200p dob mods

[lennylovit]

hi all a few of us got 200p wot mods have you done ?,

my list so far

flocked

centred focuser + center spot on tube (for lazer)

lazy susan + pads

adj legs (£1.50 each focus bargin bin)

ali center bush + ali washer

wot next ???

how tight are the spider nuts done up ????

[stevetynant]

Hi Len I've added bobs knobs d to aid in primary and secondary collimation , a setting circle and wixey for push to and added a telrad and right angle correcting spotting scope as well.now all I need to do is get the whole lot back out in the dark

again

[JamesF]

Hmm. Good point. I must leave room on my dob base for a setting circle. I shall search the DIY section for examples now

James

[lennylovit]

telrad is next on my shopping list ,wixey on order ,got right angle correcting finder on my 127 to swop over,s/steel capheads in both primary and secondary but spider is giving me grief ,collimation go's out when i put end cover on and off , spider is pulling end ring out of shape so how tight must it be ??? cannot get it right try again in the morning

[stevetynant]

It didn't seem too bad when I took it of off to flock the scope to be honest

[lennylovit]

Steve do you need a center bush and washer made ?? still got some ali bar

think got spider sorted now had it way to tight

[knobby]

Here's my efforts

The draught excluder is to stop the lazy Susan getting gritty ... or dead spiders in!

Baader clicklock EP holder

Very early stage prototype encoder for AZ setting!

[lennylovit]

good job Knobby, why dont you turn down the center bolt and get a flexi drive into bolt with the encoder above with the half nut locking the bolt on the bace board it stays sill and mount the encoder on top with the flexi drive

dont know how to post a link but look at this on ebay 300746124336

[knobby]

good job Knobby, why dont you turn down the center bolt and get a flexi drive into bolt with the encoder above with the half nut locking the bolt on the bace board it stays sill and mount the encoder on top with the flexi drive

dont know how to post a link but look at this on ebay 300746124336

Cheers Lenny

yep ... like the look of that flexi coupler, you can see what i mean by early stage prototype !

Its held together at the moment with cardboard from the Skywatcher box

The reason I used the timing belt / pulley was the encoder only seemed to work clockwise, much more fiddling to do me thinks

Also .... please accept my apologies, I've just realised that this is the South Wales group, It didn't show up on tapatalk

' I have been to Wales though, only for about 5 minutes '

thats another story

[lennylovit]

only work clockwise ?? wot the encoder or your setup , i like the encoder how much££ and from who?? that and wixey job done

[JamesF]

I think it's one of these:

http://www.axminster.co.uk/gemred-rotary-angle-encoder-with-remote-sensor-prod806698/

Quite tempted myself, I have to admit.

James

[knobby]

only work clockwise ?? wot the encoder or your setup , i like the encoder how much££ and from who?? that and wixey job done

The encoder !

[lennylovit]

thanks James , it does not say if it is one way or not

[JamesF]

Doesn't say it only works clockwise on the Axminster site and their list of possible uses includes things that can't be completely rotated. I might ask them before ordering.

James

[knobby]

hi all a few of us got 200p wot mods have you done ?,

my list so far

flocked

centred focuser + center spot on tube (for lazer)

lazy susan + pads

adj legs (£1.50 each focus bargin bin)

ali center bush + ali washer

wot next ???

how tight are the spider nuts done up ????

I like what youve done with the ali centre bush, has the same effect as my oversized M14 bolt in stopping side movement ?

[knobby]

the encoder turns both ways but reads only one way ... and it can go , round all the way and carry on, if that helps ... I can feel a video coming on !

[JamesF]

I have just emailed them to find out. If it works then it might be neater than a setting circle for my dob base, not to mention easier to make work. I guess I should have asked which way it turns as the angle increases, but that didn't occur to me at the time. Can you enlighten us, knobby?

James

[JamesF]

Ahhh, knobby, do you have it in "absolute" mode when you really want it in "relative"?

James

[knobby]

wasnt really sure what that meant ?

[JamesF]

I assume that if you set it to zero in "absolute" mode, it will tell you how far the spindle has turned in a given direction in total. Could be that it will keep going past 360 to represent multiple turns.

If you set it to "relative" mode, I'd expect it to tell you how far from the zero point you are.

The latter is the one I think you want for our porpoises.

James

[knobby]

Actually it might be OK either way, it looks likeit just goes 'minus' if you turn clockwise...

sticking it on you tube ... back in a min

[knobby]

Please excuse the appaling video, no time for tripods or fancy lighting, but i think it makes the point

http://www.youtube.com/watch?v=0qdarHcsCE0&feature=plcp

[JamesF]

Complicated stuff, this technology. Someone should invent something simpler than a dob

James

[knobby]

Complicated stuff, this technology. Someone should invent something simpler than a dob

James

Eyes !

[JamesF]

Aha. Thanks for the video. That makes sense. I guess it should work fine then, it just looks like it needs the cardboard box mod to reverse the spindle direction and make it work in the right sense for azimuth measurement?

James