rsbabcock

Oh, since I am such a rookie, would underpowering it with the Evolution .46 be better than the K&B .61  I thought it was an OS, but my friend that I bought it from put an OS carb on the K&B .61 engine. 

blvdbuzzard

Under powering it is not a good idea. You will not have the power to pull you out of a bad situation. The K&B will be a good engine. You can always throttle back. I flew mine on a worn out ASP .61, brother in law flew his with a Magnum 61. and my brother flew his with a Magnum .91.

I am pretty sure the .46 would fly it, but would take a long time to take off.


Buzz.

blvdbuzzard

rsbabcock, that little white covered piece that is being so much trouble, it is a skid that mounts at the ens of the fuse on the bottom side. If you hold the plane up to a light, you should see the shadow of the slot it glues into

I have had to cut the covering off the bottom to re-glue the landing gear blocks back in. The blocks look like they were glued with a few drops of thin Ca. I used a generous amount of epoxy to cover all of the pieces to make sure they stay in place.

Here is mine being used as a glider tug. I guess I have well over 50 flights on it carrying a payload.

http://www.youtube.com/watch?v=V5k-h-n5IVA

rsbabcock

Thanks Buzz! 

I really appreciate all your and osjose's help.  That little skid piece really had me scratching my head.  There are a few things that are just not obvious to a beginner.  The instructions were not very complete but the plane looks cool.

Your tug plane reminds me of the 747 with the space shuttle on its back.

One last stupid question......What holds the front of the wing in place.  I see the two screws that hold the back of the wing to the fuse.

I bought two of these kits so I will have crash spares.  I am getting better, but still have a ways to go.  My Park Zone T-28s are great to learn on, but this is more airplane to handle and not so forgiving. 

Thanks again!  

Bob

rsbabcock

Wow, that really was a stupid question.  I just went out to my workshop and took another look and it wasn't what I remembered.   I now see the tab on the front of the wing.  Sorry for the dumb question.

opjose

Wow that's great!

How about posting a better picture of your setup so we can steal your design!

How are you releasing the glider?

opjose

HINT:

Thin CA the heck out of that tab after you glue the wings together, to harden it.

On the first plane I received the tab was broken, so I glued it back in place, glued the wings together, drilled two holes into the tab and install steel rods to make them stronger.

rsbabcock

When you install separate servos for each aileron, I understand you cut the monocote in that section only.  Do you then fabricate a piece of thin model plywood for the servo mount and glue it to the two adjacent spars and reinstall new monocote (or whatever it is called)? 

I have three nitro airplanes including two by Hobico and an Alpha 40 from Hangar 9.  They all use a single servo for ailerons and do not flutter.  I would think there should be a way to install better hinges and a more substantial control rod.  It sure would be easier to construct with a single servo for the ailerons.  I have never used the film covering and suspect I will not have a very nice looking product in the end.  I suppose I must learn sometime and it might as well be now.

Thanks for all your great advice.

opjose

Effectively yes, though remember that light ply alone may not be enough to hold the servos... you'll want some form of re-inforcement.


The Alpha is a lower level trainer, and it too suffers from the same "problem" as this plane.

Basically the "L" pushrod mechanism used "gives" to much in flight.

Do NOT assume that everything is all right and nothing needs to be done. I though so too, assuming that this was all the result of people overpowering the plane.

My first flight with a lowly O.S. .60 FP engine ( about as powerful as an OS AX .46 ) provide otherwise. The plane fluttered like I have never seen before.

The Alpha has smaller "barn door" control surfaces. This plane has bigger ones so the problem is exacerbated.

Go ahead and cut off the "L" rod and install direct pushrods and fittings as we've indicated. You'll be thankful you did.


You're solving the wrong problem. The hinges are not to blame... it's the "play" in the way things are set up.

Ah so THAT's the problem! You're unsure... don't mistake one thing for another.

What you want to do is make things as easy for yourself as possible.

Do this:

- Cut as SQUARE area of covering, but do NOT make it overly large... you want just enough to get the ply in there.
- Cut a square mounting hole for the servo and sand out a "U" area for the wire. Make sure the servo fits.
- Cut some thin ply strips and mount them under the ply where the screws will affix when the servo is installed. Glue them in place.
- Use some more cross strips to act as a support for the ply piece you'll be gluing in.
- Try to make the ply square large enough to but up against the front and side surrounding wood.
- Glue eveything in place trying to get as smooth of a surface as possible to the adjacent wood.
- Sand any imperfections or rises so the surface feels smooth.

- Cut a LARGER square of covering ( hint fold a piece of covering back to back and cut both at once to get identical pieces. ) that will cover the servo opening and ply.
- Remove the backing from the squares, position one in place and tack it down lightly with a COVERED heat iron.
- Finish tacking the edges down, you're looking to get no wrinkes on the edges... don't worry if the covering is not taunt at first.
- Use a properly adjusted heat gun to shrink the covering while adhering it, so it becomes drum tight.

- Cut the covering from opening you made for the servo and install.
- Use a bit of trim tape to outline the patch either in the same color or in something darker.

It sounds complicated but it's VERY easy.

If you think you'll mess up, get everything ready then ask a more experienced modeler to help you finish.

Since you have more than one plane, knowing how to repair covering is a necessary skill, as are a covering iron and temperature controlled heat gun.

Dont' forget about the gear re-inforcement too! You'll need to beef up the mount and do something about the soft steel strut.

For the latter I obtained some cast off trainer struts. Cut them so I was left with an "L" shape piece.

I then secured the piece with thing copper wired at three places, to the existing gear with the "L" facing back.

I used solder to weld them together and finally affixed the arm of the "L" with straps and screws.

opjose

BTW: Pictures are worth a thousand words...

If you can wait I may try and pull the plane out of storage next weekend and shoot some shots so you can see what I did.

rsbabcock

Thanks again.  I would really like to see the pictures if it is convenient.  Sorry to be such a pest.

One of the mentors in our R/C flying club will be doing a covering seminar one of these days and I will attend for sure.

blvdbuzzard

This is how I did the dual servo mounts. I cut out a 1/8" ply mount that was 3/8" wider on all side compared to the servo. When you are done it is, sort of a rectangle doughnut. I then used 1/4" by 1/2" balsa to go between the ribs. I mounted the leading one about 2 inches behind the main spar. It is glued under the cap strip and tight to the rib. Then I positioned the ply wood plate to see where to locate the trailing cross member. After the two cross pieces are glued in, I glued the ply plate centered between the ribs. I did this in the rib bay where the landing gear blocks are. That way, I only had to cut the covering once.

I can try to get a few pictures this weekend.

The glider release is pretty easy. There are (3) #64 rubber bands attached to posts at the rear of the cradle. They go over the glider wing. They attach to pivot arms that will fall backwards when the servo moves.

I can also take a few pictures of that if you guys want. Talk about dumb questions. I just know you do not want any pictures so you can steal my design I in turn stole from some one else

The cradle is built out of 1/4" X 3/4" oak. I had a scrap around so I just ripped it on the saw, sanded, cut, fit, and epoxied.

Buzz.