5 replies to this topic

[feTTer_oTTer]

Hello,
Several years ago I bought a used Meade 8'' (MTS-SC8) OTA and later a Meade GPS Mount for it.

After several years of snow white sleeping in the basement I recently dug it out to get it upgraded.

After doing several replacements and further upgrades I would like to clean the optics.

Besides the dusty mirrors, the corrector plate has some residues which look like dew but are permanently there.

The residues appear to be at the outer and inner side, where I checked the outer one and I can wipe it off.

 

When I tried to loosen the screws for the corrector plate, I found the HEX connection already worn out.

I tried a little with my set of HEX tools (cheap ones from ebay) but decided to buy a good brand screw driver for the 1/16 HEX connection, not to beat it up even more.

My golden rule is, if a screw is making trouble coming out, it should not be going in again.

Therefore I am looking for replacements. Since I live in Germany, shops for inch threaded screws (I guess they are not metric) are hard to find and I would have to order it online without the opportunity to try it first.

Therefore I wonder if someone can tell me the specs of this screws.

 

Thanks a lot

[Jaylab]

If they are button head they would be UNC 8-32 thread.

Hex button heads are very prone to suffer hex socket damage so if a good hardened bit won't budge the **** might have to cut a slot with a carbide disk across the screw head and use a flat head screwdriver to extract..

A very close metric equivalent is a 4mm 0.7, they might work, they are very slightly smaller in OD and should engage in the existing female threads.

-Jay-

 

I guess screw got censored, can't be too careful these days! If it doesn't make it this edit, think of the profile in which a flat bladed screw driver is used and alter the appropriate part of the fastener

Edited by Jaylab, 01 October 2023 - 05:07 AM.

[WaveGuide]

Hex socket, cap head, 8-32 UNC, high tensile, 7/16" long, black screws are readily available from eBay.

Here's an example in UK, though I expect they are available on eBay everywhere: https://www.ebay.co....:Bk9SR4iNyLLdYg

 

- Jack T

[feTTer_oTTer]

Thank you very much for your fast replys.

I found a shop selling those screws (it seems it is not censored with an "s" ;-) ) and placed the order.

The screws even have a longer head, giving a longer insert for the HEX tools and should last longer.

[WaveGuide]

- - - -  placed the order.

The screws even have a longer head, giving a longer insert for the HEX tools and should last longer.

Cap head versus button head. It makes a lot of difference mechanically. Button head screws may have a nicer cosmetic effect, but are nowhere near as easy to work with.

Good luck,

- Jack T
 

[Jaylab]

Correction to my earlier post, on my old LX200 10-in the corrector plate fasteners are 6-32 1/2 in long button heads, not 8-32.

-Jay-