Meade collimation problem? = poor quality control!
Posted 19 November 2012 - 07:35 AM
A few years ago I bought a LX200R 12 "(now ACF) and immediately I noticed that optically was not right. I read a lot of the problems encountered by many CN users with poor collimation of the instrument, ie the shadow of secondary mirror, intra and extra focal images do not match. Jerry Wise has written extensively on this topic, assuming a bad orthogonality with respect to the mechanical axis of the primary mirror. Well, after many arguments read on the issue, I decided to contact a well-known Italian manufacturer of very good telescopes. He took to heart my problem and decided to inspect my instrument, correcting any defects.
After making a lot of testing to the optical bench interferometer through, found the following:
Primary mirror is not orthogonal with OTA, but manufactured well
Secondary mirror is not centered, but above worked very bad (only 1/3 of lambda) and with the edge retorted and covered by a plastic ring that reduces the diameter of 7mm.
Secondary mirror mounted concentrically not in his cell
Corrector plate, bad oriented. Matching the marks made by Meade, the result was very poor.
The center hole on the corrector is off-axis of 1.5 mm.
Removing the primary and milling of the mirror on the back (base) of almost 1mm!
Machining of the secondary mirror, with elimination of the edge retorted (with a gain of more than 6mm in diameter on) and brought to 1/6 of lambda.
Corrector plate rotated of 16 ° respect to the original reference marks Meade.
After these interventions, the instrument is perfectly aligned optical / mechanical, with a final yield truly exceptional!
An excellent work carried out by an Italian craftsman, who managed to revive a telescope definitely worked very, very bad from Meade!
P.S. some users have reported these symptoms (shadow secondary mirror significantly different between intra and extra focal images) also in some telescope ACF series.
Posted 19 November 2012 - 02:17 PM
Posted 19 November 2012 - 07:09 PM
Fortunately, I am aware that not all Meade telescopes have these problems and I am glad that your telescope is part of the many telescopes made by Meade well, who have no problem. However my telescope, apart the secondary mirror worked very badly, suffered from trivial errors assembly of the elements. These errors are clearly due to inattention during the assembly process, and not of construction, this can be easily solved in the factory, prior to shipment, with an adequate quality control of the finished product. I live in Europe and I was very lucky to find a very competent person who got their hands on work done bad from original factory, with a final cost relatively low. Here in Europe, a Meade between import taxes, the gain of official importer, the gain of the store affiliated to importer and the high cost of transport, brings the final cost of the telescope at the highest levels, far, far more expensive than in the U.S. despite the Euro / Dollar exchange favorable. If I had to ship back the telescope to Meade for correcting the problems, it would cost me a fortune, just for shipping. I do not think it is right to spend good money for bad products because not are controlled before shipping! This is a true injustice to the detriment of the end user, especially if it is thousands of miles away, on another continent. It's also true that today if a company does not perform internal quality controls, sooner or later is bound to fail miserably. Word of mouth through the internet too many unhappy customers, it can be a deadly weapon indeed.
Posted 23 November 2012 - 11:34 AM
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Posted 28 November 2012 - 11:03 PM