lenscap

A work of Ginius. 😃

As said +4 Celsius isn't cold in astro terms but @David Rawlins did you notice any dew on the set-up when the fault occurred? I had an intermittent electrical fault on an old car. It was fine in the dry but went into "limp-mode" whenever it rained, then was ok as soon as the sun came out. Moisture (from road splash) was partially earthing a 12v line which had a tiny area of damaged insulation, pulling the voltage low enough for the ECU to disable the circuit. So if I was diagnosing your mount I would be trying to provoke the fault with a water-spray bottle (not near any mains voltage of course) and seeing if it was cured with a hair drier. If so I would be looking for any damaged insulation, bent connectors or clumsy soldering that might provide an opportunity for dew-assisted earth leakage.

Hi & welcome to SGL. When your dual-axis drive is switched on and tracking (no buttons pressed) only the RA motor will run. With EQ mounts the Dec axis does not need to turn to track celestial targets. (The mount must be polar aligned to track objects.) The RA worm drive ratio on the EQ3-2 is 130 and the Dec ratio is 65 so when using the buttons to slew the mount at say 8x siderial the Dec motor will run at half the speed of the RA motor. Seems to me your kit may be working as expected. Try approximately polar aligning the mount, point the scope at a recognisable star and see if it tracks. It wont be perfect unless your Polar Alignment is good but it should keep the target in the eyepiece for many minutes.

Hi Daz, I'm a big fan of Onstep - it is much more flexible & configurable than Synscan - , but before you go ahead is your Synscan Goto in full working order and what shortcomings are you expecting to eliminate? The motors may look crappy compared to NEMA17's 😀 but they are steppers and can drive the mount at 800x siderial. You can chose motors, pulleys & microstep settings to give the same ( or slightly better ) theoretical accuracy as Synscan but in practice both systems rely on the mechanical accuracy of the mount and the EQ3-2 is not a piece of precision engineering. Belt drives will be more accurate ( and much quieter and probably require less tinkering ) than spur gears but in either case you will need to minimise the backlash in the worm drives by mechanical adjustment and carry out precise star alignments to get accurate Goto's. I think that the greatest strength of Onstep is that you can convert a manual mount to a full Goto system for maybe a third of the cost of the Synscan upgrade kit. Since you already have a Synscan Pro I wonder if you would be spending a lot of time and effort with no guarantee of significant improvement. If you go ahead the Onstep Wiki will answer most of your questions; onstep@groups.io | Wiki Good luck.

I bought one from Bristol camera recently. Very pleased with it. https://www.bristolcameras.co.uk/p-sky-watcher-6x30-right-angle-erect-image-finderscope.htm

Yes a hex-head through-bolt that fits the hexagonal recess, with a wing nut and a steel or ally flat washer (to protect the paint finish) on the other end will do the job. That's what my (cloned) tripods have. those socket-head bolts don't look original. Don't think you need felt washers.

Hi David, as said above, this looks like a job for Onstep; https://onstep.groups.io/g/main/wiki/3860 The free Onstep software runs on a diy (micro-controller based) control box attached to the mount. The controller can be directed by wifi from an Android phone/tablet running the free Onstep app and/or graphically by planetarium phone apps such as Skysafari plus or pro. Or you can direct it by planetarium software running on your PC such as Cartes du Ciel, Stellarium or Kstars depending on your operating system. The PC can be connected by wifi or USB. Have a look at the Wiki, there are lots and lots of options. I've recently finished an Onstep for my EQ5 using the WeMos D1 R32/CNC V3 board. This is the controller before I put it in a case.

That sounds more like a focus problem than a collimation issue. Is the problem present with all eyepieces or just at high power? Can you achieve sharp focus on say a distant electricity pylon in daylight? I'm wondering if the truss is extended to its maximum to enable eyepieces to come to focus.

Hi Marius, this seems like a mechanical issue to me. Since you have done a belt mod I assume you have pulleys attached to shafts by grub screws. Could one or more of the grub screws have loosened a bit over time and now slips or slips intermittently at tracking speed but still grips when the belt "grabs" the pulley at much higher slewing speeds?

You've got off to a great start by finding an EQ3-2 on a tubular steel tripod. That is much more stable than the stock extruded ally one. (smaller vibration amplitude and quicker to settle) I haven't used planetary-geared steppers myself but I've read that they can have a lot of backlash. Out of interest what type of controllers do you have? Good luck with the build.

Stopping at the first detent does not shorten the focal length or alter the focal ratio of the scope. It does push the focal plane further away from the OTA which may be necessary to enable some cameras to be correctly positioned for prime focus photography.

Noticed some very unusual and interesting kit for sale on UKAB&S. Includes optics by Lukehurst, Nichol, Sinden and Es Reid, and mounts by our very own @Peter Drew. Look for "Selling most of my kit" No connection with seller.

Young's Modulus ( stress/strain) is a measure of bending strength. In round numbers brass is about 1/2 the strength of mild steel. Dural is about 1/3 the strength of mild steel. I would go with brass which is heavier ( good for a counterweight bar) and the threads should be harder wearing.

Clever design. I don't have one of those but it seems to tick several boxes, sturdy, light, cheap and folds away to nothing. But its maximum height is 45cm, about the same as a dining chair. I mainly use 6" and larger Newts on tripods so I would need much higher than that but it might be OK with long fracs or small dobs. I suppose you could diy a fixed base for it but you would add weight and lose compactness.

I would love to try NV but its well outside my budget. Is it likely to get significantly cheaper in the next few years? I guess I'm asking if there is something inherent in the design of NV tubes that means they will remain expensive , or is it that they are currently only manufactured by defence contractors who are used to charging their taxpayers £/$/€400 for a screwdriver?

Hi Grant, Set the rig up and practice the star alignment procedure in daylight, indoors if necessary. A rough polar alignment is OK for testing, just level the mount, set the latitude & point the mount North. Then do say a 2-star alignment using Stellarium or such to see if the scope points in roughly the right directions. This should catch any gross errors caused by incorrect settings. Make sure to enter dates in American MM/DD/YYYY format. Enter leading zeroes in longitude, eg 001.xx not 1.xx Daylight Saving Time is still YES, but Time Zone is zero all year round. Good Luck.

I temporarily fitted my original Mega/Ramps Onstep to a new (to me) EQ5 while building the Wemos/CNC version for it. Just needed to reconfig the software and fit new drive belts because the shaft spacings are different to the EQ3-2. Mechanically the EQ5 build is actually easier because the RA motor can be mounted on a single off-the -shelf angle bracket just like the Dec. Now the Mega/Ramps Onstep is back on the EQ3-2 which I now use for visual, having converted the mount, and configured the Onstep software to Alt/Az. You can't do any of that with the Synscan upgrade kits, which are now about £380 !!! Congrats on your build.

For some reason that photo reminds me of "The Two Ronnies/ John Cleese" sketch. " I look up to him . . . . . . . . but I look down on him . . . . . " 😀

I assume you are controlling the mount with the Android app. You must tap "Initiallize/Park" and then "Set Time" each time you power up the controller or it will remember the time from the last session & probably be way out . Check your location lat/long.( If it is correct you don't have to enter it every time, it remembers last location.) Select your first alignment star, loosen the clutches and manually point the scope at the star, then tighten the clutches and press & confirm Align. Now select & attempt to Goto a second alignment star & note whether the RA and Dec move in the correct directions. If necessary reverse either or both motor directions. (just rotate the relevant 4-pin connector through 180 degrees to reverse a motor.) HTH

I used 6mm spiral wrap like this. https://www.ebay.co.uk/itm/160956288816?hash=item2579be0f30:g:eEoAAOxyuR5TYLhD When setting time etc note that the time zone (GMT offset in Onstep-speak) is zero in the British Isles, all year round, even when we are on BST. That caught me out. Bet you can't wait to get it pointed at some stars!

Yes, and it is even more precise if you de-focus the target to produce a large circular blob nearly as big as the fov. Then there will be no doubt when it is centered.

You need the centre to centre shaft spacing & the Pitch Diameters of the two pulleys. Dimensions of GT2 pulleys (which have 2mm tooth pitch) can be downloaded from here; https://www.pfeiferindustries.com/timing-belt-pulley-pitch-diameter-outside-diameter-charts The belt length = ( 2 x shaft spacing ) + Pi ( (PD1 +PD2)/2 ) Say you calculate about 149mm you will need a 150mm, 75 tooth belt. Edit; @Gmx76 the above formula is approximate. There is a more accurate calculator here; https://www.omnicalculator.com/physics/belt-length

In the Arduino IDE, can you confirm that you have the correct version of the correct board software installed. The board you need is the "ESP Dev Module" and you must use version "1.0.4" In the IDE click "Tools" and you should see, board "ESP Dev Module" If so highlight it, click "Boards Manager" & scroll down to" ESP32" it should be "version 1.0.4", if not click "version" and select and install version 1.0.4. I don't know if this solves your problem but worth a check.

Welcome back. I suggest you post this query on the Onstep forum. https://onstep.groups.io/g/main/topics One of the developers will usually respond in about 24 hours. Summarise your build hardware & specify exactly which ESP32 board & version number you are selecting in the Arduino board manager.

Have you tried his Twitter feed?