I was thinking about upgrading my dobsonian's helical focuser to a Crayford style focuser. I was looking at different people's designs, but was especially interested in the Kine-optics HC-1 helical Crayford design. This focuser will go through its 1.5-inch travel in just one turn, and it has a nice low profile too. The weight is much less than the standard Crayford focusers I was considering. This is important on dobsonians, of course.
Then I read a site that claimed you could build your own Crayford focuser with not much more than a drill press. I have been thinking about making my own focuser, but have no idea where I would be able to get a 2-inch ID drawtube for it. The other parts of the design sound rather doable without a lathe. Has anyone here ever attempted to make a focuser? And does anyone have any experience with the helical Crayford focuser? Just where could one get a tube with the right diameter for 2-inch eyepieces off the shelf?
If weight and cost and height were no object, I would get a dual-rate premium Crayford focuser. This is the part of the telescope you have the most contact with, and it should work well. Thanks for any advice. Dave
Then I read a site that claimed you could build your own Crayford focuser with not much more than a drill press. I have been thinking about making my own focuser, but have no idea where I would be able to get a 2-inch ID drawtube for it. The other parts of the design sound rather doable without a lathe. Has anyone here ever attempted to make a focuser? And does anyone have any experience with the helical Crayford focuser? Just where could one get a tube with the right diameter for 2-inch eyepieces off the shelf?
If weight and cost and height were no object, I would get a dual-rate premium Crayford focuser. This is the part of the telescope you have the most contact with, and it should work well. Thanks for any advice. Dave
