[atwooddon]

My experience was the same as Randy's. Contacted CNCRouterParts and they shipped the adapters as soon as they became available. Great service.

The adapters certainly solved my 'hot' stepper motor concerns. Dropped the temp on all the steppers about 30 degrees. I could not keep my hand on the steppers before, now, can hold the steppers without pain. Hot, but not scorching.

Don

[kemper45]

Thanks guys. I am very close to getting on to the electronics part of the build. A bit more fiddling with the fit of the machine on the base before that happens.

Dave

[groswald]

The "fix" cables arrived from CNCRouterParts yesterday. I installed them, plugged everything in, and let it sit for about 3 hours. At then end of that time all three steppers were very warm, but not hot. Problem solved.

If you haven't decided on an electronics package you really might want to think about the G540 package from CNCRouterParts. It is more expensive (ok, a lot more expensive) than the Chinese options, but I doubt you will get this kind of service from China!

Regards,

Randy

[bjesson]

The "fix" cables arrived from CNCRouterParts yesterday. I installed them, plugged everything in, and let it sit for about 3 hours. At then end of that time all three steppers were very warm, but not hot. Problem solved.

If you haven't decided on an electronics package you really might want to think about the G540 package from CNCRouterParts. It is more expensive (ok, a lot more expensive) than the Chinese options, but I doubt you will get this kind of service from China!

Regards,

Randy

But we are not paying for that kind of service from China I spent $220 total on entire electronics package, what did you spend on Gecko?

But yes, I will be buying a Gecko setup mainly because my friends will think I am cool once I get one

billj

[groswald]

Bill,

More than $220.00. But then I always buy the best, like the router clamps I bought online.

Randy

[groswald]

I did my first aluminum cutting over the weekend. I cut a large lightening hole in some heavy-duty landing gear. I did not push the cut. Parameters were

1. Depth of cut: 0.015"
2. Speed: 6 inches per minute
3. Cutter: 1/8" 2 flute
4. Total time to cut: 22 minutes

The cut was clean although I did find I need to surface my spoil board. I also have to get the lid done. I had tiny little aluminum chips everywhere. Everything, including me, looked like it had been through an explosion in a glitter factory.

I'm sure I can push aluminum cuts a lot harder, but wanted to start slow.

[groswald]

Dave had a question about how I did my home and limit switches, so here goes.

There are only 5 inputs available on a parallel cable. One is taken up by the E-Stop leaving four. I want to leave one available for a Z-height setter, so that leaves 3.

I decided to wire separate X and Y axis home switches and have all the remainder be limit switches. So here is what I started with. Note that I have designated my X and Y axes differently than the plans. X is left and right as you face the front opening of the machine. Y is forward and back.

• Input 1, X Axis Home, X- limit: carriage far left as you face the machine
• Input 2, Y Axis Home, Y- limit: gantry all the way forward (close to you) as you face the machine
• Input 3, X+, Y+, Z-, Z+ limits
• Input 4, future Z height

• Photo 1 shows how things look inside the electronics bay. I ran 4 wires from the input sockets on the G540 to 4 open lugs on the terminal block I installed earlier to use as a ground bus. This let me play with everything after I mounted the G540 in its final location.
  
  I also added a 4-position "European style terminal strip" I got from Radio Shack. It started life as a 12 position, but I whacked it apart so I could use 8 pins on the gantry.
  
  I ran a "home run" from each of the 4 limit switches back to this terminal strip and then used it to wire each of them in series. If you look really closely you will see they are all daisy-chained together. You could run one continuous wire to each of the switches used as limits just as easily. This lets me change my mind later without having to re-wire.
  
  
• Photo 2 is a lovely shot of the Y axis home switch. I have all of my switches triggered by some part of a truck bashing into the switch lever. All are wired normally closed (NC). I have read some stuff that suggests wiring limits normally open (NO), but that makes no sense to me. If some mechanical problem were to occur and destroy the switch the machine would continue to run amok. This way the machine should stop in nearly all cases.
  
  If you can explain why they should be NO, please do!
  
  
• Photo 3 is the X+ limit switch. On a side note, these were all taken with my brandy-new Nikon P7000 compact camera. Not quite the same image quality as the tripod mounted DSLR with a 60mm macro attached, but not bad. The P7000 was a father's day gift from my (much) better half.
  
  
• Photo 4: Y+ limit
  
  
• Photo 5: X- home
  
  
• Photo 6: This started out as the 12 position terminal block. It lets me disconnect everything from the gantry in case I need to remove it. (I had to after trying to adjust the carriage and blowing it).
  
  Note that the four terminals in the middle are for the future Z axis limits, They are jumpered for the time being. I'm not sure how useful Z axis limit switches are, and they look to be a bear to mount, so I haven't done it yet.

Regards,

Randy

[kemper45]

Thanks Randy for another very thorough and detailed answer to a question. It will take me a few reads to digest it and apply it to suit my needs but for now the idea of using the terminal block to connect to the 4 inputs keeps me moving to the finish line.

Dave

[momus_cnc]

I did my first aluminum cutting over the weekend. I cut a large lightening hole in some heavy-duty landing gear.

Randy, nice looking part. What are you using for CAM software? If it will do partial thickness tabs, it will make it easier to remove the center slug. It will also leave a shoulder that will act as a guideline to make final cleanup with a file a bit easier.

-Bob

[groswald]

Bob,

Thanks. The cut-out eliminated more than 2 oz. of useless weight. I'm going to make a couple smaller pockets in each of the legs as well.

I'm using CamBam, just forgot I didn't need the default monster tabs in aluminum. I've just started setting up some styles so I don't have to remember in the future.



Randy

[kemper45]

OK I think I have it figured out but want to run it by you first.

I have 9 NC/NO switches and I plan to use 6 of them - 2 on each axis. One switch will look after X home and X-- and the other will look after X++ (similar for Y and Z axis).

My understanding is that a NC switch will allow current to flow until it gets "hit" which closes the switch and stops the current. Likewise an NO switch allows current to flow as long as it is closed by something resting against the switch. Once the switch is opened by the something moving away from the switch current stops flowing.

Assuming I have that correct, I would then connect the NC terminal of a switch to V- and the common terminal to the input pin on the G540 (Input 1 for X, Input 2 for Y axis, Input 3 for Z axis). I then enable X -- and X home in Mach3 and configure both to Port 1, Pin 1 ; Y-- and Y home configured to Port 1, Pin 2 ; Z-- and Z home configured to Port 1, Pin 3.

Similarly I will have a second set of 3 switches mounted to the otherside of each axis, NC terminals connected to V-, common terminals connected to input pins 1, 2, 3, X++ enabled and configured to Port 1, Pin 1 ; Y++ to Port 1, Pin 2 ; Z++ to Port 1, Pin 3.

All connections to V- will go through the terminal strip ; 1 lug for each of the 3 axes. Similarly I will run all connections to the input pins through 4 lugs connected to the G540. For now I will only use inputs 1, 2 and 3 and 4 will remain available for future.

How does all that sound - am I close?

Thanks, Dave

[groswald]

Dave,

Correct for the (X-,X home) and (Y-, Y home). I have mine wired with C to Common (ground) and NC to the input pins on the G540, but that makes no difference.

I'm not sure I follow on the rest though. What you describe would be two switches, in parallel, on one port. That won't work with them wired Normally Closed. They need to be in series, otherwise the circuit won't open unless both switches are tripped.

I have all my non-homing limits connected in series on pin 3 on the Gecko; series wiring from X+, Y+, Z-, to Z+ and ending at the ground bus. I attached a schematic that should help. I left off the second terminal strip. It isn't needed and just complicates things.

[kemper45]

Randy,

Thanks for putting the schematic together, it will go a long way to me getting this right. The G540 manual shows C terminals going to the inputs and the NC terminals going to ground. You say it doesn't matter so I guess I can't screw that part up.

I was pretty sure I had read somwhere that connecting limits in series could be done and your schematic (which is now printed and will be included in my build binder) shows that to be the case.

What I am having trouble understanding (at least more trouble than most of the stuff) is how the X-, Xhome switches work. If this switch is "hit", current stops and things stop moving. I see why we want that when the switch is acting as the -ve limit. However, would this also happen when the machine is moving to its home position? If so how do we reset things so the machine can move off its home position and start to do its thing? Is that what the reset button in Mach3 is for?

Thanks for taking the time to help me along, I really struggle with the "electronics" of this type.

Dave

[bjesson]

Randy,

Thanks for putting the schematic together, it will go a long way to me getting this right. The G540 manual shows C terminals going to the inputs and the NC terminals going to ground. You say it doesn't matter so I guess I can't screw that part up.

I was pretty sure I had read somwhere that connecting limits in series could be done and your schematic (which is now printed and will be included in my build binder) shows that to be the case.

What I am having trouble understanding (at least more trouble than most of the stuff) is how the X-, Xhome switches work. If this switch is "hit", current stops and things stop moving. I see why we want that when the switch is acting as the -ve limit. However, would this also happen when the machine is moving to its home position? If so how do we reset things so the machine can move off its home position and start to do its thing? Is that what the reset button in Mach3 is for?

Thanks for taking the time to help me along, I really struggle with the "electronics" of this type.

Dave

Dave,

For my system, when I had home and limits on same switch, when i homed all axis' the switches would no longer act as limits but only home switches. They wouldnt trigger the system to stop when pressed so homing worked fine. Once homing was done the returned to limit switches again in Mach3. All the things you are worried about in this post are software configurable. Later, I put seperate limits behind each home so if the gantry traveled further then the home position it would trip the limit shortly after.

Billj

[groswald]

Dave,

Good questions. The answers are not obvious, and I struggled with them as well. The answers lie in the relationship between the G540 and the machine controller software. I'll assume that you are using Mach3 as your controller software?

It took me a while to realize that the G540 doesn't "do" anything. Well, almost nothing. From a logic perspective it simply takes commands from Mach3, translates them into an electrical format the motors can use, and sends them - along with operating voltage - to the motors. That is the sum total of its "output" capability.

On the "input" side, the G540 passes the state of inputs 1-4 to Mach3. That's it. It doesn't interpret them or do anything about them. It just passes "on" or "off" back to Mach3. This is slightly different for E-Stop as the G540 will not operate without current flowing between pin 10 and ground, but that's a different issue.

"Home" switches are only used during a homing operation. Let's say you have an X and Y home switch like I do. When I tell Mach3 to "Set All Home" it slowly drives the Y axis in the direction I set up when I set the switch. When Mach3 sees the Y home switch open it knows it has gone too far. It then drives the Y axis the other direction, even slower, until is sees the switch just go closed again. It defines that as "Y Home". It then repeats the process on the X axis.

When a limit switch is hit, the G540 dutifully passes the fact to Mach 3. If Mach3 is set up correctly it stops all motion (by stopping sending commands to the G540), and it flashes the "RESET" button and a message saying that a limit has been hit. If Mach3 is not set up correctly it will happily continue to drive the Gecko and do unpleasant things like smash limit switches. I lost two before I got it right.

One switch can perform both functions because Mach3 knows what it is doing at any point in time. If it is doing a "Home" operation then any change in the switch status is interpreted as being in the home position. If Mach3 is not doing a "home" operation then any activation of the switch is interpreted as having tripped a limit switch and everything stops.

Hope this helps!

Randy

[kemper45]

Thanks guys. I hope to spend some more time over the next few days connecting motors to the G540 and setting up Mach 3, then wiring limit/home switches. I should get an update done on my build thread also.

Randy, if you are not one already you should be a teacher. Your explanation of how the switches work got through to this slow learner at the back of the class. Well done

Dave

PS Didn't see a fan in your electronics - not necessary unless the bays are closed in?

[groswald]

Dave,

Thanks, I'm a software engineer by training and IT manager by chance, but I do a bit of teaching from time to time.

The PS has an internal fan. The G540 isn't supposed to need one below 70C or so, which is pretty hot. We'll see if I need one. I will be putting holes in the doors to encourage airflow.

As far as the electronics go, I'm starting to think that Michael's change is a great update to the design. He has duplicated the the bays on the right side. I want to add a superPID, and now I need room for it and for its 5 volt power supply. It would be great to have the power supplies with their AC feeds on one side with DC feeds through the base to the G540 and superPID on the other.

I'm now thinking I will replace the plastic doors with acrylic cases to hold everything!

Randy

[groswald]

I did some work on the Momus over the last couple of days preparing to add the lid and the side doors. Mostly to do with cleaning up the wiring.

1. Photo 1: Added a panel to clean up the ugly hole in the case side that I created to pass the CNCRouterParts cables through. I ended up cutting the molded plugs off anyway (more on that in a minute), so I was able to create a nice clean panel. The third hole is for the limit wires, and the bottom one is a mono audio jack for a tool setting probe. (More on that too) The rubber grommets came from the hardware store. The jack and plug from Radio Shorts.
   
   
2. Photo 2&3: I used a drill-extension and 1" spade bit to create a path for the AC line cord through the base. I also added a remote DB25 connector. I didn't like the heavy parallel cable hanging directly off of the board-mount DB25 on the G540. I was afraid I would break it. This solves the problem nicely. Soldering the 50 wire connections was tedious though.
   
   
3. Photo 4: Final wire routing to the carriage. I replaced the solid CAT-5 limit switch wires with 20 gauge stranded.
   
   
4. Photo 5: I also re-did my limit strategy. I now have both limit switches for an axis wired in series. This works just fine and eliminates some wires that were needed for my original strategy. I still use one limit on each axis for the home switch. I added wires for a Z+/home switch, but have not mounted it yet. I don't think I will add a Z- limit.
   
   
5. Photo 6, 8 &9: Much gooder! You see the results of the cleanup. I ended up shortening the motor-control cables to de-clutter the bay. I added the necessary current-set resistors to the G540 end of the shortened cable.
   
   I now have a full set of the CNCRouterParts "fix" cables that I don't need. Free for the asking if you need them. Otherwise I will send them back to Ahren.
   
   
6. Photo 7: The AC line cord emerging from the base.
   
   
7. Photo 10-12: My tool setter. Nifty! My implementation of the design offered by "erniebro" elsewhere in the woodworking machines forum. Lets you set an edge for X and Y and your Z height. You do have to install the "Blue" screen set for Mach3 as well as an update, but all of that is described in the thread.
   
   
8. Photo 13 is Momus all ready for a top. I mounted some low-profile T-track on each side of the spoilboard to let me mount jigs and hold-downs. I added t-nuts to the front flange and a couple of threaded inserts at the back of the base to let me screw down the spoilboard. All of them are outside the physical range of the cutter.

Regards,

Randy

[antisubae]

Awesome work! I love the way you're handling the wiring. I had a similar idea about the remote DB25 receptacle, and now that I see it in action, I'm definitely going to incorporate it into my enclosure.

Since I haven't actually built my enclosure yet, it's going to be awfully easy to mod in some of these fantastic ideas folks have been coming up with. In general I'm sticking pretty close to the plans with all the metal bits (which I'm FINALLY nearing completion of!) but it's a lot easier to fiddle around with the wood parts. Perhaps someday in the not-too-distant future, I'll have some pics of my own to share.

[kemper45]

Randy,

Nice job cleaning up the wiring. I may attempt the AC cord through the base revision but will leave the rest alone for now - I'm not a good solderer (is that a word??). I see your e-stop switch is just hanging around like mine. I have just enough room below the power supply to fit it in whe I get the doors done.

Keep the tweaks coming as they make me think of ways to finish my build.

Thanks, Dave