[Help!] What happens when the good Alt-az adjustment bolts fail?

[Aenima]

Hi there

I'm in mourning at the moment due to the death of my EQ5's altitude adjustment bolts - these being the upgraded apparently harder ones, too - last night. I got them out and saw the one with the red bit on the handle had severely warped with a little of the mounts metal left in the thread. I know enough to realise it isnt good news.

Due to the widely used upgrade bolts its obviously not a new thing so i'm wondering if anyone else has had this problem, and if so, what did they do about it?

Clearly the bolts need replacing, but seeing the stripped thread in the mount itself means at the least this base area piece will need to be replaced too - apart from the horror of being without a scope, my budget will not stretch to a new mount. I'm not really sure there will be any kind of warranty as the mount is technically a week past a year old and also I dont think skywatcher have the best customer service in the world going by what I've seen and read.

If anyone has experience of these things or can advise as to what can be done i'd be very grateful to hear from them.

Regards

Aenima

[Radar2312]

might not be too bad, sounds like you need some new adjuster bolts and a 'heli-coil' kit for the threads in the mount body. First thing to do will be establish exactly what threads they are. You may be ale to get a thread repair kit from your local Halfords, as petrol heads often use them for repairing striped threads in cylinder heads, will depend on what size you need to suit the bolts.

The repair will consist of drilling out the thread in the mount body, tapping a new thread with a special tap, then inserting a wire thread insert (looks like a spring) that basically brings the thread size down back to where you started.

As im in the engineering industry, this is pretty standard stuff for me but for the 'un-initiated' may be a tad daunting. Might be worth approaching someone at a local engineering company, if there are any!

I hope this has given you some hope.

Rick

[Steve Ward]

Sorry but I have to ask .... What were you doing to bend the up-graded bolts . . . ?

[Photosbykev]

The helicoil option will give you a much better thread to use in the future. The thread profile will be significantly better and stronger after the repair as the original tapped holes have so much slop in them that it is difficult to call it a proper tapped hole.

[Aenima]

Yes, thank you Rick. Hope is what is needed right now.

Its definitely daunting, but a relief to hear it can be remedied. I will try to look into a replacement 'bit' whatever the bottom part is called, and the bolt looks like a curly wotsit, but luckily not stuck inside.

Appreciate the advice, thank you.

Regards

Aenima

[Aenima]

My set up is non-permanent so just fine polar alignment, plus the PA feature on the handset requires the adjustments to be done with scope attached.

Otherwise usual stuff. After the bolt bent it was getting it out that likely de-threaded some of the mount.

Aenima

[Aenima]

The helicoil option will give you a much better thread to use in the future. The thread profile will be significantly better and stronger after the repair as the original tapped holes have so much slop in them that it is difficult to call it a proper tapped hole.

I like this idea. Do you know how much it would be to have someone do it?

Cheers.

Aenima

[Photosbykev]

I like this idea. Do you know how much it would be to have someone do it?

Cheers.

Aenima

It is possible to do this yourself with a reasonable amount of knowledge. Workshops routinely use helicoil inserts in aluminium to give a strong low wear rate tapped hole. If you can find a friendly workshop then it's probably about 10-15 minutes work to fit one but the cost could be anything, it really does depend on who you goto.

[Aenima]

Thanks. Yeah my diy skills dont really stretch that far, ive just been told helicoil kits can be bought but I would need it done for me.

It does sound like a better solution than replacing the base of the mount, nice one for the info there Rick, cheers.

Aenima

[coulthamst]

I'm not sure that Helicoil repairs would be satisfactory for ongoing repeated adjustment of the adjuster bolts. Might it be better to tap out a size larger- 10mm - and fit larger bolts? HEQ5 bolts might then be satisfactory, or 10mm Allen cap screws.

[Peter Drew]

I suspect that the pivot axis off the mount is too tight if you have managed to bend an upgraded adjuster and strip the threads. With both adjusting screws removed you should be able to move the head on its axis by firm hand pressure.

[Photosbykev]

I'm not sure that Helicoil repairs would be satisfactory for ongoing repeated adjustment of the adjuster bolts. Might it be better to tap out a size larger- 10mm - and fit larger bolts? HEQ5 bolts might then be satisfactory, or 10mm Allen cap screws.

Helicoils are perfect to repair this problem. They are hardened steel inserts that won't wear and are formed to a precise thread form for exactly this type of repair or strengthening function

[laser_jock99]

I'm not sure that Helicoil repairs would be satisfactory for ongoing repeated adjustment of the adjuster bolts. Might it be better to tap out a size larger- 10mm - and fit larger bolts? HEQ5 bolts might then be satisfactory, or 10mm Allen cap screws.

From an engineering point of view I'd probably go up a size too. Bigger bolt is less likely to bend again.

[Aenima]

Thank you folks, I've actually just read that there is a way to loosen off the tilting part so less stress is put on the screws - with the need to polar align each session this sounds like a good idea, should have done it before now but hadnt known the black plastic plates came off or what was under them.

Yeah, even with hardened bolts the polar routine needs great care esp when trying to use software that involves adjusting while set up with scope on.

Appreciate the feedback, cheers

Regards

Aenima

[Aenima]

I suspect that the pivot axis off the mount is too tight if you have managed to bend an upgraded adjuster and strip the threads. With both adjusting screws removed you should be able to move the head on its axis by firm hand pressure.

Thats just what happened, although to be fair the bolts only bent, it was the mount that the threads went on.

But the pivot axis, thats the one - i'm going to make sure of its looseness in future, thank you.

Regards

Aenima

[coulthamst]

Helicoils are perfect to repair this problem. They are hardened steel inserts that won't wear and are formed to a precise thread form for exactly this type of repair or strengthening function

As a skilled maintenance fitter for 38 years, our workshop would never use Helicoils for applications that were to be loosened or dismantled more than once a blue moon. We found that the Helicoils, though they did not wear out, did become loose and exit the thread with the bolt. In a situation where the tapped hole was not "blind" and of only a small depth - exactly the situation with an EQ mount - they would not retain on adjustment, hence my caveat.

[Aenima]

As a skilled maintenance fitter for 38 years, our workshop would never use Helicoils for applications that were to be loosened or dismantled more than once a blue moon. We found that the Helicoils, though they did not wear out, did become loose and exit the thread with the bolt. In a situation where the tapped hole was not "blind" and of only a small depth - exactly the situation with an EQ mount - they would not retain on adjustment, hence my caveat.

Oh, I'm thinking being the exact situation where the helicoils aren't effective would be a bit of a problem in that case. I was just about to look into getting it done as well. At least you can say what might happen from experience, which is appreciated. Though i'm still of the opinion that even with the mount and bolts replaced the same issue is likely to affect the set-up after a while.

Maybe a similar procedure to helicoil but more suited to the type of hole, metal etc. might be possible? Could I ask if you know of something that would remedy the problem but without leaving it vulnerable to the weakness that makes helicoils unsuitable in EQ mounts?

I saw a picture of a sturdy bolt, looked like it would hold a ton, but in my case - of non-permanent set-up - I need to retain the ease of adjustment involved in fine tuning polar alignment without causing damage from wear and tear on the bolts.....this is where im stuck for a proper solution regarding the more technical aspects of the metal and how to fix it.

With most types of polar aligning the adjustments need to be done while set up, and I know the EQ5 is less sturdy than HEQ5 but with lugging it outside and setting up each time the bigger mounts will give me trouble aside from the cost.

Hopefully there is a compromise between sturdy and portable, and solid and adjustable. If anyone has ideas i'd love to hear them.

Many thanks for the replies so far,

Regards

Aenima

[coulthamst]

The answer is not to over tighten the bolts when adjusting mount altitude. The temptation is to make that last small adjustment by applying extra pressure to the appropriate bolt without loosening the other, leading to bent bolts. Then extracting the bent bolt either deforms or tears the thread. Unfortunately the need for delicacy of touch is not made clear in the instructions, and many of us end up with this problem.

[continuum]

This subject is now well covered with regard to Helicoil repair. So this is just to say that I repaired my mount alt/az threads with a "helicoil" kit from Ebay ( there are loads on there). It was simple and straightforward and my repair was done a year or so ago and is absolutely fine.

Ron

[Aenima]

Yes , very much agree with the above posts - unfortunately having upgraded bolts I assumed the problem would be avoided but even the tougher mounts/bolts need extra care when polar aligning.

Still after replacing the parts I'm hoping to find a way to reinforce the whole area anyway with something like what is mentioned above just to be sure.

Many thanks to all who replied,

Regards

Aenima