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About Astro-Geek

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    Star Forming

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    Norfolk, UK
  1. When you say alloy plate, if you mean the whitish coloured disc in the centre, that's the underside of the primary mirror. A ten inch primary mirror blank is solid glass almost two inches thick, so the dried water droplet marks are totally isolated from the crucial front silvered surface. I'd agree with the theory that they're where droplets have evaporated from condensation. You could safely wipe them gently with a dampened piece of kitchen towel if you wanted to make certain, but there's no need to do even that really.
  2. A very neat solution, and as you say, one would think that Berlebach would offer it as an option. When I built my outdoor pier I wanted it to be able to carry my EQ6 or my EQ5, so I made the top plate compatible with both. It's a Skoda brake disc, (they're incredibly cheap to buy new !), with a centre hole 65mm diameter. I bolted a 6mm thick stainless steel crossbar underneath the "dome" with a 10mm clearance hole. This then accepts either an M8 or M10 long stud with a threaded knob on one end and a wingnut halfway along. I can then simply use the correct stud for either mount and screw the stud in for half an inch or so and then tighten the wingnut to pull it down onto the brake disc. Although the Eq5's 59mm diameter can potentially move around in the 65mm hole, in practice it doesn't when the centre bolt is tightened firmly down. The North locating stud is also removable via an M6 bolt, like yours.
  3. I'll second that, very easy to do, and minimal chance of disturbing anything, unlike the corrector plate on an SCT. John's rings are a huge improvement on the standard Skymax dovetail mounting IMHO. I did the same thing with mine, and the mounting is much more secure than standard, (which had just two 4mm bolts with tiny washers holding the dovetail). The ring size is indeed difficult, between standard sizes. I found a pair of Helios for mine and modified them slightly. I also put a sturdy handle on top of mine too like John, making it much easier and safer to carry and mount. An amazing telescope, great for Planets with almost 500x max magnification.
  4. I'm much obliged to you Robert. That will make the 27:1 gearbox a really good all-rounder choice for all of my focusers, the "stiffer" ones as well as the lighter ones. Having now made many tests with the non-geared 2 amp, a 5:1 geared 1.6 amp, and the recommended 27:1 0.4 amp, the PG27 seems to be a really good combination of torque and minimum amps drain, (as your PDF had said). There's only one very minor thing that still intrigues me, when I test the manual hardware in/out buttons, the step position counter on the LCD display suddenly reverts to 0 after a dozen steps or so, (with the LED lights flashing correctly). The position counter performs perfectly when controlled by the computer, with all the stepping increments, in and out, and the numeric step position is always mirrored correctly in the LCD window on the box.
  5. I'm having trouble getting EQMod working on my Skywatcher EQ5 Synscan goto mount. I'm using the Hitec USB direct lead shown in the photo. It's connected to the Synscan controller box in place of the Synscan hand controller. I'm running the latest version of Windows 10 pro and have installed the Hitec astro driver. When I look in device manager, it shows up as "Prolific USB-to-serial Comm Port (Com6), and it seems happy, with no yellow marker against it. So far so good...... But when I run the EQAscom diagnostics and try to setup the Skywatcher telescope, there are no com ports listed in the drop-down....
  6. No need for apologies, my posts on this thread have shown how I've blundered around with this. I find it tricky to judge the set current, via that tiny preset on the DRV8825 board, turning it till the motor "sounds happy".... I've just acquired another geared Nema for testing/comparison, a secondhand 5:1 Nema 17 with a rated max current of 1.68 amps. It worked ok, but was a lot heavier than the PG27 with max 0.4 amps, so I'm still admitting that the 27:1 recommended in Robert's PDF is certainly the best all-rounder for me.
  7. Thanks for the link Julian. It actually looks like the same firm I've been buying them from via Ebay. Better to get them straight from the source though, and their website is very well laid out with the various choices, with the option of selecting the UK warehouse too.
  8. Ditto all the comments about Dobs. Simplest, best all-rounder, mirrors - so no Chroma fringing, wide field f5 and high mag when necessary with Barlows. I've tried Eight, Ten, and Twelve Inch Dobs, and it depends completely on how far you will need to carry it. My twelve inch goto synscan flextube (bought secondhand), is amazing, but I can only move it by wheeling it around, and (only just possible) carrying it through an external doorway in the two constituent parts. I used to have a ten inch GSO solid tube Dob, and that was a monster to grapple with, like cuddling a four foot long heavy torpedo, so it was actually trickier to move than the twelve inch flextube. I kept my original solid tube Skywatcher eight inch Dob because it is so easily manageable in the two parts (base and OTA). I've had no experience of an eight inch flextube, but I think there would be little advantage of the folding in that size, as the solid tube is still quite manageable at about one meter long and quite light.
  9. There's another level of thought needed when considering ways to store eyepieces (and indeed, diagonals, filters etc..) I'm a sucker for neatness, and there's a couple of pictures of my cases on the "show me your eyepiece...." thread already mentioned on here. Once a collection builds up above a certain number of items though, (as it always will ! ), it becomes more awkward and perhaps risky to carry it to a dark and possibly dewy outdoor observing site. If one is lucky enough to have a permanent home observatory (lucky devils), then no problem, they can all be kept to hand, nicely cooled down, with less chance of dropping or losing anything. If though, the observing is done in the open air, in a back garden or a remote dark site, then carrying these fragile and often very expensive ancillaries needs careful consideration. The old adage "all your eggs in one basket" comes to mind when an eyepiece collection amassed over time could be worth well over 4 figures. When I tried various cases I was wary of potential mishaps, such as could the contents fall out if the case came open at an angle or fell off a table etc., or is there even any possibility of it being stolen... My much evolved system is therefore two-stage. Permanent storage is in foam lined flight cases and drawers indoors, and selected items for a predicted clear sky session are temporarily stored in individual eyepiece bottle cases in an oversize photographer's multiple pocket gilet. (It's oversize so that it can easily fit over other bulky Winter clothing). I use bottle cases so that the eyepieces are all ready to use, with the top and bottom caps already removed, as they are so easy to lose in the dark. The "loaded" Gilet is then left in my unheated conservatory late afternoon to keep it close to outside temperatures.
  10. Well I've made a start (with my Avatar)......... If anyone is searching for ideas on equipping a home observatory, there's always Google image searching, like this one: https://www.google.com/search?q=diy+observatory&client=firefox-b-d&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiJndHb7_jkAhVgURUIHSVbA0MQ_AUIESgB&biw=1535&bih=768 I torture myself with it on quite a regular basis.....
  11. The wedge arrived today, many thanks from me too, and I also hope things improve.
  12. Yes, Robert's very comprehensive software/firmware does have provision for backlash compensation, even different settings for each direction. True, a significant advantage for absolutely precise positioning. ---------------------------- Further testing developments.................... My cunning plan to use geared and non-geared motors interchangeably with the same single controller box has the disadvantage of only having one hardware setting, (the drv8825 driver board's pot) for the motor current. My two Nemas have widely different current ratings, (0.4 and 2 amps), so it's best that I stick to just one motor, to be able to set it and leave it. Also - re-reading Robert's PDF, the 0.4 amp geared motor puts far less stress on the drv8825 driver board, whereas the non-geared Nema's 2 amps is right on the limit. I therefore think I'll just use the 27:1 Nema on all of my scopes, (as per the original recommendation in the PDF ! "Mega Uber Overkill" regardless !!
  13. More thoughts..... The difference between the power of the Nema geared and non-geared motors is quite quantifiable. My non-geared motor has a torque of 45 NCM, or just under half a Newton Metre, My 27:1 geared motor has a torque of 3 NM, three Newton Metres, six times as much, despite drawing a quarter of the current, (0.4A, instead of 2A). The 5:1 geared motor (that I was tempted to get) has a torque of 97 NCM, just under one Newton Metre, so less than a third of the 27:1 (quite logically I suppose !) Second thoughts on trying to edit Robert's firmware code too, the stepsize limitation to 1-50 is within his windows application, not the Arduino firmware.
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