Electrical Schematic review

[JerryFlyGuy]

Hey all.. I've finally sat down a scratched together a wiring diagram for my system. I'd really like other's imput on how this is put together. I know the drawing is VERY .. poorly drawn.. but its my first wiring diagram so .. go easy on me

Am I doing anything horribly wrong?
Is there a better way[s]?

I've said it before.. and I'll say it again.. I'm not well
versed in "Electrical anything" so.. looking at this may
make you laugh..

For those looking for a "how to", I'm not sure this is it.. until I get some feed back.. I don't recommend using this..

If you do end up using it.. know that it was drawn by a someone with NO electrical wiring experiance or knowledge..


DISCLAIMER
USE AT YOUR OWN RISK, by downloading this file.. you absolve me of any resposibility for bodily harm,damage to person's,property and/or equipment.


Jerry [ don't you just love all these disclaimer's we have to post to cover our butt's on a public forum! ]

[Al_The_Man]

AS a few pointers as I mentioned in another post, it pays to draw a schematic in ladder form, I have included a fairly complex one as an example of a Cincinnati mill I retrofitted.
It is a bit more work, but it is easier to spot mistakes and to really be able to design the system properly.
In North American and UK the way is to draw the power lines vertically on the right and left hand side of the page, and progress from left to right.
In Continental Europe they draw the power bus top and bottom and progress top down.
With a simple drawing you can get away with physical layout as you have done, but once you start marrying different systems together it can get messy and very hard to follow & prone to error.
(I think the pdf came out ok)
Al.

[JerryFlyGuy]

Oh geepers.. ok well I've got lots more to learn about wiring diagrams..

Is there anything on this one that seem's to be a big no-no Al? or are you saying maybe I should re-draw it before you even attempt to wade in on this one

Jerry

[NC Cams]

Jerry: you've made a very nicely done layout/routing diagram for the wire as it will have to go into the cabinet form machine to machine.

However it is NOT a schematic per se thus not easy to follow unless you research every connection to every pin on every subcomponent.

Yes, it is not possible for a person who is not intimately familiar with the circuit as you are to "see" if anything is wrong. In reality, come back a week or month from now and you'll look at it the same way - like DUH, what does that mean/do???

Schematics help you follow the control activation logic. They use simple boxes and circles for the hardware as the CONNECTIONS are what need to be defined for the circuit to work, not exact pictures of the machine. Might want to get a schematic book or do some web searching.

A "free" electronics schematic capture can be d/l'd from ExpressPCB.com. You can make custom chips with custom pin numbers. Sadly, it doesn't do the multi-colored wires like you did.

Of note in a complex or simple circuit is a numbering of each and every wire with a circuit number. When 6 wires of the same color are in a harness, it is impossible to keep them straight. IF the wires are numbered at each and every connection, you simply look at for the number to make sure it is connected to the right pin. Makes it easy to do continuity checks too.

Can you do that with your drawing??? if not, maybe you might want to make it so you could. PITA now, godsend when you wire the cabinet and go to troubleshoot.

Al's schematic is a classic machine tool control layout. Fits a standard and is easy for an experienced or newbie to follow the control circuit logic - this is especially critical to be able to do if something in a control chain isn't working.

A redraw would help you better understand what's going on. After 3 or 4 redraws, you'd be amazed at how clear things become and the dumb mistakes you catch on your own.

[JerryFlyGuy]

Thanks for taking the time to reply NC, I'm definatly new at drawing anything electrical related. I took some more time and looked over Al's PDF but have to say, it just made me more confused I don' follow all the symbology so alot of it is over my head, and really.. thats ok. I'm not doing this for anything more than my own system, I'm just hoping that someone will notice any mistakes I've made and help me correct them. I realise thats a tall order due to the complexity, in addition to the poor way its drawn. However, if I get one correction out of it, if it possibly could save me a blown drive or something which would be fairly costly, esp a blown G100, it was worth it. Anyway, I could start to redraw it, however I don't think it would come out any better than it currently is. Like you say, I could do it several times.. but in the end.. its all just for one system, I'm not sure its worth doing..

If I was building and producing these.. it would definatly be worth it..however.. being as it's more of just a 'guideline' for me.. probably not..

Thanks for your comments

Jerry

[NC Cams]

You are missing the point.

Each and every item in a DC circuit is hooked between + and -. Some are directly hooked (indicator lite) and some go thru swithes, diodes, whatever to achieve circuit continuity. Currently flows from + to - ( or the other way for the traditionalists).

To get from the transformer, you go from 2 terminals, thru a diode bridge then to a cap then whereever. Some stuff in the circuit thereafter is in series and other is in parallel.

A simple circle with an M in it is a motor. A simple circle with an L in it and "rays" around it a light. The ladder schematic that Al drew uses standard symbols to do this or something at least close. It could be a box but as long as you know, that's fine.

In Al's drawing, you can wire the system wire by wire in a "flow" and check them off as you go. Checking and trouble shooting much easier.

Your drawing is essentially a page in a book. You read a book LINE BY LINE to get the data out of it. Everything is coming at you - it is hard to focus. Simply to verify polarity is impossible.

In Al's schematic, you can see how the transformer turns AC into DC. As you go down the page, you see how the first circuit works, right to left, then the second.

In "reading" from L to R you see the daisy chain of stuff that has to be on or off for something to work.

Learning to read relay logic ladders is hard IF you try to absorb the whole page all at once. Look at it line by line, item by item, L to R, Top to Bottom and learn to comprehend them that way.

WHen you do, you'll see why Al's schematic is VERY easy for a person to read, comprehend and trouble shoot. As hard is it may be for you do do, it is as hard for a person trained/experienced in ladder diagram reading to read/evaluate something NOT in that format.

At one time, Forrest Mims wrote some books that were real helpful in drawing circuits:

http://www.forrestmims.com
or
http://www.amazon.com/gp/product/pro...lance&n=283155

If you're going to get involved with CNC, it doesn't hurt to learn the lingo.

Besides, if you catch the mistake in the drawing phase, why toast a drive or motor un-necessarily.

I encourag, no, urge you to learn some rudimetary wiring diagram reading/construction skills. It will do you wonders in building and fixing DIY CNC's. Keep you from toasting expensive parts, too.

[Geof]

Am I allowed to make a comment without getting tromped on? My advice is go with the advice so far. Find a key for the symbols in Al's schematic, maybe Al can point you someplace, and puzzzle it through. You will only need to puzzle for a few hours and things will start to fall into place; it is an accelerating process. This side of your project is no less important than the mechanical stuff and you spent a lot of time bending your brain and researching that. You also need to look to the future. It is clear your project is ambititious and sort of opened ended. Probably someday you will be employing people to run and maintain your equipment and when that day comes you will be so thankful you did things conventionally.

[Mariss Freimanis]

Jerry,

I can read it OK.:-) It's late, I'm calling it a day and I will look it over more closely tomorrow; 3 things jump out though:

1) You'll bust your 'OK' LED if you don't put a current limit resistor in series with it. Use a 1K resistor.

2) No need for 1K pull-ups on you proximity sensors. They're already built into the G100.

3) The GP outputs on the G100 are open-collector, current sinking. Have your coolant SSR LED cathode go to the G100 output, not the anode.

A general comment about drawing schematics:

The purpose of a schematic diagram is to give a clear and easily readable visual presentation of how things are to be wired up. A schematic has important signal lines (outputs to inputs and visa versa) as well as obvious power supply and ground connections.

The 'obvious' connections shouldn't visually clutter-up the important connections so a kind of "shorthand" convention is used: Use a an "out arrow" (-->) from a supply connection source and label it "+5VDC". Use an "in arrow" (>--) and label it "+5VDC" everywhere +5VDC must be supplied. Do the same for ground (GND).

Where it is important how supply and ground must be routed such as a "starred" power distribution to the motor drives, by all means show it just like you have. Otherwise, using the shorthand version implies it doesn't matter if it's daisy-chainied or star distribution. This is true for all the +5VDC and GND connections to the G100.

Second, pull the schematic together; avoid unnecessarily long connection lines between components. The eye has difficulty following long parallel lines when following a signal line of interest. Decrease the spacing between individual components to avoid this.

Third, avoid crossing signal lines in a schematic as much as possible. This is accomplished by keeping closely associated components spatially together. Example, I would have had the motors near the drives and dropped the encoder connections going to the G100 below.

Drawing a clear and visually easily readable schematic is an art. Done well it should require as little effort as possible from the viewer to discern the meaning of the connections between components. A well drawn schematic is natural and easy to follow.

If this is your first drawing then you have done a very good first try. Try it a second time using the above rules and see if that result isn't much clearer.

I spend a lot of time drawing schematics only I will ever see. Why? Because in 6 months a poorly drawn scematic is just as unclear to me as it would be if stranger had drawn it. To me, the intent of the schematic has to leap off of the page.

Mariss

[Mariss Freimanis]

Al the Man, NC Cams,

Al, a very neat and clear schematic. Easily readable and logical.

That can be a problem though; please take the following as no criticism of your good advice: Ladder logic is a type of programming language. As such it follows a well organized sequential flow description in writing as well as reading.

I design electronic circuits. My tool of choice as a descriptor of what I do is the scematic diagram. That is because what I do is essentially parallel and only secondarily sequential. An electronic schematic diagram serves me best as the tool to understand what's going on.

Look a Jerry's diagram. There are no sequential interactions between the components that I can see. To me that means the best tool is the electronic schematic diagram to depict the relationships between the components.

The 'problem' as I see it is to use the wrong tool for the job. Ladder logic overlaps into schematics just like verbose programming languages overlap into ladder logic. Physics overlaps into biology just as philosophy overlaps into physics. Point is you can use a claw-hammer as a screwdriver or a screwdriver as a hammer. Doing so though is not using the best tool for the job at hand.

You could draw a ladder logic diagram for what Jerry came up with. Question is would it be as clear as his schematic? Use the right tool for the right job is what I'm saying.:-)

Mariss

[JerryFlyGuy]

I appreciate all your input, it all been duly noted and I know it was ment with best intentions.

I started this project w/ the intent of learning some, being creative, and doing something w/ my hands. However the bottom line was to build something which would translate into a company doing something that is enjoyable and challenging to me.

This being said, it has to be more than a meandering, learning experience. I have a budget and a time-line which I must follow and adhere to as best I can. I've worked on this project for nearly 1 yr, over 1/2 of which was spend on reading and reseach. I entered into this venture, knowing that the electronic portion would be my biggest hurdle, but knowing that if I could get past it, all would be well. I do plan to try and learn some more about the electronic's symbology, simply to assist in getting this wiring project completed.

However w/ deadline's looming and the need to keep moving on this project, you can understand my reluctance to sit down and study several, hundred++ pg books, and teach myself the fine art [and yes it's an art] of circuitry design.

The reason my schematic looks the way it does is simply because that's the way that I've seen them done on here and else where. [Including ones for our Accu-press equipment at work] I realize my rendition has something to be desired, but at the same time, it is possible to trace what is happening, and by simply looking at components its clear what they are.

The help I was looking for wasn't "your drawing sucks, go learn to do a better one". It was the simple stuff as Mariss has helpfully pointed out, "don't need this here.. put a resistor there".. etc. I realise that w/out some basic ciruit symbols, everything gets confusing, but there has to be some "happy meduim" doesn't there?

I will do some re-work on the drawing and try to clean it up as best I can, along w/ some added symbology [here I thought I was doing ok in that dept ] and hopefully we can reach a level where it's workable, even if it isn't a Van Gogh or a Picasso..

Again guys, I DO appreciate all your effort's in trying to get me going down the right path, just please realize too, that I'm not going to get perfect at this fast enough to get the project completed in a reasonable amount of time. Some level of "ok-ness" is going to be required.

Jerry [ I'm tired and I appoligise it any of that sounds like I'm pissed off.. I'm not.. just a bit discouraged..but mainly tired...]

[HillBilly]

The difference between Al's and Jerry's is Al's is a schematic and Jerry's is a wiring diagram. Al shows where the electricity is and Jerry shows how the wires interconnect everything. Appliances used to have both on the back of them.

As another note Al's schematic is typical to what all commercial machine tool builders supply with there machines. With this layout it is easy to refer a contact on a rung to another page and line number from where it originates.

Darek

[JerryFlyGuy]

Thanks Darek, your exactly correct in that it's not a schematic, but rather a wiring diagram. Do to my level of understanding [ of electrical stuff] I see everything as piping and things of that nature, hence.. I want a wire from the output term, to the relay, and from the relay back to ground.. thats literaly all I was thinking as I was drawing it.. line by line..

Anyway.. I've started to clean it up, and I'm actually trying the ladder part.. I'm not sure how successfull I'll be but.. I expect things will be jumping from page to page and there will be several legends to clarify labels and wire codes. I've got some holiday's coming up so.. this is what I'll most likely be doing while we travel..

Jerry