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  #361  
Old Wed 22 January 2014, 18:52
Tom Ayres
Just call me: Tom #117
 
Bassett (VA)
United States of America
I shall refer to my manual, thanks again.
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  #362  
Old Thu 23 January 2014, 05:03
KenC
Just call me: Ken
 
Klang
Malaysia
Lets get things less intertwined.
1) the definition of E-stop. Emergency Stop!!! Not something everyone press to kill boredom or stop an perfectly fine routine regularly.
2) You press E-stop to save a finger or some. so if it really fry a VFD in the process (my Chinese VFD still alive & healthy)is still good business. BTW, the spindle will stop at 1/2 a blink of an eye when its under-load & power abruptly interrupted. the load IS the break.

IMHO, VFD should take its power from the main power relay without another relay, hit E-stop & system shut down.. PERIOD
BUT being lazy, I took mine from an independent socket & still operate manually. :P

Last edited by KenC; Thu 23 January 2014 at 05:05..
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  #363  
Old Thu 23 January 2014, 06:00
Tom Ayres
Just call me: Tom #117
 
Bassett (VA)
United States of America
I had reviewed my vfd's manual and it says not to have a. Contactor between it and the disconnect. So I'm going to have to rely on the bobs e-stop to stop it. If I really wanted to protect the vfd I'd install a breaking resistor, I'll wait and see. Thanks guys.
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  #364  
Old Thu 23 January 2014, 06:09
alan254
Just call me: Al #95
 
mystic ct
United States of America
We had a discussion of this on my build, starting at post #37, Cutting some signs! Mystic, Ct MM #95. This should clear up what should and what should not stop with the e-stop.

Al
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  #365  
Old Thu 23 January 2014, 09:16
Tom Ayres
Just call me: Tom #117
 
Bassett (VA)
United States of America
Thanks Al, I'll give it a close read.
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  #366  
Old Thu 23 January 2014, 14:18
pblackburn
Just call me: Pete #98
 
South-Central Pennsylvania
United States of America
Ken is right, an estop is not a control stop or program stop. I have trouble explaining this to operators all the time. It is only for emergencies. It will usually leave power to critical processes like a PLC and the inputs but the outputs are dead.

Letting a VFD decelerate is faster than coasting that is why it is preferred. Plus if the parameters are not correct it can do a restart after power failure. Point being 'Know your VFD'.

Since most do a single phase design the contactor is usually a main line that kills all power. General wiring practice on three phase here in the US is the estop kills the control voltage which drops out the contactors. However since the VFD is powered by three phase power is still on but the control signal is lost so it acts how you have the parameters set up.

A braking resistor is for regenerative current for heavy load deceleration like slowing down a flywheel. There is a formula for your deceleration parameter based on your torque load to size the braking resistor. You should not need a braking resistor for this small motor.

I hope this clarifies some of what I typed earlier.
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  #367  
Old Sat 25 January 2014, 05:46
Tom Ayres
Just call me: Tom #117
 
Bassett (VA)
United States of America
I fully understand the function of the e-stop. After reading several manuals, build threads and listening to sound advise, I've come to the conclusion that a standard non-fused three pole breaker (220v single phase in) between the disconnect and the VFD is adequate, the pulse signal will control the spindle during e-stop by not sending pulsing signal (no pulse, no turning). No breaking resistor will be used, but still may want to step down speed in quick increments (maybe, maybe not, wait and see).

OK, that said, if anyone wants to add please do.

Next question-- The wiring diagram on the plans shows a latching switch/contactor set-up with a 110vac e-stop loop. Should I isolate a 110vac e-stop button at the control box to shut down power to entire system and use the BOB 12vdc for the rest of the machine e-stop, etc? Or, should all e-stops be of 1 voltage (be they 12vdc or 110vac)?

I kinda like the first option because I really don't want 110vac running all over the machine (maybe it's required, I don't know), feel free to chime in. thanks
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  #368  
Old Sat 25 January 2014, 06:39
jhiggins7
Just call me: John #26
 
Hebron, Ohio
United States of America
24 volt E-Stop Circuit

Tom,

I was also concerned about 110 volts running around the table for the E-Stop circuit. I considered it an unnecessary risk. So, I designed and implemented a 24 volt E-Stop circuit. It's described in my build thread.
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  #369  
Old Sat 25 January 2014, 14:22
pblackburn
Just call me: Pete #98
 
South-Central Pennsylvania
United States of America
You may feel it is worthless but realize this is meant to help.

If multiple voltages are used it is best to have them on different contact blocks on the emergency stop or control a relay. Numerous voltages are not uncommon with any industrial machine. Most have at least 4 different potentials available on a simple machine with most I work on have 10 plus.

In a very dusty environment, the lower the potential the more problems are seen. Once a contact is dirty the amount of amperage to bridge the gap increases. This is seen where a 120V contact can almost have the plastic melted on the contact block and still be functioning and the 24 VDC contact will not function with a little carbon build up present. If you have all Nema 4X enclosures then it should not be an issue. This is not to steer you away from low voltage but to let you know of the problems that can occur.

Isolation of voltages is up to the layout you choose. There are many ways to do an E-stop and have it effective with multiple voltages. The simplest is to use one voltage and series it through the Multiple Emergency stop contact blocks and have it control a relay. The relay coil voltage can be whatever you are comfortable with. This relay has sets of contacts and would control the various actions that you require. Notifying the breakout board, dropping power to your Main Line contactor, etc... This keeps the wiring simple because of less wires to and fro but there is the added milliseconds added to the circuit for stopping time. Not really a concern with this machine though.
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  #370  
Old Sat 25 January 2014, 15:23
Tom Ayres
Just call me: Tom #117
 
Bassett (VA)
United States of America
I've been mulling over the multi-voltage thing for a couple of hours now, considering the e-stops are only used in an emergency, does it really matter about the contacts as long as they are used very infrequent? I'd consider dual voltage/dual contacts on the door of the control box but still do not want 120vac through the machine. That would give me a total power and BOB shutdown at one location (that would include smoke, fire, etc) and operational shutdown/control at the machine. So maybe the serial e-stop contacts through a relay could be the answer.(sorry thinking out loud). I'm going to give it more thought based on the materials I already have in my possession and set up. I really don't think it needs to hard, just effective and reliable.
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  #371  
Old Sat 25 January 2014, 15:30
smreish
Just call me: Sean - #5, 28, 58 and others
 
Orlando, Florida
United States of America
If you study the design diagram, the 110vac side of the estop circuit if fused VERY low to keep any high current passing to the machine.
Additionally, the 22mm button allow for multiple contacts with any voltage. On my machine, I had 110vac @ .5amp fuse, 5vDC for the TTL to bob on estop, and 24DC to the Spindle disable.
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  #372  
Old Sat 25 January 2014, 15:48
Tom Ayres
Just call me: Tom #117
 
Bassett (VA)
United States of America
Now Sean how deep is your box? LOL I've got 2 types of 22mm estop buttons, one type from Factorymation and the other from Automationdirect, both handle stacking or adding more contacts. The automationdirect one just stack taking more room than necessary and the factorymation you snap in side by side and come in multiple contact configs. I can't use more than one high (I think) in the automationdirect ones in the boxes I currently have, I know I can for the others.
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  #373  
Old Sun 26 January 2014, 09:01
pblackburn
Just call me: Pete #98
 
South-Central Pennsylvania
United States of America
Looks like you are getting close.
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  #374  
Old Sun 26 January 2014, 09:08
Tom Ayres
Just call me: Tom #117
 
Bassett (VA)
United States of America
Yeah, just a few things to work out and a bit more material(s), move into position then on to rail adjustments. It won't long.
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  #375  
Old Thu 13 February 2014, 13:48
pblackburn
Just call me: Pete #98
 
South-Central Pennsylvania
United States of America
Still moving forward????
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  #376  
Old Thu 13 February 2014, 16:44
Tom Ayres
Just call me: Tom #117
 
Bassett (VA)
United States of America
Yes I am Pete. I've mounted the control panel and fabricated a panel for the VFD. Mounted it as well. Got the E-chain on. If I didn't have to shovel the 20-22" of snow (in last 24 hours) I'd be out there doing more like mount the steppers and start running wire to things. Right now I'm about to collapse, totally exhausted.
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  #377  
Old Thu 13 February 2014, 16:50
pblackburn
Just call me: Pete #98
 
South-Central Pennsylvania
United States of America
I know the snow qualms, I hurt my back on Tuesday working, now I am shoveling today. But I wouldn't change the snow for anything. I love the seasons. I am glad you are almost there.
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  #378  
Old Thu 13 February 2014, 17:34
Tom Ayres
Just call me: Tom #117
 
Bassett (VA)
United States of America
yeah I was hoping to have movement by the end of this weekend, I've got jobs lined up to start paying for itself.
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  #379  
Old Fri 14 February 2014, 01:51
Fox
Just call me: Fox
 
Amsterdam
Netherlands
You guys are building a CNC, but shoveling snow by hand, I see a discrepancy here
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  #380  
Old Fri 14 February 2014, 05:42
Tom Ayres
Just call me: Tom #117
 
Bassett (VA)
United States of America
That's ok, I was thinking of the order in which I can complete it while I was working
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  #381  
Old Mon 17 February 2014, 16:23
Tom Ayres
Just call me: Tom #117
 
Bassett (VA)
United States of America
Well this weekend got a few things off the list. I'm wiring the beast and trying to knock out a few other small things. Seems I didn't account for a couple of holes for wiring the control box but that shouldn't take too long.
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  #382  
Old Sun 23 February 2014, 18:46
Tom Ayres
Just call me: Tom #117
 
Bassett (VA)
United States of America
Well I'm down to some final wiring and just realized I need the stop blocks for the proxys. Should be done in the next couple of days. Yeah boyee!
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  #383  
Old Sun 23 February 2014, 19:08
darren salyer
Just call me: Darren #101
 
Wentzville mo
United States of America
I'm guessing Seikis post reminded you...
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  #384  
Old Mon 24 February 2014, 02:43
Tom Ayres
Just call me: Tom #117
 
Bassett (VA)
United States of America
Yep, you got it. Also before I make a video I'll have to spend a day or two cleaning the shop to look just a little like yours Darren. Sorry its not possible, too much stuff packed in there, everyone will have to accept the clutter.
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  #385  
Old Mon 24 February 2014, 05:47
darren salyer
Just call me: Darren #101
 
Wentzville mo
United States of America
Looking forward to it Tom. Based on the questions you've asked about design and toolpathing, something tells me you are going to hit the ground running and not look back.
Bet we see some really cool work come off that MM of yours.
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  #386  
Old Mon 24 February 2014, 10:23
Tom Ayres
Just call me: Tom #117
 
Bassett (VA)
United States of America
You're probably right, I've been designing things for years in my head just for a machine, things that can be taken to large retailers. Don't know if they are still relevant but keep throwing things out there to see what sticks. I've always said go big or go home.
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  #387  
Old Mon 24 February 2014, 16:20
pblackburn
Just call me: Pete #98
 
South-Central Pennsylvania
United States of America
It is always relevant, just not always trendy. But trends with time change and eventually come full circle.
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  #388  
Old Tue 25 February 2014, 02:46
Tom Ayres
Just call me: Tom #117
 
Bassett (VA)
United States of America
Pete you are absolutely right and that's what I'm counting on.
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  #389  
Old Tue 04 March 2014, 22:09
Tom Ayres
Just call me: Tom #117
 
Bassett (VA)
United States of America
Well I may or may not have a problem with my wiring, I can turn on the switch, it lights up, BOB lights come on then within 2-3 seconds the mains break. Now when I wired the PS, bob, drivers and motors direct-- no mains break, in reality the only new stuff is the estop stuff, contactor, the switches and spindle stuff (including breaker) of which I haven't even turned on. I've gone over the switch arrangement a half dozen times and can't see anything. Oh the circuit is a 20 amp 220. I have a 25 and 30 breaker readily available. I don't want to fry anything.

Any suggestions where to start. I've lost my patience...I'm going to bed....
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  #390  
Old Tue 04 March 2014, 22:44
pblackburn
Just call me: Pete #98
 
South-Central Pennsylvania
United States of America
Your best bet is to use an amp probe with a clamp to check the current draw. I do stress to use caution when inside a live panel. You do not want to become a path to ground. 50 to 100 milliamps ( 0.05 to 0.1 amps) is enough to cause death due to fibrillation of the heart even at 120VAC. Now I have warned you lets move on.

Assuming you have everything fused individually. Finger safe swing open fuse blocks make it the safest way to check. I would pull the fuses to each and power one up at a time. If you have round fuses with clip fuse holders, I recommend powering down then placing the fuses in and powering back up. I would do this until you see the problem tripping the circuit.

I am fused at 35 amp at my disconnect with a 50 amp supply circuit however the 35 amp fusing is 125% over the maximum calculated load. Remember that I have my dust collector powered through the main control panel as well. The load with nothing running is less than 10 amps per leg.

You may have too much draw on one leg of the two. Only one leg of a 2 pole switch needs to be higher than the rated draw. Breakers have to be at a 110% draw for one minute for it to trip. An instantaneous trip could indicate a short in your wiring.
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