myFocuserPro2 stepper motor choice ( again - sorry !)

[Astro-Geek]

Just now, RolandKol said:

Extra settings work once motor is disconnected

Eureka !!  Give me a few seconds..  🤓

[Astro-Geek]

No luck I'm afraid.....

I turned the 12v supply off, unplugged the USB and then the motor, then plugged the USB back in and connected to the controller, but I get the same sub menu as before....

 

[RolandKol]

Just now, Astro-Geek said:

No luck I'm afraid.....

I turned the 12v supply off, unplugged the USB and then the motor, then plugged the USB back in and connected to the controller, but I get the same sub menu as before....

 

Just unplug everything, and use app alone. It will remember extra settings once you plug all in.

[Dr_Ju_ju]

How have you set the current on the DRV8825 daughter board ??

[RolandKol]

Hmm, 

Maybe my app is a bit older also, as my Extra Settings option is visible only from Drop Down menu called Settings

[upahill]

3 minutes ago, Astro-Geek said:

I've been mindful of the overpower/overheat warnings, and I keep feeling the motor and the heatsink in the drv8825, and neither are getting warm, let alone hot.

Maybe measure what its drawing then when in use and see if its underpowered?

As an aside I see the firmware was updated <21 hours ago, with a fix to "stepperPower" - the default step size can also be manipulated in the firmware.

[Dr_Ju_ju]

Only use the updated code for testing, as I've found what may be a flaw in the code with regard to step range.....  and there's an issue with a library definition name.

[Astro-Geek]

12 minutes ago, RolandKol said:

Just unplug everything, and use app alone. It will remember extra settings once you plug all in.

Yes, that worked, I've now get a similar options screen, but unfortunately the step size seems to be restricted to 0-50.......

[Astro-Geek]

I have set the current on the drv board, as per the instructions, backed it off and then increased it till it stepped without juddering, while it was doing a plus 500.

 

[Astro-Geek]

4 minutes ago, Dr_Ju_ju said:

Only use the updated code for testing, as I've found what may be a flaw in the code with regard to step range.....  and there's an issue with a library definition name.

I'm using v 2.4.3.8, downloaded a few days ago.

Is there an updated code on that ?

[Astro-Geek]

oops, I meant myFP2.DRV8825HW203.284  (the firmware version in the controller).

I see we're now up to 290, and there's also a mention of "fixed the motor speed when the buttons are enabled", so I think I'd better reflash....

[Astro-Geek]

👍  Success........

I'm most grateful for all the suggestions and help.

I was on 284 and I've just reflashed it to the latest, v290.

What a difference !  Everything is now working really well with both motors.

They are much faster, I get the quick hum of the stepping now, instead of the Gatling Gun sound effects.  I've never used stepper motors before so I was getting a bit worried that I'd be frightening the neighbours when it was setup out in the garden....

The 27:1 now does a full revolution in 20 seconds, and the slow/medium/fast speed options now all work.

The stepsize is still restricted to 0-50, (even when the app is run without the focusser plugged in), but there's no need to increase it, as it's now very workable with the PG27.

 

[RolandKol]

2 hours ago, Astro-Geek said:

Yes, that worked, I've now get a similar options screen, but unfortunately the step size seems to be restricted to 0-50.......

I am happy to hear, you have sorted it out.

P.S.

The step size field is in microns, 

Once motor is connected to your focuser, you have to make measurements, to know your value.

How-to is in the manual and also on YouTube

Edited September 23, 2019 by RolandKol

[Dr_Ju_ju]

I've managed to sort out my issues with the latest version i.e., finger trouble & board not taking defaults unless extra settings are viewed, but as you are using a DRV8825, beware trying to drive the motors too fast as that particular driver may require fly-back diodes to smooth out the current flow.

[Astro-Geek]

8 hours ago, RolandKol said:

I am happy to hear, you have sorted it out.

P.S.

The step size field is in microns, 

Once motor is connected to your focuser, you have to make measurements, to know your value.

How-to is in the manual and also on YouTube

I have to confess that I've been focused (almost a good pun there), on getting it to work and seeing how good it is.

Robert's instructions and advice are incredibly detailed, and despite him saying read everything twice before you start, I found I'd never get going with it !

I did understand the need for calculating a 'scope's focus limits and critical range, but in my case all of my focusers are Crayford friction, rather than Racks so there's no danger of mangling anything up.  Also, I've built mine as a modular add-on, with interchangeable geared and non-geared Nemas, so that I can use the same controller on my Skymax 180 Mak, my Celestron C8 SCT, my 200PDS Newtonian, and my 300 flextube (goto) Dob.

This was the last piece in my universal remote control setup, so that I can do AP on any of my scopes in the garden whilst I sit nice and warm in the conservatory or even the house itself.  Everything runs from a NUC pc running Windows 10 that I can remote control from any PC in my house via the local network.

I'm very grateful for the help I've had in responses to this thread, they solved so many queries and problems that I had.

I think I'll start a fresh thread on here, illustrating my specific build of Robert's focuser, explaining all of my (mostly self-inflicted 🤓) pitfalls, in case it may save others from some of the grief if they're embarking on a build.

[RolandKol]

If I recall correctly (last checked around 1 year ago)

you can run 2 autofocusers with the different settings simultaneously, - maybe the updated app allows more... Please doublecheck.

I would strongly advise to use as correct step size as possible, - unless you will focus your scopes manually, but it almost eliminates the Beauty of Auto focus, which can to corrections/focus offsets due to the temperature change or filter change and etc.

For Auto Focus to work properly, - you will want to have all settings as precise as possible... I am almost sure, even so, this option will not start working fluently from the first time without an additional tinkering...

And for 4 scopes.... It may take quite a few nights....

Once you will start setting up auto focus routine, - you will see, you will want to be sure what distance 10 or 100 steps move your focuser.

For example, if your focus needs to get 50 microns correction to get back in focus, - your actual motor  1 step  is 5 microns, but app thinks it is 50, - app will order motor to make 1 step only instead of 10.

Your battle is not yet finished!

Edited September 24, 2019 by RolandKol

[dazzystar]

I'm looking for something to mount my Nema 17 PG5 to a Startravel 102. Does anyone have any 3D files I can print. I've looked in the usual placed to no avail

[RolandKol]

17 hours ago, dazzystar said:

I'm looking for something to mount my Nema 17 PG5 to a Startravel 102. Does anyone have any 3D files I can print. I've looked in the usual placed to no avail

It will be quite difficult to find the part for your specific scope and motor, - try to draft it yourself.

Similar to the one below (it may actually fit yours with a good amount of luck, will not fit.. missed PG5 part in your message initially)

https://www.thingiverse.com/thing:4705351

Edited January 15, 2022 by RolandKol

[RolandKol]

27 minutes ago, RolandKol said:

It will be quite difficult to find the part for your specific scope and motor, - try to draft it yourself.

Similar to the one below (it may actually fit yours with a good amount of luck, will not fit.. missed PG5 part in your message initially)

https://www.thingiverse.com/thing:4705351

In my case (not for your scope, so dimensions are probably different), 

I used Nema Stepper Mount bracket for around £2.5 and from ebay bought test size of Clear Polycarbonate Sheet 10mm x 50 mm x 120mm (if I recall dimensions correctly), - drilled holes  = holder....
P.S.

(10mm is probably too thick, but it is not heavy anyway)
setup does not look nice, - but works flawlessly

Edited January 15, 2022 by RolandKol

[dazzystar]

Thanks very much!

[RolandKol]

22 hours ago, dazzystar said:

Thanks very much!

Sorry, I hope it is not too late, if you will decide to go my way.
that 10mm thickness...

it actually had a purpose... in my case it aligned the shafts of the motor and the focuser....

So be careful, - slightly slimmer one may be more universal, as washers and etc can adjust the position of the motor shaft.

[dazzystar]

I'm printing some things at the moment. If it all works out, I'll post a pic!