Upgrade primary cell for 150 mm Newtonian.

[Guest]

I have recently bought a nice Orion Optics UK 150 mm Newtonian reflector. It is the older model. I have put it up for sale because collimation was an issue. It has the enclosed end cover with collimation nuts. But does not have locking nuts. Rather than continue with selling it, I would like to explore the possibility of upgrading the primary mirror cell. This would be to collimation and lock. Just where can you buy upgraded mirror cells these days? If I can do this then it may well be a lovely performer.

Edited August 21, 2020 by Guest
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[AdeKing]

I think Orion Optics will sell a primary cell, though they're not cheap.

Alternatively, have a word with Beacon Hill Telescopes, I think he's still working.

I approached him about a primary cell for the 22" Dark Star that I had at the time, but then never did anything about it.

http://beaconhilltelescopes.org.uk/

He only works via snail mail and telephone, but certainly seems to be well regarded.

I think he's semi-retired now but still building telescopes to keep him out of trouble.

Hope this helps,

Ade

[johninderby]

Yes OO does sell the mirror cells ££££

https://www.orionoptics.co.uk/ACCESSORIES/mirrorcells.html

Edited August 21, 2020 by johninderby

[Chriske]

😳

[CraigT82]

If you're handy with the tools you could make yourself one and save the cash for something else.

A cell for a 6" mirror shouldn't be too much of a challenge.

https://stellafane.org/tm/dob/ota/cell2.html

[johninderby]

Or buy one of the basic GSO cells. Must be somebody selling a used one simewhere. 🤔

https://www.teleskop-express.de/shop/product_info.php/language/en/info/p9531_GSO-Holder-for-6--Newtonian-primary-mirrors-for-the-self-construction-of-telescopes.html

[John]

Sounds like your scope is one of the old Europa models. I had the 10 inch version with the same rather basic collimation / cell arrangements. Seemed to work OK though.

My 12 inch dob is slightly more recent and does have locking bolts but I don't tend to use them unless transporting the scope in a car.

Perhaps you could add locking bolts to the arrangement that you currently have ?. They are just bolts that press against the bottom of the cell that holds the mirror.

Inside the back cover of your scope will look like this:

[Guest]

2 hours ago, John said:

Sounds like your scope is one of the old Europa models. I had the 10 inch version with the same rather basic collimation / cell arrangements. Seemed to work OK though.

My 12 inch dob is slightly more recent and does have locking bolts but I don't tend to use them unless transporting the scope in a car.

Perhaps you could add locking bolts to the arrangement that you currently have ?. They are just bolts that press against the bottom of the cell that holds the mirror.

Inside the back cover of your scope will look like this:

Interesting. Thanks John.

[John]

Just a further note on upgrading this.

The metal dish piece that forms the end plate of the scope acts as a stiffener for the alloy tube that Orion Optics use. If you replace this piece with another mirror cell, you will also need an end ring to fit the tube otherwise it will simply not be rigid enough.

You can see such an end ring in use in this Orion Optics scope fitted with a much more up to date mirror cell:

I thought long and hard about upgrading the mirror cell when I had the 10 inch version of this scope and concluded in the end that it was more trouble than it was worth.

 

 

 

[iPeace]

As it happens, I've got two 150mm newts standing unused, a GSO f/6 and a OOUK VX6L f/8. I can't promise a solution, as their fates are undecided, but I'll try to take some measurements and pics, might render some useful info as to how to proceed.

[iPeace]

Well, here they are. Take note, the OOUK is a VX6L, a later model than yours.

To me, they look different enough to suggest that the GSO (right) is not a simple drop-in replacement for the OOUK (left). The mounting screws don't seem to line up at the same distance from the end of the tube. The tube diameters also vary slightly; the OOUK's rings won't fit properly around the GSO (perhaps to be expected, the OOUK is aluminium, the GSO steel) but the inner diameter also seems to be different, so maybe a tight squeeze for the GSO's cell in the OOUK's tube.

The end ring needed for the integrity of the aluminium tube is a distinct, separate part.  Noteworthy is also the lack of dedicated locking bolts on the OOUK VX6L...

...while the GSO has plenty.

So, from where I sit and how I see it, I wouldn't advise a GSO replacement cell, unless you're prepared for some DIY (which can be fun).

 

[johninderby]

From the TS site on the GSO cell.

Practical tip from Teleskop Service - installation with adjustment option

Requirement for correct installation is an inner tube diameter of more than 176 mm. If the tube is smaller, you cannot sink the primary mirror holder into the tube.

♦ Make a ring (wood or aluminium) which fits perfectly ito your telescope tube. Mounting is done just with lateral screws.
♦ Bore three 6.5 mm holes with exactly 81.5 mm distance from the center, placed at 120° to each other. The three M6 adjustment screws go through them.
♦ For keeping the main mirror in the desired position, you need a thrust spring. Suggestion: item number TSFeder (set of 3 pieces)
♦ As adjustment screws, you can use standard hardware store products, but we offer M6 adjustment screws, too.

[John]

I wonder if it is going to be simpler and lest costly to add some locking screws to the current arrangement ?

[SiriusB]

6 hours ago, John said:

I wonder if it is going to be simpler and lest costly to add some locking screws to the current arrangement ?

Yes, maybe OP can post pic of existing cell & people can pitch in with suggestions?

My recollection of early O.O. newts was the secondary adjustment  was more a  faff than the primary?