Method

This is a difficult one as this has been wriiten up in retrospect.

The basic concept model was to use an on CD tray from an old PC sitting in a skip outside my work place. If you ever have the opportunity try taking a CD tray and the floppy drive of a PC apart. They are a lovely piece of engineering and full of motors and cogs and spindles. A KT Scientisits dream for spare parts. After cannibalising the tray I was left with the cradle and motor housing. On this housing you will find a 12 volt motor with a bevelled cog that drives a spindle 90 degrees to its turn (You can just see the motor in the image above where the red and black wires are sticking out). On the bevelled cog I attached the connector of a coaxial cable. This was to be later attached to the reel of an old video camera reel. The only reason for choosing these two items was because the fitted together nicely. Other items could be used but these were available.

Adding the panel

The image on the left is the PPL part way through its build. You can see that I have placed the 4 mm plywood to the top of the tray and you can clearly see the motor and the bevelled cog to the left. You can also see the coaxial plug protruding through a hole made in the plywood. This took a bit of fiddly measuring but it is well worth the effort as you do not want it the rub. I had to place pads of balsa wood to the front and back of the trays asthe motor was higher than the tray height. Once I was happy with this, I glued the whole lot with supaglue. If you look closely at the image you will also see the VCR tape reel ready to be mounted.

The Rollers

The rollers were my biggest headache on this project. I left the project to sit for a couple of days hoping to find inspiration. I find that during KTS builds, if you come to a problem , put it to the back of your mind and leave it for a little while. Do not rush it as the right part will come along eventually.

As I strolled around work I found an old roller from a printer cartridge that looked like it would fit the bill perfectly. I had to ensure that the rollers did not actual touch each other but had to just feather each other when they turned. A friend, Jeremy H, a human I met via Woodys Lounge suggested this. He felt that by if a thicness of paper went through the rollers then it could cause them to stuuter and slow down, he even suggested weighting the rollers to cause inertia but this was found to be unnecessary, but a good point to note.

Also note that I have a larger cog at the drive wheel than at the roller, this will mean that the rollers will revolve quicker than the drive cog allowing mor 'fling' power.

Perpendicular bisection of a chord on a circle!

I am not a great lover of rulers for measurement and have a tendency of preferring the use of a compass, especially when making very intricate measurements like the distance between tworotating cylinders. A little known method that I use to find the centre of a circle is to use the perpendicular bisection of a chord on a circle....cor bit of a mouthful.....the diagram to the left will give you a clue.

I drew around my roller to get a circle on a piece of old wood with the point of my compass needle (much more accurate than a blunt old pencil and then drew two chords(in blue). Then finding the middle point of each chord I drew a perpendicular line from each one (in red). The point where the two red lines cross is the centre of the circle....easy. Now getting my compass I can measure the radius. The distance is then twice the radius ..or the diameter of the roller.

Now I hear you say....what a waste of time Jezza when you can just scratch a mark for the diameter..I say I don't care, this is KTS and you have to learn a little science/maths along the way.

Once I got the correct sistance between the roller centrepoints I carefully drilled some holes and placed the spindles from my old video camera. Now it was a case of adding an elastic band as my drive train and run it.....worked a dream

What size plane?

Now this all came down to trial and error. Jezzarette 2 got involved in this part as is normally the case!!

We started to build a standard paper dart from A4 paper....it failed miserably...feeling a bit down hearted we tried A5, not great...A6 getting better....A7 looking good, A8 good....A9 FANTASTIC A10...couldn't do it, my paws are too big.

The very bad picture to the left shows how small an A9 plane is approximately 50mm or 2 inches!

Needless to say we were able to fling an A9 paper dart 20 feet down the garden path and it cost us NOTHING. I would say that this is another KTS project success, we tried it by had and only got 8 feet!!!!!!