled glass and redrill the holes. use a old credit card to scrape off the excess resin.

that wing looks like it could use a layer of glass on the center line. It is important to know that the resin does not add strength but makes the glass fiber bond to the surface to provide stress paths.

Good luck , hope I am not too late.

donnyman

Jimmy

The way you want to replace the hinges will work but don't use CA hinges they have short life spans use the plastic pinned hinges but coate the hinge area with vaseline to prevent the adhesive from clogging them during installation.the vaseline will prevent the adhesive from bonding so be careful. I prefer Zpoxy for this.

lamarkeiko

My Feedback: (1)

Jimmy

I removed the ca hinges on my Knockabout by applying acetone to their glue joint with a syringe and letting it soak a short while. I was then able to slowly work them out. Some of the hinges were broken off flush, so I just worked an Exato knife along side until I could free them with a tweeser. I'm not a fan of ca hinges, and I'll be, replacing them with pinned hinges.

Donny

I am planning on reinforcing the wing joint with 1/2 oz fiberglass and resin on both sides. So do you think the 1/2 oz fiberglass sheet stock will work ok for inside the cowl?

BTY, I have already proceeded to build in separate servo mounts for each aileron. I just need to figure out how th cut out the existing torque rods without too much damage and repair.

Lamar

donnyman

way to go on the hinges. the wing joint will be ok just don't gob on a lot of resin, just enough to wet the weave just squeegee off as much as you can for a clean finish. the cloth will work for the cowl but it is extremely important to clean the surface well. soap and water then a alcohol rub down, try to keep from touch the bonding surface after cleaning, again don't use a lot of resin just wet the weave and remove the rest.

your torque rods really don't have to be removed just cut off all that you don't need. or go ahead and remove them the fiber glass will reinforce that area later. I would not use two servos on a plane of this type one higher torque servo would be more than sufficient in the current set up.

lamarkeiko

My Feedback: (1)

Donny

Don't you think separate aileron servos would be advantageous for setting differential and the use of flaperons?

Lamar

donnyman

Yes it would but does this particulr plane really need all that? it has reach the stage were you have to decide what you want to deal with on this particular plane and will it yield you the results you are looking for.

I say this because I see many modelers overdo things that really don't add to the flyability of their bird and they end up with a heavy clunker that was really meant to be a simple flyer. but it is interesting to do these things.

only you can make such a call. Have fun!