Geoff Lister

7 hours ago, Gfamily said:

Handy hint - if the ground isn't level, rotate the tripod around its centre until one leg is exactly lined up with the 'up' side of the bubble level. That way you only need to shorten one leg.

I did the opposite with my Skyliner Dob base. There is no adjustment for the feet. I line-up one foot with the 'down' side of a bubble level (an addition to the base), and slide a wedge under the foot until the bubble is central.

3 minutes ago, zcjp said:

I suspect that levelling it on a tripod will be more difficult than doing it on a table top

Most tripods have an adjustable clamp on each leg, so the bubble level on the Virtuoso mount will show when the leg lengths are correct.

1 minute ago, zcjp said:

I don't suppose you can remember where you got the table from?

Sorry, I can't remember. It was probably about a decade ago.

This is a photo of my Heritage 130P. The mount base is similar to that of the Virtuoso. The plastic table/stool and glass-top table allow easy 360 degree access.

Geoff

My Skymax and Skyliner mounts have the Synscan handset, and, as mentioned by John, above, need at least +11V. As Alan also mentions, the 8-cell battery holders are a poor way of connecting to the individual cells - 16 contact points of dubious quality. I found the best way to provide portable power, was to use a series pair of 5-cell, 6V, 2600mAh NiMH packs, borrowed from radio-controlled model sailing yachts. These packs are designed to work with the peak demands of servo motors, have spot-welded connections, and are terminated with decent connectors, and, despite my best efforts at sailing, somtimes get a bit wet (no problem with astronomy). I also found a 10-cell battery holder, so, if necessary, can use NiCd or NiMH cells. A 3S LiPo battery will also work, but discharges to 9V at its rated capacity, so not quite so useful; but a buck-boost power converter may well solve that problem.

I measured the current consumption of my mounts:-

It's the auto-slew to the 2nd alignment star, that will use both axes at max rate, and highlight any poor contact resistance.

Geoff

14 hours ago, adyj1 said:

Do you have a 12v DC plug-in transformer with a 5.5mm/2.1mm barrel plug (min. 750mA ouptput)? If you were able to temporarily try the mount with a 12v supply - maybe with a mains extension lead from the house

I have used several different 12V, 1.5 or 2A, plug-top mains supplies with my various Skywatcher and Celestron mounts. These supplies came from old USB powered hubs, desk-top external hard drives, and ones supplied with LED stick-on lighting strips.

Geoff

On 27/08/2021 at 10:53, astro-erago said:

about the need to put these table top dobs onto something stable to raise them off the ground

I use a plastic patio stool/table, or, a slightly larger glass-topped patio table.

This gives an idea of some possible additions to the mount

Geoff

I have the 127mm Mak., and a Heritage 130P. Both are excellent. My 127 came as part of a Skymax setup, with a Synscan GoTo mount and handset. This is my Skymax setup, in a format similar to that of the Travelscope 70. Total weight about 11kg, with a few eyepieces and a couple of sets of batteries.

I liked it so much, that I bought a second one for my holiday home (house sold just before COVID hit) in France. This is the setup with a modified webcam in place of the eyepiece - fine for Jupiter, Saturn and the Moon. The Mak. with its longer focal length, really benefits from a tracking mount, and preferrably, full GoTo.

This is my preferred portable battery supply; the packs were "borrowed" from my radio-controlled model sailing yachts. The contact resistance is much lower than individual cells in spring-loaded plastic holders.

This is my Heritage 130P, and Virtuoso 90mm Mak. The tracking on the Virtuoso mount is good for longer, high magnification, views without having to touch the mount, and for daytime solar viewing with a solar-film filter over the front.

The Virtuoso mount will, with care, just about handle the 130P and 127 Mak OTAs; as long as I limit the maximum slewing rate; and, as a bonus, I can plug-in my Synscan handset, for full GoTo.

Geoff

10 hours ago, Cosmic Geoff said:

if you unscrew the dovetail clamp knob all the way, you will expose a large central nut. If you tighten this a bit with a box spanner, it will tighten up the vertical clutch.  The clutch should not be totally tight, for reasons which I hope are obvious, but neither should it be so slack that the clutch slips at random. 

I have the same Skymax mount, and my Skyliner Dob mount also has the same Nyloc nut. The difference between a slack axis and a tight one is a fraction of a turn of the nut. I have adjusted the clamping force, so that there is no slip in normal operation, but that it will slip if part of the OTA touches other parts of the mount or tripod.

Geoff

9 hours ago, Astro_Dad said:

I’m considering an ES 28mm 68 Deg 2 inch

I have a 2" 56mm Plossl that I use with my 10" Dob, but it only gets very occasional use. All my other eyepieces and cameras are 1.25", so to use a 2", I have to remove the 1.25" adaptor from the end of the focus draw-tube and replace it with the 2" one, then reverse the process for all the others. I have also found that I need a short extension tube to achieve focus, so adding to a bulky, and heavy, extension at the front of the tube. To compensate for the extra weight, I had to add a balance weight at the primary mirror end.

I haven't done the sums, but I would have thought a 32mm 52 1.25 Plossl would do a similar job, in a more user-friendly, and cheaper, package. I normally start my sessions with mine.

Geoff

+1 for the 32mm Plossl and 7-21mm zoom. I tend to start a session with my 32mm, and then the zoom. The zoom is particularly useful, with Jupiter & Saturn, for getting the best compromise between magnification and clarity of view.

Geoff

Hello Brad, and welcome to SGL.

I have the same system, with the older, V3, Synscan handset. Several years ago, I had problems with the azimuth axis control; not exactly your problem, but it would not align or give fine positional control. The problem was inside the azimuth gearbox cover. There is a motor control board, with several ribbon cable connectors going to the motor and the 2 encoders (motor position and, if moved manually, axis position). One of the ribbon connectors was partly disconnected from its pins. It was difficult to see, as it was on the underside of the board, and the ribbon cables have very little slack. I managed to re-seat the connector, (using manual dexterity and a dental mirror!), and the mount has behaved perfectly since.

From your description, it looks as though the motor position control loop is not getting the encoder feedback.

I have used my mount with 1.5A and 2A plug-top supplies, but the Synscan system is likely to give problems if the internal voltage drops below about 11V when doing a maximum-rate slew in both axes simultaneously, usually during the alignment auto-slew to the 2nd alignment star. This voltage drop is often caused by poor power-connector contact or thin/long (higher resistance) power leads.

Geoff

+1 for the standard focuser with the Lacerta dual-speed upgrade. I fitted the upgrade to my Skyliner 250PX and found it easy to fit, and a pleasure to use.

Geoff

Hello Chris, welcome to the forum.

I have the Skymax 127mm Mak, and I tend to start my observing sessions with my 32mm Plossl. Next, I tend to use a 8-24mm zoom, to get the best magnification/visual clarity compromise, particularly when viewing Jupiter and Saturn.

My version came with a 6x30 straight-through finderscope, and I replaced it with a 6x30 RACI version - much easier when aligning on high-altitude stars.

Geoff

I used the main objective dust-cap, supplied with the TS70 kit, and part of an A4 sheet of solar film. The main cap has a smaller secondary cap, and if this is removed, it reveals a nice hole, just right for a solar film sandwich. I made up 2 rings of cereal-packet cardboard, and using sticky film made up a solar film sandwich. I then used a bit more sticky film to mount this inside the TS70's cap.

I used a bit more of the card and some PVC electrical tape, to lengthen the sides of the cap, so it would not blow off.

Geoff

7 hours ago, Louis D said:

So, if you're way north in the summer, you can forget about this technology working during the "night".

The version of Starsense fitted in the SkyProdigy has 6 possible settings to help the alignment. "Hazy/Urban" seems to be the default. "Full Moon" is probably the best for northern summer. The others are "Suburban", "Dark", "Windy" - to ignore blurred stars, and "Custom" - it may be possible to adjust the settings to get alignment under semi-dark conditions. I have also found that, if the camera is not finding quite enough stars, it is worth doing a power down, rotate by about 20 degrees azimuth, power up and start again. If this fails, or you have obstructed views, there is a manual alignment option so you can point the 'scope towards a few areas of sky with a reasonable number of visible (through a low magnification eyepiece) stars.

Geoff

49 minutes ago, Spile said:

But do put £22 aside for a copy of Turn Left at Orion.

There is an on-line web resource site for this book at https://www.cambridge.org/turnleft

Enjoy the Heritage 130P. I have had mine for several years, and it works well for me.

Geoff

I have Starsense camera and software built-in to my Celestron SkyProdigy mount. The camera is a 640 x 480 pixel device, similar to a basic webcam, and needs fairly dark skies to "see" enough stars to perform its plate solving. If it cannot "see" several tens of stars, it tries another section of sky, but eventually gives up.

I also have the Skywatcher Skymax mount. The Synscan software requires the user to select alignment stars, and manually centre them in the eyepiece. I recon that I can perform a "Brightest Star" 2-star alignment, using bright stars such as Vega, Altair or Capella, a good 45 minutes before it is dark enough for Starsense to work. On a dark night, the Starsense system gets me aligned a couple of minutes faster than I can achieve with the Synscan system.

Geoff

Unfortunately, consumer-grade tripod-mounted optical equipment is supplied with an internal 1/4" - 20 UNC thread. It would be a brave manufacturer that used an ISO metric thread form; the returns, under warranty would be huge.

I prefer Whitworth, but my tool box contains something suitable for most imperial and metric fastenings; and if necessary, 4 different-sized adjustable spanners, pump pliers, and a Stillson wrench. My "come in handy" box (well lots of boxes and biscuit tins) contains an assortment of nuts, bolts and washers. I also invested in a 1/4" - 20 UNC tap, so I can add tripod threads at various OTA balance points on a dovetail plate.

Geoff

Mine came with 20mm, 10mm & 4mm eyepieces. I tend to use a 32mm Plossl and 7-21mm zoom.

Geoff

The dovetail bar on my Travelscope 70 fits several of my Skywatcher/Celestron mounts and has a 1/4" -20 UNC internal thread for use with much better photographic tripods (than the one supplied).

I'm not sure about this particular one, but some handsets have an internal, replacable, button cell to power the real-time clock, when the handset/mount is powered down.

Geoff

Hello, and welcome to SGL.

If you could tell us the model of the telescope, we should be able to help you. Celestron make a wide range of different telescopes, and the setup instructions are somewhat different for each type.

With any new telescope, it is worth setting it up during the day; it's much easier to focus on a distant tree/post/building, than it is a star.

Geoff

On 27/03/2021 at 19:39, chops said:

Has anyone managed to get a binoviewer working with a Daystar Scout SA60?

I have just been viewing the Sun with my SS60 + standard diagonal, Revelation binoviewer and a pair of 32mm Plossls. I could not achieve focus, so I unscrewed the black lens unit from my Celestron X2 Barlow, and screwed it into the nose-piece of the binoviewer, in place of a filter. I then had plenty of focal adjustment range. It was not as easy to get a good inter-pupil adjustment for both eyes as it is during night use, but certainly worth a bit more experimentation.

Geoff

A few years ago, I had problems with the azimuth axis on my Skyliner 250PX, particularly jumpy operation at the lower slew rates. The connector on one of the ribbon cables was partly pulled off the pins on the underside of the control board. I think it was from one of the encoders, and it was not obvious without unscrewing the board. It looks as though there was a post-design modification to feed the ribbon cables through some ferrite rings, probably to meet EMC emissions/susceptibility requirements. This makes the cables effectively shorter, and thus a tight fit under the board. I re-seated the connector, and have not had problems since.

Geoff