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cloudsweeper

Improving 8SE Focusing Sensitivity

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For a given circumferential movement, the angle turned through decreases as the focus knob radius increases.  And on the 8SE, that knob is pretty narrow.

Couldn't find anything in the shed, and no Lego tyres would fit, then an old toy truck came to the rescue - a pair of its tyres made a perfect fit, with enough friction to stay in place.

And I can still use the end of the original focus knob to gauge the improvement (i.e. reduction) in sensitivity.  

Looks good in principle anyway!

Thanks to @Knighty2112 for giving me the idea.

Doug.

 

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Edited by cloudsweeper
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Glad to be of service! ;)

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The operating radius can also be improved by using a clothes peg or modified Marmite cap.  :icon_biggrin:

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Go for a marmite cap- as Peter has already suggested. Make a 20mm hole in the middle and slide it on the ..works a treat and gives a more significant reduction factor thereby further improving focus sensitivity

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Thanks for the further suggestions everyone.  The tyres are very quick and easy, and a snug fit, but if the improvement is not all that great (yet to be tested), I'll be eating toast and Marmite for a week!

Doug.

 

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Were these the sort of things that 3d printers were supposed to be used for?

Thinking someone keeps a library of astro bits and you pay £10 or whatever to have one printed.

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If the tyres don't work out well in practice Doug I have one spare roller that I used for my mod left if you need it. :) 

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1 hour ago, Knighty2112 said:

If the tyres don't work out well in practice Doug I have one spare roller that I used for my mod left if you need it. :) 

Great offer, Gus - thanks!  Hoping to try out the tyres as soon as the rain stops!

Doug.

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I used a spare piece of outdoor ply and drilled a 20mm inner hole and then used a  80mm hole cutter for the  outer circle. Sprayed the whole thing matt black to blend in - job done! It really makes fine focusing so much easier!

WIN_20170412_19_27_23_Pro.jpg

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