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SteveBz

CG-5 Strip down. Damaged grub screw.

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Hi Guys,
I'm doing a strip down of my EQ5 according to Astro boy's instructions and I think I have a damaged grub here:

IMG_20190130_093057.thumb.jpg.eeb282097469ef8bf8ab20740d603227.jpg

Any thoughts about removing or replacing the grub?

It's the inner grub on the collar attached to the ra shaft, accessed through the outer ra setting circle.

Thanks

Steve.

 

Edited by SteveBz

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Astroboy...do you mean AstroBaby...?

Yes that does look like it’s seen better days, well, if you can’t get hold of to remove, then it looks like it will Ha e to be drilled out to next size up and re tapped... 🙁

 

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Give it an overnight soak in penetrating oil then find an allen key that's a good tight fit, maybe an imperial size that needs tapping in gently, possibly filed at the end to get a good fit.

Good luck

Dave

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22 hours ago, LightBucket said:

Astroboy...do you mean AstroBaby...?

Yes that does look like it’s seen better days, well, if you can’t get hold of to remove, then it looks like it will Ha e to be drilled out to next size up and re tapped... 🙁

 

This one here:

http://www.astronomyboy.com/cg5/

Yes, I'm reluctantly coming to that conclusion myself.  The issue is that it's still pinning the shaft underneath, so drilling will damage that too!!  🙁🙁🙁

I'm going to try to rank the suggestions in order of destructiveness and do the least destructive first.  Drilling comes towards the bottom of the list just above throwing it off a high building and hoping it jolts loose.😡

Thanks for your help.

Steve

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21 hours ago, Davey-T said:

Give it an overnight soak in penetrating oil then find an allen key that's a good tight fit, maybe an imperial size that needs tapping in gently, possibly filed at the end to get a good fit.

Good luck

Dave

That's probably the first thing to try.  I saw a suggestion (for removing hand-gun grubs) for super-gluing the allen-key in place.  My slight concern is that I might not be able to do this both of these because the oil would cause the super-glue to slip. 

Maybe I could superglue (or araldite) and then WD40 at the same time.  So let the araldite set over night one and then the wd40 over night two and try on day 3.

And then scream and shout and throw things before getting out the angle grinder.

Thanks for your help.

Steve.

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Quote

 

Hi have you tried inserting a flat headed screw driver just a tight fit into the screw head then lightly tap home and unscrew.

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1 hour ago, todick said:

Hi have you tried inserting a flat headed screw driver just a tight fit into the screw head then lightly tap home and unscrew.

No, I could try that. 

Thanks.

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If you get to the point of having to use a drill, it might perhaps be worth trying a left-handed bit that will just fit into the hole in the top of he grub screw.  Sometimes it can turn the screw out once it starts to bite in the metal.

James

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If you go for the araldite/superglue option, then clean the surfaces first using isopropanol.
This will get rid of anything mineral oil, vegetable oil or water based.
Won't touch silicone oils and grease though.

Rapid temperature cycling can be a good thing for tight screws.
Heat using a hot air blower - much hotter than a hair dryer - then chill using cold water. Today is freezing outside.

Alternatively put it into the deep freezer (-18C) for a while, then hit it with the hot air blower.

Good luck. David.
 

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So finally I soaked it in WD40 and bought new allen keys and it came apart. 

So success until next year!!

Thanks everyone

Steve.

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Might be worth replacing it when you reassemble everything?  And perhaps using a little lubricant.

James

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5 minutes ago, JamesF said:

Might be worth replacing it when you reassemble everything?  And perhaps using a little lubricant.

James

For lubricant use either Sailkote or GT85, WD40 is a horrible lubricant

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Just now, Sland said:

For lubricant use either Sailkote or GT85, WD40 is a horrible lubricant

I've never really regarded WD40 as a lubricant, but I gather it is now sold as one (I feel sure it didn't used to be).  I don't know if that's just a marketing thing or if they've changed the product to make it more "lubricanty".

James

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The "WD" stands for water dispersant.     🙂

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On 04/02/2019 at 18:34, JamesF said:

I've never really regarded WD40 as a lubricant, but I gather it is now sold as one (I feel sure it didn't used to be).  I don't know if that's just a marketing thing or if they've changed the product to make it more "lubricanty".

James

If you go into Wickes, there are a number of versions.  The original is now sold as "Penetrating" but there are many other versions for other functions.  I imagine the marketing boys will soon have one for frying chips😏.

Steve

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On 04/02/2019 at 18:25, JamesF said:

Might be worth replacing it when you reassemble everything?  And perhaps using a little lubricant.

James

Indeed.  But somehow my eagerness got the better of me and I was soon collimating my polarscope against the treeline.

I have a reminder to buy new grubs.

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