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-   -   3D Elk cutting (video) #13 - Hagerman, New Mexico (http://www.mechmate.com/forums/showthread.php?t=381)

Greg J Sun 17 June 2007 10:07

3D Elk cutting (video) #13 - Hagerman, New Mexico
 
1 Attachment(s)
Gerald and Mike,

This is a first stab at my electrical circuit (and downloading a file). I did not connect the on lamp because was not sure. In Geralds 230V/115V split-phase drawing, it didn't make sense. Just need more time to study.

I do have the PMDX-122 with the Gecko Drives drawing almost done.

Can you guys shoot holes in the design. One reason I like to draw my own schematic is it makes me understand every component. The negitive is drawing mistakes.

My attachment may be to grainy (BMP File). Boss is screaming to get some painting done. I'll try again tonight
Greg


Gerald D Sun 17 June 2007 10:18

On bottom feeding, thanks for finding that discussion, and let's just avoid it altogether. (I plan to make more graphical drawings of the components on the DIN rail and you have helped me tremendously with real industry feedback)

Switching of the neutral is something that Mike R also had big problems with, but he eventually relented when it was made clear that we only switch the neutral simultaneously with the Lives (Hots) on a single multipole switch or contactor. We never think of the Neutral as something that is connected to Ground (Earth). In fact, because we have lots of Ground Fault Protection, touching Neutral to Ground (Earth) causes a trip (fault). Look at all continental Europe 2-pin plugs for 230V - they can be inserted any way around.

Snag is, we sometimes find that an idiot swops Neutral & Hot (Live) in a distribution board upstream and we are never 100% sure which of the two wires is 230V above ground potential. Maybe something similar to the US 230V single-phase where BOTH wires are treated with equal respect.

Bottom line is that we prefer switching both wires, but only in a switch that forces them to be switched simultaneously. However, since I am going to end up producing circuits for the America's versus the non-America's, I can avoid neutral switching in the one case.

Gerald D Sun 17 June 2007 10:42

Greg, you slipped in while I posting the previous one.

Unfortunately, a couple of snags because you used a diagram that Mike since helped me to change my mind about. The best diagram to use right now is in this post. Just treat L1 and L2 as one and the same Line for 115V purposes.

The snags you have are:

- your E-stops are still in the Neutral line

- the fuse will serve little purpse there

The indicator lamp is the simplest of things to position - it sits over the coil to show if voltage is being applied to the coil.

In your power supply schematic:

- The input of your transformer shows an un-connected coil. That coil will be in parallel to the one above it for 115V, but watch the instructions from Antek VERY carefully. They should be pre-wiring it for you and just presenting 2 wires to connect to mains.

- You show the two output sections connected to each other with one vertical line. That is incorrect - the Anteks are supplied with the two sections isolated from each other. For the PMDX-122, you must maintain this isolation.

Greg J Sun 17 June 2007 11:22

Thank You Gerald,

I just bought a DWG to PDF converter, so the drawings should be of better quality. I'll make the changes and upload my revised drawing tonight.

Uh Oh, the boss is looking for me. Gotta run.

Greg

Gerald D Sun 17 June 2007 11:22

Mike N, the simultaneous disconnecting of all Lives(Hots) and Neutral is equivalent to pulling the plug - what could be safer than that? :)

Greg J Sun 17 June 2007 14:42

1 Attachment(s)
Here's my lastest control box schematic. It also shows (external to the box) E-Stops and router.

I'm new at this electronic design, so bear with me. Please poke holes in it and let me know what needs to be fixed.

Greg

Mike Nash Sun 17 June 2007 15:40

Quote:
Originally Posted by Gerald D View Post
Mike N, the simultaneous disconnecting of all Lives(Hots) and Neutral is equivalent to pulling the plug - what could be safer than that? :)
Well, yes and no. One of the issues with E-Stops in general is all of the new safety regulations that go with them. Depending on the assessed level of hazard to life and limb, it can get very pricey to properly construct an E-Stop circuit. This is true in the US as well as Europe. Worst case involves redundant contactors, safety relays (very pricey), and two pole force guided E-Stop pushbuttons.

The problem with breaking the neutral is that you don't know that it or the hot, really did break. Welded contacts are a fact of life. If you are holding a plug in your hand you can visually (or tactiley if you are vision impaired) tell that that all circuits are indeed disconnected.

Greg J Sun 17 June 2007 15:45

Is that the reasoning for putting the fuse "in front" of everything (as you and Gerald have done in the schematic). The fuse is suppose to open before something can "weld".

Greg

Marc Shlaes Sun 17 June 2007 15:59

Greg,

Would you please print that again in landscape mode???

Thanks.

Greg J Sun 17 June 2007 16:44

1 Attachment(s)
Marc,

Is that better? I'm using AutoCAD 2000 and that version doen't export PDF. I bought a DWG to PDF converter earlier today and its doing the job, but still some kinks (had to rotate in AutoCAD and save as a new dwg, then convert). If anyone has suggestions, please respond.

P.S. Still allot of errors in this drawing (no ground on the control box, etc.)
Greg

Greg J Sun 17 June 2007 17:12

OK, it prints in landscape, but there is no way anyone will be able to read the fine print. I'll start working on printable 8.5x11 sheets.

Just so you know ... I've been printing my drawings on 11x17.

Greg

Greg J Sun 17 June 2007 18:29

3 Attachment(s)
Here are 3 PDF files printable on 8.5x11. When put together they make up my other PDF called control box.

I've made some minor changes to the 3 files (added ground on control box, remove the c (common) on the 9 VDC of the PS, etc.)

These files are only for error checking of my setup. In no way do they replace what this forum or Gerald has done.

Gerald - If I'm getting carried away, let me know. I've always had this fear of multiple sets of drawings floating around and the wrong part gets fabricated (personal experience right out of college)

Greg

Marc Shlaes Sun 17 June 2007 20:17

Greg, Got it. Thanks. I found the layout easy to read, just not the size of print.

Gerald, which post has your latest version? Since the kitchen table simulation is a first step, I (electronically challenged) am working very hard to just get a clue about this stuff. I am a little bit handicapped since I have never even seen a CNC router - except on YouTube.

I don't know a proxy switch from a pig's ear. I hope when I start, that y'all will be patient with my dumb questions.

Does anyone / everyone on this forum use Skype. If so, I would love to talk for a few minutes to someone who can help me understand a couple of basic things about the operational aspects of the CNC router. Then, I think a couple of major pieces will click into place in my mind.

Anyone?

Gerald D Mon 18 June 2007 00:06

Greg, I've had the first quick peek at it. Some details a little incorrect, but the general logic is correct. Except for the relays connecting to the PMDX....

The PMDX only opens/closes a set of contacts - it does not supply power/voltage on those teminals. You need to connect the circuit to a power source to drive the coils of the relays.

Greg J Mon 18 June 2007 06:15

I thought that the PMDX contacts did supply a voltage and current to the router SSR (for example). My router SSR's input is 3-32 VDC / 16 mA.

I'll study the PDMX manual tonight.

Greg

Gerald D Mon 18 June 2007 06:59

The PMDX J7, where you show the wires now, is only a connection to the contacts of the relay on that board, immediately adjacent to the J7. But, on J8, pins 14 16 17 are okay for the SSR.

Gerald D Mon 18 June 2007 07:02

See this thread for connecting a SSR to the PMDX-122

Greg J Mon 18 June 2007 09:00

Thanks Gerald,

I sorta remember reading that thread. That's where I found out to use the SSR's in the first place. I need to start printing the threads/posts and puting them in the files of the different components.

Sorry about that. I know you are one busy person and I hate wasting your time.

Greg

Gerald D Mon 18 June 2007 12:26

PMDX GECKO.pdf:

1. Gecko company doesn't like their DC supply coming off a rail - they want separate feeds from the capacitor/s in the power supply.

2. The relay feed already discussed

3. The low-voltage E-stop does not get a dedicated 2-core cable - it shares with other cores coming off J5

4. Watch jumper positions (not shown) for G203 versus older G200 family.

Power Supply.pdf:

5. Minor point - schematic of regulated 9V section doesn't show regulator.

6. If the two SSR's are switched together, why not just get one?

7. Is 115V okay for your dust collector?

Router.pdf:

8. The switch for the router can be the original built-in switch.

9. The shields of the cable extensions must be connected to the next bit of shield.

Greg J Tue 19 June 2007 20:27

3 Attachment(s)
Gerald,

I have updated the 3 files, but still have a couple of questions.

Regarding your response 1. I'm assuming that a rail is a wire coming from the PS and I was "tapping" off that "rail". I changed the drawing to show 8 seperate wires coming from the PS and going to the Gecko's. Is that correct.

Regarding your response 2. I don't have a clue what your saying. I've read the PMDX manul 3 times and it still doesn't sink in. First, I thought the low voltage E-Stop needed its own shielded wire because, I have the second contact block on the E-Stop for main power shut off. Second, what does shareing wires coming off J5 have to do with anything. Doesn't the E-Stop get connect to J6? Maybe, because I have not determined what my jumper settings are at this time, .... heck, I don't know.

Regarding your response 3. I've added a "regulator" in the drawing, but I'm not a EE, (I'm an ME) so I'm purely guessing. I'm saying this, just so everyone knows. My PS's secondary output is 9VDC, regulated.

Regarding your response 6 and 7. I have not spec'd out a dust collector yet, so I thought I'd add a second relay/SSR. I don't know what kind of power the dust collector will use at this time. I just want to get the kitchen table project up and running first.

Thanks,
Greg

Attachment 147
Attachment 148
Attachment 149

Gerald D Tue 19 June 2007 21:13

Greg, can you mail me your .dwg? It is easier to explain the E-stop wire thing with a drawing, and easier if I start with your drawing.

Gerald D Tue 19 June 2007 23:15

I see from the time of your last post that you did this very late at night - maybe you are regret it in the morning...:)

For example: On the right side of the PMDX, you had the power suppy from the 9V regulated to the correct terminals in the earlier version, now it is moved to completely the wrong place. It was the connections to the SSR's that you were supposed to be moving.

Marc Shlaes Wed 20 June 2007 06:33

I just had a thought about the second SSR. "Regarding your response 6 and 7. I have not spec'd out a dust collector yet, so I thought I'd add a second relay/SSR."

Would a another reason to add a second SSR be to some day possibly add a vacuum hold-down system. I use vacuum bagging for laminating and it is unbelievably cool. I plan to add that at some point down the road.

The minor point is that "industrial" vacuum pumps seem to be 220v in the US. The 110v SSR could be used to activate a separate 220v SSR. Couldn't it?

However... as I think about it further, the vacuum needs to be pulling quite a bit before the router is activated so it should probably be a manual system.

Richards Wed 20 June 2007 09:13

Marc,
"Normal" 240VAC Solid State Relays are not designed to work with 1-phase 240VAC power in the U.S.A. Here, we have two 'hot' legs, but the SSR only controls one of the two 'hot' legs. That means that you could get a really good shock when you thought that the device was turned off. When I have to control 240VAC and want to use an SSR, I use the SSR to control the coil of the 2-pole relay or contactor. That way, both legs of the 240VAC 1-phase line are turned on/off.

Some people have tried using two SSR's controlled by the same digital output line to control 1-phase 240VAC. That is something that I would NEVER recommend. Things fail and if either SSR failed in the ON state, you could get a lethal shock.

Gerald D Wed 20 June 2007 10:18

Mike, your comment is very valid. That is something I never considered because I don't fully appreciate how different your 240VAC is from our 230VAC.

However, one solid pointer is emerging for me from this amateur DIY morass of dangerous ideas and schemes...... a good solid mechanical disconnect switch that isolates ALL the poles before working on ANY part of the system. . . .

. . . . . or a plug that can be pulled to kill everything (yes, also the Neutral, in case that was wired wrong too)

Gerald D Wed 20 June 2007 13:23

1 Attachment(s)
Quote:
Originally Posted by Gerald D View Post
3. The low-voltage E-stop does not get a dedicated 2-core cable - it shares with other cores coming off J5
Quote:
Originally Posted by Greg J View Post
Regarding your response 2. I don't have a clue what your saying. I've read the PMDX manul 3 times and it still doesn't sink in. First, I thought the low voltage E-Stop needed its own shielded wire because, I have the second contact block on the E-Stop for main power shut off. Second, what does shareing wires coming off J5 have to do with anything. Doesn't the E-Stop get connect to J6? Maybe, because I have not determined what my jumper settings are at this time, .... heck, I don't know.
Made a rough sketch for you (don't need to send your drawing): This only gives a rough idea of why the PMDX E-stops do not get a special cable all to themselves. I am not trying to show definitve pin numbers or functions.

Greg J Wed 20 June 2007 18:53

aaaah, I get it. I never said I was a fast learner.

Yes, I may have been staying up late working on this project. But I'm having the time of my life. Its a blast.

My BOB arrived Monday, and the stepper motors arrived today!!:D

I'll correct those 9VDC outputs from the PS and take a break. I'll have many more questions when I actually start wiring up the "kitchen table" project.

Thanks for all your help,
Greg

Greg J Sat 30 June 2007 22:26

Gerald,

Just wanted to give an update on my progress (your probably getting tired of me by now :)). I've ordered ALL parts (terminal block, contact blocks, DIN rail, etc. etc.) for the kitchen project and waiting on delivery.

I'm "thinking" about welding up the Y-car. It really is a nice design. I remember seeing somewhere in this forum that you had "automobile" design experience. My back ground is "off shore". I get a kick seeing the different "influences" of this project.

Anyways, the deeper I get into this project, the more I learn. Can't express enough what a great job you've done.

Greg

Gerald D Sun 01 July 2007 07:48

Don't make me blush. :)

Have a bit of marine experience as well. During my 2 year military conscription, 79 & 80, I was the engineer of "Scratches" (after the Chalky guy mentioned there), and became the project manager of various vessel design projects between 83 & 89. (biggest one was Drakensberg)

Greg J Thu 09 August 2007 19:34

Gerald or Mike,

I've put power to the control circuit (kitchen project). No smoke, no blown fuses, and no fires. Everything looks OK. There is one Gecko driver with a yellow light, but I can figure that out. My E-Stops work. I was in Mach 3 trying to get motors to turn and nothing happened. Well, the motors got hot, so hot that you almost couldn't touch them (please tell me I didn't damage them. They were hot for .... oh ... a couple of minutes). I E-Stopped everything and unplugged from the wall circuit.

Any suggestions as to which direction to start??

For future reference, I will be monitoring the motor housing temperature with a "heat gun".

Greg


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