ETX Tripod

*Astronomy: A Wooden ETX-90 Tripod*

With more or less simple woodworking equipment, you can build an ETX tripod.
This is somewhat of a work in progress, since the top parts have not been fully finished. You will need to be able to cut tongue and groove sections in oak. While you will want to be careful with your setups, none of this is rocket science. Note the method of adjusting the legs. It's somewhat slow, but easier, since you don't have to bend down.
	Here's the overall base without the head. The box is for the scope that goes on it.
	The top is made from oak, beveled. Each little connector is made from oak, and bolted to the platform. Furniture glides are used for a low friction surface. The center screw is used to hold the revolving head. You can see the slots cut in the outer legs from this viewpoint.
	Details of the legs. The inner piece of oak is the extensible leg and is the same size as the outside pieces. The difference is that the inner piece has two ears on it that ride inside the grooves on the outside pieces. The top brace holds the distance between the legs. The screw is attached to a wooden block on the center section. You'd really want a left hand thread for the sense of the up/down, but it works. A threaded insert in the lower block forces the inner leg up and down.
	The screw is used to attach the top of the tripod.
	This is a lock that was put on before I added the top screws. Other than holding the bottom of the legs together, it really isn't needed. Bottom of the tripod is threaded with an insert and holds a carriage bolt for a tip.
	The braces are built from two pieces of wood, with the horizontal piece beveled to match the complement of the angle of the leg. The center brace is removable. It is made of rosewood stained plywood with holes cut in it for the eyepieces.
	The top took a bit of experimentation. The center is drilled for the nut for the center bolt. A standard turnbuckle provides the capability of adjusting this for different polar inclinations. There's a small bubble level for making the thing level, and a small compass for guessing where north happens to be, just in case that section of the sky is socked in.
	Another view, placement of the turnbuckle is a bit critical, since the support for it can keep it from coming down completely.
	Top of the tripod, bottom view. The two knobs hold the telescope base to the tripod top.
	The two holes are used to access the telescope's on/off drive switch and the N/S hemisphere switches. Note that the top of the turnbuckle has been relocated a bit.
	The completed tripod. Swivel it to face north first, then level it.
It's a bit unsteady, somewhat larger legs would help with a bit thicker wood and sturdier feet. Not too bad for an ETX, though.