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Some Questions on the New FYSETC S6 Build #EQ5


Sam
 

Hi, after a month of checking in on things I'd like to convert my Vixen GP into a Go-To mount. I have chosen the FYSETC S6 build since those boards are as easy as buying apples where I live. I've always wanted to convert my mount but apart from Astronomy and College, Electronics is a no go for me and the technicality of it all is daunting at best and paralyzing at worst.

From what I gathered, I basically need:
  • FYSETC S6 V1.2 Printer Board
  • LV8729 Drivers
  • Wemos D1
  • NEO 7M GPS
  • Stepper Motors

My questions are:
  1. The cheaper price around here is the FYSETC S6 V1.3, will that suffice or do I really need to nail that specific board ver. 1.2?
  2. It says that it supports PEC sensor and ST4/SHC, what do I need to buy for this? Where do I put the ST4/SHC connector and is it an RJ45 too? What PEC sensor specifically?
  3. The NEO 7M supplies the Time and GPS right?
  4. People say use a "400 step NEMA 17 motor". When I search that term on our local marketplace I get NEMA 17s of varying specifications, different Nm, Amperage, etc... None talk about Steps while some say 200 steps but I am not sure if the Nm, Amperage or other values would suffice. Any guide on choosing the proper motor? All I am sure about is that it needs to be a NEMA 17 size. But how many phases, wires, steps, Nm, Amperage, etc. I am not sure.

I'd be happy to learn more as I go through. But right now I am really dumbfounded. Thank you or any help. :)

Regards,
Sam


Khalid Baheyeldin
 

On Sat, Sep 12, 2020 at 12:13 PM, Sam wrote:
From what I gathered, I basically need:
  • FYSETC S6 V1.2 Printer Board
  • LV8729 Drivers
  • Wemos D1
  • NEO 7M GPS
  • Stepper Motors
The GPS is optional. It is nice to have so you don't bother with setting the location,
date and time every time you power up. But that is not an issue if you have WiFi
and an Android device. Takes 30 seconds to do manually.

My questions are:
  1. The cheaper price around here is the FYSETC S6 V1.3, will that suffice or do I really need to nail that specific board ver. 1.2?
You are probably mixing the F6 (F as in Fox) with the S6 (S as in Sugar).
The former has a v1.3 version, but the latter is only v1.2.
Only the S6 is supported. Do NOT get the F6.

  1. It says that it supports PEC sensor and ST4/SHC, what do I need to buy for this? Where do I put the ST4/SHC connector and is it an RJ45 too? What PEC sensor specifically?
If you plan to use autoguiding, then don't bother with PEC for the time being.
The Vixen mounts have low PE and autoguiding takes care of it. I know because I own a Vixen and converted it to OnStep (SXD though not GP). I did own a Vixen GP in the past and PE was low. On the SXD, I added a Hall Effect sensor for PE, but once I switched to autoguiding I did not even bother connected the sensor to the board. 

After you have tested the mount under the starts for a few months, you can revisit this topic later. I have a detailed video on Youtube describing it.

The ST4 connector is a 6P6C port.

  1. The NEO 7M supplies the Time and GPS right?
Yes.
  1. People say use a "400 step NEMA 17 motor". When I search that term on our local marketplace I get NEMA 17s of varying specifications, different Nm, Amperage, etc... None talk about Steps while some say 200 steps but I am not sure if the Nm, Amperage or other values would suffice. Any guide on choosing the proper motor? All I am sure about is that it needs to be a NEMA 17 size. But how many phases, wires, steps, Nm, Amperage, etc. I am not sure.
400 step motors are less common than the regular 200 step ones.

These are two motors that are well proven with OnStep for EQ5 class mounts:

https://www.omc-stepperonline.com/nema-17-stepper-motor/nema-17-bipolar-0-9deg-36ncm-51oz-in-0-9a-5-4v-42x42x40mm-4-wires.html?

https://www.omc-stepperonline.com/nema-17-stepper-motor/Dual-Shaft-Nema-17-Bipolar-09deg-44Ncm-6248ozin-168A-28V-42x42x48mm-4-Wires.html?


Sam
 

I didn't notice the mix up there. I can now finally get the parts here by Wed start from there. Thanks especially to the motor part. That really helped clear all the mess up.

I hope we get the full implementation of this build. I understand it is experimental and might get discontinued but at least it'll let me slew! Thanks and clear skies!


Khalid Baheyeldin
 

On Sat, Sep 12, 2020 at 12:46 PM, Sam wrote:
I understand it is experimental and might get discontinued but at least it'll let me slew!
Yes, it is experimental since only a few people use it, and not everything is tested with it yet.

So far, the only annoyance is that I2C devices do not work (with the exception of the ZS04
RTC module, which works with a minor modification). Instead of I2C devices, the equivalent
SPI devices work (so instead of a BME280 I2C, we use the BME280 SPI), and all is good.

It is a good all in one board, like a much faster MKS Gen-L, where every single OnStep feature
is available, e.g. heaters ...

It is unlikely to get discontinued at this point. Even if it did, you can always stay with the
current version of software ...


Serge CLAUS
 

I replaced my MKS Gen L setup with a Fysetc S6 card. For now everything is working perfectly.
I use almost all the features (Focuser, Dew heater (BME280 SPI +DS18S20), Intervalometer, Limits, Wemos, RTC ...).
I don't use GPS because my telescope is always in the same place :-)
On the other hand, I have a preference for the TMC5160 (This must be the same for the TMC2130).
I compared the LV8729 (ESP32 CNC3 board) with the TMC5160 (Fysetc S6).
I have the impression that the micro steps are better managed.
For my autoguiding setup (EQ5):
LV8729: 1.2 - 1.5 "RMS arc
TMC5160: 0.9 - 1.2 "RMS arc
I don't know if others have seen this.


Khalid Baheyeldin
 

On Sat, Sep 12, 2020 at 02:05 PM, Serge CLAUS wrote:
I compared the LV8729 (ESP32 CNC3 board) with the TMC5160 (Fysetc S6).
I have the impression that the micro steps are better managed.
For my autoguiding setup (EQ5):
LV8729: 1.2 - 1.5 "RMS arc
TMC5160: 0.9 - 1.2 "RMS arc
I don't know if others have seen this.
This observation is worth a new topic "TMC5160 vs. LV8729".
Please include in it how you tested (different boards can cause different performance).
If you can repeat the testing with the same board, same configuration (steps per degree),
and the same night (seeing variations), that would be very informative ...
 


Howard Dutton
 

On Sat, Sep 12, 2020 at 11:05 AM, Serge CLAUS wrote:
LV8729: 1.2 - 1.5 "RMS arc
TMC5160: 0.9 - 1.2 "RMS arc
I don't know if others have seen this.
As a general rule the TMC2130 is best, the TMC5160 is close behind, the LV8729 is pretty good, the S109 ok, the DRV8825 is poor.

I said a "general rule" since it depends on the motor/driver match-up and exactly where the current is set.  If this matters at all or not depends on how much reduction is present and the type of stepper motor (400 vs. 200) etc.  With enough reduction the motor accuracy becomes essentially irrelevant no matter how good or bad it is.

https://onstep.groups.io/g/main/wiki/16270


Howard Dutton
 

On Sat, Sep 12, 2020 at 03:51 PM, Howard Dutton wrote:
With enough reduction the motor accuracy becomes essentially irrelevant no matter how good or bad it is.
Of course then there's what those reduction gears/belts/etc. do to the tracking too. :)