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Another Dob-Mod Thread.......

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Hi folks.


I thought i'd start a new thread to cover some 'upgrades' i'm planning for my trusty Orion Optics Dobsonian.

The scope in question is a 12" (300mm) F4 designated VX12 purchased about 18 months ago.




OO also do a longer F5.3 version, but i decided to opt for the shorter 1200mm version for a number of reasons.

The longer tubes that measure 1600mm are great scopes, but i found my old 10" F6.3 cumbersome and difficult

to handle and balance with a heavy binoviewer set up.

They even do a massive 16" solid tube that is huge ; literally the size of a letter box and more. What the missus would say i'm not sure....?!!


Manageability comes top of my list. 

Although my 12"F4 is no lightweight, i can handle it easily, as it takes no time at all to set up.

Its a solid tube, so theres no assembly / dis-assembly to do.

Its easily transportable : and more importantly will fit across the back seat of the car.

It didn't break the bank when i purchased it.

It has sufficient aperture FOR ME, and allows me to see a lot : most of the things our light polluted skys will allow us to see.


Like a lot of other amateurs, i've had the 'aperture fever' bug once or twice.

Before starting out with these modifications, i thought about "will i want a bigger scope in the future" ? on more than one occasion.

Would i get better views with a 16 - 20" scope ??

Probably yes, but maybe not that much better all things considered, like my 50+ year old eyes for one.


So no, i'm more than happy with this scope, and want to keep it for the duration.

It ticks all the boxes i need in the good aperture, rich field, low power, good quality, visual scope department.

It has great optics too, and i received 1/10th pv optics as a free upgrade when i ordered it

and an interferometer report which says the mirror is ticketyboo.


As a telescope enthusiast, i rather enjoy planning and completing the various upgrades that i can do.


This is what i've planned for this telescope :


1. Focuser upgrade.         Completed when i first ordered the scope. Moonlite fitted and performing very well.

                                     The standard OO focusers are pretty poor, and are not up to the job of handling a 1.5kg bino set up.                              COMPLETED

                                     This one has a non standard 60mm drawtube to assist me in focusing with all the bino / powerswitch variables.


2. Dew shield.                Purchased and performing well.

                                    OO secondary mirror on my scope is close to the top of the tube so i added a good quality Astrozap

                                    shield to keep those unwanted additional light sources to a minimum.                                                                           COMPLETED

                                    Potential balance issues aren't a problem either as the big heavy mirror more than compensates.


3. Tube covers.              Astrozap upgrades top and bottom of the tube.

                                   The supplied OO tube caps were so poor that they met the fete of my blue wheelie-bin.                                                 COMPLETED


And so far.......thats all i have done with the scope.



But more mods are in the pipeline.......


4.  Tube upgrade ??? ?       As the OO tube is only thin rolled aluminiun, i've considered 'beefing it up'.

                                         Although these tubes are lightweight, they are susceptible to knocks and at F4 collimation tolerances are tight.

                                         I've considered upgrading it to a more rigid carbon fibre type and indeed, OO would do this for me for me......for a price.


5. Fan upgrade.                   The tube already has a small fan, but there is room for improvement, i'm sure.

                                         If i upgrade the tube, i will upgrade the fan at the same time. A handle to help carry it would be nice too.


6. Flocking.                         Pending any tube upgrade, i have the flocking material ready to go.


7. 'Spider' upgrade              For a while, i have considered changing the standard OO spider (which is cheaply made) to a better quality one, and

                                        one which has a curved 3 vane design. At the same time i will install a secondary heater.

                                        The standard OO spider and secondary adjustment design could be a lot better (it doesn't hold collimation all that well)


8. Primary mirror               The standard OO mirror clips are seemingly huge and cause noticable diffraction.

   clip redesign.                 There has to be a better solution to hold the primary in securely.

                                      I have considered a sling, or even some sort of velcro arrangement.


9. Installation of              The first part of this thread. I have received them, all the way from Australia from 'Astro Devices. They are ready to install.

   encoders.                    These will work with my current Nexus DSC, and in tandem with 'Sky Safari' on the iPad.


10. The Final bit...           Purchase a Dob tracking platform. I don't need go-to, but the ability to track objects after locating them with the DSC would be nice.

                                    Where to source one from is the issue. I have one in mind, but its not cheap. I'm not up to building one either.......?




On to the encoder mod then..........here they are.

Work fitting them starts tomorrow.











Edited by Bino-viewer

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You have plenty to do Rob! But it is all good,

I bet you are itching to get started! I hope you take plenty of photos to share with us.

Looking forward to hearing more on this thread! Cheers! ?

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Exciting stuff.  Keep us updated with the encoder fitting.

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Fantastic Rob. Looks like a very neat job. It is lovely when these things work right out of the box without much hassle, and so unusual not to have to wait a couple of weeks to get a clear sky to test it out. Glad it's all coming together how you want it. ? ?

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A very enjoyable thread Rob ?

That looks a great piece of kit and simple to install too! Good result. I hope you post further on trying it out with Skysafari app etc. ?

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Thankyou all. ?


I was actually surprised with how easy these things are to fit, even for me.

The Dob encoders were actually an easier job than on the DM6, which was easy, but more fiddly.


Had i known how easy the fit was, i would have fitted them straight after buying the scope.


If anyone on here is interested in fitting encoders to your Dob scopes, i can heartily recommend Astro Devices.

I received outstanding service from them.


Various encoder options for various telescope systems are available 

If you have something different, drop Serge an email and he will work something out.


Link :








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Ok, after a 6 month layoff, its time to continue with this 'Dob-mod thread'.


I have decided to upgrade the standard aluminium tube that the scope arrived in,

to a carbon fibre version. I have sourced a supplier, in Germany, and will be ordering

the tube in the near future. It will come with everything prepared, all holes drilled correctly etc,

so should be a straightforward 'transplant'.


Once i take delivery of the new tube, i will flock it first.


I will also be upgrading the Orion Optics 'spider' secondary mirror holder.

I have something in mind, from the USA, and need to get that ordered as well.


That leaves a cooling mod to do, and one last thing.........


That one last thing is happening soon......


I have finally, after a long search, found an equatorial tracking platform for my telescope.

To be continued...

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Yes thanks Dave.

I spotted that one during my searches.


They are few and far between tbh.

A couple of places in the US, and what TS in Germany have. TS looks the best option.


I don't have the technical know-how or the tools (or the desire) to build one myself

and apparently are quite difficult to build WELL.



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