Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Review of the Hubble Optics 14 inch, f/4.6 Premium Ultra Light Dobsonian Telescope

  • Please log in to reply
56 replies to this topic

#26 ButterFly

ButterFly

    Apollo

  • *****
  • Posts: 1,468
  • Joined: 07 Sep 2018

Posted 06 October 2020 - 05:25 PM

 

It is ... it seems to be a standard Dobsonian mirror mount (pictures below).   This should distribute weight well: it's a light, small mirror so the surface should be quite solid.  

 

Should I be looking for anything specifically?

 

Edge support is absolutely critical for thin mirrors.  Sandwich mirrors are essentially two thin plates with supporting pegs between them.  The belt type sling can transfer some of the stresses from one plate to the other, which may not be cooling in the same way.  Here is TOMDEY's edge support for a much larger sandwich mirror.

 

If your seeing permits, do some star testing over many many nights.  Look out for astigmatism especially.  Here is an article by Mike Lockwood's to pin down sources of star defects: Why aren't my stars round?.  His general article A modern guide to mirror support is a must read.  If you can notice defects, swapping to another edge support may help out a lot.  Belt slings are rather ancient by now.

 

Sandwich mirrors are very responsive to temperature changes, which is a great thing, but that responsiveness can induce wavefront errors if not supported well.



#27 Chris Westland

Chris Westland

    Sputnik

  • -----
  • topic starter
  • Posts: 45
  • Joined: 12 Sep 2014

Posted 06 October 2020 - 09:14 PM

Edge support is absolutely critical for thin mirrors.  Sandwich mirrors are essentially two thin plates with supporting pegs between them.  The belt type sling can transfer some of the stresses from one plate to the other, which may not be cooling in the same way.  Here is TOMDEY's edge support for a much larger sandwich mirror.

 

If your seeing permits, do some star testing over many many nights.  Look out for astigmatism especially.  Here is an article by Mike Lockwood's to pin down sources of star defects: Why aren't my stars round?.  His general article A modern guide to mirror support is a must read.  If you can notice defects, swapping to another edge support may help out a lot.  Belt slings are rather ancient by now.

 

Sandwich mirrors are very responsive to temperature changes, which is a great thing, but that responsiveness can induce wavefront errors if not supported well.

Thank you for the references; I'll definitely read through these (they look detailed and quite interesting).  I have the HO artificial star and a 100mm convex mirror for star testing which I've used once (I also ordered a Gerd Neumann 10 l/mm Ronchi eypiece).  I didn't notice any problems, but I'm in Arizona, and thermal equilibrium isn't an issue at this time of the year.  I'll spend some more time assessing the mirror with its stock sling and report back.



#28 Teleri

Teleri

    Lift Off

  • -----
  • Posts: 13
  • Joined: 01 May 2020
  • Loc: Texas

Posted 08 October 2020 - 05:09 PM

Thank you for a detailed review!

Much appreciated!

 

A couple of Qs:

 

1. Overall mirror and mirror box weight

Per HO's specs on UL14 page, the "Optical tube" weighs 40.0 lbs.

Per their Sandwich Mirror page, a 14" mirror is ~7.8 kg = ~17.16 lbs.

Does this mean their mirror box weighs ~40-17=23 lbs? Seems high.

If you don't mind, whenever you can, will you please let us know the individual weight of the mirror and the mirror box?

 

2. Mirror adjustment time

From the time you get the scope outside to it being ready for observation, how long it takes for the mirror to reach thermal equilibrium?

 

Regards!



#29 Chris Westland

Chris Westland

    Sputnik

  • -----
  • topic starter
  • Posts: 45
  • Joined: 12 Sep 2014

Posted 08 October 2020 - 07:01 PM

Thank you for a detailed review!

Much appreciated!

 

A couple of Qs:

 

1. Overall mirror and mirror box weight

Per HO's specs on UL14 page, the "Optical tube" weighs 40.0 lbs.

Per their Sandwich Mirror page, a 14" mirror is ~7.8 kg = ~17.16 lbs.

Does this mean their mirror box weighs ~40-17=23 lbs? Seems high.

If you don't mind, whenever you can, will you please let us know the individual weight of the mirror and the mirror box?

 

2. Mirror adjustment time

From the time you get the scope outside to it being ready for observation, how long it takes for the mirror to reach thermal equilibrium?

 

Regards!

The last time I checked the base + mirror was about 30 lb, but I need to revisit this and do a proper job of weighing.  It was really hard to get the thing situated on a bathroom scale.  Once I get something that can properly weight these, I'll get some more accurate estimates for all of the components, but I think ~30 lb on the base+mirror is about right.  

 

And I'm sorry to waffle about 'thermal' time as well, but I've been in Phoenix since I received the scope, and the inside and outside (evening) temperatures have been about the same.   This is another area where I'll be posting better information once I have the tools.   I just received my "Gerd Neumann Jr. 10 mm Ronchi Eyepiece" (a German quality mounted Ronchi grating) and used it last night on Vega.  The lines in-focus and out-focus are perfectly straight, though I'd like to put this on an artificial star to eliminate seeing.  Later on in the Fall, I'll see how quickly things settle.  It is a smaller mirror, and sandwich, so I would expect fairly fast equalization. 

 

The other thing that I'm upgrading on is collimation.  I currently have a $20 Gosky laser collimator, which for the money is great (I think even better than the similar Hotech which often needs recollimation out of the box).  My only complaint is that Gosky's tube is slightly undersized, which gives it a chance to wiggle off-axis (I have little pieces of tape to center it).  Because I like shiny new things, I ordered Farpoint's box of 3: 2" laser, cheshire and autocollimator; it should be here in a few weeks.  In my experience, it pays to be OC about collimation.  Farpoint has had good reviews, plus in talking with them, they seem to be a top notch company.



#30 Teleri

Teleri

    Lift Off

  • -----
  • Posts: 13
  • Joined: 01 May 2020
  • Loc: Texas

Posted 09 October 2020 - 10:22 AM

Thanks for your reply!

 

I use delta method on my bathroom scale to weigh my check-in bags each time I fly. I step on the scale to note my weight, and then I step on again with the bag - the delta is bag's weight.

 

Looking forward to your thermal testing this Fall.

 

As for collimation, I use HoTech's 2" SCA Laser collimator. Bought it from Agena AstroProducts for $145 - totally worth it. Makes collimation on my 8" dob a total breeze even in darkness.


  • mr.otswons likes this

#31 Teleri

Teleri

    Lift Off

  • -----
  • Posts: 13
  • Joined: 01 May 2020
  • Loc: Texas

Posted 09 October 2020 - 02:19 PM

BTW... didn't realize you are a professor!

 

Respect!!



#32 Chris Westland

Chris Westland

    Sputnik

  • -----
  • topic starter
  • Posts: 45
  • Joined: 12 Sep 2014

Posted 10 October 2020 - 01:58 PM

Professor in my other life; just part of the community here.  And I didn't mean to caste aspersions at HoTech's SCA, as the system they use to position their tube in the focuser is brilliant (it does resolve Gosky's problem).  Investments in collimation are definitely worth it in my opinion.



#33 mr.otswons

mr.otswons

    Vostok 1

  • -----
  • Posts: 107
  • Joined: 26 Jun 2019
  • Loc: Norway

Posted 15 October 2020 - 03:38 PM

Thank you for the kind words.  All of the scopes come with the cut metal ruler struts that hold the encoder.  Since the Az bearing is a Chinese lazy susan ring(a 转盘)you don't have the  center stud for mounting.  I'm guessing the factory that makes these are getting metal school rulers from the local office supply store in bulk (I have a bunch of these rulers that I brought back when we returned from China).  They look nice, and the rulings help assure that the encoder mount is dead center.  You don't have the same issue with the Altitude encoder strut, because it isn't fastened at the bottom.

 

BTW Dave Kriege gave an interview about 10 years ago where he described the operations at Obsession.  He said that the original idea for the company came from John Hudak of Galaxy Optics, who liked Kriege's structure, and realized he would sell more mirrors if he didn't require buyers to DIY their own structure.  Dave keeps about 200 scopes in production / inventory at any time.  Since HO's scopes are cheaper than Obsessions and they have to be 'containered' from China to the US/Europe/Australia/etc., I'm guessing that number may be a lot larger at HO, with mirror making and structure manufacture occurring at two separate source companies.  Dave is pretty amazing as he spends a lot of time with customers; the customer outreach is not as organized at HO as it is at Obsession.

Thank you for your reply about the rulers. It's funny how hi-tech and expensive this instrument is, but then a detail like that. I like it! thanks for details on Obsession, do you have a link to this interview or something?



#34 Chris Westland

Chris Westland

    Sputnik

  • -----
  • topic starter
  • Posts: 45
  • Joined: 12 Sep 2014

Posted 15 October 2020 - 07:00 PM

Vostok, Kriege's interview can be found here.  I've spent a bit of time at "factories" (some more like garages) in the Pearl River Delta, some of which could be like Tong's factory.  Designers and workers can be very clever in making due with materials that they have.  I'm guessing HO's only "raw" material is 6063-T6 aluminum alloy tubes, angles and flat strips, and they may send welded parts out for powder coating or whatever they use for finishing.   The rulers and lazy Susan are likely produced nearby and cheap, and overall cheaper than making their own.  The mirrors on the other hand are probably produced based on Tong Liu's design at one of the many good glass / optical factories in China (probably in Shenzhen area again).  If I ever talk to Tong Liu, I'll try to get more details.



#35 BillCline1

BillCline1

    Lift Off

  • *****
  • Posts: 19
  • Joined: 08 Jan 2014
  • Loc: North Carolina

Posted 21 October 2020 - 08:22 AM

To jim molinari,  Hey Jim.  Sorry for the late reply.  I'm guessing that the scope comes air or boat from Hong Kong, but I had it ground from TX to hear in NC.  I just used there standard shipping table which specifies no ground price for U.S. but does have it under air, which was 700.00+  yuk!!  That was one serious drawback btw.  Since this post I have taken it out and the views were awesome even in the city.  Can't wait to get it out in country or mountains.  The mirror and rocker box combo was a bit heavy.  I'm not sure of weight but i would guess a good 50-55lbs.  Not sure what i'll do about that.  I also did not use the adjustable brake that's on it.  It doesnt work good and i'm going to take a look at it.  I didnt have any trouble with runaway in azimuth though.  


  • Chris Westland likes this

#36 fuadramsey

fuadramsey

    Vostok 1

  • *****
  • Posts: 109
  • Joined: 26 Jun 2007
  • Loc: Orange County, CA

Posted 21 October 2020 - 02:41 PM

I see a bass, but I can't make out what it is. Has an interesting looking thumb rest though.

 

Jamie -fellow bass player (Rat Soup).


  • Chris Westland likes this

#37 Chris Westland

Chris Westland

    Sputnik

  • -----
  • topic starter
  • Posts: 45
  • Joined: 12 Sep 2014

Posted 21 October 2020 - 10:56 PM

I see a bass, but I can't make out what it is. Has an interesting looking thumb rest though.

 

Jamie -fellow bass player (Rat Soup).

Kinda rare ... it's a Line 6 Variax Bass.  These have been out of production for a decade (Line 6 lost a bundle on the line, and ended up selling their remaining inventory at a steep loss).  They continue to sell the Variax Guitars, and these are apparently doing well.  I think it's an awesome bass; 24 basses in one.  The only downside is it is heavy.  But the tones are great, and the ability to change them with a flip of the knob is brilliant.   I'm mainly a pianist, and don't really play bass very well, but I have fun with it.



#38 charmandad

charmandad

    Lift Off

  • -----
  • Posts: 24
  • Joined: 23 Jul 2020

Posted 23 October 2020 - 02:34 AM

Thanks for this review.

It's good to see more input on HO just before I receive my telescope, though I've just been charged hundreds of AUDs of import fees due to Australia's regulation.

In regards to the production line of their business, I kind of possess a fair bit of knowledge due to the detailed documents sent to me while charging me the fees..... rather unfortunate......

It seems that these telescopes have their aluminium parts done in Yantai, Shandong, by a company named 'Astrotel Precision' which is owned by Tong Liu the CEO. This should contribute to the overall QC of the product, as it's not some randomly outsourced job. 

In regards to the optics, they seem to be produced by DKD Optics in Nanjing, China. It is actually a manufacturer for premium optics. With a bit of research in chinese forums, I'm surprised by the fact that a common view is shared that they produce better mirrors than Synta(skywatcher) and Guansheng(GSO). So that is actually exciting news.

I really hope that HO can establish a more efficient way in communicating with enthusiasts, and probably a better option in shipping as it becomes one fourth of the total price. Hope they all the best anyway.


  • Chris Westland likes this

#39 Chris Westland

Chris Westland

    Sputnik

  • -----
  • topic starter
  • Posts: 45
  • Joined: 12 Sep 2014

Posted 23 October 2020 - 04:53 PM

It seems that these telescopes have their aluminium parts done in Yantai, Shandong, by a company named 'Astrotel Precision' which is owned by Tong Liu the CEO. This should contribute to the overall QC of the product, as it's not some randomly outsourced job. 

In regards to the optics, they seem to be produced by DKD Optics in Nanjing, China. It is actually a manufacturer for premium optics. With a bit of research in chinese forums, I'm surprised by the fact that a common view is shared that they produce better mirrors than Synta(skywatcher) and Guansheng(GSO). So that is actually exciting news.

 

Thank you so much for the additional information (I'm sorry it didn't come for free).  I had no idea, and just presumed that these all came from the South.  I've never heard of either company, so I appreciate your research.

 

DKD optoelectronics website is here  ... I'd be interested in whether Astrotel Precision has a web presence.  The only thing I found related to microwave horns.

 

Could you also share a bit more of your research on the various producers of mirrors in China?



#40 Notoriousnick

Notoriousnick

    Sputnik

  • -----
  • Posts: 49
  • Joined: 31 Aug 2020
  • Loc: Adelaide, South Australia

Posted 28 October 2020 - 10:28 PM

I've just been charged hundreds of AUDs of import fees due to Australia's regulation.

I'd assume that would simply be GST as there should be no Import Duties AFAIK?


  • Chris Westland likes this

#41 Notoriousnick

Notoriousnick

    Sputnik

  • -----
  • Posts: 49
  • Joined: 31 Aug 2020
  • Loc: Adelaide, South Australia

Posted 29 October 2020 - 02:47 AM

All of the scopes come with the cut metal ruler struts that hold the encoder. 

Thanks for the great review, Chris!

 

Might I ask: when you say *all* of the scopes come with those cut metal ruler struts, does that (as far as you know) include those that aren't ordered with the encoders? If so that would make it easier to install ones own encoders if desired.

 

Certainly a scope I'll put on my wish list ... maybe the f/5 16" version bounce.gif


  • Chris Westland likes this

#42 Notoriousnick

Notoriousnick

    Sputnik

  • -----
  • Posts: 49
  • Joined: 31 Aug 2020
  • Loc: Adelaide, South Australia

Posted 31 October 2020 - 07:31 AM

Certainly a scope I'll put on my wish list ... maybe the f/5 16" version bounce.gif

Never-mind. Too late. I've ordered one snoopy2.gif


  • spaceoddity and Chris Westland like this

#43 spaceoddity

spaceoddity

    Vanguard

  • *****
  • Posts: 2,196
  • Joined: 28 Jul 2009
  • Loc: Cloudsylvania

Posted 31 October 2020 - 06:23 PM

Nice! I like my 16" truss dob but it is a heavy wooden beast - classic design with a tall mirror box. It's kind of an obsession clone but not quite as nice. I'm seriously thinking of selling it and some of my other telescopes/gear to fund a HO. I love the design, weight, portability, aluminum material of these HO UL dobs. I'd probably opt for the 16 F/5 as that still seems pretty reasonable to transport. Probably need a step ladder for zenith but I don't feel the need for a coma corrector @F/5. The waiting time and lack of response/support kind of worries me though. I wish I could just buy the structure and add my own mirrors and focuser. 



#44 Notoriousnick

Notoriousnick

    Sputnik

  • -----
  • Posts: 49
  • Joined: 31 Aug 2020
  • Loc: Adelaide, South Australia

Posted 31 October 2020 - 07:13 PM

I wish I could just buy the structure and add my own mirrors and focuser. 

I don't mind standing on a step ladder, either. Having a little more collimation tolerance at F/5 and less coma (as opposed to at F/4.5), I see as benefits.

 

I'd be very surprised if HO didn't sell their structure separately (even though it's not listed for sale separately on their website). Perhaps email them and ask?

 

There may be more delay these days than stated by HO to get the product, but then, I think for me it's worth the wait and I can always take up meditation to ease the stress of waiting bigshock.gifor hone my astronomy skills in the meantime lol.gif .


  • Chris Westland likes this

#45 Chris Westland

Chris Westland

    Sputnik

  • -----
  • topic starter
  • Posts: 45
  • Joined: 12 Sep 2014

Posted 02 November 2020 - 07:02 PM

Might I ask: when you say *all* of the scopes come with those cut metal ruler struts, does that (as far as you know) include those that aren't ordered with the encoders? If so that would make it easier to install ones own encoders if desired.

 

 

That, I don't know.  But they come with the encoders.  I agree with you on the installation, though in general, I would prefer to buy a kit, and have someone else make sure that all of the measurements are correct first.



#46 Chris Westland

Chris Westland

    Sputnik

  • -----
  • topic starter
  • Posts: 45
  • Joined: 12 Sep 2014

Posted 02 November 2020 - 07:03 PM

Never-mind. Too late. I've ordered one snoopy2.gif

Great to hear (and welcome to the club).  What size did you order?



#47 Chris Westland

Chris Westland

    Sputnik

  • -----
  • topic starter
  • Posts: 45
  • Joined: 12 Sep 2014

Posted 02 November 2020 - 07:05 PM

 I wish I could just buy the structure and add my own mirrors and focuser. 

If you check on Astromart, there is a review from 2016 about purchasing just the structure and installing a standard non-sandwich mirror.  You do have to worry about balance in that case, though it didn't seem to be a huge problem.



#48 Chris Westland

Chris Westland

    Sputnik

  • -----
  • topic starter
  • Posts: 45
  • Joined: 12 Sep 2014

Posted 02 November 2020 - 07:11 PM

A quick note.  I just purchased the GoTo system from Tong about 5 minutes ago.  I'll report on this once I've had a chance to install and play with it.  To my knowledge, no one has yet posted a review of this on the Web (at least I couldn't find anything in my Google search). 

 

I'm also working on a counterweight setup on my upper ring that I could change as easily as an eyepiece (since I need to add weight when I go to my lighter eyepieces).  I'll post when I finish.



#49 Notoriousnick

Notoriousnick

    Sputnik

  • -----
  • Posts: 49
  • Joined: 31 Aug 2020
  • Loc: Adelaide, South Australia

Posted 02 November 2020 - 09:49 PM

Great to hear (and welcome to the club).  What size did you order?

Thanks! The 16", F/5 version. I don't mind the extra height and as a  bonus, there are some cost savings and less risk of coma, etc.

 

 

That, I don't know.  But they come with the encoders.  I agree with you on the installation, though in general, I would prefer to buy a kit, and have someone else make sure that all of the measurements are correct first.

I already have a Nexus II system on my SW Dob. So I would just need new encoders, preferably 10K ones rather than the HO supplied 8K ones. I was hoping encoder brackets come with the HO telescope, even if their DSC system wasn't ordered. That way perhaps Serge at Astro Devices could make me up some 10K encoders with/for those brackets so that I can use those with the Nexus II and UL16. Either way, I'll get there in the end grin.gif.


Edited by Notoriousnick, 03 November 2020 - 01:56 AM.


#50 Chris Westland

Chris Westland

    Sputnik

  • -----
  • topic starter
  • Posts: 45
  • Joined: 12 Sep 2014

Posted 03 November 2020 - 04:16 PM

Thanks! The 16", F/5 version. I don't mind the extra height and as a  bonus, there are some cost savings and less risk of coma, etc.

 

 

I already have a Nexus II system on my SW Dob. So I would just need new encoders, preferably 10K ones rather than the HO supplied 8K ones. I was hoping encoder brackets come with the HO telescope, even if their DSC system wasn't ordered. That way perhaps Serge at Astro Devices could make me up some 10K encoders with/for those brackets so that I can use those with the Nexus II and UL16. Either way, I'll get there in the end grin.gif.

Congratulations, great choice!   I wan't initially going to get a coma corrector, but decided the improvement is worth it.  Collimation is also a bit more forgiving at f/5.   I've found that I do need to spend a bit of time with the collimation (at least initially) for the f/4.6.  I have the Farpoint tools (laser, cheshire and autocollimator) and they all are useful in fine tuning.  And it makes a difference at the eyepiece (otherwise, I'd probably be sloppier).


  • Notoriousnick likes this


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics