Last updated: 10 May 2002
Sent: Thursday, May 9, 2002 9:27:53 From: email@example.com (Richard Shoesmith) Having been frustrated by the lack of an electric focus for the ETX 70 I have built my own. I know it doesnt look elegant, but it is very effective and only cost about 32.00. The basis for the focuser is the LEGO 9v motor kit which comes with a useful selection of gears etc and the control /power box. The motor which has a quoted rpm of 350 is geared down to approx 12 rpm or roughly one turn every 5 seconds. Power is supplied by six AA batteries held in the LEGO control box which has forward and reverse buttons. A fifteen meter extension, patched into the power supply cable, gives the reach to enable focusing to be controlled from indoors by the PC when using the electronic eyepiece. Photo 1 shows the gear assembly and photo 2, the method of attachment to the scope using the dust cover for the T-mount to hold in place a thin plywood support. Richard
PS My next project is to power the scope itself. I have an 18v 1000ma power adaptor going spare. Is this suitable?
Mike here: See the Telescope Tech Tip page for lots on Power Supplies.
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