lenscap

I don't have a Vixen mount but I have a couple of clones and in both cases the safety screw is M4. M4 (coarse) is M4 x 0.7mm which is very close to the 36 tpi you have measured.

Hi Richard, if you search the Stelle Doppie database; https://www.stelledoppie.it/index2.php?section=1 for, say Epsilon Lyra and then click on "Show" for one of the pairs say Eps1 Lyr you will get a wealth of data including earliest & most recent observations (STF denotes a Struve discovery); HTH

There is an episode about light pollution in the CrowdScience series on BBC World Service (radio) at 20:32 BST tonight (3rd Sept). BBC WS is available in the UK on DAB/Freeview/Freesat etc etc. If elsewhere check your local listings. The episode will be available on BBC iPlayer "shortly after transmission". https://www.bbc.co.uk/programmes/w3ct1pqw Apparently the program is in response to a question from "Mo, an experienced stargazer from Salt Lake City". I wonder if he's an SGL member.

Thankyou. Yes I glued a paper printout of an 8" mask to the lid as a template then marked each corner of each slot with a pinhole using a bradawl, and cut them with a craft knife and ruler. For appearance sake I should have removed the bobbles with sandpaper, but they don't affect the function.

Bahtinov mask for 200mm scope made from lid of "Cadburys Roses" tub.

Yes.

Assuming you are using belt drives the GR1 values should reflect this. If using say 48T & 16T pulleys on an axis the relevant GR1 value would be 3.

If you can set the latitude of your EQ1 to 90 degrees, so that the counterweight bar is horizontal, you've got yourself an Alt/Az mount. It will still be a somewhat wobbly mount on a bouncy tripod and you may still want to ditch it, but it will be easier to manually point it at a target than in EQ mode. I now use my EQ3-2 in Alt/Az mode for visual. It's much less stressful than in EQ configuration.

My first computing lessons were in 1969 I think. We wrote out the programs in "Honeywell Timesharing Fortran" which was transfered to punched tape locally, before being transmitted to a mainframe somewhere in the USA , presumably by trans-Atlantic Teletype. I've no idea if it went by satellite or undersea cable. We got the results a week later. Having learned a bit of Fortran proved useful about a decade later since the BASIC used by the first PC's seemed to the user to be a simplified version of Fortran. Happy Days!

Well I'm using that exact version of SkySafari 6 Plus on my Android 6.0 phone and it works fine. Also Google Play store says SS6.8.6.3 requires "Android 4 and up" not Android 8. Its a puzzle. Have you posted the problem on the Simulation Curriculum forum? https://support.simulationcurriculum.com/hc/en-us/community/topics

30cm is too short, I used about 1 metre leads which is plenty. Yes buy some 4 pin Duponts, & a selection of jumper wires will be handy for adding accessories. Yes, cut it off or unsolder it. You could keep it to use as a ballast resistor for a status LED if you add one. Get some of these if they didn't come with the drivers https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313&_nkw=pcb+0.1+jumper&_sacat=0

Well the black hole could be ( in a ) Messier. 😀

Is that a tracking motor? I think you'll find it has an internal gearbox which is needed to achieve the tracking resolution necessary for long exposure photography. Driving the RA direct with an ungeared stepper would give a calculated resolution of about 0.8", so maybe 1.5" in practice. I did this on my EQ3-2 for a while. The resolution was fine for visual. Would it good enough for your EEVA plans? I don't know. You would also lose the 3:1 torque magnification. My direct driven EQ3-2 could handle a 6" Newt but struggled with an 8" (not surprising since it was about 100% overloaded 😀) so I went to belt driven. Geared steppers have been used for Onstep, mostly for Dobs where they may be the only way of achieving the required overall gear ratio. Excessive backlash in the internal gearbox has been a problem. The vast majority of EQ builds use belt drives which have little backlash & tend to be quieter than gear sets. HTH

On the EQ3-2 the RA driven pulley will foul the RA clutch lever unless you do something to avoid it. I cut away part of the lever which you can just see in the bottom left this pic. This works but if I was repeating the build I would use a shaft extension something like this to move the driven pulley outboard to clear the lever. https://www.ebay.co.uk/itm/143565881640?epid=1974551016&hash=item216d318128:g:pU8AAOSwMNxXaROM Maybe you could find a 6mm rigid coupling plus a short length of 6mm D shaft a bit cheaper. You can adjust your RA motor mounting bracket(s) to maintain pulley alignment. Once you have mounted the motors & pulleys you can measure the shaft spacings and calculate the belt lengths. Onward & upward!

Hi Dave, and welcome to SGL. I think £680 is a fair price for a used 12" Skywatcher flextube dob. Two of these sold recently with asking prices of £700 &£750 on UKAB&S; https://www.astrobuysell.com/uk/results.php New 12" dobs list for about £1100 at FLO and 2/3 of the new price is a typical rule of thumb for used kit in good condition. Good luck.

The controller uses less than 500 mA when tracking and a maximum of about 1A ( at a nominal 12V DC ) when slewing both axes together with an 8" Newt on board. Any reliable source of 12V DC that can supply say, 3A or more will do. I generally use a 12V, 7Ah, scooter battery which runs for 5 or 6 hours between charges. If I did all-nighters I would use a 17Ah battery. Referring to the photo of the WeMos R32/CNC V3 in my previous post, the only soldered joints are the 2 that connect the power cables to the crocodile clips. I suppose you could use screw terminals. Some of the optional features that you may decide to add, require some soldering, but there's nothing too challenging. I've just noticed that the WeMos R32/CNC V3 section of the Wiki has been updated. It's much improved - well worth a look .https://onstep.groups.io/g/main/wiki/19670 Good luck with your Onstep journey.

If johninderby made tripod dollys . . . . . 😀

Hi Ian, and welcome to SGL. Have you aligned the Astrofi as described on page 7 of the manual? https://celestron-site-support-files.s3.amazonaws.com/support_files/22201_22202_22203_Astro Fi_Telescope_Manual_5languages_USA_F_BW.pdf

Just a Skywatcher 6 x 30 RACI Finderscope for my 150p. Been looking for one of these for months but everywhere has been sold out. And FLO don't seem to stock the RACI version at all. Noticed stock at Bristol Cameras. Ordered Wednesday, delivered Friday by RM. They're still showing "in stock" as I type.

Hi Peter, Yes the motors in the Goto kit are much more capable than the dual-axis tracking motors. The dual-axis motors are adequate for tracking & for short slews to centre targets in the eyepiece. People who have tried to use them as a basis for diy Goto systems have found that they can only slew at a maximum of 50x to 60x siderial rate, which is useless for the long slews that you need for Goto's. Slewing from one side of the sky to the other could take nearly 15 minutes! The proper Goto kit will slew at 600x to 800x siderial.

Drive Trains for an EQ3-2 Onstep conversion. I suggest NEMA 17, 400 step , bipolar steppers using 32 microsteps with 3:1 belt drives. Each motor needs at least 50 ounce.inches of torque.The RA worm ratio on the EQ3-2 is 130:1 so the tracking resolution will be 0.26 arc sec which is similar to a Synscan system. (360 x 3600) / (130 x 3 x 400 x 32) = 0.26 The Dec worm ratio is 65:1 so if you are guiding you could use 64 microsteps on the Dec for symmetry if you wish. Motors; https://www.omc-stepperonline.com/nema-17-stepper-motor/nema-17-bipolar-0-9deg-44ncm-62-3oz-in-1-68a-2-8v-42x42x47mm-4-wires.html Pulleys; 16 tooth & 48 tooth GT2 pulleys will give you a 3:1 ratio. 6mm wide belts will be adequate. Select bores to suit the motors (5mm) and the worm shafts (6mm). https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2499334.m570.l1311&_nkw=gt2+timing+pulley&_sacat=0 You could use these brackets. One of them will mount the Dec motor. You could use 2 of them in a "U" or "Z" arrangement to mount the RA motor. There are other options. I used 1 angle bracket & a diy hardwood block for the RA on my EQ3-2. (see pic) . Or search for EQ3 on thingiverse for 3D printed brackets. Angle Brackets Dec Dec RA RA Those are the main items. If you go ahead with the build post as many questions as you like. Hope this is enough to get you started.

Hi Alan and welcome to SGL. Assuming that your PS1000 came with a Celestron Equatorial mount this single-axis motor drive will enable you to track your targets once you have found them manually. https://www.bristolcameras.co.uk/p-celestron-astromaster-powerseeker-motor-drive-93514-.htm To find targets automatically you would need a "Goto" system but I don't believe there is one available for this set-up.

All the info you need to build an Onstep Goto is in the Wiki, which can be confusing because there are at least 10 microcontroller boards to choose from, ranging from custom designed pcb's to which you solder each component, to off-the-shelf modules that require little or no soldering. I built my first Onstep for my EQ3-2 a few years ago using the Arduino Mega 2560/Ramps 1.5 board. This works fine but better boards are now available. 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. The lower board (that the power jack plugs into) is the WeMos D1 R32 microcontroller board which runs the Onstep software. The CNC V3 shield (with all the yellow headers) just plugs into it. It has sockets for the stepper drivers, and pins to which you can connect various optional bells & whistles. The two stepper drivers, (I used LV8729's, with the blue heatsinks) plug into the CNC V3 without the need for any wiring. Just configure & upload the Onstep software to the WeMos, connect the power & the motors & you have a basic functional Onstep controller that can be directed by the Onstep app and/or Skysafari via Bluetooth from your phone, or by Stellarium/CdC/Kstars etc by USB from your laptop. https://www.ebay.co.uk/itm/152975590787 https://wiki.keyestudio.com/Ks0160_keyestudio_CNC_Shield_V3 https://wiki.fysetc.com/LV8729_V1.0/ I'll post some notes on the mechanical side of the build tomorrow.

According to the Synscan Manual, Rate 5 on the hand control is 64x siderial. https://skywatcher.com/download/manual/synscan-hand-control-and-synscan-app/

Hi Greg, I'm sure you're aware that the maximum slewing speed of the Simple Dream is 60x siderial which is much too slow to be practical for long slews. ( Typical Goto systems slew at 600x to 800x or more. At 60x a meridian flip would take about 15 minutes ! ) So you would have to loosen the clutches and push the scope close to your target before engaging the Simple Dream "micro Goto" and a planetarium app to zero in. If you are handy & want a full-speed Goto you could build an OnStep Goto system using Nema 17 motors for around £100. https://onstep.groups.io/g/main/wiki/3860 Good luck.