Have a look at the original Plycycle here .

19 March 2014

Gluing the frame part one.

There was a window of warmer weather last weekend which allowed me to do the first epoxy resin work on the frame this year. I glued the left hand quarters of the frame together.... making a half. A small but significant step.
I Mixed up the West System epoxy, 'wetted' up the two sides and then spread on the resin with microfibers for the main bond. All god so far. it was only when i cane to clamp it all together that i remembered that last time I had to borrow extra g-clamps. I had forgotten to do this so I had to improvise. I used what clamps I did have to hold the main sections and then to clamp the remaining areas I placed the frame on some wooden blocks and then used some heavy engineering bricks from my back garden to apply pressure. it wasn't quite enough so I put a tool box on top of the bricks.

Make shift clamping in action.

I am pleased to say that it worked. The bond is good. however I will be borrowing more clamps as it really is much easier that way.

10 March 2014

Laying out the pieces.

I had a good stint on the build this weekend, and the main aim was to lay out the main pieces and see how it all looked. This was the first time all the main bits have come together and actually resemble a bicycle. Finally! It was a mile stone.

After I got over the fact that it looks like a bike, I started to take a more critical look at how it was actually shaping up. As it turned out there was a much larger gap between the rear wheel and the frame than i had anticipated. I think this was because when I first set the geometry I was going to use track style drop outs as I had on the Plycycle Mk1. But I changed to vertical drop outs, and although the geometry lines are the same, the place in which the wheel sits is set, and it is quite far back. I hadn't appreciated how much difference this would make. Not to worry though, it is a wooden frame and it is simple to shorten the stays, but this changes the angles of the rear triangle. I couldn't change the bottom stay fixing as it is surrounded by the main frame, however the top stay junction is fairly simple. So I set about the fix and an hour later it was done. See the before and after pics below.

 Before fix. Large wheel gap.

After fix. Wheel closer in.

I also notice now that the angle that I had placed the forks on is not great. They are just placed on, but along the pencil line I had thought would be best. I think that the problem is the opposite to the rear wheel. I think that the front wheel needs to come forward, away from the frame a tad. I will have to look at that properly when I have the head tube made and ready to fit.

Putting  a temp wheel in made me realize that it will be much more critical getting the rear drop outs in the correct place now that i am using vertical rather than track style. With track style there is a bit of wiggle room when bolting the wheel in as you can slide the wheel left and right a tiny bit to get a good alignment. However with the vertical drop outs the wheel is set, one position only. I think I will need to make a jig fot the final gluing.

6 March 2014

Rear stay rough assembly.

Over the winter I have managed to get some time to tinkering done on various bits and pieces on the frame. Mostly it was tidying up details and making joins more accurate.

Rear drop outs rough assembly.

 The biggest step forward has been the shaping and fitting of the metal work to connect the rear stays to the drop outs.
I am doing it loosely at the moment to get the fitting. I will then spot bond the metal work in place with an epoxy ready for braising. I have to be sure of the fit as I don't really want to have to remake the metal parts, so it is has to work first time. This system worked well on the Plycycle Mk1 so I think it should be fine this time too.
Incidentally I bought the drop out ready made and raw tubing from Ceeway.