orion optics mirror cell holder

[bottletopburly]

Has anyone ever swapped the  stock mirror cell holder on a sw200pds for an Orion optics mirror cell holder can it be done simply enough  ,if so was it worth doing ,does the primary hold better collimation.

[NGC 1502]

 

Not done that exact job. However I have adapted mirror cells to use in a telescope different to the one originally intended, and made cells from aluminium and also plywood.

The cell to tube attachment may have to be ground down or spacers added accordingly to make it fit.  If you’re a bit of a DIY sort of person it’s not difficult at all.

You need to ensure that your mirror will fit the cell.  Mirrors can vary in exact diameter from the nominal size, and thickness can vary too.   Most primary cells can be adjusted for a good fit, or spacers added.  Mirrors must not be tightly held or the precise optical figure may be distorted. On the other hand only tiny clearances are needed, if there’s too much slop, the mirror can shift with loss of collimation.   Collimation springs should be strong, this helps to hold collimation adjustments.

HTH, Ed.

[bottletopburly]

7 hours ago, NGC 1502 said:

 

Not done that exact job. However I have adapted mirror cells to use in a telescope different to the one originally intended, and made cells from aluminium and also plywood.

The cell to tube attachment may have to be ground down or spacers added accordingly to make it fit.  If you’re a bit of a DIY sort of person it’s not difficult at all.

You need to ensure that your mirror will fit the cell.  Mirrors can vary in exact diameter from the nominal size, and thickness can vary too.   Most primary cells can be adjusted for a good fit, or spacers added.  Mirrors must not be tightly held or the precise optical figure may be distorted. On the other hand only tiny clearances are needed, if there’s too much slop, the mirror can shift with loss of collimation.   Collimation springs should be strong, this helps to hold collimation adjustments.

HTH, Ed.

Thanks Ed

[Piero]

The Orion optics mirror size is in millimetres (e.g. 200mm), whereas skywatcher mirrors are in inches (8 inch). Not sure that you can do that. Other members might confirm or dismiss this, though.

[dannybgoode]

12 minutes ago, Piero said:

The Orion optics mirror size is in millimetres (e.g. 200mm), whereas skywatcher mirrors are in inches (8 inch). Not sure that you can do that. Other members might confirm or dismiss this, though.

I think even SW are mm hence the 150, 200, 250 etc in their model range. They are then approximated to inches for the US market and put more ‘experienced’ observers here in the UK. 

[Piero]

9 hours ago, dannybgoode said:

I think even SW are mm hence the 150, 200, 250 etc in their model range. They are then approximated to inches for the US market and put more ‘experienced’ observers here in the UK. 

The aperture of my skywatcher Dobson is 203mm or 8in, not 200mm.

[John]

Orion Optics tube diameters are smaller than Skywatchers are by quite a few mm.  The Orion Optics primary mirrors are also a little smaller than the Chinese manufacturers ones as well.

Thats not to say that an Orion Optics primary cell cannot be fitted to a Skywatcher scope but some modifications will be needed. Telescope Services in Germany sell primary mirror cells, as an alternative:

https://www.teleskop-express.de/shop/product_info.php/language/en/info/p9621_TS-Optics-ONTC-Hauptspiegelzelle-fuer-8--Newton-Spiegel.html

[Peter Drew]

I don't recall much in the way of complaints about the Skywatcher primary mirror cells, if anything just the strength of the collimation springs. I would have thought that upgrading these would be cheaper and less hassle than swapping cells.   ?

[dannybgoode]

1 hour ago, Piero said:

The aperture of my skywatcher Dobson is 203mm or 8in, not 200mm.

Or 7.99213 to be precise  

[John]

53 minutes ago, Peter Drew said:

I don't recall much in the way of complaints about the Skywatcher primary mirror cells, if anything just the strength of the collimation springs. I would have thought that upgrading these would be cheaper and less hassle than swapping cells.   ?

I agree. The Skywatcher cells on scopes that I've owned have been simple but did the job pretty well. The Meade / GSO made ones I did have some issues with. Rather thin counter cells and definitely weak springs with those.

 

[bottletopburly]

59 minutes ago, Peter Drew said:

I don't recall much in the way of complaints about the Skywatcher primary mirror cells, if anything just the strength of the collimation springs. I would have thought that upgrading these would be cheaper and less hassle than swapping cells.   ?

 Do you have any links to better springs Peter .

[Peter Drew]

I don't have a specific answer to this as it's not an issue I've had to address. Several SGL members have though, I suggest you post a "what springs?" question.   ?

[jam1e1]

i cant answer directly, however be aware on my OO when i adjusted the mirror cell holding/collimation screws it affected the depth i had to put my paracorr in and therefore come to focus - point being you may need extension tube or hope that focus point will match.