Second Thoughts

After deciding to upgrade to a 6" secondary coil I got on the phone to Trent Plastics to order the relevant pieces of perspex. These consisted of a 810mm length of 150mm diameter clear acrylic with a 3mm thick wall and two 144mm diameter 15mm thick clear acrylic discs which will be inserted inside the ends of large tube and form the top and base of the secondary coil. I normally deal with a guy called Levi who is always on the ball, I was a little concerned that the discs would not be a good fit inside the 150mm tube due to variations in wall thickness that occurs in extruded acrylic tube so I asked Levi to check the fit of these discs inside the large tube. Three days later and a long cardboard covered tube turned up. I checked the fit of the discs and they were a perfect close push fit inside the large tube.

The above pic shows the 150mm diameter tube, it still has the protective plastic film and I have added masking tape so I can mark the position of the 8 4mm holes that will accept the M4 nylon bolts to locate the top and bottom perspex end caps.

Here are the 2 end caps. They are sitting on a 12mm thick 500mm clear acylic disc which will be the base for the primary coil. The disc on the left is for the bottom of the secondary coil and will be secured to the primary coil base by 8 M8 40mm Nylon bolts. You can see I have already marked the disc for drilling.

The holes need to be drilled to 6.8mm and then tapped for the M8 bolts. This means the bolts will be captive in the secondary coil base which is needed as there will be no access to the bolt heads once the secondary coil is assembled.

Assembled so you get the idea.

The base disc will attach to the secondary coil tube by 8 X 20mm M4 nylon bolts which will be located equidistant around the circumference at a height of 7.5mm.

Starting to get worryingly large!!