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Posts posted by SnakeyJ

  1. 15 hours ago, Ben the Ignorant said:

    This is one of the A2 bolts that's been enduring the weather for at least twenty-two years, that lamp was already converted to sodium when I moved into this neighborhood. No one to clean it up but shiny after all those years. Note that there is some lateral color because the photo was taken through a Baader Hyperion 10mm, which are notorious for that, but the Sun's reflection on the bolt at the center causes no fringing, thanks to the very good correction of the FPL-51 80mm f/7 doublet.

    The clamp is either aluminum or stainless, too, and didn't suffer any corrosion either.

    Thanks Ben - amazing condition given 20 years exposure to British weather.   I'm sure that 20 years will see me through.


    Interesting that the street light, a traditional bane of  UK astronomers, can prove to be such a useful tool.   In my area we changed over to LED some 4-5 years ago, I expect the contractors will have scrimped on fittings, but will take a closer look now!

  2. 2 hours ago, Chriske said:

    Very hard to machine indeed SS.
    That's why I rarely use it. I use brass instead. Polished it looks awesome.


    It certainly would look awesome, but a fair amount of polishing to keep it gleaming - would look great for that cyber punk effect (like the Great Weatherall Refractor below) and a little denser than SS, but also fair bit more expensive to buy.

    Image result for the great weatherall refractor


    The stainless surfaces up nicely with Carbide tooling on my lathe and no problems so far with drilling, boring and tapping ops - though I did use the feed and suds pump for the finishing cuts.

  3. On 12/07/2019 at 00:16, JamesF said:

    Not seen you posting for some time, Jake.  Good to know you're still here :)

    My gut feeling is that it's better to have more weight closer to the mount than less weight further out in order to reduce the moment of inertia (which varies with the square of the distance from the axis of rotation, IIRC).  You've got a lot of weight there though.  What's on the business end of the mount?  The OO 250?


    Hi James, and thanks for your response - I do still dip in and follow the forum and progress on your obs, but have been busy with my daughter and very little time and energy for astronomy.   I have managed to sort my bijou 8x8' workshop and trying to get my new planetary setup running.


    My rig is quite unweildy, with an OO 14" swinging on old style CGE Pro, within a 2.2m pulsar dome.   To shift the OTA CoB forward sufficiently to operate in the dome, I had to add almost 5kg of lead flashing wrapped around the front of the OTA.   This is held in steel rings between two 14" losmandy dovetails.   All up with camera, ADC and Barlow's, just under 30kg.


    I'm hoping the OO ultra grade optics, smaller CO and open tube will give the C14's a run for the money and have a couple of years yet to tweak before Jupiter, Mars and Saturn become decent UK targets. 


    Certainly not expecting this to perform for LX imaging, but with CMOS sensitivity improving, exposure rates commonly over 100fps at f15-f20 and the rig reasonably sheltered from the wind, it should be stable enough.

  4. Just now, fozzybear said:

    we use 316 at work but would cost a fortune to ship an offcut to you we waste a lot.... but recycle it... anyway, how about a steel billet and then cold glavanise it (spraycan) cheaper?

    316 is good, but much more expensive and harder to machine, though a few inserts or taking lighter cuts makes little real difference to me at home.


    Cold galvanise, paint or electro plate all good enough for me, but it would be nice to do stainless if I could find a bit.  

  5. I managed to source some 32mm diameter 304 grade SS at a sensible price for another project, but have enough left to make an extended counterweight shaft for my cge pro.


    Looks great and machines nicely - pretty sure it will do the job and stay shiny in my obs, but just wanted a second opinion.


    The original is 15.5" X 1.25" including turned down externally threaded end at 1" X 16tpi  but thinking I might add 7-8" and reduce the number of weights (currently 25kg, original Celestron 10kg, 2 X SW 5kg and 2 X 2.5 iron gym weights).


    (BTW - I'm still looking for some cheap/free 8" SS billet bar - about 10" should suffice and a powered hacksaw/ bandsaw.... )

  6. I'm another vote for the 224MC, which has provided excellent some excellent results when I've had the chance to get out!

    The camera delivers high frame rates, even at F20 on my 10" OO (TV 3x barlow with some extension), commonly over 120fps on  640x480 ROI.    The camera's sensitivity has been a big step up from my previous QHY5LII mono (ASI120MM equiv) and much less fuss with the processing - though worth stressing that best results do require the ADC (particularly for planetary imaging from UK Latitudes).     A capture laptop with USB3 and a decent SSD drive can also bump the price up if you don't already have them.



  7. Love that Neil - how wonderful to literally fly over the lunar surface like this!  The enhanced relief adds new understanding to the structure and wide variation in the lunar surface.   Any chance you can post up the original source image for comparison with the video?

  8. 48 minutes ago, mapstar said:

    The 'producing' bit may be a bit misleading as most of the parts are made and sourced in china and the far east and have been since the 600 group was rationalised in the late 90's.


    Made in Britain is a dying breed I'm afraid. Very sad. 

    This saddens me too, it would be nice to see some real production behind British badged brands, even if we outsourced the castings and heavier production.   The global economy has all but killed off UK production.    At least I know my Mk1 Bantam is 100% British built and powered by Brook's Motors of Huddersfield.    It may be old and worn, but will certainly see me out ;) 

    Oddly enough a Dalian lathe did come up for sale locally - it looked well equipped and not a lot of money, but rather too big for my workshop and I'm not keen on another hernia!



    • Like 1

  9. Forgot the photos this morning, but a much better run at machining a test bar yesterday.    I was running this on 20mm black mild steel bar, so a little lumpy and naturally some chatter at 7" out from the chuck, but the results were considerably better and I was able to get a reasonable first pass on this.    Still measuring in metric with the micrometer, but I machined to 19.25mm at 20mm from the chuck jaws and ran out to 19.30mm at 150mm (170mm from chuck).   Quite a taper, but heading in the right direction. I should be able to resolve this with precision levelling of the bed and tweaks to the head alignment.     I will do the subsequent test cuts with a taper mounted collet chuck, which should give much more accurate alignment and see if I can source some truer bright steel bar stock.

  10. 20 minutes ago, noah4x4 said:

    As a resident of Colchester (UK) since 2001, I found this thread a fascinating diversion to my morning. I had never heard of 'Colchester Bantam Lathes'. Decided I must do more research.

    The original company was a pioneer in the industrial revolution and has a huge reputation for quality, but all production in Essex ceased in 1995 and was moved to Heckmonwike, Yorkshire where the company continues to trade as Colchester Machine Tools.  

    At least production wasn't moved to the Far East, but if Parma Ham can't be bred in Suffolk and Champagne produced in Kent, how could this be allowed to happen?  It is also so unlike Yorkshire folk to accept anything not branded from the Ridings, or is The Only Way Is Essex as regards machine tools?


    Hi Noah - I was posted with HQ 19 Infantry Bde, Goojerat Baracks, Colchester myself between '88-90 courtesy of the Army.   Without doubt the best and friendliest garrison town in UK and many fond memories of the town and surrounding area.   My only claim to fame would be entertaining and photographing Atkinson, Fry, Laurie and Robinson with the band of the 3 Royal Anglian, when they filmed the title sequence for Black Adder Goes Forth - Stephen Fry, Tony Robinson and Hugh Laurie were great fun, but Rowan Atkinson was very aloof and withdrawn.      Genius together as they played off each other as they seemed to make the gags up as they went along.

    Colchester Machine Tools are still very much up and running and producing/exporting quite a lot of machine tools - Looks like they are mostly CNC driven now, but they still sell the traditional centre lathes Student and Master models - bet they cost a fair few shillings though.     I think the move to Yorkshire was part of the rationalisation of Harrison and Colchester under 600 Group Plc, both brands are still produced.

    It's good to see that England is still producing and exporting some machine tools!

  11. Thanks Gina and Damian  - definitely getting there.     I've just lashed out on a proper 0.0001" dial test indicator Mitutoyo so should be able to get the bearings properly adjusted and then complete the levelling and alignment.

    This engineering kit is almost as expensive as the astro toys - Hopefully I can turn a few projects out rather than just making piles of swarf and getting oil everywhere! 

    • Like 2

  12. I spent most of the night stressing over this, but finally decided it must be the spindle bearings that had worked loose.    The manual says these should be tightened so the end float is 1/10000" or 0.00254mm measured on the face of a flat centre in the spindle nose and 'the spindle remains free to turn by hand'   Rather subjective, but I checked mine and I was reading around 0.05mm on my cheap Chinese dial indicator, or 20x the specification.      I've decided to tighten the bearing up to 0.01mm making sure that it still had a good free spin on the spindle.


    I then cautiously ran the lathe up through the gears to it's max 1600rpm - much quieter now and the eccentricity seems to have been largely removed.    I will borrow a proper dial indicator to double check this during the week, but the surfacing looks much better on a piece of bar stock, certainly sufficient for my needs and I will have another go at sorting out the head alignment. properly.


    • Like 1

  13. 've been using my lathe a little of late, but was worrying this week as I was starting to see more chatter and some very poor finishes.

    I decided to check alignment and brought a 10" length of 1" steel bar home as a test piece on Friday night.    The idea was to take a light surface cut over 6" and then mic this up to confirm any run out.   However the results were dire and very noisy as I moved further from the headstock.    I put a clean piece in and ran a dial indicator along the saddle - it was way out.

    Having slept on it I decided to properly inspect the head today and stripped it down


    It all looked clean and well lubed inside, but then I decided to put a centre in check this - Houston we have a serious problem...

    At this point the panic was setting in - I reread the manual and did a quick Google and decided to check the bearings.


    Apparently these Gamet bearings are seriously expensive £6-700 + vat for the pair!


    A cup of coffee and a think - how can it be so bad? There's no obvious play in the bearings or spindle.     It has to be the centre?   I decided indicate the spindle nose.

    Not amazing, but at least it's back in the right ball park.


    Now I always wipe a Morse taper out before use and I've now given this a proper clean out, but still seeing a big alignment error 0.3-0.4mm with this center.   I get about half the error with another center that also came with the lathe.


    I'm guessing that I have some damage to the spindle taper and may need to hone this out to remove any high spot's.    But is it actually possible to bend a center?



    Sorry, excuse the duplicate video at below - unable to edit this out having started the post on my phone!

  14. I purchased this here 12 months ago from AstroMick, but have not had the opportunity to use at all.

    Excellent condition and boxed, c/w original software CD, spare desiccant tablets, plug, mains PSU, cigar lighter socket and USB2 cable.

    Full specification at https://www.firstlightoptics.com/atik-cameras/atik_414ex.html

    £ 650 inclusive of UK postage.    Payment paypal (+fees) or bank transfer.







  15. 9 hours ago, JamesF said:

    I made two for my 10" flextube dob from the lids of paint tubs glued to a disc of 3mm ply with a wooden drawer knob fixed in the middle for a handle.


    Ah now the ply is an excellent suggestion and I like the idea of the drawer knob as a handle, perhaps if I steam it I can also bend it around the radius of the OTA - it will certainly be cheap, easy to cut and should bond well with Gorilla glue - I will knock up a steam box/bag and have a quick play.

  16. I want to make up new end caps for both of my OO Newts (replacing the thin/brittle and not terribly useful thermoplastic ones supplied by OO).        I was thinking of wrapping and laminating some kitchen laminate edging strip to get a close fit around the end of the tube, with some DC Fix flocking to help with 'stiction' and prevent wear damage, and perhaps some 2mm aluminium sheet for the round.    I'm more concerned about fit/durability than aesthetics, but could pretty the whole thing up by flocking internally and perhaps spray or wrap the outside.


    Just wondering if anyone had any thoughts or suggestions on better materials/method for end caps?

  17. 6 minutes ago, Stub Mandrel said:

    Rub it with a soft pencil then wipe off the excess?

    An excellent and practical engineers solution - I messed about in photoshop for 15 minutes and managed to get:

         F4.6 1/10  

         080805PR01 (or possibly RR01).


    No entirely certain on this, but it appears the reference is date/project reference so hopefully this will be enough for OO to retrieve the certificate/results.

    • Like 2
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