How long does it take for the curse to pass??

[elusiver]

It's coming up to a week now.. and I STILL haven't had a chance to get my scope out properly.. it's been raining and miserable and overcast and.. typical melbourne weather.. the worst part is that it's usually kinda sunny in the mornings.. which gets my hopes up on my way to work.. then the rain comes..

since i've been confined to the indoors.. and so excited with my new dob.. i've been doing some stuff to it.

Centre Spotted the primary
'Played' with collimation
Installed a slew knob
Put in teflon sliders and milk bottle washers
Installed carry handles
Put in a bump pad


But the 2 things i've done that i'm most proud of is the installation of a fan, even though it probably wasn't needed.. i took out the plate behind the mirror and it was just sitting there.. asking to me modded to hold a fan.
I also made a finder scope illuminator.. outta my own design(although i'm sure someone else has done something similar). Initially i was thinking to use mikes method.. but then i figured it's want something I could take off when not in used so that i could put the finderscope cap on. I've attached pics

I've also taken photo's and stuff of all my mods as the works progressed.. i might write up a diary(i don't wanna call it a guide cause i'm not experience enough to guide people yet).

so yeah.. when will i be able to get my scope out!!!????

el

[ballaratdragons (Ken)]

Very clever mods el. Well done.

The weather will clear up when you pack the scope completely away and pull the dob base apart! But it will only clear up until you pull the scope back out again LOL

[[1ponders] (Paul)]

Hmmmm....lets see....I bought my scope in early october last year, we'd had 7 months of drought. It started raining the next day (I actually got to use it the first night) and in the next 6 months I got to use it about a dozen times.

Does that answer you question?

[Thiink]

Well done on the mods! It's good to have something to do while the clouds are around, try and get as many Icemods (tm) as you can done that you think need doing and it should make first light a whole lot more enjoyable! I think you picked the worst month to buy the telescope, its been clouds galore (well here at least)!

I've attached an image of what happened to me when my 10" dob turned up in Feb this year. I wasn't happy!

ps. can we have img back Ice?

[Starkler (Geoff)]

Half of the fun of owning a dob is modifying and customising it to suit

Thats a mean looking fan there , how did you cut a circular hole in the plate? Actually the plate seals against the back of the mirror cell, so you wont get much airflow that way. Better to make a plate or board which seals against the back of the scope and blows on the mirror, then around the sides and up the tube.

[slice of heaven]

I hope youve a few more mods to do.
With the amount of rain we're having youve plenty of time to trick that scope up a bit more.
Maybe by the weekend, fingers crossed.

[elusiver]

Starkler I've actually got the fan running in reverse.. drawing the air out.. i figured it'd suck the air through the front of the tube. I didn't really want to blow air up the tube cause it might blow dust and stuff up the tube which would then fall and settle on the face mirror. I've used a bit of paper to test it out and with the fan on there is the slightest bit of movent of air going from the front of the tub down towards the mirror.. which is what i was aiming for as i didn't really want a huge gust. The hole is acutally square, with four triangles cut out to make an 'X' in the middle to mount the fan, which is a 120mm Antec fan.. i initially went with an 80mm fan.. but then i though i'd get abit more air movement for a lot less revs(and noise!) with a 120mm.. and it only cost $19 so it was sweet I used a dremel to cut the holes


Next step will be to ad some protractor marking thingy's.. are they called setting circles???

then if the rain and clouds still don't break i'm gonna have a go at making an electronic focuser, with a hand control unit, which will be based on a jaycar stepping motor kit which retails for about $50..

i think i'll just have to keep telling myself.. we need the rain.. we need the rain.. we need the rain..

el

[RAJAH235]

Nice mods, el. Did you think of putting the LEDs inside the finder, pointing towards the objective? Only need 1 normal red LED for this. How are you powering them? 2 x AA's?
Make your setting circles as big as you can for better accuracy. L.

[elusiver]

i thought of it, but i was afraid it would be too bright... plus my initial plan was to make a sort off 'light spreader' setup out of hot glue.. gives almost a cold cathode sort of even glow.. but didn't end up going that way casue onoce i got to that stage it was good enough.. i've actually used larger LED's than i initially planned(5mm instead of 3mm)... but am glad now cause they help hold the 'cap' in place. I've got them running off 2 x aa's with a 21ohm resistor in parallel.. and they just put out the faintest glow.. abit more than enough to see the crosshairs.. but i'll have to see how it goes 'in the field'.. i've only tested in a dark room. But yeah.. just wanted something i could simply remove when the scope wasn't in action so that i could fit the finderscope cap on.

el

[RAJAH235]

el, PTN, if you have a 21ohm res. in parallel, then it's connected the wrong way. The resistor should be in series & be about 300 ohm. I have a 3 mm *normal*,(not hi-brite), red LED with a 2k7 resistor in series, inside facing the objective, & it just illuminates the X hairs nicely. But then I'm running off 12 volts. (as long as you don't exceed 20 mA, but at that current, it will be bright).Try using a 5k/10k pot. in the circuit with a 150 ohm resistor in series with it to adjust the brightness, then measure the pot. value & sub a fixed resistor. How about velcro/rubber bands to hold the 2 x AA holder on the finder? This would make it self contained. HTH. L.

[elusiver]

rajah.. i know the connecting led's in parallel is 'wrong'.. but i like it.. i've done a few projects with leds connected in parallel and i've always ended up with the result that wanted. I have got velcro to attach the battery holder.. it didn't come up well on the pic though.. the battery holder just attaches to the base fo the finderscope holder.. maybe if i end up getting or making up a dsc setup i'll reset all my stuff to run off a 12v..

got the scope out tonight .. and i think the mods will be taking the back seat for a while.. i need a barlow and some new eyepieces i think

also had some issues.. i don't know if it was my eyes.. or the seeing.. or more likely that my collimation was off or i was doing something wrong.. but i was getting like.. wriggly worms. that's the best way i can describe it. Like if i looked at a star.. in focus.. you could kinda see the worms moving 'in' the star.. but as i moved it out of focus the worms would get bigger and more of them and they move around and stuff.. it was kinda freaky.. IS THAT NORMAL?!?! i don't want my dob to have WORMS.. i only just got it..

the full moon was freakin awesome.. but it was very very bright.. to the point where i got that thing where you get a blind spot on your eye like if you accidentally look at the sun.. put on the moon filter.. kinda helped abit.. i've looked at the moon lotsa times with my little d1ckies scope and never had the problem.. i guess it shows how good the 8" really is..

el

[RAJAH235]

el, From what I gather, the 'worms' are a combination of bad seeing conditions & the 'floaties' in your eyeball. Most noticeable on brighter objects @ reasonably high mag & either side of focus. I think.
When viewing the moon, I kinda like to use my .96 ND filter. Others do not. I find that I pick up details better. You have already noted the diff. in light gathering ability in your 8", compared to the 60 mm.
Have fun with your mods. L.