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I had everything set up for an evenings imaging, when near disaster struck. I was in the process of polar aligning the mount, and was just giving the lower latitude bolt a final tweak. Immediately I felt something was not right, there was no tension on the bolt, it was turning too easily, next moment the telescope shot forward, luckily I had hold of it, and it was securely in the saddle. What happened, the latitude bolt had stripped the threads in the mount.

 

My solution is to drill the hole with a 10mm drill, and tap a new thread to take a 90mm x 12mm x 1.50 class 10.9 bolt. I will replace both of the crappy skywatcher latitude bolts.

 

I dread to think what could have happened had the bolt give way during slewing or imaging. I'm not very happy, but it could have been a lot worse, and a more expensive fix.

 

Brian

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20 minutes ago, GazAstro said:

Ouch, lucky that nothing else was damaged ... It's crazy that they're still designed that way !

Yeah, steel bolts into an aluminium thread is a poor design fault. Hopefully it should be a simple fix that will last another few years.

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I would look into "Helicoil" thread repair kit. They replace the striped threads. The kit comes with a drill, tap, insert tool, and helicoil threads. They look like a small spring. drill out the old threads, tap new threads, and insert the coil and finished.

many racing mechanics will take a new aluminum engine and replace all the original threads with "Helicoil" threads. 

Here, they are found at auto repair stores or online. I have used them for years.

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A very worthwhile post:

not only is it of interest as to the solution, but it makes others aware of a ‘weak link’ and could therefore prevent others suffering the same fate. I would imagine the ‘steel bolt in an alloy thread’ will apply to other Skywatcher mounts and not just the EQ6.

 

thanks for the post.

 

martin

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8 hours ago, rwillits said:

I would look into "Helicoil" thread repair kit. They replace the striped threads. The kit comes with a drill, tap, insert tool, and helicoil threads. They look like a small spring. drill out the old threads, tap new threads, and insert the coil and finished.

many racing mechanics will take a new aluminum engine and replace all the original threads with "Helicoil" threads. 

Here, they are found at auto repair stores or online. I have used them for years.

Thanks for the info, sounds like a great solution to the problem. Unfortunately there are no kits available here, and getting one from China is a 4 week wait.

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1 hour ago, Marmot said:

A very worthwhile post:

not only is it of interest as to the solution, but it makes others aware of a ‘weak link’ and could therefore prevent others suffering the same fate. I would imagine the ‘steel bolt in an alloy thread’ will apply to other Skywatcher mounts and not just the EQ6.

 

thanks for the post.

 

martin

My mount is 15 years old, and has had a lot of use over the years. Obviously the infamous bolts on EQ mounts with their inability to adjust the latitude easily, has caused wear on the threads in the mount.

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1 hour ago, TerryMcK said:

a bullet dodged there Brian. Thankfully you have been able to fix it.

The cure is a lot cheaper than a replacement mount, scope, or both. I decided to wait for a helicoil kit, it seems the best solution, if they can hold down a cylinder head, a mount should be no problem. I'm going to replace the terrible Skywatcher bolts with M10 titanium hex socket bolts. I will need to use an allen key to adjust the bolts, but I don't see it as a problem. The latitude won't change much between sessions.

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49 minutes ago, paulgrover68 said:

Lucky escape - as someone who has had a fair few EQ6 issues this I feel your pain.  I think the takeaway is that with the EQ6 it's not a case of if... it's when.

 

Hope it all pans out okay.

I think Skywatcher mounts are designed by a committee, the cheaper ones certainly have a lot of issues regarding design and materials used.

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Posted (edited)
5 hours ago, MarkAR said:

A lucky escape, could have been a pricey disaster.

You are not joking, I was so lucky to be standing at the side of the mount when it failed. Another two minutes I would have been slewing to the target. I would advise anyone with a Skywatcher mount to check for any sign of lateral play in the latitude bolts, it could be a sign the thread are being stripped.

Edited by AstronomyUkraine
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15 minutes ago, Carastro said:

Yikes.  Are these the original bolts that came with the mount?  

 

Carole 

Yes Carole, but the bolts are fine. What happened is the threads inside the mount have been stripped. With the mount being made of aluminium it is softer than the steel bolts. I can fix it so it is better than it came out of the factory, so thankfully no harm done, except for the inconvenience. Of course since it happened, I have had two clear nights, but it could have been worse.

 

Brian

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Update!

 

Since having this mishap with my mount, the weather here has been great, 6 out of 7 clear nights. I reckon I have lost around 35 hours of imaging time, tonight is also going to be clear. It will be another week at least before I receive the tools needed to do a good repair on the mount. I wish I had just drilled out the hole, tapped it for a 12 mm bolt, and left it at that, except the same thing could happen again. At least with a steel insert, the threads won't get stripped.

 

Brian

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