[issdaol (Phil)]

Continuing on from earlier:

Anyone that has done significant visual observation over many years knows that rock solid stability is key to removing those annoying vibrations and movements that play havoc with focus and make whatever you are looking at a jittery or blurry mess. Often this gets forgotten about or people put up with it to a large degree but for myself I hate it so I try to put my systems together with the view to eliminating it as much as possible.

TREX EM400 Adaptor & Tripod
So step one was selection of tripod for use with the TREX. I had a spare Takahashi EM400 Metal Tripod which is one of the best and most stable tripods around. It has a load rating of 490kg (yes almost 1/2 tonne) witch as far as I can determine is by far the largest load rating of any Astronomical tripod I have been able to find.

Only problem being was the head does not match the TREX Mount or the TREX Pier connection. So an adapter had to be thought up. For this I took inspiration from my Takahashi EM400 mount coupling. As you can see from the pictures the top of the tripod is circular so the an adapter was made up that almost exactly mirrors the one on the bottom of a EM400. We later found out that this piece can actually be ordered from Takahashi (although they don't advertise it) but it would have needed slight modifications anyway to connect to the TREX Pier so we were happy that what we had was perfect for our purposes.

TREX Pier & Pier Adaptors
A pier adaptor was required to raise the mount up to an acceptable viewing level. I prefer this method rather than raising the tripod legs as it keeps the centre of gravity low. Again a major factor in stability especially on uneven terrain and with heavy loads.

In the pictures you can see the top of the pier and how it mates to to the bottom of the TREX using a locating nut and hole (similar to the Vixen mounts and tripod heads), secured by a large bolt through the middle. Then the Pier tube is secured by 3 cap screws around the circumference.

A special modification to the bottom of the pier was devised using a circular slab of aluminum (black) with a protrusion that fitted through the hole of the EM400 mating cap. This is then bolted underneath the cap and the whole pier is again attached by 3 cap screws around the circumference. In the pictures you can see all separate pieces and the last picture show the pier in its final position bolted to the top of the EM400 mating cap/adaptor and on top of the tripod. So apart from the Pier tube and the TREX connection all of these components were custom made and finished. Again great detail and engineering on behalf of the factory to turn out these parts.

The great thing about all this is that when situated on top of the tripod, the three mating screws around the perimeter of the mating adapter can be minute loosened and the whole lot swiveled to allow slight adjustments in alignment to point true south or north.

Also the connection of all of the components takes minutes to achieve as all of the parts are precisely engineered to mate together and there are no concerns of screws being loose or off center.

Need to get back to work so I will come back later with the final discussion and pictures on the mount head and telescope mating.

Cheers