ES 12" Dob

[Lorne]

This is not so much an observing performance review but more of an "unpack and first time build" report. I bought this from Bresser in Germany as a display item and on opening the boxes it felt as if they had never been opened. The parts were all well encased in polystyrene foam and the easy instructions made it a simple job to assemble - I was aware of previous build reviews that paint was of a dubious finish with rusty spots and some of the threaded holes were sometimes tight and there were signs of swarf in the rocker and mirror box. There was no sign of bad paint, dodgy threads or swarf  to be seen - maybe ES have responded and upped there QC procedures. 

On attaching the upper assembly, I moved the truss fixings to the alternate set of holes to put the focuser at approx 45 degrees instead of  horizontal as supplied. Again, there was no sign of this Scope having been built for display. The supplied red dot finder doesn't appeal to me but I attached it anyway for testing.

The primary mirror comes covered in tissue type paper and on removing this, it showed the first signs of being a display model - the centre spot was already in place. I have read previous reviews that said the centre spot is supplied for the new owner to DIY. 

The supplied collimation instructions are pretty basic - check secondary is round by eye. Adjustment is simplicity in itself - 3 thumbscrews perpendicular to any secondary adjusters I have ever used on my previous scopes. I attached my laser at this point just to tweek slightly. 

For the primary, again no usual collimation tools are mentioned - only the supplied long Allen key with a plastic shield to protect the primary mirror. All ES suggest is that you get the reflections through the focuser tube concentric. Again, I used my laser. Adjustment was again simple - tweek the 3 front facing Allen cap screws with the supplied tool. All done from the front. Easy? It was in the comfort of my warm living room, a final judgement awaits when out at a dark site somewhere. 

A foam matting type material is supplied for a light shield to fit - by velcro - opposite the supplied 10:1 rack and pinion focuser. On first impressions it is as smooth as a Crayford type and if I hadn't seen before using it, I would've sworn it was a Crayford.  

On standing back to admire the finished scope it was just starting to get dark and I realised it was clear - although very windy outside. I got the scope outside  - in 2 parts assisted by my daughter into the garden. Capella was about the brightest in my limited view so stuck my 20mm EP in and roughly aligned the "finder" to the scope.  I defocused either way and was happy with the "airy disc" I could see. 

I pointed the scope to M31 but it was faint in the not completely dark sky so I tried for the double cluster - just managed to get it in view when it started to snow! Still clear above me but the strong wind was blowing it in from away in the distance. This time I lifted the scope into the garage on my own, something I don't recommend - I'll get a wheeled base made up like I had for my old Flextube.  Not the longest first light but enough to let me know I'm going to enjoy this scope. 

In conclusion:

I'll need a better finder. I had a Telrad before but I reckon a Rigel Quikfinder would look better on the minimalist upper tube assembly, already ordered from FLO.

I'll mark up the truss poles for easy identification for consistent assembly - should minimise collimation issues.

I'll get a fabric shroud, not just for stray light but to stop things falling on the mirror. It looks pretty exposed. 

I'll fill in the gaps in the UTA round about the focuser, probably flocked flexible black plastic..

A wheeled base will be made for ease of moving around the garden, not so important for dark sites.

I'm not 100% convinced on the focuser position, I'll experiment on my first few set-ups.  

Anyway, enough of my rambling! Thanks for reading.

L.

 

 

 

 

[Bart]

Pics, pics, pics!

[Lorne]

9 minutes ago, Bart said:

Pics, pics, pics!

I'll add some next chance I get

[John]

Thanks for posting that initial report. It's good to see that ES have addressed some of the issues encountered by the "early adopters"

[Lorne]

A few pics added as requested...

A view into the mirror showing the forward facing primary collimating screws.

The 10:1 ratio R&P focuser, very smooth in action.

My now colour coded truss poles should help with consistency in building and speed up collimation. The simple red dot finder is shown too - that will be replaced as soon as my Rigel QF gets delivered.

A close up of the alt bearing showing a textured metal sheet to give "stiction" against the plastic pads on the rocker box.

The exposed looking secondary and supplied foam light shield. I'll fill in the gaps all the way round with flocked black plastic.

 

The primary mirror looks pretty exposed. A stretchy black material shroud will protect this as well as helping to keep dew at bay.

The secondary mirror collimating screws. Simple to adjust.

[Daniel-K]

is it sturdy? the upper truss brackets look nicer than the SW ultra compact scope. 

[Lorne]

1 hour ago, Daniel-K said:

is it sturdy? the upper truss brackets look nicer than the SW ultra compact scope. 

It looks sturdy enough for normal use, it doesn't flex around when I swing it around on the base. I wouldn't like to take a chance with it getting dropped or blown over in the wind mind you!

[Demon Barber]

Hi Lorne,nice report and photo`s you could always get a sheet of Kydex it comes in different thicknesses,this is the same material as used in Obsession scopes and can add rigidity as well as being very light.

Try the Robert Horne Group for Kydex.

Regards

Mike

[swamp thing]

On 3 February 2016 at 23:54, Demon Barber said:

Hi Lorne,nice report and photo`s you could always get a sheet of Kydex it comes in different thicknesses,this is the same material as used in Obsession scopes and can add rigidity as well as being very light.

Try the Robert Horne Group for Kydex.

Regards

Mike

Thanks for that Mike. Was looking for where I could get this in the UK  

[Demon Barber]

Hi Steve,only downside is you can only buy it it full sheets 8x4 but it has so many uses it eventually pays off.

Regards

Mike

[niallk]

Congrats on the scope!  Great to hear that you had no issues - the ES dobs look good, with some interesting features Every report I've read commented on good optics as well.  Best of luck!