Wednesday, July 20, 2011

Aileron time

Well, I flew someone else's plane using only elevator and ailerons, with both on the same stick and loved it.  I decided that since this is the normal configuration for transmitters, I should use that configuration now and not incur a learning curve later.

Now I have ailerons to install.

 I started by ordering two servos (9 gram), Y cable, and extension cables from  When they arrived and I opened the package, I was a little concerned with these servos.  OK, I know I bought the cheapest ones they had, but still I thought I may have made a mistake.  But now after installing them and testing them out, I love them!  They are great little servos and faster than the stock ones installed.
 The start of measuring the ailerons. This was a bit tricky as I had no plans and only suggestions from the Internet as to how far to start them from the root of the wing.  Some people said 5" and others said 2".  I decided on about 3.5" and then took them out to just before the wing tip bends up.  This will still give me a full aileron if I decide to cut the wing tips off.

The first cut.  Very nerve racking. I also decided to make them 2" deep.  I had seen others make them only about 1", and then go on to later add extensions. I would rather have to tune them back on the linkage side then add to them latter with extra foam or balsa.             

First aileron all cut out.  Now to make a duplicate on the other side.

Start of installing the hinges.  I had originally cut everything square with the intention of doing a hinge like I did for the tail.  Boy was that a failure.  I found out that that type of hinge works best on thin edges only and on the thick cross section I was now working with, they had way too much play.  So I changed gears and went to the bevel cut and top side tape hinge.  A much better plan.

Hinges installed.  Just used strapping tape.  I had fully intended to use a single strip of clear packing tape, or at least to cut even sized pieces and to a neater job, but I got impatient and just used them like they are.

I needed some control horns and did not want to go out and buy some.  I was also too impatient to wait for an order to arrive.  So, I did some research on how to make my own, and this is what I settled on.

I made my own control horns from an old AT&T SIM card (see it in the picture?).  These were just pushed into slots cut with a razor knife and then glued with a bead of hot glue.  To make the slot I just lined them up with the servo arm, tilted them over, and cut down the edge with my hobby knife (the one in the picture).

Both servos installed.  I hot glued the Y cable connectors into openings cut just below and behind the leading edge of the wing (sorry, no pictures of this.  Maybe later See update below).  These were not as easy as I had thought they would be.  When I started planning them, I realized that there was not a lot of room as the power switch and the air scoop I installed were right where I wanted them to be.  Well, I found room.

 UPDATE - here are photos of the Y cable with the socket ends secured in the sides of the fuselage.

Detail shots of the servos and the control horns installed.  You can just see the hot glue beads on either side of the horns.  I made cut-outs in the wings for the servos by setting them in place and cutting around them with a hobby knife.  I then cut out the foam as best as I could and used a hot nail head (held with pliers) to smooth out the bottom of the cut-out.  The servos only sit in about half of their thickness.  I figured that would be good enough.  They were then just hot glued in.
Check out the snazzy push rods.  They were made from one large paper clip! From this photo you can just make out that the servo is at the end of, and just to one side of the wing spar.

Aileron test before flying.  Not the best video as I was doing the camera and controls (who needs a tripod!).

First flight.  Actually 3 flights!  And yeah, I flew it with masking tape holding the servo leads down.

I really like how the plane flies now and am waiting for my first chance to find out how well it performs in a wind.

See my other blog post rcflyingfun flapperons to see how I upgraded this to flapperons with a new 6 channel radio and mixing.

Thanks for stopping by my blog and please post comments, good or bad.  Be sure to come back and check for future posts.

Power play

We are now having some good flying weather so I went flying again.  Now I had some issues with the throttle.  I started experiencing the typically reported Wild Hawk speed controller issues with the power cutting out and coming back on.

In reviewing all the reported issues I could find on the Internet, I could not find solutions that did not include replacing the speed controller and motor.

Well I started reviewing all the facts.  The speed controller is set to shutdown the motor when the battery voltage drops below a certain level.  I'm using home made 3 cell series li-ion battery pack.  I found that the batteries I am using (18650 series) have a max discharge rate of about 4 amps (~2C).  One of the cells in the pack shows a slightly lower voltage than the others.

with this info, I think I can say that what is going on is that with this battery the motor is pulling more than it can supply so the battery is compensating by lowering it voltage.  This voltage drop tells the speed controller to shut down the motor and only supply the servos.

I tested this by hooking up a battery monitor to the charge connector and then ran the motor through various speeds.  Sure enough, after a bit, especially at high speed, the battery voltage dropped and the motor started stuttering and finally shut down.  Interesting enough, I noticed that the speed controller got really hot.

Any way, the next time out I used the NiMH battery and flew for a long time and had no issues.  Problem solved?  Now I'm looking for a real LiPo pack for the more power and run time I was looking for.

Thanks for stopping by my blog and please post comments, good or bad.  Be sure to come back and check for future posts.

Flying again

Well, I finally got a chance to fly again.  It was still a little windy but I wanted to fly anyway.

The new hinges on the tail worked great!  I love these new hinges!

OK, that might all be fine, but the wind took control on a low turn and I hit full power nose down into the ground.  Broke the nose off of the plane, again.

 Can't really see the full extent of the damage but you can see it's seriously tweaked.  This is also after I spent a good half hour taking all of the tape off.  You have to tape these really good, especially while learning.

 Now you can see some of the damage.

I had to completely disconnect the nose to realy fix it right, so I did.
All nicely glued back together!

 Well, I took the opportunity to do some updates while I was at it.  I decided to do some spoon scoops to try to improve cooling.

This is the nose hole I started with.  This is up front by the battery.
 The spoon cut real easy with an Exacto saw blade.
 I marked the location with a pen so I would know where to place a bead of hot glue
 This seemed like the best place for the exhaust port.
You can see them both installed in this view.  Not real easy to see, but they are there.

Thanks for stopping by my blog and please post comments, good or bad.  Be sure to come back and check for future posts.

Saturday, July 2, 2011

Hinged Again

Ok, no sooner did I buy the CA glue and the thin hinges, and I saw a video about making tape hinges.  This was the best hinge advice ever!  The idea is that you take strips of tape about an inch long.  These are joined together by overlapping them about 1/4 of an inch sticky side to sticky side.  These are then run from one side of one surface to the other side of the other surface.  Oh heck, this will make much more sense if you just watch the video.  The part you'll want is about 5 minutes in.

 So, here is my progress on installing this type of hinge.

This hinging system is awesome! They move  so freely and have so much more movement.  I no longer have any issues with the tail spar yawing when the servos move full lock.

Well I'm still waiting for he weather to behave and allow for some nice flying.  So far any time I've been able to get out, the wind has been 10mph and higher.  We'll see.

Thanks for stopping by my blog and please post comments, good or bad.  Be sure to come back and check for future posts.