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Re: CGE Pro help

davel
 

Hello, Chad; One question, have you finalized the design of the motor mount adapter yet? As I have mentioned before, I have a customer's CGE Pro that has dead electronics, and we are planning a move to the OnStep system. Once I have a printable file I will commence with the electronics and software.

Your printed adapter looks like a winner, for simplicity's sake and my sanity. I'm planning on getting the adapters printed at Shapeways if no alternate comes around. I have NO previous experience with Shapeways, is the Fusion file linked in your post sufficient to send them, or do I need other detail drawings? There is a possibility of getting the final design machined at reasonable cost, but I would like to try out the system before committing to a machined part. 3D prototyping is a real advance in this hobby. Thanks, Dave


Re: Steppers with Planetary Gear boxes

George Cushing
 

It's difficult to say what would be suitable without a brief description of your intended project. 

This NEMA17 produces about 18 watts power and 62 Oz-in torque before considering the gear reduction. That which gets you to something like 6.5ft-lb. The motor has a 8mm output shaft to deal with all that torque. Great motor for an extruder, if that's what you want.

General rule: avoid reducers involving gears. They create backlash. Yes, most mounts violate this rule by employing worm gears. The rational is they produce large reductions and we only have to deal with one gear interface to get it.

BTW, 4mm output shafts aren't common. Step motors come with 3, 5, 6 and 8mm shafts. Four mm is 0.1574803", close to 5/32" (0.15625), but the current NEMA (National Electrical Manufactures' Assn (U.S.A)) were adapted from those that adopted 1/8th, 3/16th, 1/4, and 5/16th inch shafts to the nearest metric size.



Re: Raspberry PI Kills onStep #wemos

Johnnie Pattison
 

User error. Added a power switch and had a solder short. 


On Wed, Aug 4, 2021, 8:38 AM George Cushing <stm32bluepill@...> wrote:
Which controller?


Re: Raspberry PI Kills onStep #wemos

George Cushing
 

Which controller?


Re: Meade RCX400 Control board

George Cushing
 

I've sold about 125 kits and assembled controllers powered by the ESP32 and found it to be the least problematic of any of the processors. It powers the MaxESP32, which is a fairly feature rich and thus more complex controller. I've put about 70 out in the world. So implementing their features generates frequent questions, but the ESP32, which is found in four OnStep controllers I'm familiar with, is the easy part.


Steppers with Planetary Gear boxes

Peter Boreland
 

I would appreciate input on the idea of using steppers with planetary gearboxes, or a source of small inline planetary gearboxes that have output shafts of 1/4" or less (4mm for instance).

Here is an example of one such motor: https://www.oyostepper.com/goods-300-Nema-17-Stepper-Motor-Bipolar-L%3D48mm-w-Gear-Ratio-19-1-Planetary-Gearbox.html but its output shaft is too big at 8mm.

I'm sure there are better options. I've only just started my hunt.

This would be used for the Dec axis only where a step size of less than 0.56 arc-sec if preferred for optimal guiding. Something in the range of 0.14 arc-sec. Could be larger 0.17 or smaller 0.11 works well too.

Peter


Re: OLED 1.3inch resolution issue fix

 

Thanks Dave 

I reupload tomorrow n try again. :) 
The for your help ~ appreciate .


Re: Raspberry PI Kills onStep #wemos

JOAN
 

It would be interesting to know the OnStep HW you use.


Re: CGE conversion

alekstad46@...
 

I connected the motor, but in the Onstep app, pressing the focus down button only rotates in one direction. As long as I keep the button pressed, the motor rotates in one direction, as soon as I release the button, the motor returns back to the starting position. There is no rotation on pressing the up button in the other direction.


Raspberry PI Kills onStep #wemos

Johnnie Pattison
 

I'm trying to use my OnStep controller with a Raspberry Pi. If I do not have power plugged into the controller, just the pi via USB,  I can see OnStep and configure kstars, etc. But when I plug the power into the OnStep controller, It dies. Power with no USB works fine. USB with no power works, but no power to steppers. Power and USB kills onStep. Power and USB on my laptop does not have this effect.


Re: Meade RCX400 Control board

Claudio Arena
 

Thank you both for the information. I will look better at both options.
In case I went with keeping the DC servo, and making the conversion to Step/Dir interface, is there a preferred micro/control board at the moment?

From what I've seen the Mega2560 is discouraged, and the ESP32 might be a bit buggy.
Is this correct?

If I wanted to put the control board inside the mount, would the MiniPCB version 1 be a good option?
Or would you suggest me something else to get started?

Thanks!


Slew rate again / beginner #ascom #bluepill

David Underwood
 

I posted earlier about go- to going too far. This was resolved for DEC axis when I found a GT2. pully. which was in a package as 16 tooth was really 20.
   Now a different problem: RA tracks at correct rate but only slews half as far as it should. E.g. I change hours in ascom hub by 6 hours and it slews 45 degrees.  

    Am I missing something in bluepill config. ?
David Underwood


Re: CGE conversion

Alexander Varakin
 

You can see how I connected the focuser on the 2nd picture:  The driver for the focuser is the 2nd from the left, purple in color. I used DRV8825 for focuser which is ok for this purpose

Here is my config.h.  If I remember correctly, I just flipped  #define FOCUSER1  from OFF to ON:
// AXIS4 FOCUSER 1
// see https://onstep.groups.io/g/main/wiki/6-Configuration#AXIS4
#define FOCUSER1                      ON //    OFF, ON to enable this focuser.                                               Option
#define AXIS4_STEPS_PER_MICRON        0.5 //    0.5, n. Steps per micrometer. Figure this out by testing or other means.      Adjust
#define AXIS4_SLEW_RATE_DESIRED       200 //    500, n, Where n=200..5000 (um/s.) Max microns/second. In DC mode, max pwr %   Adjust
 
#define AXIS4_DRIVER_MODEL            OFF //    OFF, TMC2130, TMC5160. Leave OFF for all drivers models except these.         Option
#define AXIS4_DRIVER_MICROSTEPS       OFF //    OFF, n. Microstep mode when tracking.                   For TMC2130, TMC5160. Option
#define AXIS4_DRIVER_IHOLD            OFF //    OFF, n, (mA.) Current standstill. OFF uses IRUN/2.0.                  "       Option
#define AXIS4_DRIVER_IRUN             OFF //    OFF, n, (mA.) Current tracking, appropriate for stepper/driver/etc.   "       Option
#define AXIS4_DRIVER_POWER_DOWN       OFF //    OFF, ON Powers off the motor at stand-still.                                  Option
#define AXIS4_DRIVER_REVERSE          OFF //    OFF, ON Reverses movement direction, or reverse wiring instead to correct.    Option
#define AXIS4_DRIVER_DC_MODE          OFF //    OFF, DRV8825 for pwm dc motor control on stepper driver outputs.              Option
 
#define AXIS4_LIMIT_MIN_RATE           50 //     50, n. Where n=1..1000 (um/s.) Minimum microns/second. In DC mode, min pwr.  Adjust
#define AXIS4_LIMIT_MIN                 0 //      0, n. Where n=0..500 (millimeters.) Minimum allowed position.               Adjust
#define AXIS4_LIMIT_MAX                50 //     50, n. Where n=0..500 (millimeters.) Maximum allowed position.               Adjust
 


Re: Random N / S direction change Onstep Android app.

 

Thank you for all the answers.
Indeed it's my fault because having a new mount (friction mount from JTW Astronomy) I wanted to see its behavior during changes of direction ..... without using a celestial map !! therefore impossible for me to know where the telescope was pointing! and indeed, if at Onstep startup it points the NPC and my telescope points in another direction, there can only be one big problem!

Thank you all once again!


Re: Random N / S direction change Onstep Android app.

Khalid Baheyeldin
 

This is the most Frequently Asked Question on OnStep. Read the link.


Re: Focuser for MaxEsp3

Seven Jones
 

Thank you Dave. That explains a lot. 


Re: Random N / S direction change Onstep Android app.

Drew 🔭📷🚴‍♂️
 
Edited

It doesn't really depend on how close you are to Polaris. It has everything to do with true North and the direction you pressed on the controller.

Here is how I explain the behavior.

The basic rule is that it always wants to go North when you press the N button.

OnStep starts with the telescope at NCP (North Celestial pole). Pressing the N button will cause the telescope to head South. This is the only direction it can go since it is already at North. Release the button and press North again. It will reverse direction because now it can and will go North. Keep holding the button passing the polar axis (scope aligned with mount) and it  will continue, but now it is actually going South. Let go of the button and press North again. It will reverse direction again,  heading North.

This can take awhile to wrap your head around. Play with it and it will become obvious.  Of course, all of this is reversed for our friends below  the equator.


Re: Onstep total beginner question #EQ3 #bluepill

Francois94
 

Here is my setup  and indeed , if i stand south of the mount , pushing the 3 O'clock button , the RA axis is turning CCW:


Re: Random N / S direction change Onstep Android app.

Chad Gray
 

I also questioned this.  The N/S gets flipped depending on how close you are to Polaris.  I think there is an explanation on the FAQ.


On Tue, Aug 3, 2021 at 11:16 AM adraasch <araasch@...> wrote:
How close to the pole are you when you make these moves?

Arlen

On Tue, Aug 3, 2021 at 11:07 AM Dahle <dahle@...> wrote:
‌Hello,
I just saw when using the Onstep app on Android (tablet) that the N / S direction was random.
Let me explain: I press the N key, the telescope goes south. I press the S key, the telescope goes south, I press the N key again, the telescope goes north. After all is back to normal. The case is random and does not always do.
Sometimes it is enough to press the E / W keys (which have no problem) for this to happen again.

Any ideas?

Thank you!


Re: Random N / S direction change Onstep Android app.

adraasch
 

How close to the pole are you when you make these moves?

Arlen

On Tue, Aug 3, 2021 at 11:07 AM Dahle <dahle@...> wrote:
‌Hello,
I just saw when using the Onstep app on Android (tablet) that the N / S direction was random.
Let me explain: I press the N key, the telescope goes south. I press the S key, the telescope goes south, I press the N key again, the telescope goes north. After all is back to normal. The case is random and does not always do.
Sometimes it is enough to press the E / W keys (which have no problem) for this to happen again.

Any ideas?

Thank you!

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