Upgraded Primary Springs for 12" Skywatcher Dob Suggestions

[kirkster501]

Hi all,

Could someone recommend some upgraded springs please for the back of the mirror cell?  One of the springs on mine, because it has been compressed so long (and they are rubbish to start with) has lost its "springiness" and it is almost impossible to collimate the scope since it is not pressing the mirror sufficiently.

Thanks, Steve

 

[Stu]

Are these any good Steve? I used some on a 10” cell which has still to see first light but they seem to be up to the job.

https://www.365astronomy.com/Farpoint-12-LightBridge-Spring-Only-Primary-Upgrade-Kit.html

[Northernlight]

Stu, did you find that your spring upgrade helped with your scope. Did it help with colimation ?

[Rob_UK_SE]

I have found the Bob’s Knobs springs to be really good and certainly stiffer than the standard Meade and Sky Watcher offerings. Due to their website, I’m never clear about Rother Valley Optics’ stock levels, but this is their link as they appear to be the only UK supplier offering them at the moment: https://www.rothervalleyoptics.co.uk/bobs-knobs-meade-lightbridge-primary-springs.html

The last set I ordered were imported from the States and did arrive within a couple of weeks. This is the direct link (option D): http://www.bobsknobs.com/Newt/page45/NewtPri.html

Edited August 25, 2020 by Rob_UK_SE

[callisto]

58 minutes ago, Rob_UK_SE said:

I have found the Bob’s Knobs springs to be really good and certainly stiffer than the standard Meade and Sky Watcher offerings. Due to their website, I’m never clear about Rother Valley Optics’ stock levels, but this is their link as they appear to be the only UK supplier offering them at the moment: https://www.rothervalleyoptics.co.uk/bobs-knobs-meade-lightbridge-primary-springs.html

The last set I ordered were imported from the States and did arrive within a couple of weeks. This is the direct link (option D): http://www.bobsknobs.com/Newt/page45/NewtPri.html

I ordered mine direct from bobsknobs in the US with no problems at all

[NGC 1502]

All good info above.

If using springs for collimation from any source -

If you can compress them by hand, they’re not strong enough.  For large mirror cells - car or motorcycle engine valve springs are a possibility.

Ed.