using the templates from above, I think u can find ur way with pieces of wood, a few dowels, and alumumnium piping of different diameters. as for the cone shaps an stuff... look for somehting that fits in every store you come across.I got one from Rufkin toys, and although I used a lot of his parts, I could have done it myself entirly.
most convenient from the rufkin toy one was that I instantly had the right measurments, but I changed the structure quite alot, it was pretty fragile being entirly made of resin.
base of the 2 tubes are now wooden dowels, running from one end to another, it's alot more durable thsi way, not that accurate but still...