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Orion Optics 14 inch Dobsonian


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So in the end, after much deliberation, I ordered the 14" Orion Optics Dobsonian.  As you may know, this comes with a light aluminium tube.  I have read some reports regarding tube flexing with heavy eyepiece loads, but I was wondering if anyone had any first hand experience of this?  I'm sure it will be fine with just a paracorr and an eyepiece etc, but what about binocular use or if I wanted to get into astrophotography - would this potentially cause any issues?

They offer an upgrade to strengthen the tube - a stainless steel part with a radius block inside the tube.  What's a radius block?  However, they want an extra £450 for this.  This seems steep and is as much as a new scope of decent quality!  Do I need it?

Thanks!

Nic

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5 minutes ago, Astro_Nic said:

So in the end, after much deliberation, I ordered the 14" Orion Optics Dobsonian.  As you may know, this comes with a light aluminium tube.  I have read some reports regarding tube flexing with heavy eyepiece loads, but I was wondering if anyone had any first hand experience of this?  I'm sure it will be fine with just a paracorr and an eyepiece etc, but what about binocular use or if I wanted to get into astrophotography - would this potentially cause any issues?

They offer an upgrade to strengthen the tube - a stainless steel part with a radius block inside the tube.  What's a radius block?  However, they want an extra £450 for this.  This seems steep and is as much as a new scope of decent quality!  Do I need it?

Thanks!

Nic

Congratulations on the purchase 👍 From what I've read the Orion stuff is always well rated so it should be a cracker!

A radius block is just a curved piece to fit the shape of the tube, have to admin £450 does sound steep

If the flex concerns are just around the focuser area, maybe think about some additional tube rings and a couple of dovetails / bars to site either side, should add some rigidity?

Hell if the budget allows, there's always the carbon fibre tube option... 

 

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Congratulations - I used to have an old Orion Optics DX300 (12" f/4 telescope) which I used on a G11 Losmandy mount. It was quite light, although in the case of that telescope it was because the tube was made of quite thin aluminium. 

If you're any good at woodwork you could make a radius block out of wood, it would be much cheaper than £450.

Hope you enjoy the scope - when I first saw the moon through a 12" reflector I was taken aback how bright it was and how much detail you could see, so a 14" scope should be even better. 

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3 minutes ago, johninderby said:

Never found it a problem with my old OO 14” dob. I did however have OO fit the Baader Steeltrack that I supplied instead of the stock focuser. Also chose a different tube colour..

F6E6DB46-B7CA-4BEC-B31B-314CFC7F320D.jpeg

It's good I got married young because I don't understand how a woman doesn't look at that and want to sleep with the man who owns it. Anyone can walk into a showroom and buy a Porsche, but a huge dob setup like that? That takes class.

This is the pic you lead with on Tindr, right?

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18 minutes ago, johninderby said:

Never found it a problem with my old OO 14” dob. I did however have OO fit the Baader Steeltrack that I supplied instead of the stock focuser. Also chose a different tube colour..

F6E6DB46-B7CA-4BEC-B31B-314CFC7F320D.jpeg

The consumables for that must have been pretty heavy tho, John 🤔

26000E4B-075E-407A-8BAA-05AB2D851C30.jpeg.83f6eff236d1078cd9d019037b4c8e7c.jpeg

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I have the exact same scope and it's absolutely fine with a Paracorr and an Ethos 21.  It'a as much about distance as weight..cascading lots of accessories puts up the bending moment quite quickly.

I will admit, I've had exactly the same thought process in the past and have considered reinforcing the tube with a couple of 1/4 inch square bars on the inside using the focusser screws for fixing, thus spreading the bending moment over a longer section of the tube. . However it's never been really necessary. I'm sure by now OO would have addressed the problem if enough people were seeing it. 

But....given your plans you will need a Barlow before the binocular assembly to "pull" the focal plane out of the tube, followed by the Denkmeier or whatever,..and then a couple of eyepieces on top. I'd do a few sums and add up the bending moments and see if you can simulate the load first before you drop that sort of wedge..

What is true is that the tube dents quite easily if you happen to knock it at 3am while putting it away....but that's the price for a lighter tube compared to steel of similar thickness. 

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As with ri above, never personally had a concern regarding flexing with a VX14 on their dob mount. This is with regard to using some heavy e.ps: 21E, 31N, 41N, paracorr, baader steel track focuser, finder scope. Wouldn't wish to (personally) add any additional modifications, therefore increasing the weight to this tube or mount. 

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I have the VX8, also an aluminum tube. I dont know if people are not entirely honest, if it doesnt affect visual, or i got a weaker than average model but the tube is by far the weakest part of the VX series.

 

Mine is (and always was) noticeably not round. The secondary mirror supports are very weak and have to be tightened quite a bit to be stable. They are tight and it is stable, end of story? Not quite, they have dented the front into a square shape. The rear is aldo dented to a triangular shape because of the 3 point attachment of the mirror cell to the tube walls. The denting means diffraction spikes are not symmetrical because the tube is not round, but other than that just cosmetic damage.

 

For what its worth i have never noticed these in visual use.

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2 hours ago, ONIKKINEN said:

I have the VX8, also an aluminum tube. I dont know if people are not entirely honest, if it doesnt affect visual, or i got a weaker than average model but the tube is by far the weakest part of the VX series.

 

Mine is (and always was) noticeably not round. The secondary mirror supports are very weak and have to be tightened quite a bit to be stable. They are tight and it is stable, end of story? Not quite, they have dented the front into a square shape. The rear is aldo dented to a triangular shape because of the 3 point attachment of the mirror cell to the tube walls. The denting means diffraction spikes are not symmetrical because the tube is not round, but other than that just cosmetic damage.

 

For what its worth i have never noticed these in visual use.

Sorry your scope isn't perfect....makes me think maybe it does need some extra support....but £450 for a piece of steel? 

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4 hours ago, johninderby said:

Never found it a problem with my old OO 14” dob. I did however have OO fit the Baader Steeltrack that I supplied instead of the stock focuser. Also chose a different tube colour..

F6E6DB46-B7CA-4BEC-B31B-314CFC7F320D.jpeg

Wow the scope looks epic in blue!  I enquired about a colour change and they wanted £250....was tempted!  What's all the other electronics you have attached to it?  and where did you get the cart?, light shield and finder?!

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20 minutes ago, Astro_Nic said:

Sorry your scope isn't perfect....makes me think maybe it does need some extra support....but £450 for a piece of steel? 

Its a minor inconvenience at best  and only because i image with mine. The VX series is not meant to be perfect, its meant to be nice optics in a good enough package around them. Very appropriately priced in my opinion.

Edit: not the extra bit that is, i wouldnt dream of paying that much for a support piece.

Edited by ONIKKINEN
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3 hours ago, ONIKKINEN said:

I have the VX8, also an aluminum tube. I dont know if people are not entirely honest, if it doesnt affect visual, or i got a weaker than average model but the tube is by far the weakest part of the VX series.

 

Mine is (and always was) noticeably not round. The secondary mirror supports are very weak and have to be tightened quite a bit to be stable. They are tight and it is stable, end of story? Not quite, they have dented the front into a square shape. The rear is aldo dented to a triangular shape because of the 3 point attachment of the mirror cell to the tube walls. The denting means diffraction spikes are not symmetrical because the tube is not round, but other than that just cosmetic damage.

 

For what its worth i have never noticed these in visual use.

Sorry to hear that. I only use mine - a VX8L supported on a dob mount, for visual and have not had any discernible concern, yielding excellent outcomes. I would expect that the comments are based upon entirely honest personal experiences, yet may expect that others could yet comment to differ, perhaps imply that they did however consider or require a reinforced method, perhaps. 

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7 hours ago, Astro_Nic said:

  What's a radius block?  However, they want an extra £450 for this.  This seems steep and is as much as a new scope of decent quality! 

Nic

Fair comment . It seems (and is) a fortune for a bit of metal. But the sad fact is that the cost of getting a piece of precision metalwork done on a one-off basis in the UK tends to incur this sort of cost by the time the engineering drawing, setting up time, materials, anodising, labour and reasonable profit are all factored in. If you can find a mate with a lathe and mill I'm sure he can knock one out from a bit of scrap for 50 quid and a couple of beers as a favour and it will be just as good...but factories can't work that way. I work in an industry where laying out a grand for a one-off prototype bit of metal is the norm. 

A reasonable question would be why they are not fitted as standard, made from cheaper aluminium rather than stainless steel. In that case, you would get a batch of 20 made at once, all for a much lower unit cost. The answer is that the tube is just about good enough not to need it. They've been selling these things for over 10 years now successfully without reinforcement which I suppose makes that aspect of the design fit for purpose. They do seem to change parts every now and then presumably in response to customer feedback or supply shortages.

I have to admit, I always treat mine with kid gloves when moving it around..

A similar thing exists with their AG range where you can order some reinforcing rings for the focuser if you're intending using very heavy cameras. The cost of the rings is of the same order as your radius block, but are rather more complex to machine since there are multiple parts involved.  But because they are using the same part for the tube rings, the unit cost is comparatively reasonable for the number of machining operations through economies of scale (but still expensive!). Similarly with the AG, you have to specify the adapter dimensions you need to match the coma corrector to your particular camera assembly for the back focus. These are made individually to customer's requirements and are subsequently expensive. I bought mine off their scrap stall at Astrofest for 20 quid and modded them myself..looks like some customers got their dimensions wrong!

In a way it's best to be grateful we have a choice. If you want decent quality at minimum cost then go the Skywatcher route, but they won't stop the factory in China for a different paint job.  If you want something a bit bespoke with slightly better quality optics then OO can often oblige..at a cost and often a wait. 

Edited by rl
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