Not a good look

[Shawn]

I left the dome open the other day to air it out a bit, now the scope was pionted nowhere near ecliptic, all lens caps I thought were on, but the missing lenscap on one of my finders still managed to melt the crosshairs...somewhere during the course of morning..... Crap...


Its the Meade one too, I wonder if its fixable.....

They must be plastic, anybody else done this stoopid trick...:ashamed:

S

[sheeny]

Not me Shawn, but Sausageman had a similar calamity at IISAC this year. I haven't heard whether he repaired the finder or bought a new one. When his was pulled apart, there was a melt track across the back of the inside of the finder (as well as the cross hairs of course) and the finder optics were clouded as a result.

If you are contemplating perhaps just replacing the cross hairs, I suggest you check the optics for any clouding, and see if it can be cleaned without damaging any coatings on the lenses.

Sorry to hear about the damage. It's just so easily done...

Al.

[Shawn]

There is no clouding, and the crosshairs are still there, but they look like a dead spider with four legs, and big glob in the middle big enough to obscure a full moon, well nearly. :), Im wondering if I can repair it...

S

[Shawn]

heres the damage, scanned image....

how do i fix it , any ideas...??

[Outbackmanyep]

Surely a 2nd hand riflescope, like a 3 to 9 X 40 , would suffice would it??

In have about 5 or 6 2nd hand rifle scopes......

I tried to fix my finder scope on my 60mm refractor years and years ago, i did manage to use a soldering iron to melt the new crosshairs in, but the thing was that the copper wire i used from 2mm automotive wire made it look furry....like the copper had bumps on it.

[Shawn]

Thanks for that outbackman, I wont try that then, I reckon a spider web might work... just a thought...

[Nightshift]

Looks like a pretty simple fix to me. Just cut out the old one's with a sharp blade (look like they may be nylon) and glue in two new hairs in the same position as the old glue marks. Use either pig bristle from a paintbrush or what has been used for many years in older equipment, hairs from a horses tail. Choose a black horse with a sense of humour though.

Dennis.

[erick]

Hi Shawn

I replaced the crosshairs in my GSO Finderscope - see here

http://www.iceinspace.com.au/forum/showthread.php?t=20812

Photo shows new crosshairs in place. Original were fine copper wire which was easily displaced (minimum glue in the factory??) I used slightly thicker copper wire out of the earth wire in some low amp (8?) mains cable.

Here's a bit more detail on what I did:-

"Re crosshairs. I used a sharp knife to remove the previous crosshairs and glue from the four notches. I then had some copper wire from a piece of electricity mains cable which was a little thicker than the original, but seemed OK - still very flexible. I held the wire across the two opposing notches with thumb on one side and fingers of the other, held down tightly against the tabletop. I tried to stretch it taut. Then I added a small wipe of "superglue" to each notch, then held firm for several minutes. On releasing, it had taken. I repeated with the other crosshair. Then I left to set for a few hours, then cut off the excess wire with edge cutters. I used the point of my knife blade to push the little hangover into the thread - in the correct direction so it trailed as the crosshair ferrule was screwed into place. As it turns out, I've had it off and on several times since, but the crosshairs have remained firmly in place and taut."

In the photo, you can see the white colour where the superglue outgassed onto the surrounding plastic in the ferrule. I hope it has stopped now I've rebuilt the scope. But this is a basic Finderscope, doing nothing special - so some crap on the lenses doesn't worry me much - but nothing seen for some days. The slightly thicker crosshairs are an advantage to me since the previous ones were difficult to see under dark skies. I'm still working on "illuminating" the crosshairs so I can see them better in the absolute dark. I've got a great set of red LEDS, fully variable illumination- but still not providing enough light - I have some more ideas to try before I start drilling into the FinderScope body or eyepiece body but I'll do that if I have to! :scared::)

[Shawn]

Great Info Guys, appreciated...

I pulled apart a set of the cellphone earsets, very thin braided wires, measured at .0015' thats .0005 half a thou thinner than the nylon ones.
did the super glue trick, as suggested...You beauty, lovely thin straight crosshairs...

Cheers Guys....

S

[Shawn]

I put a red led in the hood, that you can set to flash at predetermined interval via the illum reticle support and h/box, this causes the crosshairs two be sillouhetted against the star background breifly every couple of seconds,,works OK too...

[Outbackmanyep]

great stuff!
Hope it all goes well....make sure the copper wire doesnt get moisture on it, otherwise with corrosion you might get furry looking crosshairs!

Cheers!

[Shawn]

Hadnt thought of that, I did try the hairs that came in the same wired bundle but the croshairs were too thin , at least I know I can opt for those if the copper does corrode, It shouldnt though, as a matter of course in the tropics I stash those little pill bottle gel sacks in anything, I have one know inside the finder just in front of the crosshair reticle outside of the optical path. stuck on with a bit of superglue..I stick em in eye caps, lens caps, optical tubes, tool kit. etc etc etc, it helps for sure..

More of a mould deterent, but should look after the copper, I hope...Good piont, cheers...

S

[ballaratdragons]

Shawn, I used my daughter hair for my crosshairs in my reticle EP. Works like a charm :thumbsup:

[Shawn]

Fixed it....

[erick]

.........and you almost have that rectangular star centred! :D

[Shawn]

Its worked out so that the size of the square is the same size as the FOV as the imaging chip....:P


;)

[Shawn]

And before you ask, yes I got out my calculator, did the sums, made a jig based on the answers of the sums... then completely fluked it...LOL

S