23 replies to this topic

[M J W J]

As some of you may know one of my other hobbies is flying RC planes. Its something I have done for the last 14 years and during that period I have not had a lot of planes. I've had the same two for the best part of a decade and have just kept servicing them.

 

With more and more restrictions being placed on aeromodellers its probably only going to be a matter of time before IC glow fuel planes are banned outright. The club I am a member of already has restrictions imposed on it by the council. After having a bit more money to spare due to my new job and with the price of LiPo batteries and brushless motors coming down I though it was time to venture into electric planes.

 

I've flown a fair few other people's electric models and have been impressed with the performance but what I have never particularly liked is the cheap construction of ARTF (almost ready to fly) planes which most electric aircraft generally are.

 

Over 14 years of flying planes and my dad demolishing a fair few (my dad also flies) we have accumulated a lot of spare parts and balsa wood. I came across a plan in an issue of RCM&E (model plane magazine) for a plane called an Alco-frolic. It is a mid wing aerobatic plane which can knife edge. This is something that neither of my aircraft can do.

 

I ordered the plans and have started to build one. I started about 2 months ago and have just done a little be here and there on it.

 

These are the plans and below is a link to where you can purchase them. I will be using a 3s 3200 mAh LiPo battery and 575W brushless out runner. My radio gear is futaba.

 

 

http://gb.trapletshop.com/alco-frolic

 

With all planes the first thing is to build the wing. A lot of people start with the fuselage and then find the tail doesn't line up with the wing. All wings start with the ribs being made and sanded together into the correct shape. A couple of metal templates were made out of some 18 gauge sheet steel

 

 

The plans show a balsa wood spar being used. I'm never a fan of balsa wood spars in planes so despite adding a small amount of weight I used 1/4" hardwood for the spars. I did consider using 3/16" carbon fibre tube buts it can be a bit awkward to glue to (I've done this for another plane I built years ago). I cut the spars out along with the leading edge and trailing edges. These are 1/8" medium balsa wood.

 

 

I then proceeded to glue all the ribs to one side spar. I didn't take a picture of that. Today I have finally turned the wings over and glued the other spars in place.

 

 

I hope by the end of the week to have joined the wings together and have the leading and trailing edges glued in place.

[Domneon]

funny this should pop up, my Grandad has been machining a 5cc two stroke engine from scratch

 

Also had a neighbour who flew large scale aerobatic planes

 

will be watching this!

[Old Bob]

That takes me back a good few years!

 

Bob

[Ben_O]

Interesting.

[M J W J]

Last night I glued the two wings together. Its not much but I wish to take my time with this plane and not rush it. The straighter, lighter and more balanced a plane is the better they fly.

 

 

I used a couple of pieces of left over 1/4" spar to reinforce the joint. Once the webbing (bits that go between the top and bottom spars) is in place it will add even more strength.

 

 

Its not quite all of them but it took a fair few clams to hold the bits in place. There is a the old joke of "how many clamps do you need to build a radio control plane?" Answer: "One more than you've got". I think this applies to holding panels in place when you weld them in too.

[M J W J]

Over the last few days I have had chance to do a bit more.

 

First was to fit the reinforcement piece to which the trailing edge (bit at the rear) overlaps on to the wing. This also helps to re-enforce the joint in the wing

 

 

Before the trailing edges could be fitted I needed to trim the ends to the correct shape. The overhang the end of the wings and make up part of the wing tips.

 

 

Next was to glue on the trailing edge pieces. These were held in place with a mixture of rubber bands and dress making pins as the glue set. I also had to hold the wing down flat on a surface to prevent it from ending up warped. Not easy when a wing is curved so as usual I got creative with the holding and clamping methods. Thanks Dad for the spirit level. There is also the draw from my flight box, a file and the glue bottle being used to hold things down. Small paper shims were used to hold things in exactly the right position

 

 

 

More clamps required

 

Finally tonight I have glued in the two leading edge (front of the wing) parts of the wing. Again it has to be all held flat and rubber bands are used to hold it in place.

 

Next step is to make the re-enforcement parts and the fuselage former at the front of the wing. These have to be made all together as the holes need to line up perfectly. Two dowels will protrude from the front of the wing locating it into the fuselage and the rear of the wing will be held in place with a plastic bolt.

[Ben_O]

Great skill mate!

 

Don't think i would have the patients to do this.

 

Ben

[meathead]

Very interesting..I've never seen a build of one of these before

[M J W J]

Great skill mate!

 

Don't think i would have the patients to do this.

 

Ben

They don't require as much paitence as building restoring a mini. Its much easier to work with tennon saws and craft knives than tin snips and mig welders.

 

Very interesting..I've never seen a build of one of these before

Not many people build their own planes these days. With the introduction of ARTF (almost ready to fly) the hobby has become much more disposeable and allows people to fly without the hassle of having to build their plane. When I first started I had to build my plane.

 

I was hoping to get more done to this this week and was hoping to post an update earlier in the week.

 

I made the reinforcements for the wing dowels. These locate the wing into the fuselage as the wing is removed to aid storage and transport. The reinforcements and the fuselage former F2 are all made together to ensure that the holes align. The former F2 (bottom in the picture) is made from two pieces of 1/8" light ply glued together and the other two pieces are just 1/8" light ply

 

These were then glued in (another mass of clamps required) and then the two wing dowels were cut and glued in place.

 

I cut out all the parts for the wing tip last Sunday afternoon and former F5 out of the remaining piece of 1/16" hard balsa wood after making two of the wing tip pieces.

 

And finally tonight I glued two parts of the wing tip together ready to be attached to the wing (again getting creative with the holding methods)

 

Someone sent me a message in the week asking why I wasn't building this on a pin board or something else that I could pin the parts to. The answer to this is that I would be if it hadn't be for the fact my dad moved my board while I went away from university and when I came back 4 years later and went to use it found it had bowed under its own weight when being stood upright.

[M J W J]

I've been busy over the last week with getting rid of a car and clearing out my garage of a load of scrap but I have managed to do a little to this.

 

I started with the capping on the wing. This is made of 1/16th medium balsa wood. It might not sound a lot but it adds an awful lot of strength to the wing and more importantly a lot of rigidity.

 

One side.

 

Then the other (I need more dress making pins as I have broken loads over the years)

 

I found I don't have enough 1/16th balsa to finish the wing. As the Cosford Model airshow is on in a few weeks I am going to wait until then to buy some more.

 

I therefore turned my attention to the tail. As I have changed the batteries from 10 cell NiCads to 3 cell LiPos which are a lot lighter, I need to get rid of some weight off the tail or add it to the nose (lightening the tail is a much better option). I have therefore decided to make a built up tail plane rather than cut it from a single sheet of 1/4" balsa. I have all the parts cut out ready for the tail. I just need to glue them together now and sand them to shape.

 

 

The thin strip you see will span diagonally between the thicker parts. I will cut this to shape and size once the rest is glued together. A tip for anyone making a plane. If you need 1/4" by 1/8" strips (that what the strip is) and you don't want to buy a strip of it, cut a 1/8" wide strip off a 1/4" thick sheet rather than a 1/4" wide strip off a 1/8" thick sheet. This way if your cut is a little off you don't have to spend ages sanding it down to the correct size and you end up with a straighter top and bottom edge.

[M J W J]

Its been a while since I updated this. With a lack of materials not a lot got done but after going to Cosford Model show (and getting very wet as it chucked it down) I now have the material needed to finish this.

 

I spent Monday night making and fitting some of the wing underside capping (the wing is upside down in the picture).

 

This centre bit is where the wing sits on the fuselage.

 

I also spent some time cutting strips wide enough to make the wing webbing. The webbing goes from the top to bottom spar in the wing to help stiffen it. The grain also has to run vertically between the top and bottom spar so the webbing has to be cut out in a certain way.

 

 

I also cut the trailing edge top and bottom capping strips. These are 1/4" wide by 1/16" thick.

 

 

The purpose of the capping is to strengthen and stiffen the wing. By adding it to the top of the ribs and trailing edge it makes them into a sort of I section which is much stronger. According to the plans there is no capping on this wing apart from the leading edge up to the spars. I decided for the small gain in weight I would add it. It also makes putting the covering material on afterwards easier as it gives you more area to iron it down onto.

 

Last night I sanded the top side of the trailing edge into shape and glued the capping strips on.

 

 

[M J W J]

Last night I managed to glue the missing part of the under side capping in the middle. I purposely made them slightly too big so they can be sanded down  to the side of the ribs.

 

 

I also made as many rib capping strips, form the scrap of 1/16th balsa I had and glued them in. I need to cut some other larger parts out of the 1/16th balsa I bought from the show and then I know what I have left to finish making the rib capping strips from.

 

 

I also cut out one more piece of webbing.

 

I realised that my build board (3/4" piece of MDF) had slightly flexed so I moved it and supported it with another work mate. I then used some heavy bits of metal to hold the wing down in position as the capping is glued on which will keep the wing in shape.

[Domneon]

What do you know of older rc engines? I have a few in the garage at a loose end

[M J W J]

Everything else I own is glow fuel and have become pretty good with them (out of necessity really).

 

What do you want to know about them?

 

Tuning a 2 stroke petrol or glow fuel engine is pretty much the same except for the initial settings. When they don't run its usually down to a few basic things, the main one being dirt in the carbs preventing fuel from getting through.

[Domneon]

i know enough about running them etc, I actually want rid of them

 

I have at least one Irvine glow engine, and two very small engines where theres no separate head that i think came from a powered glider. An old sort where you set the engine speed and throw it, then glide once the fuel runs out