Fit my own crosshairs?

[erick]

I'm a bit stingy to invest money in a reticle eyepiece, illuminated or otherwise if I think I could knock something up. I just want a set of cross hairs (single probably, but double would be even better) on a shortish focal length eyepiece. At the moment, I want it to more clearly monitor the performance of an EQ platform I'm playing with, but it would be handy for more accurately aligning the finderscope.

I'm looking at my 9mm GSO plossl and wondering how to add a set of cross hairs? Anyone done this? An option, I guess, is to fit a set of cross hairs to a 1.25" filter (minus glass) and screw that in.

Apologies if there is a thread or ten on this already. Yes I've checked out Ken and the tale of his daughter's hair!

Maybe one can buy a 1.25" "filter" with cross hairs already fitted?

Thanks all.
Eric :help:

[gbeal]

Eric,
way back I used a filament of contact adhesive glue, the stuff that you can't get rid of when you dip a stick into the pot.
Having said that I did have a crosshair reticle which was etched onto a disk of plastic. I put it away for a rainy day, but can't remember where.
Maybe a washer at the focal plane, with the glue things on it? Next you will want to illuminate it?

[Shawn]

Eric

I made a one ,

Copied and pasted from other forum

>>>>>I applied my x hair repair methods to a 40mm Vixen EP, a wanted a better way of framing objects with visible stars or features...Using this 40 mm in daylight I noticed that the butt end of the chrome barrel bit was in clear focus and chrome, cheap nasty piece of work, but OK optically.. I thought since I dont use it for anything other than a paperweight it might make a good framing reticle with the right x hairs...

The procedure is simple

Find a bit of polystyrene foam about an inch thick.

Cut a hole in it big enough for the barrel bit that you have unscrewed from the EP to fit through,

puch 4 pins into the foam at quadrants,

Wrap the thinest wire you can find around the pins in such a way you have double xhairs framing a tiny square in the middle. Dont worry about getting the wires striaght and tight at this piont,
The wire in earbuds is very fine, or you can use the fibre strengthening fibre, either or...

put the barrel bit upside down on the table,

and drop the hole over the barrel bit
the weight will straighten the wires and make them even and taught.

brush on super glue where the wires cross the back of the barrel bit

Wait till dry

Snip jig loose with pair of sharp scissors...

re assemble..

I found that the square frame in the 40mm on the 100mm is roughly equal to the image size of the 14er and the 350...

Paint the chrome bit black will your in there, it works well....

S
<<<<<<<


Shawn

[Blue Skies]

I've got a couple of old solenoids with fine copper wire in them that I use to replace broken crosshairs. I'm not sure that I'd go as far as they did in the 'old days' and use actual spider web as the hairs!

The other thing I thought I would comment on is that the hairs need to be in the focal plane of the eyepiece, and that is not always conveniently at the end of the barrel where the filters go. From my observation of fixing broken ones there is usually and extra ring that gets screwed in up the barrel that hold the hairs and can be placed in just the right spot. This could make it a bit tricky to fix one up at home - something I've thought of doing myself occasionally too. Let us know how it goes, with pictures!

[mill]

Erick
I can fit crosshairs on my 9mm gso plossl and do a straight swap over.
Makes it easier :)

[ballaratdragons]

Eric,

whatever you use as the crosshairs (wire looks like rope inside the EP), it must be, as mentioned above, in the focal plane! This cannot be stressed enough. If they aren't in the focal plane they simply do not work :thumbsup:

[mill]

As Ken said.
And the smaller the fr the eyepiece is the harder it is to do and the thinner the wire has to be.
25mm is easy 9mm is hard to do.

[erick]

Hmmmm... Sobering advice, thanks all. I'll have to think, then maybe experiment - firstly to locate the focal plane of the eyepiece I plan to use. And I hadn't realised how fine the strands will have to be. Purchasing is starting to make lots of sense.

[ballaratdragons]

Eric, I use a 25mm for the 'daughters hair' EP. (I think :confused:)

[mill]

As i said i can make you one for free.

[erick]

Martin, I'll call and discuss in the next few days. Thanks.

[space oddity]

Russell optics, Meadview Arizona make a 25mm crosshair eyepiece, list price $ US 25:thumbsup:. They are out of stock at the moment :(and Gary Russell refuses to sell outside of the U.S.:screwy: even if I pay and have goods sent to a cousin in N .J. OK though to have someone in the US buy one from the website then send it to US address and then have it sent here, remembering that surface mail is no longer available:(. If you do have someone able to buy in the states, I would love to buy one of their 72 or 85 mm eyepieces for those W I D E objects. Spoke to Bintel the other day with exactly the same question,same answer, crosshairs need to be in focal plane. An Erfle design is the only one that you could possibly get away with it. In the end, bought a 10-35 illuminated reticle zoom eyepiece on Ebay to use for star centering for my GOTO . Email me in a couple of months time when it has arrived from Europe and I have had time and skies to try it out.

[ballaratdragons]

The advantage of a Toucam!

The tiny chip only shows a close up of the centre of the FOV, acting as a 6mm EP. So, what you see on screen is just like a 6mm EP.

Place the curser on a star, or the centre of the object itself, or open a guiding program and use the programs crosshair, and BINGO, an illuminated reticle ;)

Well, that's how I do it anyway. :)
Don't have to stare into an EP, just sit back and see if it moves on the monitor.

[erick]

Thanks Ken, I can try that with the gear I have. A task to do during the camp when I get back to my webcam and get it working properly.

[mill]

Erick just spend about 3 hours doing the double cross and it is ok now.
There is only one slight imperfection :mad2:
Just tell me if you can live with that :shrug:
Will bring the eyepiece with me to Snake Valley.
Pics below.
First pic looking through the eyepiece , second pic close up of the hairs in the 9mm eyepiece.
Sorry i could not resist :P
Made crosshairs from one string of teeth floss and stretched it till it was spiderweb thin, and it is very very thin. pic number three.
Personally i like the hair in the first pic better.

[erick]

Martin, that certainly is impressive! Not only the crosshairs but that you have three hours of patience. I don't think I would have got past 30 min!

That will do just what I want, thanks. The "imperfection" won't worry me.

OK swap plossls at SV camp, plus I owe you, mate!

[AstroRudi]

Hi,
do you know what Window colors are ? Children love them in Germany ! http://www.artsncrafts-ideas.com/kid-windows-painting.php
I made a cross wire for my eyepiece with the hair of my wife. But before making the cross, I put some self-lightening window color (for children !!) on a paper and draw the hair through this plot of color.
Now, when I take my torch / flashlight and give a short light input into the eyepiece, the cross-hair is shining - let's say - for one hour without any problem !
Clear Skies
Rudi

[erick]

That's very interesting Rudi. I gather it is a paint that will fluoresce for a while after being lit with white light. I'll search for these "window colour" kits - must be available in Australia. Thanks.