Extra weights for the CEM70

[paul]

To avoid a nasty tripod leg bash I've moved my 250mm OTA up the tube rings and added weight at the mirror end to re-balance in DEC. I now have significant RA imbalance and I find myself needing an extra 2-5kg of counter weight. With official weights being difficult to find in stock I've taken a gamble and ordered 2x2.5kg plate weights with a claimed 28mm bore.

The 28mm quick release clamps  for these weights have arrived and fit the counter weight shaft very firmly when clamped shut. I can't imagine them moving easily. The weights should arrive soon. I'm hoping that will reduce the number of lost subs.

[MarkAR]

Sounds like a good plan, post up some piccies when done 👍

[paul]

Advertised as 1.1" or 28mm weight plates they fit well and the clamps do their job.

 

 

I've not drilled and tapped anything harder that Al before but I do have a spare weight to experiment with.

For those of you interested I found the weight plates at £28 for 2x2.5kg on eBay. The clamps I picked up from Amazon for £8. 

[AstronomyUkraine]

4 minutes ago, paul said:

I've not drilled and tapped anything harder that Al before but I do have a spare weight to experiment with.

For those of you interested I found the weight plates at £28 for 2x2.5kg on eBay. The clamps I picked up from Amazon for £8. 

Great solution, and a lot cheaper than paying 79 euro for one 5kg weight, or 129 for a 9.5kg weight. It might not look aesthetically pleasing, but as long as it does the job, does it matter?

[TerryMcK]

An excellent solution. I too balked at the price of iOptron weights and will use your method when I buy my CEM70

[Marmot]

Nice post🙂

I do find it interesting looking at peoples DIY solutions to issues they come across. There seem to be all sorts of products out there and quite often a little bit of thought and research will result in a practical solution thats more budget friendly than going to one of the branded purpose made items.

I never knew those little clamps existed!  

[paul]

Its not pretty but I can't see it in the dark so style isn't a big concern. I might try some glow in the dark paint😁.

The clamps are very firm at least for the 2.5kg weight - easy to adjust up and down. If I was considering a larger weight then I would definitely place it it the end of the shaft and use the ioptron weight to tune the balance.

[AstronomyUkraine]

On 5/7/2021 at 9:56 AM, TerryMcK said:

An excellent solution. I too balked at the price of iOptron weights and will use your method when I buy my CEM70

Could be worse, you could own a Software Bisque ME II mount. 465 euro for a 13.5kg counterweight.

[AstronomyUkraine]

3 hours ago, paul said:

Its not pretty but I can't see it in the dark so style isn't a big concern. I might try some glow in the dark paint😁.

The clamps are very firm at least for the 2.5kg weight - easy to adjust up and down. If I was considering a larger weight then I would definitely place it it the end of the shaft and use the ioptron weight to tune the balance.

I have two white Skywatcher weights on my mount, and a black Celestron weight. It does the job, so I don't worry about it.