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There is no problem earthing the bolt with the plate. What you MUST NOT do is earth both ends of the bolt as this would present a shorted turn to the coil.Quote:
so if i mount the coil on a plate and the plate is earthed , will that not in turn earth the bolt holding the coil? will that be enough or will i have to earth the bolt also
Regarding the button I have not seen one before are you sure it is not just a vent. Clive
maybe a vent as you said . i'll fire off an email to the supplier and see what comes back. cheers Clive
i'm in the process of building the power supply and would like to know if thermal compound is used on the base of the rectifier and on the base of the capacitor. i don't know if it's advisable to mount these without it. i had a look online for paste but keep getting paste for cpu's .
will this do?
I mount the rectifier with thermal paste you don't use it on the caps. Paste for the cpu should be fine. ..CliveQuote:
Originally Posted by PAULRO
i decided to test the coil with a power up so i used a safe block , hooked up the brown and blue to 230 vac i then joined black and yellow together and red and orange together on the secondary and put them in a terminal connector . when i engaged the safe block the coil hummed for about a second and then stopped. i checked the fuse in the safe block ( 13 amp ) and it was blown so i tried again and the same thing happened. i metered the connector and obviously got no reading . am i correct in thinking that i should not have blown the fuse and should have 50v ac across the terminals?
Do you have a link for the coil?
You need to connect the two sec. coils in series so join red and yellow and measure black and orange 50V It might well blow the fuse on start up with a 625w coil
..Clive
http://www.airlinktransformers.com/c...nge/CM0625225/
just my luck to blow fuses. i thought i might have connected it wrong or perhaps i shouldn't have tested in in the manner in which i did. should i wait to get the rest of the supply hooked up or would that matter?
Ok short black and yellow together and take the output from red and orange then you should see 50V You have connected them in parallel . I think the fuse is blowing because of the surge. ..CliveQuote:
Originally Posted by PAULRO
cheers Clive , 52.1 beautiful V ac.
finally got back to the power supply and got it set up . i'm reading 73 V DC . is this o.k. ? i know that 68 v dc is the magic number . is there a way to reduce it other than reducing the number of windings. i would not be comfortable with stripping out the coil to achieve that.
Its fine at that and are measuring it without a load as well also the mains voltage will fluctuate.Quote:
Originally Posted by PAULRO
How about a pic. ..Clive
What drives are you using.? If 80V max then it will be fine but if 75V max then it's a little close for comfort because as Clive says mains does fluctuate. When your reading 73Vdc what is the Mains input reading.?Quote:
Originally Posted by PAULRO
Also as Clive says you have no load so connect the drives with motors attached and then check.
I'm waiting for the drives ( EM806) ,bob ( PLC4x-G2) , and motion control( PLCM-E3) card to arrive from Zapp. I just have the 70 V DC supply hooked up . i 'm hoping i'll have the electronics from Zapp tomorrow because i'll have a weekend run at the panel so hopefully the voltage will drop when i hook up the electronics and motors as you say. i 'm reading a steady 230 v ac at the input side. i haven't got the bleed resistor hooked up either and i'm still reading 45 v dc at the cap even though i powered it up for a minute or so yesterday. still, this is progress for me because i never built a supply before , so hats off once again to the heads sharing the knowledge.
my electronics won't be with me until monday / tuesday . i had an email stating they're in transit , i put some more bits on the back plate i had an old 5vdc power supply plug in type set a side for the motion control card . i couldn't get a din mounted supply locally and i didn't want to wait for ebay so i'll give this a try. i still have to change the fans around on the box i'll tackle that tomorrow . i hope!!!
Can I make a few suggestions.!!
I wouldn't locate the VFD and the PSU next to the BOB and Motion control card and drives. Both these are very noisey devices and they could introduce noise onto the signal wires.
Ideally you want them furthest away from any signal devices like BOB and Drives.
Personally i'd have PSU and VFD at top and Drives/BOB/Control at bottom with Connections/24V psu etc in between with separation.
I had to put a breaker into my main board to support the extra load for this cnc and i forgot to power down my p.c. so the end result was a p.c. with a blown power supply .
i had a spare one from another m/c but it had different connectors so i spent the morning cutting and pasting.... who needs it ? anyway i changed the panel around and put the noisy bits on top i have to put more fuse holders, terminals etc. in tomorrow.
i 'm just getting back into the build today and i have the electronics mounted on the back plate. i have a query regarding the fuses for the 70 V DC power supply. i have the fuses on the negative side of the supply , is that o.k. ?
Its good practise to put fuses in the +ve side and the mcb for the input to the transformer appears to be 3A I would think you need more like 6A because of the inrush to the coil and rate it to a motor type ..CliveQuote:
Originally Posted by PAULRO
cheers Clive , i have a 6A in there , i just for got to update the dwg.! i better change the fuses around .:applause:
O.K. state of play so far is that i have the back panel in the cabinet and i'm doing some electrical dwgs so i can at least give myself a fighting chance to get it right . i have a couple of queries before i go and start lashing in wires though. this is what i think i know from reading the posts , so i just need some nudging .
1......am i correct in saying that i need a separate input for the slave home switch?
2 .... i need a separate input for the rest of the home switches combined in series.
3... because i'm combining both limits and home into a single switch i must keep the e stop on a separate input.
4... i also need an input for feed / hold
5..... and an input for stop.
bring my total of inputs to 5 ( MAX. allowed)
i also have alarm terminals on my drive so i'm curious about how i can get these in to an input. i will post some drawings of my proposed electrics as soon as i'm finished.
Ok
1: = yes
2: = yes
3: = yes
4: = yes
5: = yes
You can add an extra two BOB's to your motion controller if you like then you would have 15 inputs. ..Clive
If your going to have a feed hold button then you need a Cycle start button to get going again so you'll need an input for that. No point having External feed hold button without cycle Start.!
Also with homing and Slaving then you need to make sure " Home slave with Master" is UN-Ticked in General Config.
Also UN-Tick " Home sw Safety" if your sharing limit & home switches as the switch will be treat as Limit when homing and E-stop the system.
With #3 then you don't need E-stop on it's own Input if wired in series with limits just Set the E-stop Pin to same number as the input your using.! Then when switch is pressed Both Limit and E-stop Led will light in Diagnostics.
I thought that if i use 1 input for the limits and estop i won;t be able to reset because the m/c will be on a limit thereby inhibiting a reset. or have i got this all wrong? i think i will leave the feed / hold out for the time being and just go with e/stop, stop, limits /home, and A home. at least until i become more familiar and have a better understanding of the process. I also have another input dedicated for force turn off enable so i will use this to take a fault signal from the drives.
I couldn't upload a PDF so i had to save as a jpeg. who needs it? Anyway , here's my proposed wiring diagram for the BOB. I have 1 more input left. XP30 is a dedicated forced turning off ENABLE. My understanding of this is that if a fault occurs in a drive then the alarm will trigger an input to XP30 and the drive will be disabled. is this a correct assumption?
Ok
1: = yes
2: = yes
3: = yes
4: = yes
5: = yes
You can add an extra two BOB's to your motion controller if you like then you would have 15 inputs. ..Clive
maybe down the road i might contemplate an extra BOB . i have to get this set up right first and get very familiar with the whole process.:jaded:
right guys, this is probably a dumb question but i ask it any way, if 1 switch can be used as a home switch and limit switch to monitor an axis ( that's 4 switches in total for X,Y,Z, including a separate switch for the slaved A axis home) why would some builders need 3 switches per axis , total of 10 including a separate switch for the slaved A axis home? if the limits are separate to the home would they not need an extra input to the already limited no. available on the LPT port? there is also a cost factor for the extra switches. i have to be missing something here.
My build so far has accommodation for an e stop hard wired to drop out the drives and as an input to the BOB for MACH 3. is there a need for a hard wired stop switch on the panel door? and if so how does it differ from an estop? I'm sure i can stop and pause the machine from MACH 3. is this adequate?
is it ok to use the main switch to drop out the power supply to the drives or should i have a switch after the power supply to control the drives and leave the power supply powered up when configuring the drives. does it matter?
i think i'm at a stage where i need to get the machine up and running with an adequate level of safety built in. i can then add the extras as i become more familiar and comfortable with the experience. any thoughts on the above would be appreciated.
Sorry delay replying went out last night for a pint which turned into Gallon then Amnesia.!! . . Well No and yes to getting it wrong.?Quote:
Originally Posted by PAULRO
Mach as feature called Auto Limit Override which lets you Reset after Limit trip so you can Back off.
But With the E-stop then if your combining Limits and E-stop in same circuit and using Relays for hardware driven system (which you really should be) then you will need some Limit over ride Switch to reset the Relays. If using this setup then you can use the same Relay to inform Mach e-stop Happened and then just set Limits to watch same Pin if you want. With a Hardware driven safety system all your really doing is informing software an E-stop happened so it halts the Code and won't Reset until fault cleared. The actual safety side is done by the Relays and Never should be done by software.
Now personally I don't combine E-stop and limits because limit trip isn't an Emergency it's more positional error. I have Limits and Homes combined and limits do 2 jobs they Inform the Control limit as tripped and they disable the Enable on the drive so Motors are still locked but won't recieve signals.
Again a Limit override button is needed if disabeling the Enables on drives. If you don't disable the drives and just Inform the control you can get away with using Mach's Auto limit override feature.
Ok well couple reasons for 3 switches is if they wanted to home all axis at same time, Mach standard way would do Z first then Y then X which takes longer than if all Axis move at same time. Other reason is to have Home switch in a different place to limit switch.Quote:
Originally Posted by PAULRO
If you want to cut down on Switches and Wire then just use 1 switch and have it travel with the Axis being tripped by targets at each end.
For DIY use then you don't need Hard wired door switch IMO but if you did want a Simple setup then Yes just run switch in series with E-stop circuit.
Correct way would be a Door contactor that won't let you Open door without turning power off but they are Expensive and OTT for DIY user with Common sense.
To me even in DIY use then Safety is still important but does need to be kept real.
If you use a Hardware Driven E-stop Circuit that disables power to anything that can hurt you using Contactors and relays then it's more than safe enough. You should never rely on software for Emergency stopping the machine.
Like I say Limits are not an Emergency incident so just Halting and prohibiting machine movement is ok.
If your unsure of how to build Safe E-stop system with Relays etc then let me know and I'll knock you something up.
that's the way i would like to have my set up . a separate estop that drops out the power supply which in turn drops out the drives.
my limits and home switches combined and informing mach 3 when they are triggered.
so if i'm reading you correctly then the limit switch when triggered is also wired to the enable on the drive thereby disabling the drives so that's when the override is required? or i can use the limit switch trigger input to MACH 3 to stop the motors and use the Auto Limit Overide feature. ?
l
The way I do it is to use a Relay for limits. This means I can use 24V thru the switches to power the relay coil, in my case Proximity switches, which gives best immunity against noise.Quote:
Originally Posted by PAULRO
The drive enables are then sent thru one set of NC contacts, The Limit input is sent thru another set NO contacts.
Override is by way of Momentary button and Alarm buzzer to between 24V and relay coil to allow limit switch to be over ridden.
picture paints 1000 words.!
Attachment 15017
yeah, the picture makes it all clear now. thanks Jazz. that's a great circuit i'll have to use that if you don't mind.
that has cleared up a lot of queries for me . the enable was really puzzling , as in do i wire it or do i leave it unconnected, but that picture, as you say paints a thousand words. if i connect the enable +,- as in the picture does that mean i don't need the enable +,- connected to the BOBs corresponding terminals?
1 last query to get me further down the road if you don't mind, am i right in saying that the limit input to the bob and on to MACH 3 is enough to get the motors into reverse when the override is triggered?
Probably not but Depends on the BOB.! . . . what are you using.?Quote:
Originally Posted by PAULRO
It's common for the Enable on drives to not be connected but in this case we are using it to ensure no signals get to the drives so no movement can happen while at same time leaving the motors energised and Holding position.
Yes but you have to Hold down the Override Button to allow Mach to Reset so you can Reverse off the switch at which point the Relay will stay ON and mach will remain Reset untill something changes. Over riding anything should be warned about and thats why I use a buzzer but it is optional.Quote:
Originally Posted by PAULRO
i'm using a PLC4x-G2 breakout boardhttp://www.mycncuk.com/attachment.ph...id=15018&stc=1 .
Ok well think things could all change now if you wanted because I'm pretty sure that Bob can handle 24v thru it's inputs.? The manual certainly shows them using 12V.
So in this case you could remove the Relays and run 24V thru the Limit switches wired in series just the same but directly to the BOB Limit inputs. I think you'd still need an Over ride button as the Inputs are driving the Enable output so Mach's Auto limit override won't turn these back on.
Then connect the Enables on the BOB to the Enables on drives.
Or just go with my first suggestion if you prefer and want to play safe regards what the Inputs can handle.!
New pic.
Edit: Yes those inputs have 30V Max so your good to go with this Pic.
Attachment 15019
i have my drives on the back plate and i'm at the point of wiring up the signals from the B.O.B. . I am using shielded twisted pair, 24 awg , 6 core, for the pulse, direction & enable signals. do i earth the shield or leave it ? the cable run is not very long and its in the cabinet. i know i 'll earth the shield of all the out side cables once they return to the cabinet , (star connection). i'll be using shrink wrap to tidy up the loose ends when i trim the cable back.
i could use 8 core twisted pair ( shielded) and that would bring my alarms from all drives back to a terminal block where i can wire into from my power supply. i have to read up a bit more on the alarms though, the more i read the more questions i have!
Will be fine without shield to earth for short runs just try to keep any signal wires away from higher voltage wires like Mains.
Paulro
I have used just cat5 twisted pair to each drive cable for the step/dir etc just keep them away from the motor cy cables.
Not necessary to screen them
i thought i had cat 5 cable but it turned out to be shielded 3 pair twisted so used that. the cat 5 cable wil surly turn up now that i have the drives wired. i have yet to wire the fault terminals from the em806 drives to the dedicated estop input which disables the drives once triggered but i can't find any examples on the forum so if any one can shed some light to get the subject......... i also set the micro stepping to 1600, is this o.k.?
1600 MS is fine.Quote:
Originally Posted by PAULRO
Several ways to use the Fault signal but an easy and safe way is use a Relay with the coils wired in parallel running thru fault signals set Active low and the E-stop running thru a NC contact. This way when any of the drives fault triggers it turns on the relay which opens the NC contact triggering the e-stop.
The E-stop should then kill power to the drives which in turn drops power to the relay allowing E-stop Reset and the drive fault is cleared because power was removed and fault reset on new start up.!
Other way is not very safe as it's relying on control software to stop machine but very easy to wire. It also doesn't clear the fault so you'll need to reset the drives manually. ( For this to work set Input to Active High in Mach3)
drawn both to show.
Attachment 15103
Thanks for that Jazz, i got totally confused trying to accommodate a hardwired circuit with the e stop and an alarm input to the BOB( both versions of what you have sketched). my BOB has a dedicated input for force turning off the ENABLE, at least i think that's what it does. i'm trying to use just 1 relay and as it stands and i have that in the PSU & e/ stop circuit. I have updated the dwg to reflect what i think is your schematic. i probably don't need an input from the alarm drives to the BOB. i got caught up in thinking that an input to MACH 3 was required. i also had a look at Eddies dwg and saw that the alarms from his drives were in series so that added more ??????. as in connecting a ground wire to the positive terminal of the alarm drive and out the negative terminal and on to the next drives positive terminal etc. that really had me confused along with a dose of the flu which got my head in a spin. i don't need an e/stop signal to the BOB so on reflection , or do i?