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Hi all,

bit of a long post coming up in stages but I thought I'd share this as it may help out others.

A few weeks ago while I was packing away my kit I noticed that the leg clamps on my Celestron CPC tripod had cracks in them right where they join the spreader.

Two had cracks right the way through & one was halfway through. I hadn't noticed this before but have no idea how long they had been like this.

Very thankful that I spotted it before they completely gave way & my tripod collapsed with my scope etc still mounted.

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When I got home I did a bit of research and found various threads on CN about leg clamps cracking.

Also what I found out was that these clamps were actually plastic, all this time I assumed they were cast aluminium.

Anyway, as the scope/tripod was less than 2 years old, (Celestron's warranty length), I sent Celestron Tech an email.

They eventually got back to me saying that I would need to contact my dealer initially or failing that, the UK distributor David Hinds.

Straight away I shot off two emails, one to my dealer @FLO & also to David Hinds stating what has happened etc & also asking what to do as the sheer weight of the tripod made it uneconomic to keep shipping around after all the clamps are available to purchase for £14 each.

D Hinds responded saying that they no longer deal with retail unless the item was initially purchased from them & told me to contact my dealer.

@FLO  responded also and were absolutely brilliant, they asked me to take pictures of the tripod showing it's overall condition & send these to them including the pics of the cracked leg clamps. They would then forward these pics to D Hinds who would then make a decision as to whether this issue would be covered by the warranty.

Within a day @FLO replied and said Celestron (D Hinds) had agreed to cover the clamps under warranty & are sending them to me FOC.

A few days later the replacement clamps arrived.

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No I set about replacing the broken clamps.

Initially I removed the 4 grub screws from each leg base hoping that they would just slide off and then similarly I could just slide off each of the broken clamps & slide the new ones on.

This didn't work, it would seem like the leg bases are secured in place by other means too, glue or press fitting etc..

Eventually I found a way to do the job.

  • remove the leg extender clamp lever by loosening it

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  • remove the leg clamp securing bolt, washer & nut

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  • carefully spread the leg clamp open & ease it down over the leg base to remove it

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refitting is a reversal of the above procedure but remember to leave the leg clamp bolt loose until located in the correct position with the leg spreader.

I would suggest warming the new clamps a little i.e. with a hairdryer as they are quite stiff & you do not want to risk breaking them while prising open.

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After replacing the leg clamps and seen as I had removed each leg from the tripod top in order to more easily do the job, I thought it would be wise to upgrade the joint system where the top of each leg attaches to the tripod top.

Before I even started removing each leg prior to replacing the leg clamps I did notice that these top joints were a little stiff & pulling the legs apart caused a lateral twisting movement on the leg clamps exactly where they had cracked, so it was a fatigue issue due to poor quality design/manufacture.

Also, there was excessive play in the spreader to leg clamp joints & the spreader to centre boss joints.

The original shims from the top of each leg were plastic, all differing thicknesses and pretty mangled

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there were no shims at either end of the spreader bars.

Edited by 1CM69
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I spent a lot of time with a feeler gauge checking & triple checking the slop in every moving joint, marking each part to match it's counterpart so I knew exactly how each part went back together.

I found that each of the leg to tripod top joint slop varied; 0.8mm, 0.9mm & 1.0mm but the spreader arms all were pretty much identical at 2.0mm.

Next was to find a simple but robust way to fix this slop.

First I thought about using PTFE/Teflon washers being as they are self lubricating but these turned out to be very hard to get in the correct sizes & were stupid money.

Eventually I went for Stainless Steel Shim Washers from ACCU & I ordered some M10 for the leg top joints & M8 for the spreader arm joints both in 0.1mm & 0.2mm

I found that Stainless Steel does not cause a galvanic reaction with the die cast aluminium of the tripod, so ideal.

The plan was to use two shims together each side of the leg top joint bolt, forming a basic shim bearing and to lubricate it with graphite powder.

The spreader arm joints would just need a single washer each side of threader spacer as they were purely there to take up the extra slop.

Shims duly arrived. 

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Very simple task of putting the tripod back together with all shims in situ.

Last job was tightening the leg clamp bolts when I had made sure they were all in the correct place.

Graphite powder, well that's another story, bleeding stuff gets everywhere & wouldn't stay where I wanted it. Yeah, very good lube but too messy.

In the end I lubed all the moving joints with dry PTFE spray & will keep this up as regular maintenance.

Here's a short video showing just how easily the tripod now operates.

 

Thanks for reading..,

Kirk

Edited by 1CM69
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48 minutes ago, Grant said:

Excellent write-up Kirk - very useful information :)

Thanks Grant

6 minutes ago, JohnSadlerAstro said:

It's good you got the issue sorted out in the end--FLO are where it's at with customer service! :)

John

It was definitely a Phew moment & yes @FLO are great when it comes to CS

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