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Upgrade the losmandy G11 = super mount

Posted by Michael Tzukran   12/09/2017 00:00:AM

High Guiding Accuracy, Amazing Mechanical

Stability, High Weight Capacity





Weight:



I have put together a 150mm Takahashi weighing 15kg, a 71 mm Takahashi as a guiding scope. The total weight of the equipment was 25kg including

mechanical accessories.



When I purchased the equipment, I was warned by the seller, that the equipment was too heavy for the specific mount. After using the equipment, and analyzing the results of the photographs that were taken, I have noticed that the stars were elliptically shaped instead of clear round shape stars as expected, also small and faint details in the nebulae were missing and generelly, the photographs were not clear and sharp. The same results were reflected after analyzing graphs using “phd” guiding software.



A friend of mine, having the same Losmandy G11 Gemini 2 mount, with a Takahashi 130 mm telescope and a Takahashi 88 mm guiding telescope assembled to it, suggested that by reducing some weight from the equipment and implementing some mechanical improvements to the mount, I could possibly achieve optimal results…



In order to improve the system (mount and the assembled equipment...) performance, being affected by the system weight, the tube rings securing the equipment to the mount were first modified by the milling of the rings. Secondly, the "Dove Tails" which were the base, have also been modified (milled).



In addition, the mount's balancing rod was extended and the weight of the counter weights was reduced in order to increase the stabilizing moment value. During the work to improve the mount, backlash was observed in the Dec axis and R.A., which led to the conclusion that it is not enough to modify the tube rings and "Dov Tails" base. In order to cancel the backlash, I have replaced the original mount clutches with conical clutches that I prepared myself in both axis – Dec & Ra. In adition to that I replaced the shaft encoders with more accurate ones (instead of the originals).

After the mount and equipment modifications were completed, the system performance was tested for several months in order to examine the reliability and the accuracy of the guiding process…The results were amazing!



Analysis of the results revealed a deviation smaller than 0.25 pixels throughout a whole night of guiding! The results are reflected in the following "PHD" guiding software graph



After the mount and equipment modifications were completed, the system performance was tested for several months in order to examine the reliability and the accuracy of the guiding process…The results did not disappoint.



Conclusions



Getting the high guiding results allows a long exposure (30 min for each frame&hellipwink which allows photographing using a "H-Alpha" 3 nm filter with a cooling unit (generating -15c) and DSLR6 camera for much longer time (all night&hellipwink.

Modification of all the system allows:



Using a load  that is heavier then the specified weight for the mount.



Increasing the guiding accuracy by reducing weight, cancelling backlash and using more accurate encoders and reliable conical clutches.



Getting clear and high resolution pictures with a deviation no more than 0.25 pixels (Also in windy conditions&hellipwink.    



The modification was implemented in another 5 losmandy mounts systems, getting the same results. by using the same "modification kits" (Built specially for those purposes) getting same high guiding accuracy results!!! 



Following is a picture of ic 434, was photographed using our Losmandy modified systems:





You can cut and paste the following address to view it at high resolution: https://www.michaelastro.com/halphaic434



You can find the Original Article and more info here: https://www.michaelastro.com/g11upgrade



Thank you

Michael & Gili