saac

Pretty sure there is an episode of Universe where Brian Cox shows how dust and fine particles are clumped together under electrostatic forces prior to gravity becoming the dominant role in their further aggregation of mass. He shows a nice demonstration using a perspex tank full of dust on a zero gravity flight. 

Jim 

Dan so long as it allows you to identify he centre of the mirror I'm guessing it will not matter. Most folk use one of the sticky hole reinforcements you use on punched paper to put into a ring binder.

Jim 

On 26/06/2019 at 20:23, Michael Kieth Adams said:

Wow, what did I start?  Again I will state that just because we can’t imagine how to do it does not mean it can’t be done.  

Yes but unless we root our proposition in what physics we do know then what we are left with  leaves the realm of science and becomes something else.  We should resist making up any old narrative.

Jim 

2 hours ago, Vondragonnoggin said:

There were previously two commercial offering’s aimed at the Astro community in the US. One offered a device called the Collins I3 eyepiece and actually was partnered with Televue to make its oculars in 15mm and 25mm focal lengths. The other product was a product called the Binocular Photon Machine. BiPH for short which used an 18mm size thin film  gen 3 GaAs Intensifier in a housing that coupled a Russian designed panoramic biocular.

 

Thanks for that Vondragonnoggin.   I think if we are going to see NV be a commercial success in the astro market then we need to watch what happens in the USA first , that's where it will happen.  I think it's just waiting for that breakthrough moment where there is enough uptake to drive the retail price down.  We needs lots of enthusiastic early adopters.  

I love that tag line on the Collins website "Messier would have owned one"    brilliant  and true .

Jim 

On 03/05/2019 at 22:38, GavStar said:

I would love to show you the views through a white phosphor NV monocular attached to, say, a 4 inch refractor. It sure feels like the real thing to me. ?

I would love to see that. I honestly think that NV represents  a "disrupter" technology that will shape the amateur market in the decade ahead. I can't wait until prices start to fall.  The  video of the white phosphor NV in use (posted earlier) I thought was simply amazing. I wish I had one   Gav Star, if you ever find yourself up in Fife bring your NV kit and I will give you free bed and breakfast  

Jim  

It's a lovely area Mike and anything that brings a little bit of inward investment has got to be good. 

Jim 

News about funding for new visitors centre.  Definetly welcome.  

"

Plans for a new dark sky visitor centre in the south of Scotland have secured £300,000 in funding.

The centre will be created at the former Johnston Primary in Kirkcudbright after gaining support from the South of Scotland Economic Partnership (SOSEP).

The project will also see a planetarium created at the site."

BBC Dark Sky Visitor Centre Kirkcudbright

Jim 

On 06/04/2019 at 10:05, Gina said:

Wheels ON tracks works well for me.

And me, the depth of the track is too shallow to cause problems with water, ice or general clogging up. 

Jim 

25 minutes ago, Paul73 said:

Thanks for posting. The diagram seems to sum things up nicely.

I’d be surprised if the nice people at Daystar aren’t having a look at this.

Paul

Absolutely, to be honest I think we are going to see a few manufacturers taking the initiative on this.  I mean think about it,  this is exactly how you open up your market  - now  the view at the eyepiece looks remotely like the picture on the box.  problem though is the high cost and the tech restrictions placed on the technology by the USA.   My bet is that within 10 years we will be seeing a commercial offering aimed specifically at the astro market. 

Jim 

 It basically places an optical amplifier in the optical train - usually electronic in form of a photon multiplier tube. If you google general use of Night Vision aids then that would be a good starting point. 

Jim 

Never mind how many angels are dancing on the pin head  - just admire the dance .

Jim 

If people are interested then surely they will post and discuss wherever the post falls; I must admit I very rarely take any notice of where a particular thread is grouped. In any respect the search function at the top will search out relevant posts no matter where they are on the forum. NV definitely has my interest so Ill be keeping a watch on this section. 

Jim 

58 minutes ago, Thalestris24 said:

I guess this is one sort of NV? Though is a couple of years old. I've seen some awesome enhancement systems online not so long ago. Very expensive I think!

Louise

ps at the end of the day it involves looking at a screen images in real time rather than detecting the actual photons on your retina that have travelled across time and space

Now that is nice, I do like that; that would be really useful as well at outreach sessions. 

Jim 

Dave I noticed that your truss tube blocks are similar to the Moonlite blocks but that yours are are split while the Moolite are one piece. Your socket also looks to be deep enough to fully capture the ball.  I'm guessing this means that you would need to unscrew the two block halves to allow insertion or removal of the ball. I can see that this would be a bit of a faff on assembly/disassembly.  With the Moonlite design the socket is not as deep as yours so the ball can be inserted and removed freely; the socket is also slightly oversized for the ball.  A single threaded hand turned screw is then used to secure the ball in the socket on assembly. I wonder if this would help with the faff you mention concerning the blocks or was that to do with the printing process. In either respect your blocks look pretty neat and maybe worth pursuing.

Looking forward to the rest of your build you look on track to end up with a fine truss tube set up.  I'm envious of your CNC machine  

Jim 

2 hours ago, popeye85 said:

Thanks JOC. At the minute I am still trying to get my head around allot of terminology. When words like 'azimiuth' , 'rocker box' and 'polar aligning' are thrown around i get completely lost so was looking for someone to basically explain how this would work using layman terms and I think I have got it now. Cheers 

Polar align  - point your telescope at polaris and adjust it so that polaris falls in the centre of the eyepiece (that will give a rough polar align in a dob)

Azimuth  - the angle ( 0 - 360 degrees) that you have rotated your telescope from North through East direction.

Rocker Box - the part of the Dob telescope that holds the tube and allows it to rotate both up and down (altitude) and around (azimuth).

There are some really helpful tutorials on youtube for general Dob use and use of setting circles. I'm trawling through some at the moment to get information on setting up setting circles using encoders and arduino on the school's Dob. You Tube really is helpful as well as the Hackster site for info, I'd be lost without it.   

Jim 

4 hours ago, popeye85 said:

Ok cheers. So how wood you use that on a dob mount and what setting up is required?

Popeye take a look at stepenwolf's article in BBC Sky At Night (6th post on this thread)  it tells you how to use the setting circle together with a "Wixy" (digital angle finder). Here's and extract of Steve's article 

" First, point the telescope at Polaris (nominally 0°) or centre a known star in the eyepiece. Then rotate the setting circle until the pointer aligns with the star’s azimuth. The scope can then be set to any azimuth by rotating the rocker box until the pointer aligns with the required angle. The telescope’s altitude angle can be set by placing the digital inclinometer on the rocker box base and setting it to zero then placing it on the telescope and adjusting the telescope to read the correct angle."  BBC Sky At Night Article

Jim 

Gina yes I do like that little meter, it's really reliable too. I have an old (1950 ish) AVO meter as well for a further bakelite  fix    I'm a big steam punk fan and my original intention was to finish of the observatory in that kind of style. I found a lot of supplies in the states for meters and switches but not so readily available here in the UK.  Maybe a project when I have more time on my hands. 

Jim 

James, I was really disappointed when the first one failed as otherwise they are generally of a good build quality.  The replacement (which drives my mount) has been working fine now for the best part of a year although I have just noticed the output voltage has just recently crept up to 14 V (used to be steady at 13.8 V).  I got the second unit, again because I thought the general build quality was good, and was annoyed that it failed in the same way having only ever been in dry warm storage for a year.  Anyway, I think there must be a faulty component somewhere in the supply chain - interesting that the unit was discontinued when I had picked up the second one  (I got it at a discount).  If you haven't already done it then I would attach a voltmeter  to the output permanently just to give you confidence. I'm seriously thinking about replacing my simple panel meter on the first with a constant voltage meter like I did on the second unit.  

Jim 

Hopefully the last update on this story. Despite the experience from the first Maplin bench supply unit I bought a second one about a year ago .  I tested it on getting it home and all was ok; I didn't need it in the obsy straight away so it has been sitting in its box for the best part of the past year. Guess what I found when I went to install it - yep the voltage regulator had failed just like the first unit and was defaulting to an output of 21V instead of the stated 13.8V.  What is it with me and these bench supplies   Our technician at school confirmed that it was the voltage regulator that was goosed.  With Maplin having gone into receivership I had no return possibility and I was reluctant to scrap it.   So I've installed a little  programmable constant voltage/current programmable controller.  Installation was relatively straightforward and all seems to be working well so far - still need to test it under load.  So looking for the silver lining I now have a variable power supply  - fingers crossed  

I noticed that there is a another version of this unit styled  " with communication module" - If  I understand it correctly, it looks to be a usb module that would allow for remote monitoring of the output. I may consider doing a similar mod for the bench supply I have supplying the mount - could be useful for remote monitoring.  I wonder if anybody has any experience with such a setup or similar?

Programmable Voltage Controller

Programmable Voltage Controller with communication module

Jim 

Kev I should add , I really enjoyed your build you have a cracking obsy there. I think everybody will tell you the thing that makes the biggest change is having a permanent setup. When I did mine a few years back I could not resist coming home from work and opening the roof just for the sake of it - I was like the instructor from the movie The Karate Kid - roof open - roof closed, wax on - wax off    I still catch myself opening the roof during the day time, big smile on face, just because I can.

JIm  

15 minutes ago, Gina said:

You should be alright Jim, you're just starting and when you retire you will have the time - whether you will have the money is another matter.  I have been astro imaging for 7 years now.

That's the irony , i'll be swapping time for less purchase power    I better start saving for that 10 micron mount , it won't be getting bought in retirement  

Jim 

Gina I know exactly how you feel regarding balancing the cost/usage thing.  I'm really restricting my equipment spend now. With a few years to go until retirement I really can only make use of it at weekends or holidays and then it is of course as always weather dependant. I will be lucky if I get an imaging session each month now through to spring.  I'm at the stage where I have a reasonable mount (AZ Eq6 GT)  a second hand one shot  CCD (starlight express) and have just got a guiding package together. My last purchase was a copy of PixInsight (thank you tax rebate).  My obsy was the biggest expense as well. All in all it has taken me about 4 - 5 years to get to this stage  - produced my 1st proper guided astro photograph two weeks ago (M13) and was quite chuffed.  The cost/usage ratio is a hard one to reconcile but what I would say is that I guess we get more out of it than just time actually imaging.  Maybe if we included all the positives we get from the interest, including the intangibles that impact the likes of  well-being, we would not be so hard on ourselves. Some folk would spend as much on pets, drink or clothes. Hey you gotta spend it  

Jim 

I thought cammo paint came in one can just like tartan paint     

Jim 

It is a corrosion protection - it should be removed abrasively prior to welding.   Cold bright steel is simply black bar  that has been given further processing, generally such as cold rolling, to improve dimensional tolerances. Black steel has no further machining done on it so is not as dimensionally stable as bright steel - generally used where dimensional tolerance is of less of a concern.  Easiest way to remove the black coating is to use an angle grinder and surface skim it. 

Jim 

Must be a British supplier surely?

Jim