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Offline BR549

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Re: Limit switch issues
« Reply #110 on: December 27, 2015, 04:39:04 PM »
Power outages can be handed a variety of ways . The simple way it to use a UPS backup and have Mach3 setup to respond to an outage by stop machining move to a known location and shut down. Then when the ouage is ove simply set the reference again and restart.

Generators CAN be made whisper quiet as well . BUT that would not be cost effective to run a generator for 12 hours of machining on a what if senario.

As to your comment about your locality MAKING their own electricity instead of buying it off the grid. There is NO WAY you could do that as cheap as buying it. NOT EVEN CLOSE . I worked in that industry for years.

(;-) TP
Re: Limit switch issues
« Reply #111 on: December 27, 2015, 05:37:29 PM »
truncated to save space

The work side is another completely independant set of coords that YOU the operator use to setup work and reference to for machining parts.  Why are they called offsets ? because they are ALL an offset from the original refhome position that the machine uses for reference. The word offset can be either in NOUN form or a VERB. You can "offset" a position or you can use an "offset".

To be able to reset after a work stop ( outage ) all you have to do is Reset teh Work 0,0,0 to what it was originally on the table. To use the centerpoint of the tool is very hard to do. Using the side of the tool is very easy and very accurate. But yo have to realize you are setting it up as an offset so teh centerpoint of the tool will be established.

When you first setup the material i would machine a simple  L corner somewhere on teh material that runs up and down and left and right to the table motion. That will give you a reference point for X and Y axis. Record those positions somewhere in case you need them to set back up after a work stop. To reset the table simply move the tool over and touch off the tool to that spot in X and Y then set the dro for each axis to that value. NOW your machine is set back up to the exact point on the material (part). THAT is just one way of doing it there ARE many ways it can be done.

Another would be to use accurate home switches and Work offsets to setup the part then if needed you can simply refhome and go to the correct offset.

However you do it just pick a method and stick with it. ONCE you have figured it out you can restart a dozen times and it will machine correctly each time.

(;-) TP





Thanks, I've gathered that after the last couple of days....see, in regards to the terminology, when they say THE offsets, I take that as a noun....

I'd be interested to know how you can set the machine coordinates manually....I don't know how, but my machine coordinates are like -100" so when I tell it to go home (home being 0) I think it's trying to move my x axis 100" to the right to get to zero....wouldn't be a problem if I had a limit/home switch over there.....

Your routed groove is a great idea. What I have done is tack two 1/8" strips of pine to the table to use as my home....only problem is, the machine doesn't know this.....

I agree, centering a 1/4" round bit is difficult...the problem with using the edge is the software I design stuff with, and generate g codes with, uses the centre of the bit as home, and I could program it to use an offset of half the diameter of my first bit, but that would mean I'd have to manually do it for every drawing....considering I do about 500 a year, errr doesn't sound like fun to me haha then it would also depend on what first bit I used. Could be 1/4" could be 1/8" could be a 3/16"....3 mm or 6 mm....

Offline ger21

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Re: Limit switch issues
« Reply #112 on: December 27, 2015, 05:42:04 PM »
Quote
I'd be interested to know how you can set the machine coordinates manually

You don't. Machine coordinates can only be zeroed by homing the axis.
Homing direction is defined in Config > Homing/Limits with the Home Negative option. When checked, it homes in the negative direction. When unchecked, it homes in the positive direction.
Mach3 travels until it hits a switch, and has no idea where that switch may be.
Gerry

2010 Screenset
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JointCAM Dovetail and Box Joint software
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Re: Limit switch issues
« Reply #113 on: December 27, 2015, 05:56:54 PM »
Power outages can be handed a variety of ways . The simple way it to use a UPS backup and have Mach3 setup to respond to an outage by stop machining move to a known location and shut down. Then when the ouage is ove simply set the reference again and restart.

Generators CAN be made whisper quiet as well . BUT that would not be cost effective to run a generator for 12 hours of machining on a what if senario.

As to your comment about your locality MAKING their own electricity instead of buying it off the grid. There is NO WAY you could do that as cheap as buying it. NOT EVEN CLOSE . I worked in that industry for years.

(;-) TP

Yeah, the whisper quiet ones are crazy expensive though.....and yes, it is inefficient to run it all the time due to a might have or what if scenario..

As for generating our power locally....initially I would tend to agree....but considering we have (actually a major protest against it) a hydro electric project going in to a local water fall we could really in fact create our own "grid".

In addition, I ran off the grid for almost a year when I ran into financial difficulties. I ran my whole house off a 5000 peak wattage gennie...Now I was very careful about what I could use and when, and I used about half the kwh than when I was on the gird, but due to the price of our electricity, delivery charge, debt retirement, 13% tax, TOS pricing, It cost me about $160 per month in gasoline, vs over $220 for being on the grid....

It was only a 110v gennie so I didn't use the stove, and the fridge was basically unplugged during the day, (because I didn't run it when I wasn't around). I bought a small 110V water heater for my naval showers....I had a wood/electric furnace for heat which worked on convection when there was no power...and it worked quite well frankly.....

Yes, you would "think" that running on the grid would be cheap...but not here.....we pay some of the highest rates in North America, ludicrous considering our total usage is half of what it was 20 years ago and we are almost daily selling electricity to the US at a loss....The auditor general just last week announced that we paid over $13 BILLION dollars too much for our electricity over the past 10 years....at the time they also posted the number of residential customers and I did the math....without accounting for the customers that had large homes/were large consumers and those small homes/small consumers, we paid about $7000 each too much for our electricity....or about $60 per month, to me, that's 33%.....

ANyhow, back to cnc lol....(and yes, electricity prices are a bone of contention with everyone in my province due to us getting continually hosed by the government run power agency)

Offline BR549

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Re: Limit switch issues
« Reply #114 on: December 27, 2015, 09:20:45 PM »
What you need to understand about commercial power generation is you have to generate 24 hrs a day 7 days a week whether they need it or not. It is called demand that demand has to be available. Also generators HAVE to run at rated speed to maintan Freq .  so there is NO throttling them down off peak.  Being on grid you buy blocks of power on the hour to match YOUR demand size. IF you do not need 100 MW at 1 oclock in the morning you do not BUY 100 mw for that hour. You do NOT have that option on self generation. You wont even get close as local generation.  

Hydro is nice but it has pitfalls as well.  Size is teh biggest consideration with hydro.  You also have to account for line losses where you get ZERO return on a large amount of power you produce or buy for that matter.

You would still HAVE to buy standby blocks of peaker power in the event of a component failure on the hydro side grid.

IF you try to isolate your self and do a total Self Gen then their may NOT be any available demain power for you reserved on the grid IF you needed it as backup.

I have never seen a local self gen able to meet Grid power pricing in the real 24/7 world where demand has to be met 24/7.

Back to CNC Unless you TELL it where home is it has no idea UNLESS you are using absolute encoders that maintain their position values 24/7 by battery backups that maintain teh encoders power.

AND what you are refering to as home is probable work home not machine home rememeber those are 2 different things do not get them confused.

As to resetting with an L notch you are NOT resetting 0,0 as per say but you are simply establishing a reference point that is tied to 0,0 . It may be at X24 Y10 or X0Y24 or anywhere.

When you touch off the side of the bit you do not Zero teh DRO only set it to what it read as normal setup was.

ONLY if you used the notch as X0Y0 would you have to apply an offset. When you touch off on X then with a .250 bit you set teh Dro as -.125 and  Y it would be Y-.125  that way the center of the tool would be at X0.000 Y0.000  .

Clear as mud yes ? Once you get it locked into your CNC brain then it will make perfect sense. Until then it is just mumbo jumbo.

The way around all this is to ONLY use a machine that was preengineered and Configured to use Accurate switchs or Absolute encoders and Always use a CAM and always establish the Part 0,0 from Cam.  But with that you LOOSE most of  the flexibilty that CNC offers to you.

Now you get to work (fixture) offsets G54-G59 and larger. These are preset features so you can establish multiple Work home(0,0,0) anywhere on teh table and can call teh offsets into play by just calling teh G# such as IF I set up G55 to X10 Y10  and I was in G54 mode . When I called the G55 then the machine switchs the work home(0,0,0) to the amount of offset I configured for G55 X+10 and Y+10 and THAT position becomes the new work home(0,0,0).  THat way you can setup many fixtures locations on the table and simply call then on demand.. You can also use this on teh same part to apply a feature to multiple areas on teh part using the same exact gcode for each feature. Say I was doing a cabinet dorr that had 4 panels that each panel had teh same design. I would only need the actual Gcode for 1 feature then use work offsets to be able to cut those features in each of the 4 panels. NOW you can build libaries of features and call them on demand. Yu no longe have to bild each door as a total unique parts that you have to Draw and Cam each time.

AND that is just the start it gets even better as you learn more of CNC's unique features. BUT you do have to LEARN IT it will not pop into your head in the middle of the night.   Some people are capable of  learning it faster than others or are more determined to do so (;-).

The total process can be extremely complicated and rightfully so as the process is extremely powerfull . Therefore NO for the most part it can not nor should not be DUMBED down one bit.  YOU have to step up to the plate and learn it IF you want to master it.

Just a thought,

(;-) TP
Re: Limit switch issues
« Reply #115 on: December 27, 2015, 10:01:50 PM »
I understand how "on the grid" power generation works...to a certain degree. If I remember the info during the tour of the Niagra Generating station, I seem to recall the guide stating that in off peak hours, they shut down generators and or divert water away from them.....so at 1 am, on a tuesday, in June, for the past 10 years demand has been 100 MW, why would you run every generator at every generating station at 100%? A sane person would say "to meet that demand I have to run 25% of my generating capacity therefore I can shut down 65% of my generators, I'll keep the extra 40% capacity JIC.....then when demand increases at 5 am, at 3 I'll start to spool up all my generators to be ready when that demand hits.

WHat is 100% LUDICROUS is to keep all your generators running at 100% capacity then sell that excess energy at a LOSS. Then because either I'm an idiot, or the system is flawed, I'll charge all my customers a premium because I have a system that is inefficient.

See, the biggest issue with electricity generation, least in Ontario, is there is NO competition. A "supplier" is given carte blanche to do whatever the hell they want, with NO recourse...

I'll tell you one clue that the system is flawed: back in the day when generating your own electricity was as rare as an albino raccoon, a guy in Kingston Ontario built himself some windmills to power his farm. He disconnected from the grid (for the most part) and then...what the hell is this? He got a bill from Ontario Hydro for the electricity HE was generating....he got a lawyer and discovered that Ontario Hydro had a monopoly contract (which is illegal in Canada) to recoup the revenue from ALL electricity generated in Ontario, whether they made it or not....Well, the bills piled up, and he took Ontario Hydro to court....FINALLY a judge with common sense ruled that Hydro One was operating an illegal monopoly, made them pay the farmer's legal bills, AND pay him 6 cents per KWH for every KWH of energy HE generated which he fed back into the grid....So now, if you DO have solar, wind or geo-thermal electricity generation and you're connected to the grid, Hydro One (the new name) has to pay YOU for that electricity....
Re: Limit switch issues
« Reply #116 on: December 27, 2015, 10:12:25 PM »
Ok, back to CNC....

I followed all the instructions to the letter
Read the documentation from the links provided.
Watched the tutorial (video) on how to set your switches as home/limit

ARRGHHHHHHHHHHHHHHHHH X was still grinding.....

So, I said to myself: self? maybe you'll just have to live with it....No, I'm going to keep at it until I figure out what the royal duck is going on. But before I muck about trying to get it set up where I DON'T want Y home to be, I'm going to move the switch to the other end. Not to get into details about that but it took a little while but I got'er done.

Followed the instructions again, step by step, watched the video, paused it after I make the changes....

X axis was STILL grinding...what the (*(*@%^%@^%#^%& is going on? I rechecked the settings watched the videos again, checked, rechecked, checked again,...then WATCHED closely as the axis were moving..........WELL, part of my z axis "head" was hitting the frame before it hit the x switch. So I put at "probe" on the Y axis so that the part that was preventing x from hitting the frame, didn't.....voila everything is working (well, I still have to figure out how to get the axis off the switches after homing them)........

So, remember when I said the company who built my machine really had to be just a nob in a garage? Remember I said he had no real engineering or design experience? How there were many design flaws in my system mecanics? Well I thought, could it be that FROM THE FACTORY, something was hitting the frame when the switch was at the other end?

Sure enough, when I moved everything to the other end, a part of the x axis WAS hitting the frame before the switch so the SWITCH WAS NEVER CONTACTED!

« Last Edit: December 27, 2015, 10:15:00 PM by MuskokaMike »

Offline BR549

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Re: Limit switch issues
« Reply #117 on: December 27, 2015, 11:00:51 PM »
NO you will NOT just shut down and restart large power station generators .  LARGE generators do NOT tolerate load shifting very well. Remember you HAVE to maint frequency precisely . Picking up and dropping off load can damage large generators so they nomally do NOT like power spikes or load drops. It is easy to collaspe the entire LOCAL grid if you suddenly drop a large generator off line or try to pickup a large load all at one time.

Some companies even use LARGE resistor banks to use as load banks and maintain load on teh generators under light demand periods YEP just burning up Money heating the air. But for the most part they have no other options but risk collasping teh local grid which has at times collasped a regional grid.

That is why they make peaker generator stations now to help balance loads under unique demand periods of heavy loads and light loads. These generators are normally Natural Gas fired turbines and small generators and can be brought online and offline as needed to balance loads BUT they are very expensive to run compared to power plant units.  So peaker power is very expensive to buy or produce.

(;-) TP

Re: Limit switch issues
« Reply #118 on: December 28, 2015, 12:02:14 AM »
So, what you're saying is, my idea of protesting getting raped by our power provider would work?

My protest would be to organize everyone in town at a given time, to turn on every light, crank up their baseboard heaters, turn on every burner on their stove, crank the oven up to 500 degrees, then go to their break panel, then switch their main breaker off......then 5 mins later flick it on....then 5 minutes later flick it off....
Re: Limit switch issues
« Reply #119 on: December 28, 2015, 12:17:08 AM »
Ok, looked through the manual, watched the video on homing and can't find where I tell mach3 to back off from the homing switches by x amount...

Anyone have any ideas?