[wmgeorge]

I just got my DeskCNC card and 3 G202 Gecko's hooked up and working to some old Eastern Air Devices steppers on my Mill-Drill. No smoke and it worked the first time! In fact it works great!!!

Minor Issues:
#1 I know the written instructions make it pretty plain for terminal #10 Common, meaning 5 VDC +, but I was just looking at the drive and it just says "Common", which from my background can mean the common or some cases grounded side of an AC transformer. In fact I already had the black wires or negative side of the 5 VDC control source hooked up!!
A simple + Common marking on the drive would work for me. For those of you wiring right now, the #10 terminal is + 5VDC from your signal generator, the Step and Direction connections are really the - side of this signal voltage source.

#2. I know it says Microstepping drive, but gee I find out what that really means is you need 10X the steps you might think. It is a 1/10 step motor drive which means if you have 200 step motors, and belt drive reduction, and 10 tpi screws.... well it all worked out. Had the old thinking cap on for a few minutes.

Happy camper in Iowa.

[ynneb]

#2. I know it says Microstepping drive, but gee I find out what that really means is you need 10X the steps you might think. It is a 1/10 step motor drive which means if you have 200 step motors, and belt drive reduction, and 10 tpi screws.... well it all worked out. Had the old thinking cap on for a few minutes.

From my understanding an existing 200 step motor per revolution would become 2000 steps per revolution. Are you agreeing with this or dissagreeing, I can quite understand what you are saying ?
You will not need to change your belt reductions, just the settings in your controlling software. The end result is just a higher resolution. (Thats a good thing)

[widgitmaster]

My intention is to build a one stop file that includes everything from wiring the printer ports, building a power supply, wiring the drives, etc.

What else should I include in this drawing?

First comment: Nearly every site on the web calls the motor windings A+, A-, B+,B- You should include that to reduce confusion.

Second Comment: My power supply has a huge capacitor, a diode bridge, and a large hollow resistor across the top of the capacitor. Is is optional and why?


Eric

[widgitmaster]

I found another schematic on this site too
http://www.rogersmachine.net/CNCwiring.html

Wow, I really like the MPG that Rogers Machine has to offer!

Eric

[wmgeorge]

Yes agree. I have a 10 TPI leadscrew and belt reduction 2:1 so I ended up with 40,000 SPI (steps per inch) setting in my software. Once you've done this it is not a problem and understand that Micro stepper means 1/10 step, which I don't ever recall seeing, but I'm sure its there!

From my understanding an existing 200 step motor per revolution would become 2000 steps per revolution. Are you agreeing with this or dissagreeing, I can quite understand what you are saying ?
You will not need to change your belt reductions, just the settings in your controlling software. The end result is just a higher resolution. (Thats a good thing)

[ynneb]

First comment: Nearly every site on the web calls the motor windings A+, A-, B+,B- You should include that to reduce confusion.

This is only a drawing of the power supply. There is no reference to steppers or drivers, I am not sure what you mean ?

Second Comment: My power supply has a huge capacitor, a diode bridge, and a large hollow resistor across the top of the capacitor. Is is optional and why?

The resistor that you are refering to is not shown in my drawing, is called a bleed resistor. Its function is to discharge the capacitor when the power supply is turned off. If your power supply is turned off, the capacitor can still hold current and can cause a problem when wireing to the drives. Similar to hot swapping wires. You can make your power supply swich trun on/off both the AC and DC sides at the same time, instead of using a resistor. I guess as good practice it is better to have the resistor, but it is not essentail in the running of the power supply.

[garagefela]

In reponse to the bleed resistor, I had asked a question about this a while ago and got some good replies.
In short it can either be wired directly onto the capacitors so it is online whenever the power supply is on and bleeding down when power supply is off OR wired to the off position of the power switch, the resistor wont actually be online when power supply is on but will bleed down when the switch is thrown to the off position.

I suppose the danger doing it the switch way is that you can pull the power lead to the power supply without flicking the switch to the off position and still have the capacitors left in a charged state. ZAP ZAP.

Cheers all M

[futura]

Hello, I'm new to this site so this is my first post.

I've been researching this topic of late and looking for an easy to implement solution for installing a 4 axis type system on a custom multipurpose milling system (10' bed) that I'm designing. I'm a fabricator with limited electronics experience, but consider myself a relatively quick learner with good technical/computer application skills. I haven't come across a Gecko turnkey solution so I'm trying create it myself as it seems some of you seem to have doing.

Gecko seems to provide a nice product and I'm thinking of using G202 or G212 motors and G101G-rex (with RabbitIndustries RCM-3600) however choosing and installing the other required components without error is a bit complex and hope I can get this together without having to reinvent the wheel (frying components). I would initially be running Mach2/3 software via laptop USB if possible.

It would be ideal if I could get a shopping list, (products with model #'s) for all the other parts needed (power supplies, connectors, enclosure etc.) and step by step directions for laying out the controller box including installation, configuring and bench testing this type of system. Can anyone provide access to information derived from a successfull implementation of a similar existing system? Photos, drawings, list of parts, anything you can share is greatly appreciated. Thanks!

[CJL5585]

futura:
Hello, I'm new to this site so this is my first post.

It would be ideal if I could get a shopping list, (products with model #'s) for all the other parts needed (power supplies, connectors, enclosure etc.) and step by step directions for laying out the controller box including installation, configuring and bench testing this type of system. Can anyone provide access to information derived from a successfull implementation of a similar existing system? Photos, drawings, list of parts, anything you can share is greatly appreciated. Thanks!

--------------------------------------------------------------
Welcome to the site.

I do not believe that there is a thread on this site that addresses all your shopping list, but I could be wrong.

Is this a commercial venture, or a personal project? The reason that I ask is because designer liability comes into play on a commercial job.

There are several threads that address using Gecko drives such as this one. There are others that address power supplies, limit switches, home switches, and so forth.

Again, Welcome
Jerry

[futura]

Thanks for the quick reply. I'm building it for my personal use and completely understand the issues regarding liability.

I assume that people are successfully using a number of different combinations of components and thought they may like to share their experiences and component combination. I'm smart enough not to try and re-invent the wheel but sometimes not smart enough to stop trying


Thanks for the welcome Jerry, it's quite the site!

Larry

[ger21]

Hello, I'm new to this site so this is my first post.

I've been researching this topic of late and looking for an easy to implement solution for installing a 4 axis type system on a custom multipurpose milling system (10' bed) that I'm designing. I'm a fabricator with limited electronics experience, but consider myself a relatively quick learner with good technical/computer application skills. I haven't come across a Gecko turnkey solution so I'm trying create it myself as it seems some of you seem to have doing.

Gecko seems to provide a nice product and I'm thinking of using G202 or G212 motors and G101G-rex (with RabbitIndustries RCM-3600) however choosing and installing the other required components without error is a bit complex and hope I can get this together without having to reinvent the wheel (frying components). I would initially be running Mach2/3 software via laptop USB if possible.

It would be ideal if I could get a shopping list, (products with model #'s) for all the other parts needed (power supplies, connectors, enclosure etc.) and step by step directions for laying out the controller box including installation, configuring and bench testing this type of system. Can anyone provide access to information derived from a successfull implementation of a similar existing system? Photos, drawings, list of parts, anything you can share is greatly appreciated. Thanks!

You might want to read this from the Gecko website. http://www.geckodrive.com/photos/Step_motor_basics.pdf

You can purchase a complet Gecko controller kit here. http://www.seanet.com/~dmauch/Products2.htm


Mach2/3 don't work with USB. Parallel port only. The Grex running under Mach4 will use ethernet, not USB.

[mikie]

Hi guys,

I had a rewquirement to draw up a G201 wiring schematic yesterday and through some conversations with people have decided it would be advantagous to post this schematic on this thread for other to reference.

Before we proceed, please be aware this is used in my setup and i WILL not be responsible if it fries your circuit. Please use this diagram as a reference and if you do notice something which is incorrect, please advise me and i will look into it.

Issues:

I have drawn the limit switches as active "low", which sucks. There is a diagram somewhere in the zone which shows how to use transitors for wiring the limit switches. This will allow you to cater for breaks in wiring, as such, if the wiring breaks, the input to pin 7 on the Gecko is forced low and the machine halts in this axis. This is a recommedation of the zone for limit switch wiring.

I have inserted resistor value which correspond to the size of my motors. Please refer to the manual or top cover for your appropriate resistor value.

I have also only used 1 limit switch on my Z-axis. You may wish to use two, but i wouldn't know why.

Cheers
Michael

[tag1987]

You might want to check with Gecko...I believe Mariss discourages people from using the Disable pin on his stepper drives. Last time I checked he suggest removing the 5volts to stop the drive.

[futura]

You might want to read this from the Gecko website. http://www.geckodrive.com/photos/Step_motor_basics.pdf

You can purchase a complet Gecko controller kit here. http://www.seanet.com/~dmauch/Products2.htm


Mach2/3 don't work with USB. Parallel port only. The Grex running under Mach4 will use ethernet, not USB.

Thanks Gerry for the information. I had started reading through the first link earlier, and the second link looks like the ticket. Great site!

[CJL5585]

Hi guys,

I had a rewquirement to draw up a G201 wiring schematic yesterday and through some conversations with people have decided it would be advantagous to post this schematic on this thread for other to reference.

Before we proceed, please be aware this is used in my setup and i WILL not be responsible if it fries your circuit. Please use this diagram as a reference and if you do notice something which is incorrect, please advise me and i will look into it.

Issues:

I have drawn the limit switches as active "low", which sucks. There is a diagram somewhere in the zone which shows how to use transitors for wiring the limit switches. This will allow you to cater for breaks in wiring, as such, if the wiring breaks, the input to pin 7 on the Gecko is forced low and the machine halts in this axis. This is a recommedation of the zone for limit switch wiring.

I have inserted resistor value which correspond to the size of my motors. Please refer to the manual or top cover for your appropriate resistor value.

I have also only used 1 limit switch on my Z-axis. You may wish to use two, but i wouldn't know why.

Cheers
Michael

Would like to recommend some changes to the schematic.

1. The 48 VDC power supply leads are shown daisy changed from one drive to another. The recommended method is a seperate +V AND -V wire from the supply to each of the drives with the +V line being fused. This is per the Gecko manuals.

2. The -5 VDC line does not connect to the -48 Volt power supply. The -5 VDC goes to pins 18 thru 25 on the breakout board. This references the +5 VDC on the Gecko drive to the TTL logic voltage furnished from the computer power supply through the parallel port. Connecting the commons togather as per the schematic can cause ground loops and transfer voltage spikes thru the breakout board into the computer via the parallel port and can smoke the parallel port electronics. Without the -5 VDC connection to pins 18 thru 25, there is an incomplete (Open) circuit and the drives will NOT output any voltage to the stepping motors. Therefore, there is not any movement in any axis via the jog function, or a g-code program.

3. The disable function as shown wired through a limit switch could cause one to loose part of their anatomy due to the fact that if the machine stops and one attempts to physically troubleshoot or clear the limit (without disabling the voltage to the drives), as soon as the limit is cleared, the machine is going to start moving at whatever the feedrate is at that point in time.

4. You might want to do more research on limit switches. Since the limit switch function uses a normally closed switch (per safety regulations in the USA) and the limit functions on most hobby CNC systems are interfaced thru the breakout board and parallel port, some systems use 5 Volts and others may use 12 or 24 Volts.

Jerry

[mikie]

Hey Jerry,

1. Yes I will change the way this is drawn. have my drives wired in the manner you suggest, i just didn't reflect this in the diag.

2. I don't use a break out board. So i will not reflect this. My diagram does not have the +5Vdc connected to the 48Vdc supply, but the +5Vdc supply via the blue line.

3. I agree, but something is better than nothing and for those starting out it is better than waiting and getting a circuit rigged up with transistors to pull the pin the other way. I have a caveats around this and is also suggested in my " issues" section.

4. Once again, i don't use a breakout board and as such will not reflect your point in my diag.

I have attcahed the ammended version.

/Mikie

[mikie]

Guys,

Can some one tell me if i should have the parrallel port "ground" pin also grounded to the common ground if i am not sourcing the +5Vdc from my PC?

I would assume this is required, or atleast best practice

/Mikie

[mikie]

Jerry,

To confirm on you point 2.
Quote"The -5 VDC goes to pins 18 thru 25 on the breakout board"

This is the same as per the DB25 pin out I assume/read, then you are saying to Ground the +5Vdc input.

My original machine used the USB port for power, I had the grounds all tied in together, it did work until the other night until it fried the gecko and PC.

I just did not see any other way of being able to provide +5Vdc to Pin 10 on the Gecko. I mean this is what the top cover asks for and what the manual asks for.

Extract from G201_REV5-Manual "(TERM. 10) +5VDC Connect this terminal to the controller +5VDC power supply"

I mean, all of this is still unclear to me and I suspect this common grounding did fry my machine.

Can you please explain this setup to me further, so that i can get a better picture of what is happening on Pin 10.

Also,

Can i assume that the Gecko is deriving power to the electrics via the power in Pin 1 & 2, and that Pin 10 is purely for the TTL circuitry to function properly?

Thanks in advance
Michael

[mikie]

Okay,

Further to all of this,
I knew I had asked this question to Mariss at some stage, and I found my email to him in an archived folder.

My question and Mariss's answer

-------------------
Subject: Question


The “Step” and “Direction” inputs are designed to interface with current-sink drivers such as

standard TTL logic or open-collector transistors, which sink to ground. As a result the isolator

common (+ 5VDC) must be returned to the controller +5 VDC supply to complete the circuit.

Hi,

From the above extract, could you please confirm a couple of things for me.

I have hooked up my Y-Axis to a Gecko tonight and found that I have no motion.

Upon reading more of the manual you sent, the above extract confused me a bit.

Is the controller the computer? If not, what is it and how should I hook it up to make the Gecko function correctly.

Could i assume as this isn't hooked up that my problem lies with this?

Answer from Mariss

If you are using a PC then it is the 'controller' . Connect COMMON (terminal 10) to your PC 5VDC supply. The game port pin 1 is a place where you can find 5V.


So i am going to hook pin 1 to all of my gecko pin 10. I will ammend my diagram to suit.

/Michael

[CJL5585]

Jerry,

To confirm on you point 2.
Quote"The -5 VDC goes to pins 18 thru 25 on the breakout board"

This is the same as per the DB25 pin out I assume/read, then you are saying to Ground the +5Vdc input.

My original machine used the USB port for power, I had the grounds all tied in together, it did work until the other night until it fried the gecko and PC.

I just did not see any other way of being able to provide +5Vdc to Pin 10 on the Gecko. I mean this is what the top cover asks for and what the manual asks for.

Extract from G201_REV5-Manual "(TERM. 10) +5VDC Connect this terminal to the controller +5VDC power supply"

I mean, all of this is still unclear to me and I suspect this common grounding did fry my machine.

Can you please explain this setup to me further, so that i can get a better picture of what is happening on Pin 10.

Also,

Can i assume that the Gecko is deriving power to the electrics via the power in Pin 1 & 2, and that Pin 10 is purely for the TTL circuitry to function properly?

Thanks in advance
Michael

First, a breakout board would have the same pinout as the Parallel printer port DB-25 connector.

Terminal #10 on the Gecko drive requires +5 Volts DC. This is normally an external 5 VDC logic supply due to the fact that a lot of computers and most laptops cannot supply (source) the current levels required by ANY external driver on a consistant basis.

You are correct that the driver voltage for the steppers are Terminals 1 and 2.

Last night I drew a wiring diagram on the Gecko drives and uploaded it to the site. It will show you exactly how everything wires up.

Your assumption that pins 18 thru 25 are the same as the DB-25 are correct. This is where the common (-) wire of the 5 Volt supply goes.

To simplify, it works like this:
The +5 Volts goes to the Gecko terminal 10 (designated common for some odd reason - very mis-leading to me). This voltage supplies the voltage for the optoisolators for the step and direction inputs. So when the step output from the computer is low, it sinks (draws) current thru the optocoupler from the voltage source attached to Terminal 10 on the Gecko drive. For this reason, the external supply (5V) common side (the - wire) must go to the common or ground side of the parallel port. These commons are the pins 18 thru 25 on the printer port.

Look at my new post called "My wiring diagram for Gecko drives 201, 210, ...) and you can see the various wiring. Then if you have more questions, then I will answer them.

Jerry