Cheap EQ Goto SimpleDream Onstep

[Gmx76]

Yes its a tracking motor. 🙂

Thanks for the explanation, and it makes sense. I think one person on the onstep page did an eq3-2 direct driven but looks like he used gears. 

[Gmx76]

@Lens cap so all the electronic parts have arrived and i have a question. My Nema 17 motors have come with fairly short (30cm) cables with no connectors, just bare cables. Is this enough length, and do i need to buy a couple of Dupont 4 pin connectors?

[Gmx76]

[fozzybear]

make sure to read the Wiki regarding cutting out the the resistor on the cnc3 shield  R1 if going the wemos and cnc3 shield  route

https://onstep.groups.io/g/main/wiki/19670

Andy

[Gmx76]

3 minutes ago, fozzybear said:

make sure to read the Wiki regarding cutting out the the resistor on the cnc3 shield  R1 if going the wemos and cnc3 shield  route

https://onstep.groups.io/g/main/wiki/19670

Andy

Thanks I did see that.  I just literally cut it off? Don't need to do anything else? 

[fozzybear]

3 minutes ago, Gmx76 said:

Thanks I did see that.  I just literally cut it off? Don't need to do anything else? 

you will need some jumpers (2pin) connectors for the microstepping if not already have them they go underneath the the stepper drivers on the cnc3 driverboard. As per your question on the leads for the motors only being 30cm long it is up to you if you want to make them longer if so just use arduino jumper leads with a female connection or use the jumper leads if using a case to then a 4 pole connector then you can always extend your motor cable to a connector with heatshrink after soldering the cable.

have a ganders at this albeit for an eq5 mount if not already seen

OnStep-W32-CNCV3-EQ5-Build-Instructions.pdf

[fozzybear]

17 minutes ago, Gmx76 said:

Don't need to do anything else? 

Follow the Wiki as per the configuration read it a couple of times as at first for me made no sence as you have an exel file to input data then a website link to generate the config.h file

https://onstep.groups.io/g/main/wiki/19670

any probs post on the onstep group

Edited August 17, 2021 by fozzybear
spelling

[Gmx76]

you will need some jumpers (2pin) connectors for the microstepping if not already have them they go underneath the the stepper drivers on the cnc3 driverboard.

sorry can you be totally explicit, what do I need (can you send a link) Thanks @fozzybear

Edited August 18, 2021 by Gmx76
Cheng

[fozzybear]

7 minutes ago, Gmx76 said:

you will need some jumpers (2pin) connectors for the microstepping if not already have them they go underneath the the stepper drivers on the cnc3 driverboard.

sorry can you be totally explicit, what do I need and do with them? Thanks @fozzybear

this is the shield i have and you need jumpers to determine the microstepping size on both axis 

CNC Shield V3 Bundle_EN.pdf

Edited August 18, 2021 by fozzybear

[fozzybear]

what drivers are you planning on using? LV8729's  have a look at the spec sheet and look at microstepping  section relates to jumpers ms1,ms2,ms3 in turn it is m0,m1,m2 on the board

LV8729 V1.0 - FYSETC WIKI

[JamesF]

On 03/08/2021 at 16:32, lenscap said:

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.

I managed to avoid this with my EQ3-2 conversion (which is uses AstroEQ, but the motor side of things is pretty much the same, but the drive belt runs right on he inside edge of the pulley (slightly different from yours, in that it doesn't have the side plates -- I perhaps used a different type of belt/pulley).  Then in the end I got nervous and 3d-printed a new lever with a thinned down top edge to ensure clearance

James

[fozzybear]

16 minutes ago, fozzybear said:

sorry can you be totally explicit, what do I need and do with them

if you read the eq5 build you will get the idea of what you need to do albeit the specs will/maybe different for your mount i.e gear ratio.

[Gmx76]

7 minutes ago, fozzybear said:

what drivers are you planning on using? LV8729's  have a look at the spec sheet and look at microstepping  section relates to jumpers ms1,ms2,ms3 in turn it is m0,m1,m2 on the board

LV8729 V1.0 - FYSETC WIKI

Yes its these I got thanks

[JamesF]

4 hours ago, Gmx76 said:

@Lens cap so all the electronic parts have arrived and i have a question. My Nema 17 motors have come with fairly short (30cm) cables with no connectors, just bare cables. Is this enough length, and do i need to buy a couple of Dupont 4 pin connectors?

I used smaller motors (NEMA14, I think) for my conversion and the leads were even shorter, so I got some 4P4C (commonly called RJ11, IIRC) connectors and fixed the sockets to the motor mounting brackets with the motor wires soldered to the pins.  Then separate cables run from the control unit to these sockets.  I have a nagging feeling that the cables might actually just be ST4 guide cables that I had lying about.  I put some heatshrink over the four wires for each motor, too, just to keep them together.  It's not pretty, but it does the job.

James

[fozzybear]

@lenscap quoted "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."

so that would inturn equate to jumpers "on" 1/32microsteps M0 and M2 then if 1/64microsteps then M1,M2 for X/Y drivers does that make sence ?

[Gmx76]

8 hours ago, fozzybear said:

this is the shield i have and you need jumpers to determine the microstepping size on both axis 

CNC Shield V3 Bundle_EN.pdf 1.41 MB · 2 downloads

Just had a read of this, that's a really well laid out guide and should make things easier. thanks for sharing that

[lenscap]

13 hours ago, Gmx76 said:

My Nema 17 motors have come with fairly short (30cm) cables with no connectors, just bare cables. Is this enough length, and do i need to buy a couple of Dupont 4 pin connectors?

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.

 

10 hours ago, Gmx76 said:

I just literally cut it off? Don't need to do anything else? 

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.

 

9 hours ago, Gmx76 said:

you will need some jumpers (2pin) connectors for the microstepping if not already have them they go underneath the the stepper drivers on the cnc3 driverboard.

sorry can you be totally explicit, what do I need (can you send a link) Thanks @fozzybear

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

 

[Gmx76]

great thanks @lenscap

[fozzybear]

hope the above info in the thread helps you in your step forward.... Baffled me to start with

Edited August 18, 2021 by fozzybear
spelling

[Gmx76]

Got some jumpers and cables on order, but in meantime trying the firmware load. Do these look like correct settings?

[lenscap]

8 minutes ago, Gmx76 said:

Do these look like correct settings?

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.

[Gmx76]

I'm following your recommendation on an earlier reply:

"Pulleys;  16 tooth & 48 tooth GT2 pulleys will give you a 3:1 ratio. "

So I should put 3 for both GR1 values?

[lenscap]

39 minutes ago, Gmx76 said:

So I should put 3 for both GR1 values?

Yes.

[Gmx76]

Back to it ...

 

Have some progress but when I flash the device i get this

Hard resetting via RTS pin...

 

If I use :GVP# in Serial Monitor i get #On-Step returned, and can even connect to it via cable and get a response using Sky Planetarium and ASCOM driver.

But if I power down and power back on, there is no communication as if its not saved to EEPROM.

Any ideas @lenscap or anyone else?

Thanks

 

 

[lenscap]

Welcome back.

I suggest you post this query on the Onstep forum. https://onstep.groups.io/g/main/topics

One of the developers will usually respond in about 24 hours. Summarise your build hardware & specify exactly which ESP32 board & version number you are selecting in the Arduino board manager.