Could someone tell me what size this C11 screw/bolt thread is?

[ncjunk]

Hi,

I have attached a photo of a screw and I think it is M6 (well its 6mm diameter but its not a standard M6 thread) but I don´t know specifically what I have to ask for when I order one. I need one slightly longer than this for mounting another telescope on top of my C11.

I understand I need the diameter (6mm?) and then the pitch?

Thanks for any help.

[michael.h.f.wilkinson]

Could it be a 1/4" thread? That is coarser than M6x1 and is about 6mm in diameter (6.35mm to be exact). This is also used in photo tripods so you can check by testing if it screws easily into a camera's tripod thread.

[ncjunk]

Yep it screws into my Nikon D50 so its a 1/4" thread? Is that the common reference I need to ask for?

Thanks for the reply

[Psychobilly]

1/4-20 UNC or 1/4" BSW...

[ncjunk]

Thanks Peter thats what I´m after.... funnily enough I thought you would know and probably off the top of your head ;-)

A screws too mechanical for me...give me an IC741 op amp any day..

[Psychobilly]

No worries... Zeus is my friend... my only friend....

[michael.h.f.wilkinson]

Thanks Peter thats what I´m after.... funnily enough I thought you would know and probably off the top of your head ;-)

A screws too mechanical for me...give me an IC741 op amp any day..

I prefer the TL071 JFET-input opamp, does every thing the 741 does but more precisely;)

[ncjunk]

I prefer the TL071 JFET-input opamp, does every thing the 741 does but more precisely;)

How dare you! the 741 was my faithfull friend from school all the way to University...I would rather sell my Brother than use anything else!

oh wait...I´ve just realised the only one I have at the moments a CA3130...looks like I´ve been cheating on the 741....

I may have gone off topic slightly....

[Merlin66]

Neil,

Where did these knurled screws fit on the C11....and what do they do/ hold in place???

[michael.h.f.wilkinson]

How dare you! the 741 was my faithfull friend from school all the way to University...I would rather sell my Brother than use anything else!

oh wait...I´ve just realised the only one I have at the moments a CA3130...looks like I´ve been cheating on the 741....

I may have gone off topic slightly....

I used to have the 741 as mainstay, but then found newer designs better (the lure of newer silicon(e) ). Haven't traded in the missus, so I know what being faithful is about.

[ncjunk]

On my c11 i have two black bits of metal that are located on the side of the scope one at the eye piece end and one at the secondary mirror end. Each one has two holes for screws. One side curved to fit to the scope and other side flat. These look designed to take a rail in order to attach another scope. So i have created a plate to fit that has a couple of guide scope rings on it. I didn't know what screws would fit though hence the question.

[Peter Drew]

If tthe screws are genuine C11 then they will be 1/4 UNC, same pitch as 1/4 BSW but will have 60 degree thread form instead of 55 degree for the BSW. .

[Merlin66]

Neil,

Thanks for that - understood.

(I don't have these "extra" radius blocks on mine, but I have fitted an ADM minirail)

[m.tweedy]

Neil,

Thanks for that - understood.

(I don't have these "extra" radius blocks on mine, but I have fitted an ADM minirail)

same here.

[ncjunk]

Sorry to ressurect this but i ordered some screws and the ones that came are veeerrrryyyy small. This WILL be my error during ordering but i cant afford another mistake so can anyone post a link to a page where i can buy these? And please please make it idiot proof, use single syllable words and do a pretty diagram involving puppets if possible.

I had that sinking feeling when i opened up my package and though...thats not very big! (i looked for some in the local hardware stor today but only metric)

Thanks!

[Merlin66]

PM sent

[ncjunk]

Just so you can mock me...the one on the right is what i want the one on the left is what i bought....so much easier in a hardware store...

[Merlin66]

Give me the length you need and I'll send a couple.

[michael.h.f.wilkinson]

Just so you can mock me...the one on the right is what i want the one on the left is what i bought....so much easier in a hardware store...

Looks like an m3 they sent you

[yeti monster]

A digital caliper is my best friend (eyes too old to read my faithful Vernier anymore), after Zeus of course.... that and a lifetime of working with threaded fasteners...

[ncjunk]

I have a mental block with anything vaguely mechanical. A screw is mechanical in my book! :-)