Alan64

After the thinner washers were cut out, dressed and polished, it was no go. They were simply too thick to combine with the thicker washers, so off to the sander they went... After several hours, sanding and testing, over and over, I finally arrived at the magic numbers... I didn't sand the thicker washers at all; dressed and polished only. The motion is solid, and smooth(bronze would be smoother still), but that's neither here nor there, given the range of movement, and the rarest of need to move it. Rather, I have exchanged plastic and paint for metal, and in joining the two sections together...

Of the thinner aluminum, pilot-holes have been drilled, and the washers described... For the latitude-axis, I realise that I'm going to a lot of trouble, "The plastic washers are fine", but I'm on a mission, and to rid this mount-head of every last bit of plastic as is possible.

The spokes and part of the hub were levelled, more or less, with a Dremel tool and a diamond-bit... Then, the areas were sanded, and polished with steel-wool and lemon-oil... The other side, that I said was level, is satisfactorily. The hub does rise above the spokes, but I don't dare to decrease its thickness... The washers should easily conform to that side; or rather, it must.

In determining the extra thickness required for the latitude-axis, I used these four 0.0095"/0.24mm pieces cut from a sheet of aluminum-flashing, as test-shims, a pair for each side... That's a total of 0.019"/0.48mm for each pair, and when combined with the thicker washers results in a total thickness of 0.059"/1.5mm for each side of the axis, for a snug union. But I wasn't about to make four washers out of the flashing, so I went out yesterday to my big-box, hardware/lumber haunts. The 0.019" sheets were out of stock at the first store, despite showing "3" online, but at the second store I found this sheet... That sheet is ever so slightly thicker, and at 0.025"/0.64mm. Now, take a look at this... The other side is smooth, even, and level, however the side illustrated is not; a close-up... The spokes are thickened, along their lengths from the hub to the rim. After I level those, I may very well need the extra 0.006"/0.15mm thickness. Stay tuned.

I have a Meade LX70, which is also a Synta EQ-5. I received it recently, as new discontinued-stock... I'm in the process of "hyper tuning" it. It's a very good mount-head. Enjoy.

Before the circles were described, a very tiny drill-bit was used to create a pilot-hole for the compass's leg. Using increasingly larger bits, for accuracy, I enlarged the holes to their final diameter: 25/64", or 9.9mm... The holes fit a little tightly over the latitude-axis's bolt, therefore the exact measurement must be metric, and at 10mm. This should be done before the washers are cut out from the sheet.

Just now, the thicker sheet of phosphor-bronze arrived... I had ordered it Sunday night. That was fast. The roll came with a "pedigree" even... The chemical analysis is most interesting, and may offer some insight as to how difficult it is to cut and fashion.

Two 58mm diameters have been described onto one of the aluminum sheets... There are actually two circles for each, one slightly smaller than the other, and to help craft them more accurately.

Over here, I had to scramble to get a longer-focus achromat larger than a 60mm, longer than f/10 or f/11. Long-focus 80mm and 90mm instruments are unavailable, so I've had to make do with the 70mm instruments, which isn't a bad thing, not at all. It's actually a superb balance between ergonomics and optical performance. With that Meade "Polaris" 70mm f/12.9 achromat no longer in production, the only other option is the Celestron "AstroMaster" variant, which I have already... ...and which I detest, due to its impossible focusser. I can't trust a focusser that I can't enhance, for a straight, true racking motion, and slop-free. I'm still catching my breath over having landed that Meade.

From across the "pond", an analogy... Orion Telescopes, of California, discontinued its very popular ST80 a few years ago... ...and replaced it with the CT80("C", for more cheaply constructed?)... Apparently so, as it was not well received, not at all. It's still available for purchase, however. Then, recently, Orion re-released its ST80 as a result. Incidentally, the Meade "Infinity" and "Adventure" ST80s are the exact same telescope, but are now discontinued due to Orion's recent "annexation" of Meade. But that is not necessarily the case with the "StarTravel" and "StarQuest" ST102s, although they did remind me of the aforementioned.

The other half of the latitude-axis has been stripped of its paint... I may have to touch up the white paint here and there, but no problem. We will want it ship-shape, and in Bristol fashion.

If you're hankering for a short, "fast" 102mm f/4.9 achromat, I'd recommend this kit... https://www.firstlightoptics.com/sky-watcher-starquest/sky-watcher-starquest-102r-f49-achromatic-refractor-telescope.html You can track objects easily with the equatorial mount, and I believe that it can be converted into an easier-to-use, casual-use alt-azimuth. In any event, the "StarTravel" variants are backordered for the foreseeable future. Oh, one more thing...<tweaks right side of dastardly moustache>... The "StarTravel" 102mm may very well be better constructed than the "StarQuest" variant(more metal, less plastic), but I cannot state that as an absolute, as they are not before me. If they were, I'd find out quick. Let's just say I have my doubts.

I have an Antares 805, an 80mm f/6 achromat, only 80mm longer than the ubiquitous ST80... The white dot just above the telescope is the Moon. There, I was using it to observe Comet 46P-Wirtenan on 12/16/2018, and with my only 2" eyepiece, a 32mm 70°. Over a period of about 30 minutes, I did see the comet move against the stars in the background, which verified itself. Last December, after owning it for over five years, I finally placed a 4mm into the telescope, at 120x... You can see a bit of false-colour here and there, not too bad, but then, that's an 80mm at f/6. I should note that the live view, with the eye, was considerably sharper than that image. Everyone should own and experience a short, "fast" achromat, one at most, and the ST102 will be an excellent example. The equatorial mount that comes with the telescope is of a newer design, and refreshing. You may be able to convert the equatorial into an alt-azimuth, and by throwing the RA-axis all the way back to 90°... The counterweight must be used, still, to balance that side of the mount, and the slow-motion controls can be used as well for tracking.

A 90/900 achromat would be an even better all-rounder, and would be well supported upon an AZ-5. Yes, it's longer, but it can be stood up and stored on its front end, vertically. I suppose a 70/900 would be out of the question, although I got one recently, an OTA, no mount... This is its Sky-Watcher equivalent, the "Capricorn"... https://www.firstlightoptics.com/evostar/sky-watcher-capricorn-70-eq1-refractor.html At f/12.9, it would exhibit virtually no false-colour, albeit a bit on the dim side, although a 70mm does perform quite well under darker skies.

Deep-sky objects and vistas will appear brighter through the 102mm f/5 achromat. False-colour will be considerable when viewing brighter objects, however the perception of same varies from individual to individual; some are bothered by it, others are not. The 90mm f/6.7 would exhibit noticeably less false-colour when viewing brighter objects, if that is a concern.

On occasion, I search within eBay looking for used books on a wide range of astronomical subjects; for example... https://www.ebay.co.uk/sch/i.html?_from=R40&_nkw=astronomy+books&_sacat=0&rt=nc&LH_ItemCondition=2750|4000|5000|6000

Whilst waiting for the thicker bronze to arrive, I turned towards the latitude-axis, and removed the paint from the bearing surfaces of the mount's base. Who paints bearing surfaces... Next, I will need to remove the paint from the area circled in red, but only from the top surface, and for both sides... Incidentally, I found no stray paint anywhere inside the mount-head's axes, none whatsoever. I don't know if any of my fellow members have ever heard of Etsy... https://www.etsy.com/ ...but that's where I found sheets of 0.040"/1mm thick aluminum... The seller listed the sheets only as being 18-gauge. I was concerned that it might not be exactly the thickness needed, but my fears were allayed once I measured a sheet with calipers. I will be making the two single washers for the latitude-axis from that, one for each side, and to replace the four 0.020"/0.5mm clear-plastic washers provided by the factory.

Welcome, Jason. I got my first telescope at the age of eight, or nine; yes, it's been a while... It now looks as I feel. Where do you live in this cwazy universe? That was not a typo. I won't be able to help you spend your money on a new telescope until I know where you live.

There is this, and with your existing kit... https://www.youtube.com/watch?v=RJVXCO2Vwac This, a fun, economical telescope for getting into deep-sky astrophotography. It's configured to reach focus easily with a DSLR... https://www.firstlightoptics.com/reflectors/skywatcher-explorer-130p-ds-ota.html Here's a thread about it... https://stargazerslounge.com/topic/210593-imaging-with-the-130pds/ Unfortunately, they're not available in the States. I'd love to have one myself. All we have here in so far as solid-tube 130mm f/5 Newtonians are instruments with 1.25" plastic focussers, and for visual-use mostly if not exclusively; for examples... https://www.telescope.com/Telescopes/Reflector-Telescopes/Reflector-Telescopes-for-Beginners/Orion-SpaceProbe-130ST-Equatorial-Reflector-Telescope/pc/1/c/11/sc/339/p/9007.uts?refineByCategoryId=339 https://www.telescopesplus.com/products/zhumell-z130-portable-altazimuth-reflector-telescope https://www.bhphotovideo.com/c/product/468744-USA/Vixen_Optics_2604_R130Sf_5_1_130mm_Reflector_Telescope.html?ap=y&smp=y In that you seem to be keen on taking pictures, I would move mountains to get that photographic 130mm f/5 Newtonian. You'd need an equatorial mount, but not necessarily a go-to; simply motorised at the RA-axis, to get your feet wet, and a bit more besides.

I've never been particularly fond of crow, nor humble pie. With that being said... I never did get a chance to take my Vixen GPD apart, as I only had it for about two years, and long before I'd have a need to do so. I've been using K&S Metals .008"/0.20mm phosphor-bronze sheets for a few years, and for my telescopes and mounts. You get used to doing that, so that when the next project comes up, out comes the same thickness of bronze. It had always been satisfactory, but not in this instance, admittedly. It was this last washer I made... ...35mm i.d., 40mm o.d., that enabled me to finally see that the 0.020"/0.5mm thickness of the original plastic washers is correct, and necessary. Else, the RA-worm gear will move up and down a bit, along the shaft, albeit slightly. Given that, and with the mating of the worm and gear ever present in the back of my mind, I have placed an order for 0.020"/0.5mm thick phosphor-bronze, a 6"/152mm wide x 50"/127cm long roll. In addition, I have always been leery, suspicious, regarding all manner of products manufactured in mainland China. But then, I am reminded that the quality of their bicycles is world-renowned, although that born out of necessity.

Scratch this... This outside area(arrowed in green) is lower than the outer diameter of the RA-axis' sealed-bearing... The RA worm-gear bears against that outermost surface, and not the bearing itself which is raised slightly. Hence... Now, that bronze washer that I just made is for the RA worm-gear to bear against. It's similar to the original plastic washer, but it's more precise. Behold... It's not even greased, yet the gear spins ever so smoothly and easily, and the bronze washer does not oscillate in the very least, as the plastic washer glaringly did. The raised area of this part of the axis is what, in theory, bears against the inner, rotating portion of the sealed bearing... Now to make a washer for that union next...

I've a couple of reflectors, one a Newtonian and the other a catadioptric, with spherical, primary mirrors. I've centre-spotted the latter... https://garyseronik.com/centre-dotting-your-scopes-primary-mirror/ For durability, use a reinforcement-ring of polyvinyl(plastic), instead of paper. It has been said that a spherical primary-mirror does not need centre-spotting, since it's a perfectly round bowl, a portion of a perfect sphere, but that's a technical point. I like to know where everything is, particularly the centre of the primary-mirror, within the scenes exhibited through my sight-tube and collimation-cap. You're at perfect liberty to use a laser-collimator, but given the quality of entry-level units I strongly urge the use of passive tools, a Cheshire/sight-tube and a collimation-cap, instead...

Nice shots. "You’re a better man than I am, Gunga Din!", and in wanting to attempt deep-sky shots with a DSLR, with a manual mount, and a 6" f/8 Newtonian to boot. I use a point-and-shoot, and soon an SLR, but only for the brighter objects; instant shots... That's a sampler, and courtesy of my Orion "StarBlast 6", a 6" f/5 Newtonian, which used to be mounted à la Dobson... I took those images with a now-defunct Canon S110(lens error). Since that time, I've used an old, 2002 Minolta DiMAGE F100 point-and-shoot, and I have a new old-stock Nikon 1 S1 waiting in the wings. Are you planning to attach the camera directly to the visual-back, or position it over eyepieces? If the latter, I'd suggest an SLR rather.

I can't wait, either. But it's going to be slow go.

I can see the three primary clips, evenly ; good. However, there in the centre, the larger, fatter circle needs to be directly over the smaller, thin one. As it sits, it's okay for low-power observations, as a great many are out of the box, out the gate, but not so good for the higher and highest powers of which a 130mm aperture is capable. Your 130/900 is configured, designed, for medium-to-high powers, but the collimation is going to have to be spot on for sharp, pleasing images at those powers. It is at the higher and highest powers where "Wow!" and "Look at that!" are exclaimed aloud.