Re: Comet C/2019 Y4 (ATLAS)

Khalid Baheyeldin

Very nice Roman.
I don't see a distinct tail though. Perhaps it is a vantage point or distance thing, and it was not showing on the 14th, but showed it on the 18th?

Re: New SHC Board design


Phenomenal!  I've got my name on your spreadsheet.

Jim Simpson

Re: OnStep and Dobsonian mount

Howard Dutton

OnStep and Dobsonian mount

Gilberto Nunes

Hi there  

Any one here has success in adopt Step in a Dobsonian mount?
I have a small telescop (114mm) mounted in a homemade dobsonian mount and would like to add OnStep on it... 

Any advice would be appreciated...  Thanks 
Gilberto Nunes Ferreira

Re: Jiggle when tracking

Howard Dutton

On Sat, Mar 21, 2020 at 08:59 AM, Antonio wrote:
No matter "the DRV8825 is notorious for not stepping smoothly (Howard)", a lot of users of an Onstep group where I buy the shield reports it fine.
If this is a kit with motors included, where someone has confirmed the DRV8825's work reasonably well with these exact stepper motors then no problem, you're good.

If not the fact remains the DRV8825 has major issues and doesn't work well with a wide variety of stepper motors.  And generally speaking the drive ratios of your mount put you in the ball-park of full steps going by once every two seconds or so (if using 400 step motors) which is also consistent with this type of problem and/or the stepper driver current Vref not being tuned properly.

I'll continue to assume one of these issues are the problem until you provide some feedback to convince me otherwise.

Re: Jiggle when tracking


They have 60x20 tooth.  As I said... in the DEC there are a machinized extension, but firmly attached.
The jiggle occurs at +/- 2 seconds frequency no matter the position of the tube.

Em 22/03/2020 20:36, Aisling Lightworks escreveu:

How much reduction does your assembly have? Are you coupled directly to your worm?

SHC Pushbutton Source...

Martin Bonfiore

I found some pushbutton switches that I purchased for building an SHC and thought others might be interested.  Note: they are not surface mount and they may not/won't fit the stock design without some modifications...which is fine with me though YMMV.  
What is nice is that they are tactile switches with build in LEDs...seems like lighted switches might be handy for this application... and the price is not outrageous.  Check out All Electronics.  I find them a good source of various electronic sundries and reasonable surplus prices.

Re: Question about dew heater control.

Howard Dutton

On Sun, Mar 22, 2020 at 07:38 AM, Aisling Lightworks wrote:
Thanks for making my life easier, Howard! If I wasn't unemployed due to the outbreak I'd donate more money to the cause.
I'm happy to help, and I'll probably be using it myself at some point.

More importantly, take care.

Re: Jiggle when tracking

hitosi sato

Hi Antonio
I saw your video.
My impression is that the vibration is about a few Hz. Probably 2 to 5 Hz.
I think it is necessary to inquire both electrical and mechanical factors.
If that vibration is an electrical factor, how many steps does the motor move? Calculates backward from the overall reduction ratio.
If you want to check quickly, replace the 8825 for RA with the 8825 for DEC?
If it's a mechanical factor,
Probably because there is no necessary gap in the gear, it feels like hunting belt.
Especially, the gear tends to cause such vibration if there is no backlash.


Re: Comet C/2019 Y4 (ATLAS)

Roman Hujer

C/2019 Y4 (ATLAS) 2020-03-14 22:30 UT, Bulovka Czech Repubiic, Newton 150/750mm, MPCC M III, Canon EOS 1300D, 30x120sec ISO1600. Dark, Flat, Bias, EQ5 OnStep, ASIAIR + SkySafari Pro, PixInsight .

This photo is first lihgt from my new EQ5 OnStep :-)

Re: New SHC Board design

John Scherer

These look great Jerry,  I've got my name on the list ;-)  Those Hammond enclosures are really nice.

Re: New SHC Board design

Jay Murphy


Re: New SHC Board design


Since Howard tweaked the SHC code to support my new board I went ahead and laid out the hole placement and made a fixture to hold the top half. Looks like it should work. I am having to space the board up 1/8” from the bottom standoffs.  

A few pics and one with the plastic I plan on using yo make the display cover from. 

Re: Jiggle when tracking

Jay Murphy

How much reduction does your assembly have? Are you coupled directly to your worm?

Re: Jiggle when tracking

Jay Murphy

4Nm should be more than enough. My mount moves 25 Kg with ease using 59Ncm motors.

Re: G11 - Direct Drive vs Belt for long focal length imaging

Jay Murphy

That's awesome! As soon as I get over the virus I'm going to be doing stuff like this with my kids. You've got a future engineer on your hands there. And congrats on the build.

Re: Comet C/2019 Y4 (ATLAS)

Jay Murphy

Nice capture! I'm hoping to see this comet soon. 

Comet C/2019 Y4 (ATLAS)

Khalid Baheyeldin

(Taking this out from a now crowded thread).

I first saw Comet! C/2019 Y4 ATLAS by chance. I was imaging M82, and it showed up in KStars. The above image is a crop from 120 seconds @ ISO 400. Nothing spectacular, but it does show a tiny tail.

Some sources say that it may be a fragment of the Great Comet of 1844/1845 CE, since the orbits match.

According to Cartes de Ciels, it is supposed to brighten up considerably in late May as its reaches perihelion inside of Mercury's orbit, and may reach magnitude -11 (so as bright as the moon). It will be a dawn comet though.

I then took a time lapse video of the C/2019 Y4 (ATLAS) comet.

Here is a video made using CdC on when it will brighten up, and where in the sky.

The attached .csv file has the expected positions and magnitude pre-sunrise until perihelion.
You can open it in Excel or OpenOffice.

Re: guiding issue with PHD2 after meridian flip


No ploblem


Re: PEC Transfer Format

Julian Bauknecht

tyvm, looks very good, but still dont know why it dosnt work for me. I think it has something to do with the Instein Onstep Controller, because today i tried to record a PEC File directly from the Webinterface, but PEC Status stays at: Record waiting for index to arrive for ever. I think best way is, i write Roberto from Instein directly regarding this Problem. Easiest way i would like to flash it for my self with the newest OnStep V3 then i could configer everything for my own, but i have to ask Roberto  for a Pinmap or measure it myself, because i dont think that a standard Pinmap would work with this board.

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