Any reflector “experts” in England?

[Mr Spock]

1 hour ago, Mandy D said:

I had not thought of using the American spelling for centre (AKA center).

It's disappointing when British (FLO) (and European) websites use the American spelling for things. 

Centre/central, metre/metric - it's not centeral or meteric is it? 

[Captain Scarlet]

It could be argued that the centering is actually less important for AP than for visual, because you can even out the illumination with flats.

[Mandy D]

@Captain Scarlet Yes, I guess you can, but I don't bother with flats for the Moon and the human eye does an amazing job of dealing with all sorts of optical problems. Whatever the case, if we have everything correct at the scope and camera levels, it is one thing less to worry about.

[a6400]

9 hours ago, Astrobits said:

I did reply to you pm's. The last one yesterday. Unfortunately I am not always able to reply to messages immediately, I do have other things to do and it might be day's before I can find time to respond. 

Nigel

I'm confused since last reply from you seems to be from Monday 10.55,

and then I replied with a list of things I would like to change/fix same day at 22.16.

Perhaps you haven't seen my latest reply? 

 

[a6400]

Overall what I need now the most is for someone to help me remove both mirrors safely and wash them.

I can manage secondary but I'm afraid to touch primary.

 

Edited September 28, 2023 by a6400

[Spile]

Cleaning the primary mirror of the 200P is very straightforward. If there is a challenge it’s prising out the mirror assembly as it is a tight fit in the ota. If you believe there is something missing or unclear in my guide, then let me know and I will update it.

As for collimation and concentricity of the secondary... The outer edge should be circular and concentric. It’s the reflection (it’s dark because it’s looking at the inside of the sight tube) of the secondary that is offset but it is still circular.

If the secondary is centred but still not quite circular and assuming your focuser is square to the main tube, you can either leave it as is and move onto the primary or you can keep tweaking to get it circular. I find loosening the assembly so it’s in my palm allows me to confirm there is a position that is just right.

As for which guide is right for you, I’d recommend reading as many as you can and picking out the parts that make sense to you. I came up with a=b nomenclature because using diagrams worked for me but were all learn in different ways so find one that works for you. Writing your own guide could be your salvation…

[John]

1 hour ago, Spile said:

Cleaning the primary mirror of the 200P is very straightforward.

The original poster has one of these:

The principles are the same as with a smaller scope but it's getting the mirrors safely in and out of the cells, especially the primary, is likely to be more challenging with the 16 inch Explore Scientific than with the 200P dob I think. When I had a 12 inch Meade the primary was held in place with a number of sticky pads on the rear as well as the mirror clips. Each pad had to be loosened and then cut away. A tricky task.

The reason that I'm wary of being able to help, apart from lacking the time, is that I don't know the ES design so my advice based on Skywatcher, Meade and more lately Orion Optics dobs might mislead rather than help.

I think the original posters best bet is to ask around forums (especially CN because there are more of these in the USA I think) to find someone who has actually removed and cleaned mirrors from an ES dob, preferably the 16 inch version, and find out from them about the process and any little quirks / issues that might be encountered and any tips to make the task easier.

I did the same with the Meade 12 inch and so at least I knew that there would be sticky pads (16 of them !) to deal with and had some tips for how to handle them before starting the task.

 

 

Edited September 29, 2023 by John

[Spile]

9 hours ago, John said:

The original poster has one of these:

 

I do apologise. I have no idea why I got that from.

[Mutley]

On 28/09/2023 at 14:50, Captain Scarlet said:

almost all techniques for require the centre-spot of the primary to actually be in the centre. In both primary mirrors I have measured, this was not the case, one grossly so

Bit off topic but this needs amplifying. No one ever mentions centre spot placement, and it's so fundamental. @Captain Scarlet your post from last year -the 345 triangle method was a game changer for me. Works really well.

 

 

 

[bosun21]

On 28/09/2023 at 14:08, Mandy D said:

. Googling the term along with astronomy brings up nothing helpful and neither RVO nor FLO seem to list such a thing.

There’s 4 in stock at FLO 👍.

[Mandy D]

32 minutes ago, bosun21 said:

There’s 4 in stock at FLO 👍.

Yes, thank you. I already know this and am in the process of orerding one from them.. If you go back through the posts and also read the text in your screenshot you can spot where I, a Brit, was having difficulty. The product name has been Americanised and is probably something that @FLO should attend to if they wish to sell more of these things. The correct spelling, at least in the UK, is centre.

[Ricochet]

24 minutes ago, Mandy D said:

The correct spelling, at least in the UK, is centre.

I don’t think the name is derived from centre, but from concentric, with a standard -er suffix, as in a tool that makes the mirrors appear concentric, so Concenter is correct. Additionally, as it is a name, the spelling given by the manufacturer is correct in all countries. I certainly don’t change the spelling of my name if I cross the border from one country to another. 

[a6400]

I'm confused as to what should I use to collimate my scope in the easiest way, there is multiple tools.

I need to be able to do it quickly and in dark setting if possible.

Maybe I should invest more and get that auto collimator that you connect to a laptop?

[a6400]

Also I was told somewhere that with Cheshire you don't go for aligning the crosshair with spider vanes but isn't it what they are doing here?

 

[Ricochet]

12 hours ago, John said:

The reason that I'm wary of being able to help, apart from lacking the time, is that I don't know the ES design

Reading through a previously linked thread it looks like it might be held in place by some sort of sling system with screws that are extremely fiddly to reinsert.

[a6400]

10 minutes ago, Ricochet said:

Reading through a previously linked thread it looks like it might be held in place by some sort of sling system with screws that are extremely fiddly to reinsert.

There is 3 screws afaik and a strap that protects it from falling out.

https://www.cloudynights.com/topic/749709-explore-scientific-16-truss-tube-dob-gen-ii-my-experience/

 

 

I also think about adding large PC fan in the rockerbox, but it would be far from mirror so not sure it would help?

https://www.amazon.co.uk/Noctua-redux-1700-Performance-Cooling-1700RPM/dp/B07CG2PGY6/ref=sr_1_10?crid=2HQ6HZ4R290UJ&keywords=large+pc+fan&qid=1696022724&sprefix=large+pc+fan%2Caps%2C81&sr=8-10

Edited September 29, 2023 by a6400

[Mandy D]

17 minutes ago, Ricochet said:

I don’t think the name is derived from centre, but from concentric, with a standard -er suffix, as in a tool that makes the mirrors appear concentric, so Concenter is correct. Additionally, as it is a name, the spelling given by the manufacturer is correct in all countries. I certainly don’t change the spelling of my name if I cross the border from one country to another. 

It matters very little how the word was derived. The discussion came about because @Mr Spock gave me advice on collimating my telescope earlier in this thread and used the spelling concentre, which most of us assumed to be correct, because it is only logical that we Brits would spell such a word this way. Unfortunately, this caused significant confusion until someone else posted a link and the problem became apparent. It is not about what you or the manufacturer think is the correct spelling, it is about potential customers finding the desired product.

Yes, the manufacturer has the right to spell product names however they wish, but that does not automatically make it good practice or wise. You suggest that you would not change the spelling of your name when in a foreign country, but if your name were (let's say) Richard, the French would almost certainly spell it Ricard and, to your ears, mispronounce it. An even more extreme example is a certain diminutive of Amanda, rather than Mandy, which is Manda, but if that were your given name you might not want to use it in Russia! 🤣

[John]

8 minutes ago, Mandy D said:

It matters very little how the word was derived. The discussion came about because @Mr Spock gave me advice on collimating my telescope earlier in this thread and used the spelling concentre, which most of us assumed to be correct, because it is only logical that we Brits would spell such a word this way. Unfortunately, this caused significant confusion until someone else posted a link and the problem became apparent. It is not about what you or the manufacturer think is the correct spelling, it is about potential customers finding the desired product.

Yes, the manufacturer has the right to spell product names however they wish, but that does not automatically make it good practice or wise. You suggest that you would not change the spelling of your name when in a foreign country, but if your name were (let's say) Richard, the French would almost certainly spell it Ricard and, to your ears, mispronounce it. An even more extreme example is a certain diminutive of Amanda, rather than Mandy, which is Manda, but if that were your given name you might not want to use it in Russia! 🤣

I'm sure this will help the original poster no end with their issues 😁

[a6400]

11 minutes ago, Mandy D said:

It matters very little how the word was derived. The discussion came about because @Mr Spock gave me advice on collimating my telescope earlier in this thread and used the spelling concentre, which most of us assumed to be correct, because it is only logical that we Brits would spell such a word this way. Unfortunately, this caused significant confusion until someone else posted a link and the problem became apparent. It is not about what you or the manufacturer think is the correct spelling, it is about potential customers finding the desired product.

Yes, the manufacturer has the right to spell product names however they wish, but that does not automatically make it good practice or wise. You suggest that you would not change the spelling of your name when in a foreign country, but if your name were (let's say) Richard, the French would almost certainly spell it Ricard and, to your ears, mispronounce it. An even more extreme example is a certain diminutive of Amanda, rather than Mandy, which is Manda, but if that were your given name you might not want to use it in Russia! 🤣

Please stop the offtopic, no offence.

Thanks

[Mr Spock]

44 minutes ago, Ricochet said:

I don’t think the name is derived from centre, but from concentric

Concentr ic - concentr e - centr al - centr e. 'Center' is confusing for English speakers 

Definition of 'centric'

(ˈsɛntrɪk IPA Pronunciation Guide) or centrical
ADJECTIVE
1. being central or having a centre
2. relating to or originating at a nerve centre
3.  botany
a.  Also: concentric
(of vascular bundles) having one type of tissue completely surrounding the other
b. (of leaves, such as those of the onion) cylindrical

However, getting people to use English correctly is a pointless exercise, so I quit  

[Mandy D]

4 minutes ago, Mr Spock said:

Concentr ic - concentr e - centr al - centr e. 'Center' is confusing for English speakers 

Definition of 'centric'

(ˈsɛntrɪk IPA Pronunciation Guide) or centrical
ADJECTIVE
1. being central or having a centre
2. relating to or originating at a nerve centre
3.  botany
a.  Also: concentric
(of vascular bundles) having one type of tissue completely surrounding the other
b. (of leaves, such as those of the onion) cylindrical

However, getting people to use English correctly is a pointless exercise, so I quit  

I have tagged FLO in an earlier post, in the hope that they can help fellow astronomers by also including the (more) British-English spelling in their website. As you know, this caused me problems when trying to follow your advice, but we have now resolved that.

Thank you. I am ordering the device from Flo.

Edited September 29, 2023 by Mandy D
Dang typos!

[CraigT82]

9 hours ago, a6400 said:

Also I was told somewhere that with Cheshire you don't go for aligning the crosshair with spider vanes but isn't it what they are doing here?

 

I’m not sure why they are turning the sight tube to align the cross hairs with the spider vanes in that video. There isn’t any need for it. The cross hair in the sight tube is just to give you a centre reference as you look through the peephole: Doesn’t matter which way the crosshairs run. 
 

To primary collimate large newts in the dark a laser is by far the best option I’ve found. Something that allows you to see the collimating effect from the rear of the scope whilst you turn the screws. 
I use a Howie Glatter tublug with a cheap laser in it, works a treat but the tublug isn’t cheap. It employs a barlow element in the end so it doesn’t matter if you laser is slightly miscollimated itself.

[niallk]

16 hours ago, a6400 said:

I'm confused as to what should I use to collimate my scope in the easiest way, there is multiple tools.

I need to be able to do it quickly and in dark setting if possible.

Maybe I should invest more and get that auto collimator that you connect to a laptop?

I used a Cheshire & sight tube combo for my 250px, but only during daylight.

I now use an Astrosystems laser for collimation my truss 15" dob - in the dark!  It usually takes less than 2 mins.  The laser must be itself collimated ... if it is not centrally aligned with respect to its housing when placed in the focuser, then you won't successfully collimate your scope.  My Astrosystems one is factory cal'ed, and I have not had to adjust it.

[a6400]

I have heard of Barlowed (any barlow) laser collimation and that the laser doesn’t have to be itself collimated.

Is that an option?

[Ricochet]

1 hour ago, a6400 said:

I have heard of Barlowed (any barlow) laser collimation and that the laser doesn’t have to be itself collimated.

Is that an option?

Yes, for primary collimation. For collimation in the dark I would suggest leaving the secondary and just doing the primary. You could use a normal laser method you half do the secondary but if you've collimated in the light the secondary should be much less prone to movement than the larger primary.