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Replacement springs for Primary mirror bolts


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Hi , I have just purchased a set of Bobs Knobs (12" meade) for my GSO 12" scope ... the screws were a bit tight but fitted ... anyway the springs supplied with the scope are nothing short of useless ( why do manufacturers do such things?) ... Can anyone advise me on replacements ... Rother Valley do offer 3 replacement screws that look heavy duty but are quite short ( and expensive when you take into account delivery ) . Amazon do a colour co-ordinated spring range , i really am not sure about how much tension  the springs should  have . 

Any ideas ?

Stu  

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16 minutes ago, johninderby said:

Telescope express does some HD replacement springs but shipping is as much as the cost of the springs.

https://www.teleskop-express.de/shop/product_info.php/language/en/info/p6967_TS-Optics-reinforced-springs-for-main-mirror-cell---set-of-three.html

still a bit cheaper than RVO ... but only just ... thanks John . I just sourced a video on YouTube . The guy used springs bought from Amazon . They are a bit longer though (20mm) as opposed to the RVO ones which look like thay are about 10mm . Still if the screws are long enough then they will work .

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I bought a single length of spring off ebay. 15mm OD and 2mm wire Thickness (130N/mm). Was the cheapest way to do it but you will need to cut the spring into the required lengths and then finish the ends which is easily done if you have a blowtorch.  
 
https://stargazerslounge.com/topic/376811-adventures-with-an-old-sw-300p/?do=findComment&comment=4081880

 

Edited by CraigT82
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29 minutes ago, CraigT82 said:

I bought a single length of spring off ebay. 15mm OD and 2mm wire Thickness (130Nm/mm). Was the cheapest way to do it but you will need to cut the spring into the required lengths and then finish the ends which is easily done if you have a blowtorch. 

I don't get on well with the standard collimation arrangement of these cells: three adjustment screws and three locking screws. The adjustment screws have coils springs but these are pretty feeble and so I have fitted much stronger springs to enable me to get rid of the locking screws altogether. 
 


    I bought a length of 15mm OD compression spring with 2mm wire and cut this into the required lengths. I finished the ends of each of the three springa by heating and manipulating the ends and then grinding a flat. These springs are very strong with a 130N/mm compression strength. 
 


    
 
https://stargazerslounge.com/topic/376811-adventures-with-an-old-sw-300p/?do=findComment&comment=4081880

 

Craig , i empathise with the collimation arrangement . The springs are less than adequate . 

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Case Closed guys .... i have bit the bullet and ordered the springs from RVO . To be fair to them , they explained exactly the inside diameter and length , and were very helpful as usual . ( i am a bit  peeved about the price but if you want it then you have to pay for it i suppose ) 

Thanks for your input . 

 

Stu 

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