http://tech.groups.yahoo.com/group/TALScopes/ TAL Telescopes Fri, 06 Nov 2009 03:18:51 GMT rob wood http://tech.groups.yahoo.com/group/TALScopes/message/13334 http://tech.groups.yahoo.com/group/TALScopes/message/13334 Hoping i read your question correct!!Had the same sought of problem with my motor/gearbox.May be the shaft is not engaging the the reduction gear because of Thu, 05 Nov 2009 11:42:43 GMT andrew554495 http://tech.groups.yahoo.com/group/TALScopes/message/13333 http://tech.groups.yahoo.com/group/TALScopes/message/13333 Hi Richard. Sounds like the motor reduction gearbox is suspect. My mount showed similar problems before I replaced mine. Here's a link to a pic of my worn Thu, 05 Nov 2009 01:08:40 GMT rdschwier http://tech.groups.yahoo.com/group/TALScopes/message/13332 http://tech.groups.yahoo.com/group/TALScopes/message/13332 Just acquired this mount and RA drive is intermittent. The motor shaft appears to have too much play and must be in just the right position to engage inside Tue, 03 Nov 2009 04:19:12 GMT Lou http://tech.groups.yahoo.com/group/TALScopes/message/13331 http://tech.groups.yahoo.com/group/TALScopes/message/13331 Hi Rob, Glad you liked the motor, but understand the main bearing is no good. The 2M is an f/8 which dates back to the 1950's. The spherical mirror is on the Mon, 02 Nov 2009 01:13:00 GMT Stephen.B.Forbes http://tech.groups.yahoo.com/group/TALScopes/message/13330 http://tech.groups.yahoo.com/group/TALScopes/message/13330 The original motor rotates in a clockwise direction at 1/5 rpm. I hope that helps. CS Steve ... From: rob wood To: TALScopes@yahoogroups.com Sent: Sunday, 01 Mon, 02 Nov 2009 01:06:09 GMT rob wood http://tech.groups.yahoo.com/group/TALScopes/message/13329 http://tech.groups.yahoo.com/group/TALScopes/message/13329 Hi All....A query on the rotation of the motor running the RA Axis.! Does anybody have any information as to the direction of the shaft rotation of the motor Sat, 31 Oct 2009 09:28:52 GMT hyranscolde http://tech.groups.yahoo.com/group/TALScopes/message/13328 http://tech.groups.yahoo.com/group/TALScopes/message/13328 Is this not just simple geometry? An ellipse is a conic section, in this case the cone is the light cone. However, the centre of the ellipse is not at the axis Thu, 29 Oct 2009 03:17:45 GMT hwnewton http://tech.groups.yahoo.com/group/TALScopes/message/13327 http://tech.groups.yahoo.com/group/TALScopes/message/13327 The original reference to sky and telescope for collimating a newtonian was a very wise reference. I just read through it and it includes as a sidebar some Tue, 27 Oct 2009 22:59:28 GMT Telescopes & Astronomy http://tech.groups.yahoo.com/group/TALScopes/message/13326 http://tech.groups.yahoo.com/group/TALScopes/message/13326 Hi all, Information from Texereau's book is correct in regards to Offsetting the secondary. It is also more important the larger the scope. If you draw a Tue, 27 Oct 2009 04:20:44 GMT hwnewton http://tech.groups.yahoo.com/group/TALScopes/message/13325 http://tech.groups.yahoo.com/group/TALScopes/message/13325 This is clearly one of those subjects that can get grossly out of control and into heated discussions. Lets see if we can avoid that. I looked at 2 web sites Tue, 27 Oct 2009 04:02:24 GMT Wolf Lonczyk http://tech.groups.yahoo.com/group/TALScopes/message/13324 http://tech.groups.yahoo.com/group/TALScopes/message/13324 Hi, according to Newtwin the offset for a 6" f/8 System should be around 0,05mm. Nothing to worry about. Viele Grüße Wolf Tue, 27 Oct 2009 04:02:12 GMT mischamichl http://tech.groups.yahoo.com/group/TALScopes/message/13323 http://tech.groups.yahoo.com/group/TALScopes/message/13323 Hi Hal, sorry, I have to disagree. Offsetting the secondary mirror is not a notion, but necessary in fast newton systems. If you don't offset with f/5 and Tue, 27 Oct 2009 04:02:10 GMT scopecrazy http://tech.groups.yahoo.com/group/TALScopes/message/13322 http://tech.groups.yahoo.com/group/TALScopes/message/13322 Re seconday mirror "Off Set" ... I'm quite sure that this is indeed well known as a requirement for proper alignment of the the primary and secondary mirrors Tue, 27 Oct 2009 04:01:54 GMT themouldyone http://tech.groups.yahoo.com/group/TALScopes/message/13321 http://tech.groups.yahoo.com/group/TALScopes/message/13321 The instruction book for my TAL2 No.92 (recently sold) says center the secondary i bought a cheshire collimator for this and the results were brilliant. Try Tue, 27 Oct 2009 03:23:55 GMT gurneyfan67 http://tech.groups.yahoo.com/group/TALScopes/message/13320 http://tech.groups.yahoo.com/group/TALScopes/message/13320 Hello, Have a look at the Sky and Telescope site in the Do It Yourself under collimating a Newtonian Telescope. It was the eye opener for me. Hope this helps