I had an old video tripod which the fluid head had broken off. Basically what I was left with was a stand that couldn't be rotated or angled. Being on a budget I decided to put this to use rather than get a commercial tripod.
I mounted a flat board to it and then angled another board to hold eyepieces and the Autostar handbox. I made these wide enough for later expansion and to use as storage space for lens caps etc...
This set up works great in the Alt/Az position but I thought I may as well make an equatorial mount for the top. I could have simply made it fixed for my site but wanting portablility I opted for an adjustable one. Another few bits of wood, hinges and locking screws and I was done. A final spray with matt black to finish the job! I had most things lying around so all this project cost me was around AU$12 for the primer and paint!
The only problem with the equatorial section is that the cables can sometimes get caught up with movement - so modification may be made a bit further down the track (SEE BELOW). It seems the ETX90 would suit this mount though - it's cables remain fixed when the scope rotates ... but the ETX70's move as they plug into the fork arm and not the base.
A - Base board measuring 450mm x 150mm x 15mm with mounting at bottom to fit tripod