CNC 1 - G540

The motor controller

This past Friday my Gecko G540 finally came in. It took a few years before I bought one. There are many reasons as to why but I'll stick to the subject. Basically I want to eventually convert my harborfreight mini mill to cnc. I've had this mill for a while now, but my intentions was always to convert it to cnc. I want to document this process as much as possible as it's not something you do overnight. This is also my first cnc item so I have a long way to go, but I just want to make sure that others have a good idea as to what this is and does in case they are interested in cnc machining as well.  I'm just a novice so I still have a lot to learn myself, but I like to document things in an easy to follow manner so others can understand. So I hope this will be of some interest or just a nice read for anyone. I will be adding items and or pages as they come up. I'll try to keep them in an order that will be easy to follow. This is just the start of my cnc project.
June 15, 2012

The parts:
Mini Mill Item # 44991 found on this page (This one is from harborfreight, but a few others are available) - http://www.harborfreight.com/catalogsearch/result?q=mill

Gecko G540 (There are many re-sellers out there, the current version as of this writing is 8) - http://www.geckodrive.com/geckodrive-step-motor-drives/g540.html

Manual - http://www.geckodrive.com/images/cms_files/images/G540%20REV8%20Manual.pdf


This is the motor controller that I will be using. This is what you get.

The connectors.


The bottom.

These are the included DB9 plugs and casings. I got 4 of each. It looks like these are what plug into the G540 as I just tested them on there as I write this. So basically it looks like these get soldered to one end of the cable, and the other end goes to the motor themselves. It wasn't that obvious to me so I just wanted to make it clear. I'm just going do the parts count for now.

To open the case, put a small flat screw driver from the side of the tab and push up. I found this to be the best way to do this. Do this on the opposite side and pull the middle cover out as you do this. This is one of the toughest cases I have had to open. It's hard as heck so I ended up bending the tab a bit and it shows unfortunately. Before I did it this way of course. The reason I guess was designed this way, or at least one of the reasons is that the case is used as a heat sink. I think a screw on case may work too and keep you from making your brand new G540 look old after you open it. The reason I opened it was to find out what version it was and also to see if the trim pot on the edge could be moved to match the hole. It's off on mine and well, it turns out the holes on the cover may be a bit off, but the last one was really off on my G540. I'm not sure how much I will need to trim, but that would make it very hard to do. A couple of the other trims are a bit off, but I think I can get to them at least. Unfortunately the case gets chipped easily when taking it apart. The good thing is you only need to do this on one end.

Here's the inside of the G540. I don't know why the seller Wrote E2 on it.

These are the individual geckos on the bottom. One for each axis. I like how nice and small this is.


A closer look.



The other side of the DB9 board connections.



The geckos are held by two 2mm hex screws. I'm glad I opened it up because I found my screws were pretty lose on all four. So I snug them down because the bottom of the case is what also acts as the heat sink.


Here's where the bottom of the case makes contact. This is very important.


As you can see the trim pot on the edge is right on, so it can't be moved. It looks like the case cover will have to be fixed if the board is left this way.

Here's a look inside the top cover.


Here's the only writing on this board. I'm still not sure where ver. 8 is written as it's just a bunch of numbers. I only know that the trim pots were moved to the top cover on version 8 so far. I guess this explains why they're a bit off.


Another close up of the board writing. I sure hope someone can help me decrypt the writing on this board.


Finally here you can see that the edge pot has been shaved on the side to make it fit. I guess it's more like force to make it fit. So far what I've found is minor and cosmetic. I have yet to test this as this is my first cnc part. I wanted to start with this to see where I want to go. What motors to get, etc. So far so good as I have found that you only need 4 wire motors to use with the gecko G540. By starting with the gecko I also know that I don't need the resistor if the motors are 3.5A I think it was. So it really depends on what motors you get.


The next step is the motor wires. It is recommended to use 22awg size wire. I went to frys and saw they had a 4 wire conductor that was 22awg and about 25ft.  Unfortunately at the moment I don't know how many wires I need to solder, so I ended up not buying anything until I can figure that out. I just wanted to get started on the soldering of the plugs which frankly I'm not to crazy about, but it is what it is. I don't mind. This is what a project is for, to learn how each part is put together. Until then I hope this is at least interesting to see.


CNC 2 - Motors
CNC 3 - Power Supply
CNC 4 - Wiring
CNC 5 - Software

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