ATM/DIY

ATM & other do it yourself projects

Be afraid, be very afraid!!! – Baader 8-24 Zoom lens stripdown

Hi folks

Some of you may remember that I picked up a Baader 8-24 zoom lens from Astrofest a couple of years ago for £60. It was complete but the mechanism was a bit crunchy and sticking. Eventually it packed up completely. This left me with two choices, abandon it, or to attempt a very complicated and almost impossible rebuild.

Anyone who knows me would guess that I went for the second option!! So, heart in mouth, I went for it

I would immediately stress that, unless you are very technical, or completely mad (like me), **** DO NOT ATTEMPT THIS ****. There are lots of tiny screws, lenses and spacers and plenty of grease.

The problem I found was that there are three rollers/ guides that run in a helical groove. See the screwhead to the left of the 20 in the first picture. If you look at the second picture you can see there is no roller. The screw of that, and the third roller , had sheared. These screws are tiny M1.8 x 4mm screws.

This is where the fun part/ insanity started, as I had to either extract the sheared screws or drill them out with a 1.3mm drill. It wasn’t possible to extract them so I had do some very nervous and careful drilling. This also involved a complete stripdown to clean everything. I mentioned plenty of grease … it was everywhere!!!

I gave everything a good clean and (eventually) got it all back together, and IT WORKED!! Yayyyy . I now have two working zoom lenses

Image intensifier photographs from observing session 17-18/11/2017 (home-made image intensified eyepiece, Samsung S7 phone, Orion UK 10″ Dobsonian, Lichfield)

The following photographs were taken during the observing session at LRO, Lichfield, UK, by Andrew and Damian 17-18/11/2017. Photographs were taken from views through our two 10″ Orion Dobsonian Telescopes, using our home-made (ATM) image intensified eyepieces and my Samsung S7 smart phone hand held at the eyepiece end of the image intensified eyepiece.

The home made image intensified eyepieces were made using old 2nd world war image intensifier tubes purchased from ebay for £50 each a few years ago. They give good views although suffer from significant image distortion towards the edge. However, they represent excellent value for money and provide a quite different way of observing the night sky. Although technically what you see through these image intensified eyepieces is not a direct view of the night sky but instead an electronic image, they give an excellent “through the eyepiece” experience because of where they are located (in the focuser) and the intimate experience of observer and telescope is therefore retained, albeit with a green view!

Andy & Damian

Andromeda-Galaxy-Satellite-M31 & M32-Image-intensified-eyepiece-10-in-Dob-17-181117.jpg (below):

Christmas-Tree-Open-Cluster-NGC2264-Image-intensified-eyepiece-10-in-Dob-17-181117.jpg (below):

Crab-Nebula-M1-Image-intensified-eyepiece-10-in-Dob-17-181117.jpg (below):

Eskimo-Plantary-Nebula-NGC2392-Image-intensified-eyepiece-10-in-Dob-181117.jpg (below):

Galaxies-M81-M82-image-intensified-eyepiece-10-in-Dob-17-181117.jpg (below):

Hubble-variable-nebula-NGC2261-Image-intensified-eyepiece-10-in-Dob-181117.jpg (below):

Open-clusters-M35-NGC2158-image-intensified-eyepiece-10-in-Dob-17-181117.jpg (below):

Orion-Nebula-M42-image-intensified-eyepiece-10-in-Dob-17-181117.jpg (below):

Pleiades-Open-Cluster-M45-image-intensified-eyepiece-10-in-Dob-17-181117.jpg (below):

Scale for focussing tube

Hi, it’s useful to know the focussing position especially when imaging and using different combinations of filters/ lenses with the camera, although my sky watcher 120 Evostar has a graduated Crayford focuser, the newly acquired ST102 doesn’t, so rather than replace the rack & pinion focuser with a calibrated Crayford I managed to source some transparent adhesive scale tape, which I have attached to barrel, after cleaning the area with some isopropyl alcohol, its still on but have yet to put it to use. The tape was relatively cheap, and I do have an excess of repeating 40cm lengths, so if any one fancies adding a scale to their focussing tube get in contact.

 

Pete Hill

Leisure Battery Powerbank

Hi Folks

Here’s my latest creation. I wanted a heavy duty power tank but I’ve always struggle to find a suitable box. Most plastic boxes have the handle on the lid, so all of the weight of the box is held on what are usually quite flimsy plastic catches. Anyway, after some searching I found this box on eBay for £19.99. The handle is attached to the main body and is made of substantial aluminium tube:-

http://www.ebay.co.uk/itm/Heavy-Duty-Grey-Tool-Storage-Box-Chest-DIY-Plastic-Toolbox-Art-Crafts-Organiser/401316342387?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

I’ve fitted an inverter, a double mains socket with 2 x 5V 2.4A USB outlets, and 3 x 12V outlets. I picked up a second hand battery for £20.

The box is pretty sturdy and I’m going to put a plywood board on the lid. It is then strong enough to stand/ sit on

Cheers

Solargraph – ready!

Yes, a day or so early… but I’m off straight after work tomorrow night to see my mum at her caravan in South Wales – so it was today or never!

This is second time lucky for this location (between Leominster and my run to my B&B). Two years ago (after waiting for the full six months) I returned to collect to find the hole had been, I think, pecked through!

The best way to get a fine pin hole you see is to drill a bigger hole first into the tin. Then cover with strong (turkey) foil and then pierce that with a needle to get a nice fine hole. Only for the birds to be attracted by the shiny foil and peck it out!!!

Well not this time birds! Used a No1 drill to go straight through the can – see how you get on with that…

I suppose we’ll find out in six months then!

It’ll be interesting to see if the wire fence (which the camera is behind so the sheep don’t rub against it), will come out in focus or be a surreal blur with the Church as the main focus…

Julie has instructions to start the one at home, my sister has hers, J’s dad has his and Andy has two as well…

And you can have one as well come the meeting at the end of the month. Yes, we’ll be a few days past the longest day, but still loads of time to get a great image – I’ve used up the paper and got six new ones ready to go. £5 a pop – first come first served, monies going towards the observatory fund.

Damian

Ha Solar Observing – Quark First Light 17/6/17

Have been umming and ahing for months (years!) over one of these Hydrogen Alpha ‘eyepieces’… Andy has been saying I should get one as well for ages…. but I was put off by the increasing price (they’ve gone from £650 at launch to £1099 now) and the reports of quality control issues and the response from the manufacturers to sort the problems… Whilst I’m sure there are issues, it doesn’t take many to make a lot of noise on the web…

So, when one came up on AB&S just over a week ago, including a 32mm Televue Plossl eyepiece I decided to take the plunge (despite the decent price giving me slight worries that something may be amiss).

I’d made contact with the seller in the week, exchanged contact details and all appeared OK – he sounded like a decent chap. He duly delivered it by hand on the Friday evening and we spent an hour having an ‘astro’ chat over a cuppa!

It seems that he just could “not get on with the Quark” (perhaps he thought it wasn’t a ‘good’ one, hence the inclusion of the eyepiece..?) In hindsight, I wonder if the actual issue was his scope – a Celestron 102ST, or more likely the focuser not being ‘true’. It wouldn’t take much droop for the incoming light to loose its parallelism and make the Quark go off-band…?

Anyway, surprise, surprise the wife was away over the weekend AND Saturday was clear – perhaps ‘new equipment syndrome’ doesn’t affect solar gear!?

Looking at the various ‘Solar Imaging/Observing’ threads on the forums you get better views first or last thing in the day… by the time though I’d done my chores, finished the Club’s Solargraphs and set the scope up, it was lunchtime (I’d even got up early just so I could make a new sun-shield for the scope – where does the time go?!)

With some trepidation I placed the Quark in the 2″ Televue Everbright diagonal (fitted with a 2″ extension tube sitting inside the focuser end and a Baader 2″ UV/IR cut filter) and waited for the Quark to come up to temperature before taking a peak…

No full disk solar views here (as expected – done the homework you see)!

With the Quark’s inbuilt Barlow, the 816mm f/8 Takahashi TSA-102s is effectively running at F/32 and 3264mm focal length (Daystar recommend between f/27-32 for the best performance). The Televue 32mm Plossl included in the sale giving a hefty 102x mag.

Thankfully the Quark appears to be a good one with a fairly tight bandpass (Angstrom). No apparent ‘sweet spot’ – just an evenly illuminated and focused view across the field, no ‘banding’ either… loads of surface detail – boiling in and out of focus.

The Quark came initially from The Widescreen Centre who had stuck a note to the box: “Dimmer image, good prominence views and EXCELLENT surface details. Would be good for imaging with CCD.”

Once that was out of the way I took a picture with the iPhone6 held up to the eyepiece (which I’ve always found REALLY difficult to do), to send to Andy (who was coming over for an afternoon of solar observing/imaging with his Equinox 80 and Quark).

Then we **enjoyed a good few hours observing, trying out some different eyepieces (Andy’s 17mm Vixen is too much for my set-up at 192x), experimenting with our DMK cameras and I got the sketch pad out as well.

**Plus having to help Andy sort his usual issues – looking for the correct size Allen key to tighten his scope to it’s mounting(!), finding the Baader solar film so he could make a filter for his ‘standard finder’, trying to rub the scratch off the back door he kindly added, etc, etc !     😉

Can you spot his helper…?

No, the guinea pig isn’t real !

 

Very pleased with the purchase and I think that really does complete the astro purchases…well the ‘big’ ones anyway…

Already purchased this morning a S/H 40mm Televue Plossl for a less magnified view when conditions don’t allow more (81x) and now looking for a 25mm TV Plossl (130x) to complete the solar set-up!

Even better, it gives the old Tak refractor a new purpose after it had become somewhat redundant after importing the TEC140 ED APO. It becomes the ‘solar scope’ with the Quark for Ha and white light views with the Baader Cool Ceramic Herschel Wedge.

 

Images taken over the space of 3-4 minutes with iPhone6

 

Sketches: white pencil on black art card. All with 32mm Plossl @ 102x

Prominence – only a single frame from a (second hand) old ‘Firewire’ DMK41 (it’s first light as well), captured at 2.41pm – the same one as that drawn first at 2pm above. Controlled via OACapture on my 2016/17 MacBook Pro.

‘Controlled’ in the loosest of terms(!)’, no idea what I was really doing with webcam imaging and trying to MANUALLY guide the mount at f/32… perhaps one day I’ll get the hand tracking control unit from the States that was promised 2+ years ago….  ;-(

Damian