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Alan64

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Everything posted by Alan64

  1. The grain of the maple runs perpendicular to that of the lauan, or meranti, whichever, and for added strength.
  2. After the drilling and cutting-out, you tidy up the rough edges, oft very rough, with a rotary-tool and a small sanding-drum; then sandpaper and steel-wool to smooth and polish, and by hand.
  3. The telescope in question is a 76mm f/4 Newtonian. The design has been around since 1668. This is how it works... ...the light from an object enters the tube and travels all the way down to the big mirror at the bottom. Since the surface of the big mirror is curved, the light of the image begins to form a cone once it leaves that surface. After the light gathered by the big mirror leaves that surface, the light heads back up to the front of the tube, and to the little mirror. By the time the cone of light reaches the little mirror near the front of the tube, the cone is much narrower. The little mirror then sends the tip of the cone of light to the eyepiece, and the image formed to the eye and mind of the observer. Being that the telescope is an f/4, it will require a more precise collimation, the alignment of the mirrors inside the tube in relation to the focusser, and in order to enjoy sharp and pleasing images. Don't automatically assume that the telescope was collimated upon its arrival. Collimation instructions... http://www.astro-baby.com/astrobaby/help/collimation-guide-newtonian-reflector/ https://garyseronik.com/a-beginners-guide-to-collimation/ In addition, the focal-length of the telescope is awfully short, at 300mm. If a barlow did not come with the kit, you might want one if you want to see any details of the objects you're looking at; for example... https://www.365astronomy.com/GSO-2x-Barlow-2-Element-Achromatic-Barlow.html Without a barlow, that 10mm will give you a power of 30x, and rather low; with the 2x-barlow, 60x, yet still a bit low. Now, with a 3x-barlow and the 10mm, you'd get a power of 90x.
  4. Time-consuming, but it is what it is if you want it...
  5. Lovely brass, although not quite as lovely as bronze...
  6. The cut-outs have been shaped, and all the pieces sanded down. Here they are in the same box within which they were stripped... Now to cut out the brass...
  7. The first, actually second, set of legs has been prepared further, sanded down, numbered, and in preparation for the brass, then the dye...
  8. Indeed, and as they fall off the barge from overseas. Aside from the need to finish it, the trick is not to overload it, and then to enjoy an ultimate in grab 'n' go.
  9. The off-setting, which occurs automatically during a normal collimation procedure, looks to be correct, however the center-spot should be centered within the light-grey circle, but it's off a bit. Here's the collimation scene from my 150mm f/5... ...and well collimated. In the past, I had made a mock-up, using that scene, and to simulate how the scene of the AWB "OneSky", and the same as your own, should appear... Incidentally, you did well in choosing an f/5 Newtonian, and the shortest I would suggest for those first starting out.
  10. The mount-head is done for the most part; just a few odds and ends to which to tend... ...like clamp-screws for the saddle, a lock-nut for the latitude bolt, a lock-washer or other for the latitude-clamp; little things like that. My, it certainly is a diminutive, li'l darling... Incidentally, that Coke can is two years out of date, and it seemed swollen a bit, so I took it outside and threw it up into the air onto the road, then threw it in the bin. I didn't want it to explode one night whilst I slept. Now I don't have me prop. Today, I'm working on my legs... I have to get those cut-outs just right, and then epoxy that .010"-thick brass over each, a total of six. I may apply something or other over the outsides as well, and to further strengthen the wood there, since it's now thinner. I wonder if I should dye the legs first before applying the brass...
  11. Thanks all. With the RA-clamp locked, there is only half of a millimeter, if that much, of movement in either direction; not nearly a full measure of same. I may then hold the mount with one hand, and with a little effort twist the worm shaft with the fingers of the other, and round it goes in a complete circle without a hitch; nothing short of marvelous, the motion. I removed the steel washers from the axes' lock-nuts, leaving only the bronze washers, and I must say the improvement was rather noticeable afterwards; those rotten steel washers, they're history now. Also, I feel that I used PTFE as a shim for the stepped RA-bore... ...in a pinch, with the now-obvious and most preferred solution having escaped me at the time. The PTFE shim was .015" in thickness, so I made two shims of .008" phosphor-bronze, and for a total of .016"... I made the inner shim 1mm shorter than the outer... ...a more solid interface, and it shows when testing the axis. Incidentally, PTFE is subject to creeping, spreading out over time, and what amounts to nothing more than deterioration. Hindsight is not only 20/20, but also most fortuitous. I don't think I can add or do a single, solitary thing extra to these axes.
  12. I had to cut down the right-angled portion of a hex-key to batten down the bolts. Anyhoo, I had gotten three of these smaller bronze washers for the worm assembly... ...but I needed only two in the end; one polished only, and one with its O.D. ground down in order to recess into the hole of the threaded yoke... The one that's recessed is barely visible on the right... The motions throughout are most satisfactory, but I do expect that it will need a tweaking here and there once a telescope is mounted upon it.
  13. Earlier, I took the block and the bolt with me. I went straight to the standard nut-checker and...<drum-roll, please>... ...10-32... Being that this is a Chinese clone of Japanese design and manufacture, why isn't everything in metric??? I would like to extend my thanks to Themos for urging caution when working within this area of the mount-head, for it is of the utmost importance not to torque-down the bolts when reassembling.
  14. Drat, the longer bolts will not thread inward. I took the original bolt with me and fed it into the nut-checker. Later today I will take the threaded block itself.
  15. Oh, I'm always careful, save for that one time...
  16. The outing today was successful... The originals are 12mm in length, whilst the next size up at my local hardware is 20mm, so I thought about lock-washers in addition. The bolts turned out to be M5s, and as I had suspected. I may have to cut them down slightly, I don't know yet.
  17. The DEC-control components, before... ...and after... The spring and the actuator are noticeably cleaner. But the insides of the two housings for the spring were rusty, particularly the larger. You can tell by the outside surface of the smaller one. I didn't take photos of what I sanded and scoured out of them, as I'll leave that to your imagination. I did spend at least an hour doing so. The components freshly-lubed and installed...
  18. In hunting for my aluminum stock, I ran across this aluminum yardstick that my father had exposed to some sort of solvent which erased about half of the indicators, so I thought, "Why not?"... It just so happens that with the thicknesses of the yardstick and the thinner sheet combined, the two measured out to a total thickness of, believe it or not, 2.5mm or 1/10". Actually, from end to end, an average of 2.7mm, but who's counting... But as fate would have it, the bolts to fasten the assemblage are too short. That means yet another trip to my local hardware at the county seat, but I don't mind as I love the place.
  19. This is the only 120mm "Omni XLT", and with an equatorial mount instead... https://www.firstlightoptics.com/omni-xlt-series/celestron-omni-xlt-120.html Incidentally, that one would exhibit the least amount of false-colour when viewing brighter objects. Perhaps you were referring to this one... https://www.firstlightoptics.com/omni-xlt-series/celestron-omni-xlt-102-az.html That one would exhibit a little more, but not too terribly much. On the other hand, the "Startravel" 120mm would be as a kaleidoscope when viewing brighter objects, yet ideally suited for the dimmer deep-sky-objects and vistas.
  20. There was a rather thick layer of paint on the worm-block's mating substrate as well, and tenacious... I would assume that the horizontal and vertical centers of the worm should mate and mesh with same of the RA-gear, and as precisely as this level of manufacturing will allow... ...a 2.5mm, or 1/10" gap. I didn't realise that the paint was that thick.
  21. Yet again, I had to remove paint, from the worm-block's bottom surface and within all of the threaded and non-threaded holes... The RA-axis now has its clamp-pin... The depth of that hole is 12mm. I made the pin 5mm in height. The DEC clamp-pin; out with the old steel one, in with the new one of brass... That sort of looks like a steam-engine, and a train to the stars. I had second thoughts on using the clamping-knobs from the spare "AstroMaster" CG-2, as they just didn't look like they went with this "PowerSeeker" CG-2. After all, I do want this one to appear as original as possible, and the original thumbscrews, now with the brass-pins, are not difficult at all to batten down or loosen. These thumbscrews are, as a matter of fact, charming, and at the same time, subtle, tasteful. No need for the flashy stainless-steel there. They also match the thumbscrews for what will be the wooden legs for this mount-head...
  22. I decided against a shim for the needle-thrust bearing, as the slop was only .010" all around. Here, the RA bearing and washers are lubed and ready to go... ...and to fit against and into the RA bore with its finalised PTFE shim in place... The bronze lock-nut washer... The mount-head with the axes completed, and with the RA-gear cover installed... The RA bearing and washers all nice 'n' comfy-cozy... Next up, the worm assembly... "Pickering, this is going to be ghastly!"
  23. I have a spare Meade EQ-2 mount-head, and from a warranty claim(a wonky DEC shaft). For the RA-gear of the EQ-2, there's a plastic, protective cover... It just so happens, that with a slight modification, it will integrate with this EQ-1 as well. After chopping off a bit, to clear the worm assembly, I sanded the cover throughout and painted it with the rattle-can of hammered-black... I wanted to add it, not so much for the RA-gear, but to protect the needle-thrust bearing from dirt and dust. I won't know if it will interfere with the motor-drive until the latter's attachment. The cover's permanent inclusion will therefore depend wholly upon that. Whilst waiting, ever waiting, on that paint to cure, I corrected one of three problems remaining before I can complete the RA-axis, and the mount-head itself. The scale of this mount is of such a diminutive size that just as I had abandoned that of the DEC-axis, so for the RA-axis: its 1/16"-thick sintered-bronze washer for the needle-thrust bearing. Yes, I had to make yet another thin, bronze washer, the sixth, and this time round being definitively the last, for the axes anyway. Three for each axis I've had to make in the end... As for that of the DEC, for the RA-axis its bearing is now enveloped between identical bronze washers... Before, and after... I will have more of the flange to insert into the PTFE-lined, stepped bore of the base, and the lock-nut will have more room to seat; win-win. Trial-and-error is the name of the game when renovating these mounts. Now to do something about this slop, and the second to the last issue... Do you see it? Look closely. ? Now, we can't have that.
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