Step direction signal converted to CW-,CW+, CCW-, CCW+

[ok engineering]

Ok, so I'm rebuilding my 3d printer and I've come across a compatability issue. My controller has step/dir output pins. The drives have the CW-,CW+, CCW-, CCW+ inputs.

I haven't been able to get this to work correctly.

First I tried,
cw- and ccw- together going to ground
cw+ to step signal
ccw+ to direction signal

On controller connector I have

Pin1 = step

Pin3 = direction

Pin2 and pin4 ground to pin 18

Like this the motor runs quickly one direction but very slowly the other direction.

It also travels less in the slow direction.


I undid all that.

Then I,

Set Parameter 4 to 1

I have a DC DC converter going from 24vdc to 5vdc. The positive side of 5vdc output runs to CW+ and CCW+ (pins 1 & 3)

The step signal is run to CW- (pin 2)

The direction signal is run to CCW- (pin 4)

The motor runs one direction until it crashes. No matter how far I tell it to go. Nothing happens in the other direction.

So I'm at a loss. Pleeeeease help.

If I'm understanding it correctly some people have used some sort of logic gate based circuit. Unfortunately for now, that's just over my head.

The board is a azteeg x5 gt
The drives are stonker (China)

Basic component files are attached.

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[john-100]

this old thread may help :-

http://www.cnczone.com/forums/mach-4...ml#post1931922

from the post







It will be easier to find the later 74HCT00 than the original 7400 that dates from the 1960's

just make sure you get the 14- PDIP version
(= plastic 14 pin package with pins that fit the 0.1" grid found on vero / perf board
its easier to start with than the 14-TSSOP used on surface mount PCB's )


https://www.digikey.co.uk/product-de...081-5-ND/38232

john

[ok engineering]

Hey John,

Thanks for the info. I want to make sure I'm understanding correctly. My drive had 4 inputs. The 7400 diagram is showing only two out puts?

[john-100]

you have 2 opto-isolated inputs : - step clock wise and step anti- clock wise

connect the plus CW & CCW to +5V

the negative CW to pin 11 of the 7400
and the negative CCW to pin 6



John

[ok engineering]

Thank you sir, I'll give that a go and post my results.

[john-100]

thats OK

If it helps you to visualise how it works



what type of prototype board do you intend to use ??

this is one version available



John

[ok engineering]

Thanks again John. I got some little boards but it looks like the one u posted would have been easier.

[ok engineering]

Ok so is there any reason why the nte7426 ic would not work? I attached the info.
I also attached a sketch of how I wired it. It is mirrored to make it easier on me.

With it done this way the motor constantly rotates clockwise. If I jog + it continues to rotate. If I jog - it still rotates clockwise but slower. Any ideas?

[john-100]

I would of thought it would work with a 7426
the only difference is the 7426 has open collector outputs that can only sink current to ground

what happens with no connection to the servo driver inputs ?

what happens with 5V connected to just the CW input
then with 5V connected to just the CCW input

it should only move with step pulses to one input




John

[ok engineering]

Not sure if this matters but I'm using a dc-dc converter to go from 24vdc to 5vdc and then pulling ground and +5vdc from there. Also motor is spinning on its own on system power up before the controller board is connected.

If I remove the connection from from the drive nothing happens connected or not connected to controller.

With +5vdc connected to CW+ and not connected to CCW+ nothing happens and same for vice versa.

[john-100]

if this is how you have wired the control



then the only thing I can think of is the DC / DC converter may be the problem
if it can not supply enough current to every thing

John

[ok engineering]

Would you mind posting a link for the 100uf and .1uf so I can make sure I am getting the correct components?

[ok engineering]

Hey John, nevermind linking parts for me. I believe I've got it now. Thanks to you my new best friend. Lol.

[john-100]

only just read your post ,
its taken a while to un-install the last windows up date and then have a go re-installing them
you know how it goes when it installs too many at once


the capacitors don't need to be exactly the values in the diagram

the electrolytic can be 100uF to 470 uF , 10V to 25 V what is easiest to find
the usual practice is to connect a 0.1 uF 50V ceramin capacitor across the 5V supply to every 1 or 2 TTL IC's
placing the capacitor close as practical to the supply pins


seeing your location

I guess you have looked at local suppliers
like Mouser Electronics Mouser Electronics - Electronic Components Distributor
or Allied electronics inc Allied Electronics - Industrial Automation & Control Products Distributor (RS Components in USA )


I usually start with Farnell or RS Components in the UK

John

[ok engineering]

Actually I have a Fry's electronics store down the street. I lucked out with them actually having something I need finally.