Small rigid router - Design advise needed

Fitted and aligned the Y ball skrew and complete Z axis, so most of the mechanical parts are done now.

z front plate before all the drilling and tapping
http://www.mycncuk.com/attachment.ph...id=14523&stc=1

Had to but join rails for my Z due to a change in plans. Was quite surprised as the carriages runs very smoothly over the joint with absolutely no click or resistance, so it seams feasible to join rails if one has to.
http://www.mycncuk.com/attachment.ph...id=14524&stc=1

z stepper mount
http://www.mycncuk.com/attachment.ph...id=14526&stc=1
http://www.mycncuk.com/attachment.ph...id=14525&stc=1

100mm spindle fitted just to see if all the holes line up etc.
http://www.mycncuk.com/attachment.ph...id=14527&stc=1

Now time to start with the control box which is about where I run out of skill and creativety. Wish Eddy could pop over to my place to help a bit:-) I sort of know what needs to be connected but I cant figure out a good layout to do a neat job with routing all that wires etc.

Quote:

---

Originally Posted by mitchejc

Wish Eddy could pop over to my place to help a bit:-)

---

Bit too far I think :highly_amused:
Here's a few things to keep in mind;

1. Use a proper metal electrical panel with backplate
2. The size of the panel is not the space you get, it's how big the backplate is and the distance it is from the inside of the door.
3. Two items are sort of fixed, terminals across the bottom or up one side, a door mounted isolator positioned along the edge of the door that opens.
4. Use CAD to draw rectangles representing the guts of the enclosure, i.e. backplate, terminal rail, door isolator, drivers, power supplies, bob + interfaces, fuses/circuit brreakers, relays, trunking, vfd, etc.
5. Just drag the rectangles about to get the best layout, the space you need is going to be bigger than you think.
6. Obey any rules regarding ventilation, and keep large transformers away from sensitive items like the bob
7. Use the cable trunking to route power cables in one and signal cables in the other.
8. The backplate will have an earth point, use this as your earth star point, you can use the DIN rail mounted earth terminals I used to make life easier.
9. Use proper terminating glands for the type of cable you will be using
10. Get a crimping tool and some bootlace ferrules, cable number markers make a better job too.
11. Use tri rated single core cables inside the panel, check the standard colours for panels used in your area, e.g. here it's black for AC power, blue for 24 DC, etc.
12. Make provision for cooling fans, ideally some blowing in and some sucking out. The ones sucking in should draw air through a replaceable filter, you need to keep a higher pressure inside
the panel so dirt is not sucked in through gaps.
13. Use DIN rail to mount everything.
14. Use quite deep trunking, it fills up quickly.
15. there must be more :eagerness:

Quote:

---

Originally Posted by EddyCurrent

Bit too far I think :highly_amused:

---

Eddie, are you sure? Only an 11 hour flight I'll supply all the beer and sunshine you can tolerate :-)


Thanks for the very detailed reply, much appreciated. I'll go thru it with a fine comb tonight and google the stuff you are referring to that I'm not familiar with.

Quote:

---

Originally Posted by mitchejc

I'll supply all the beer and sunshine you can tolerate :-)

---

you got your ticket yet eddy :)

Outch, got some prices on steel cabinets. My budget is experiencing a severe hangover to get the machine this far so are there perhaps any cheaper options that's feasible and then hopefully upgrade later? My other problem is that I don't have any tools to cut holes etc into a steel box so I have to factor that into the price. I understand why a steel cabinet is the best choice but can one get away with a wooden box with a metal back plate or something to that effect?

lol i almost fell over at the prices ....

i went to visit a friend one day, and found an awesome box in his neighbors garage which he said i could have !!!

look into having a 2mm box laser cut, its still cheaper than buying one, you just have to draw it

+1 on the SIZE of the box , my box is quite big .... or so i thought lol

Quote:

---

My other problem is that I don't have any tools to cut holes etc into a steel box so I have to factor that into the price.

---

I see a pillar drill and hand electric drill in your shop. :highly_amused: 600 x 600 x 300 should more than big enough, You don't need to put the VFD inside the control box. Just how big a box was you considering? ..Clive

http://www.mycncuk.com/attachment.ph...id=14535&stc=1

@blackrat, maybe laser cutting sheet metal is a good plan as I know its going to cost way less than what these enclosures cost but I'm probably going to have a very hard time to arc weld it together. I've tried welding thinner material but it was hit and miss and I burned holes like you wont believe even with 2mm rods, so there's much to learn in that department.

Clive, now that's a great looking box! Those LCD displays really got my imagination going... Can I extend the offer for free beer and sunshine to you :-) I'm a bit scared of butchering an expensive box with what tools I have. I have not done the layout yet as suggested by Eddy but I was guessing maybe 600x400x300 as a ballpark? Content would be 1x PC ATX Powersupply, BOB, VFD(vfd face outside the box) 4 x Drivers and few relays. The driver are quite big at something like 180x160x60 if I recall correctly and I would like some spare space for future expansion.

Excuse my ignorance but what's those white square things in your box?

Try and get smaller rods, years ago before i got my TIG setup i was trying to patch up a car and only had a stick welder but got some rods from the Local BOC outlet, think they were about 1mm dia but had a substantial flux coating and was told it contained iron fillings, worked OK on thin plate so 2mm plate you should be fine if you could find some.
Know the feeling about the price of steel cabinets, Norweb insisted i had to buy a specific size/type of cabinet/kiosk. It cost 600GBP
Regards
Mike

Quote:

---

Originally Posted by mitchejc

@blackrat
Clive, now that's a great looking box! Those LCD displays really got my imagination going... Can I extend the offer for free beer and sunshine to you :-) I'm a bit scared of butchering an expensive box with what tools I have. I have not done the layout yet as suggested by Eddy but I was guessing maybe 600x400x300 as a ballpark? Content would be 1x PC ATX Powersupply, BOB, VFD(vfd face outside the box) 4 x Drivers and few relays. The driver are quite big at something like 180x160x60 if I recall correctly and I would like some spare space for future expansion.

Excuse my ignorance but what's those white square things in your box?

---

I don't think you will get all that in that size box. I would think twice before putting the ATX inside the main control box as beside the board you would need a power supply, hard drive fan etc plus all the connecter to the monitor, keyboard mouse.
.
The LCD displays were from China about £2 each, the housing for them was done with a 3D printer. The white square things are the 5V and 24V power supply's there also another converter to step up the 5V to 12V to power the motion control board. 24V for the E-stop and 5V for the BOB.
.
I don't think many people on here put the VFD inside the control box. Remember most of these box housings have a bottom plate that you remove and make the holes for the connectors so if you f#%~k it up you just make a new plate.
.
Does the free offer include the flights. :yahoo: :beer: only kidding. ..Clive

As I said earlier;

5. . . . , the space you need is going to be bigger than you think. :whistle:

If you don't do it on CAD then cut some cardboard shapes full size to represent the electrical items and shuffle them about.
I was going to say, if you look at standard panels that will give you some dimensions to aim for. It troubles me that after all that excellent mechanical work you want to scrimp on an enclosure.:sorrow:

Dont forget safety circuitry, ideally a Pilz, which you can get second hand off ebay. If you cant get a Pilz then folks make do with small relays.

Gents, thanks for all the great info! I'll do the layout this weekend and figure out what size I actually need but I'm getting the feeling I'm in for a nasty surprise. I don't plan to put the PC inside the box and the PC power supply is only to power my bob, switches and relays. I'll read up on the Pilz thing to figure out what its for.

1) What's the reason for not putting the vfd in the box? Heat or electrical noise? Mine has lots of ventilation holes in it and I was thinking the best way to keep aluminium chips out of it was to put it inside my box but if that's a bad plan I need to rethink my strategy?

2) I got 4 x 80mm PC fans for the cooling. The uncool neon green ones with the LEDS but they were cheap:-) Was thinking 3 sucking air in thru a filter at the box bottom and one out at the top left. Would that provide enough airflow considering the climate is quite hot here and 35deg Cel. or higher is not that rare. I tried one just to get a feel and it did not exactly blow my hair back at 12V so I don't know.

I really don't want to scimp on the box but if I want see this thing cutting in the next few months I don't much of a choice. Its going to be incredibly hard to be patient while saving up for a box...

-I do it like Eddy said, shuffling the pieces until i am happy.

-The VFD for a 2-3kw spindle is prohibitively big to put inside enclosure. Plus it could mean more thick cables and so on. Plus the cooling flow. Better put that somewhere you can see it all time.

-About the fans-make them all not to suck. This is wrong, it sucks :hysterical:. Make them take away the air and fit exchangeable air filter somehow. Cheap car motorcycle tuning filter or whatever similar. You don't want dust inside.

-I dont have PILZ, could somebody explain how, why?




Now just another idea:

I also hate spending money on expensive boxes. On any boxes. On my current build i decided to use whatever i had at hand. So i had some plastic sheet and 1mm aluminum with self adhesive backing. I fixed them together and used as legs the M5 allen screws for the Hiwin, as i bought a 500pieces box.

Most importantly i decided al the cables to go at the back and not be seen, plus the aluminum plate screens them additionally.


When i finish the machine i will build myself an enclosure . At least when i spend money will spend them properly and buy aluminum and make it beautifull or at least as i like.

As i left at the left/right side of the plate 15mm free, this will slide into the new box where cheap aluminum U profile will play the role of slide.

Some pictures to get an idea. Yeah, i was tired so some holes are not drilled in a line, i have to repair that. Money should be wisely spend on a DIY build. Buying the connectors and terminals separately and soldering them in my case resulted at least in 350eur savings.

Do you see the empty space at the right side of the drives? thats for eventual 5th 6th axis. The empty space bellow the BOB also is for whatever. When i started the build i did not know. Now i know for what it will be.
LEAVE EMPTY SPACES. YOU WILL NEED THEM LATER.


http://www.mycncuk.com/attachment.ph...id=14538&stc=1 http://www.mycncuk.com/attachment.ph...id=14539&stc=1http://www.mycncuk.com/attachment.ph...id=14540&stc=1

Quote:

---

Originally Posted by silyavski

-About the fans-make them all not to suck. This is wrong, it sucks :hysterical:. Make them take away the air and fit exchangeable air filter somehow. Cheap car motorcycle tuning filter or whatever similar. You don't want dust inside.

---

Whatever you do with the fans there are two things that are a must, there is no other way;

1. Air entering the cabinet must be filtered.
2. The pressure inside the cabinet must be higher then the pressure outside.

My vfd is inside the panel, this is industry norm if done correctly and the manufacturers rules are obeyed. If you do put it in another enclosure then it will also need fans and filters.
Also you can either save money or do it right the choice is yours but only if the machine is for your own use.

This shows a typical layout of a bigger panel but you can see they keep the power control items away from the signal items.
https://www.youtube.com/watch?v=XY3gwpR67WU

Quote:

---

Originally Posted by EddyCurrent

2. The pressure inside the cabinet must be higher then the pressure outside.

---

Eddie, i believe its the other way around. The pressure in the case should be Negative. Not Positive.

Anyway its relatively speaking, cause if a car filter lets 200HP engine breath easily without obstruction, it could provide enough airflow for some small ventilators :-)


Rule #2: Have More Exhaust Fans Than Intake Fans (Negative Pressure)
http://www.tomshardware.co.uk/faq/id...uter-cool.html


PS. Forgot to say before. Heat rises, hence the drives where i placed them, so they don't heat all the enclosure

Quote:

---

Originally Posted by silyavski

Eddie, i believe its the other way around. The pressure in the case should be Negative. Not Positive.

---

Well like I've said before, people can do what they want, I've worked in industrial electrics all my life and if any panels or switch rooms had been negative pressure they would have failed on a regular basis because of sucking in crap through every little gap. If you've ever worked in a Steel Works you would know what I mean.
If you can be sure the only way in for the air is via the filter then in this case it might be okay.

The very bottom line here for eaxmple;
"The only air introduced into the cabinet is filtered before it enters the Vortex Cooler. Vortex Enclosure Coolers maintain approximately 6” W.C. positive pressure inside the control cabinet."
http://www.vortexair.biz/Cooling/Vor...texcooler.html

Here; http://www.nexflowair.com/panel-cooler.php; "Prevents dirt contamination by keeping enclosure at positive pressure"

And another thing, here in the UK it's not such a problem but in the OP's case where it can get very hot, it's no use blowing hot air into the panel and expecting it to be cooled, at some point a proper cooling system might need to be employed.

Thanks for the help so far.

I'm not sure if this post is to try and validate my assumptions or a cry for help?


I've gathered a lot of info on here and elsewhere and frankly, my head is spinning wrt to the controll box, wood or metal aside. I understand how to connect my drivers and VFD to my controller and I have confirmed my understanding by testing it without blowing anything up but if I look at the great control box projects and circuits on here, there's apparently a hell of lot more to it than that e.g. safety circuits and all sorts of contactors, relays etc. which has me questioning my plan. I'm trying to figure out whats really the bare essentials. I am guilty of some serious OTT stuff but when it comes to the electrics/electronics I just don't have the experience or knowledge to pull off anything elaborate.


My requirements are simple and I'm trying to achieve it in the simplest way possible. Please correct me if I'm missing essential safety requirements


1) I need an Estop that will let mach3 know its pressed and to disable my drivers but will leave the spindle running. My estop switch has a separate NC and a NO circuit so when pressed I'm thinking to use the normally open circuit to send a signal to mach3 and the NC circuit to disable my drivers.
No relays or anything fancy, just 1 x 5V circuit to my controller to let mach3 know and one 5V circuit running thru my 4 drivers enable pins in serial. With this approach I understand if I click estop in Mach3 it will stop sending instructions to my controller but it will not disable my drivers which is fine with me.


2) I'll operate my VFD manually wrt to run and stop and only use my controllers 0-10V output to change speed. Nothing else, no relays etc

3) Don't really have a plan what to do with the fault signals from my drivers? I need to disable all drivers if any one faults but not sure how to accomplish this in the most basic fashion? Maybe that's the stuff I see in other control boxes that I don't have the foggiest clue about :-)

4) Limits and Home switches. I actaully considered not fitting any as I've never run my old machine into the limits but my build is a lot smaller than that so its probably a bad idea. I'm thinking of fitting limit switches for Xmix,Xmax,Ymin,YMax and Zmax with one NC circuit running thru all the switches in serial. I'm not too concerned about homing as my controller do not have the capability for dual x axis home anyway and on my old machine I always cut from a G54,55... offset and I can't foresee me using the new one any differently. I'll configure mach3 to use the limit switches for homing for whatever its worth.


5) My control panel will consist of only the EStop switch and a 220v 24Amp circuit breaker that will cut all power to the machine (controller, drivers, vfd and waterpump) Guess which one I'll be going for when the sh%t really hits the fan :-)


6) My waterpump will run all the time when the main circuit breaker is on. In time I'll figure out how to use the build in relay in my VFD and use that to switch the waterpump on and off.


7) Apart from proper grounding of all the 220V stuff I have no additional safety anything, no contactors, no filters, no relays, no nothing.


Is this a realistic workable plan as a first stab at my control box or am being ignorant?


Sorry for the long winded post!

what controller you are using? If it works without a plugin with mach3 it certainly can home double long axis separately.


It will be best to start stop the spindle with relay and control the RPM via 0-10V. What is the model of your VFD?

We will help here so you do it right. Its not difficult.

Mitchejc, its totally feasible just take your time.
When I started I looked into the electrical before the mechanicals (which was a mistake) and I think in the end had I not stopped I'd have had 3 iterations of my control box, the first one had no safety and Jazz and Andy intervened to help.

I would start with power, get the PSU's in and working, then get the safety system arranged to kill the power as needed with the combination of limits and estops. Then I'd go for the bob and make sure that the safety circuitry can send the right signals to that. From there I'd work on home and limits to the bob and then you've got the guts of a working control system, motors and drivers are usually a function of the right wires in the right place, not much scope for creativity or screwing that up, maybe there's some motor tuning via drivers but that’s icing once the rest is done, not saying its not important, just most likely done near the end.

The critical thing in IMO right now is figure out the safety and control (limits and home), there's lots of good advice on the forum, limits NC, estop the same etc.. Personally I found it challenging to get into all the relays and drew comfort from the reliability of the pilz, they are available second hard and if you can get one I don’t think you'll regret it. Even starting out with some power and a pilz with a reset button and the estop circuit will build your confidence a lot.

Lots of folks have great advice, some of it is a bit overwhelming when you're a beginner, I'd proceed as outlined and add the frills like spindle control, water pump, etc once you’ve got power, safety and comms to the PC via the bob sorted.

Ps. I needed a bigger box each time I added a new feature, either get one bigger than you need or figure out the basics without a box first.

The panel for my own machine was called "OTT for DIY" at the time but I disagree, for me it was just normal. For example if you could easily produce mechanical items to a particular tolerance and finish, why would you choose to make one inferior ? I can see that cost is a factor but that does not mean you make it less safe, you just have to reduce the number of features while keeping the core safety aspects.

I think the thing going amis here guys is the difference in cooling vs contamination free.

So, what you should have is a negatively pressurised enclosure but also have filters on the intake to stop contamination.

Cleaning a filter would typically be less evolved than cleaning a populated enclosure.

Like Eddy says, do what you want but put "safety" as close to the top of the priority list as you care for, heat control is one of the higher items on my safety check list ;-)

.Me

Something like this is perfectly enough http://www.hobbyking.com/hobbyking/s..._Gas_Car_.html
Most of these filters filters if they are a good brand, could filter up to 5 microns with excellent flow.

http://www.mycncuk.com/attachment.ph...id=14568&stc=1

Definitely the enclosure has to be airtight apart from the filter , i thought that was clear, who wants to spend time cleaning enclosures. And a good thing to note is that when cleaning filter enclosure with a compressor, we Must be sure the air is dry. Spitting water drops on a couple of hundreds euro BOB could hurt.

But as i see it, there is not a law or something. I would say - negative pressure if all is in straight line and easy to cool. Intake ventilators to help the airflow if necessary, especially when there are some obstructions, otherwise-not. Hot things, air out- up in the enclosure, intake from bottom. All in straight line without obstruction if possible.

I would say also - forget 12v PC fans and similar. 220V - ~20-30w ventilator or 2. One all time, second when necessary. Little OTT here will not hurt.

Quote:

---

Originally Posted by silyavski

what controller you are using? If it works without a plugin with mach3 it certainly can home double long axis separately.


It will be best to start stop the spindle with relay and control the RPM via 0-10V. What is the model of your VFD?

We will help here so you do it right. Its not difficult.

---

Thanks silyavski. I'll be using a cheap controller I bought before I joined this group and I hope to upgrade to CSLABS CSMIO/IP-M later this year so no dual axis homing.

In bench testing I've been able to control my VFD speed from controller but I'm unable to figure out how to switch it on and off with my controller. My VFD is a Sunfar E300. The model number says E300-2S0022L. Attached is the manual

http://www.mycncuk.com/attachment.ph...&stc=1&thumb=1

Quote:

---

Originally Posted by TonyD

Mitchejc, its totally feasible just take your time.
When I started I looked into the electrical before...

---

Tony, thanks for the info and reassurance. Your suggested approach makes sense and I'm going to follow that. I had a look on the PILZ website but there's a lot of stuff. Sorry for my ignorance but what does this thing do on a high level and where does it fit in? Which model number should I be looking for to get some docs?

Quote:

---

Originally Posted by EddyCurrent

The panel for my own machine was called "OTT for DIY" at the time but I disagree, for me it was just normal. For example if you could easily produce mechanical items to a particular tolerance and finish, why would you choose to make one inferior ? I can see that cost is a factor but that does not mean you make it less safe, you just have to reduce the number of features while keeping the core safety aspects.

---

Thx Eddy, I get what you are saying. What is the absolute minimum core safety aspects considering I'm the only one who is ever going to be using this machine and I do have 100's of hours machining time on my old router so I've got a fair idea of what can go wrong from an operating point of view? In my mind estop is a nice to have as long as I have a nice big circuit breaker handy that will cut power to everything :-)

Quote:

---

Originally Posted by silyavski

Something like this is perfectly enough... Little OTT here will not hurt.

---

Thx, these type of filters are a good plan. I think you are right about the 12V PC fans, they are weak and I'll go for a bigger 220v fan or two. I'm not sure I'll be able get my box 100% air tight where the wires come in etc so it might be better for me to put my big fans on the bottom (cooling air input side) with filters to try and get a bit of positive pressure then I don't have to worry about small aluminium chips getting into my box.

Quote:

---

Originally Posted by mitchejc

Thanks silyavski. I'll be using a cheap controller I bought before I joined this group and I hope to upgrade to CSLABS CSMIO/IP-M later this year so no dual axis homing.

In bench testing I've been able to control my VFD speed from controller but I'm unable to figure out how to switch it on and off with my controller. My VFD is a Sunfar E300. The model number says E300-2S0022L. Attached is the manual

http://www.mycncuk.com/attachment.ph...&stc=1&thumb=1

---

These are the basic steps to make the VFD work with your spindle:

F0. 0 1: External input signal (0~10V / 0~20mA)


F0. 2 1st part of LED 1:Control by external terminal
F0. 2 3rd part of LED 1: Valid
F0. 2 4th part of LED: Self-startup when power-on 0: Prohibit




F0. 4 Upper freq [F0.3] ~ 1000 Hz 400/ if your spindle is 24000rpm, if not divide RPM/60


Check if these 2 are by default 10: if not set
F0.5 Acc time 10:
F0.6 Dec time 10:


Spindle speed control:
connect from BOB to terminals 10V/+/ and CM/common/
F1. 1 AI input upper volt [F1.0] ~ 10.0V , Leave that to 10 if you board outputs 0-10VDC for spindle control, change to 5 if the board outputs 0-5VDC
F1. 3 Max setting freq 400/if your spindle is 24000rpm




Protection:
connect terminals Ta Tb /NC normally closed/ to the ESTOP circuit, so that if the inverter trips it will stop the machine


When you are finished with all of the above:
F0. 10 Parameter read-in protection 2: Only allow to modify this parameter


How to turn it on off and the speed control:

not all the info is relevant to your case, so remember your settings from above, but read about mach 3 , relay assignment and checking the speeds. You will need a cheap tacho
If you dont have a relay output/alsmost impossible/ , you will need a cheap ??V relay/depends of voltage output of your board/ from ebay.

http://www.cjh.com.au//PWM%20Spindle...ng%20Mach3.pdf

Quote:

---

Originally Posted by mitchejc

Sorry for my ignorance but what does this thing do on a high level and where does it fit in? Which model number should I be looking for to get some docs?

---

In crude terms, imagine two relays in parallel, both powered by a feed via the normally-closed estop switch. Each relay has a normally-open contact and these are wired in series and used to supply a control voltage to the external system - exactly what it does is up to you. So, in operation, both relays are activated, both relay contacts closed, and external system enabled. Hit the estop, the relays drop out, and the external system is disabled. Two relays mean that even if one contact sticks, the estop still works. For greater reliability, the two relays can be fed via a double-pole estop switch and two cables although I'm not sure if many people go this far. As it stands, though, the system would restart when the estop button is released or unlocked, so the safety relay box has a couple more relays which are associated with a reset or enable external switch which has to be pressed to get the main relays into their operational state. My Pilz relay actually has three sets of contacts so it can control three independent external systems/devices (maybe enable inputs on stepper drivers, ditto on VFD, and estop input to Mach3, for example). And that's one of the simpler Pilz devices! I bought mine as a new-but-obsolete version from eBay so the model number isn't very relevant (and I can't remember it off-hand).

As to where it fits in - a normal estop setup can only switch one circuit. Generally, you want to switch more than that (as per comments above) so you are going to need some kind of relay setup or somesuch to handle multiple independent circuits, but for emergency use it needs to be reliable which a single relay might not be. Add in the need for an explicit reset switch so if estop is hit, then things really stay off, and it gets a bit more complicated still. The Pilz "relay" packages all that functionality into one box. You might want to trip the relay with the limit switches as well as estop but that's a decision for the machine builder.

Safety relay info from a previous post.
http://www.mycncuk.com/threads/7723-...0325#post60325

@ Silyavski, thank you very much for taking the time to go thru my VFD manual to help me. I think I'll get it going now and I will also connect the VFD failure relay to my EStop circuit.

@Neale, Ahh, thx, now that makes a lot more sense to me. I can now see why one would use this. I guess emulating the functionality by using a few relays that drop out on estop would not be impossible but getting the reset functionality to work would be very difficult for me, so it would be a lot easier to just use a component. Had a look on RS-online but new they are expensive so I'll try and find a second hand or discontinued one from a seller thas will to send here. Just wondered why on earth they call some models a PNOZ, do they know what it sounds like when you pronounce it in english :-)

@Eddy, thanks that's a very useful link.

BTW you guys were right, I did a cad layout of my control box this weekend and its MUCH larger than I thought if I follow the component manufacture's guidelines for spacing between parts. I'm going to need a small lotto win to complete this machine if I want a nice PNOZ, a steel enclosure and a CSMIO/IP-M. Scratching around to see if I can't maybe liquidate some other redundant hobby stuff :-)

Just thought I'd post an update. My build has been delayed a bit mostly due to lack of budget but I finally got going again. Got lucky and a friend contacted me to cut 6 x bench-rest rifle stocks which helped a bit for the hobby cash-flow. My stock making hobby is what what got me into cnc in the first place :-) Here's a pic of one getting cut
http://www.mycncuk.com/attachment.ph...id=15330&stc=1



Anyway back to the topic. Got a nice 800x600x220mm steel cabinet for a very reasonable price (+- 70GBP). I was concerned about my ability to cut holes etc in the steel but got it done relatively painlessly using a Dremel and those small clip-in cutting disks.


http://www.mycncuk.com/attachment.ph...id=15334&stc=1

I cut a alu panel to replace the steel one that came with the box.
http://www.mycncuk.com/attachment.ph...id=15333&stc=1http://www.mycncuk.com/attachment.ph...id=15341&stc=1


I made an air filter box with a cheap car filter to house my huge fan and keep stuff out of my control box.
http://www.mycncuk.com/attachment.ph...id=15338&stc=1http://www.mycncuk.com/attachment.ph...id=15339&stc=1http://www.mycncuk.com/attachment.ph...id=15340&stc=1


I think I have figured out what I want to do with my wiring. I'm a bit further along but these were the last photos I took.
http://www.mycncuk.com/attachment.ph...id=15336&stc=1http://www.mycncuk.com/attachment.ph...id=15337&stc=1

WHOOHAA, its running! :excitement:

Finally completed my control box. Decided to chuck 4 of the safety circuit relays and replaced it with an Arduino which resulted in a simpler overall setup. E-Stop button works as expected and any fault or position loss will stop all motion.
http://www.mycncuk.com/attachment.ph...id=15522&stc=1

Steppers now mounted
http://www.mycncuk.com/attachment.ph...id=15524&stc=1

Have to do the wiring of the machine now, fit cable chains, zero and limit switches etc but could not resist to try a few test cuts. No machine bed yet so I just clamped a vice on a few blocks of wood. Took a lot of effort to get this far but thinks are finally comming together and I'm absolutely over the moon with how the machine cuts. Part below was cut 15mm deep with a 6mm HSS endmill at 1000mm/min @ 3mmDOC and finishing cut at 500mm/min and 6mm DOC.
http://www.mycncuk.com/attachment.ph...id=15521&stc=1
http://www.mycncuk.com/attachment.ph...id=15523&stc=1

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Originally Posted by mitchejc

Decided to chuck 4 of the safety circuit relays and replaced it with an Arduino which resulted in a simpler overall setup. E-Stop button works as expected and any fault or position loss will stop all motion.

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Looking good but how do you work out that an Arduino can replace Safety Relay/s.?. . . . It's a Computer.!! . . . . . . In which case you may have just saved your self the hassle altogether and just used the I/O you had already.! (unless you didn't have enough I/O to start with.!)

Thanks Jazz. Apologies, that came across wrong, ill try to explain. I wanted any fault signal to disable all movement and I could not figure out an easy way to combine the 4 stepper driver fault signals into one so I got them to switch 4 small relays and then wired the relay switches in serial so if any one opens it cuts my 5v enable circuit etc.

There are probably better solutions but I replaced those 4 relays with the arduino using 4 inputs and 1 output. Arduino Inputs connected to stepper driver fault outputs and the 1 output connected to all driver enables and spindle relay. The few lines of code check the inputs and if any change is detected it takes the output pin low disabling all drivers and switch the spindle off. Ive tested this to death and it works like a charm.

Not sure I understand what you mean about the spare IOs. I do have spare inputs available on my controller but i dont want to rely on mach3 alone to stop everything or is that not what you mean?

I think what he's getting at is how u had it setup with the 4 relays, why the need for Arduino, are you then doing somthing else once a fault is detected?

Mechanical vs Digital I guess.

.Me

Yep, Lee I had one relay per driver with the fault signal driving the relay so a fault on any driver would open that relay which would break my enable circuit which ran in series thru the 4 relays + spindle fault relay. So you are correct, I just replaced the simple logic that the electro-mechanical parts performed with digital.

Please keep in mind I'm very much a noob when it comes to this electrical and electronic stuff so how do you gents combine these sinking type stepper fault signals?

Quote:

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Originally Posted by mitchejc

Not sure I understand what you mean about the spare IOs. I do have spare inputs available on my controller but i dont want to rely on mach3 alone to stop everything or is that not what you mean?

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What I mean is that there's no difference between Mach3 inputs and Arduino inputs Both are using and relying on Computers for safety.(BAD news) So if you had the spare inputs you may have well just used I/O on controller.

Regards the Drive fault signal and Relay then you only needed 1 relay and wire the drive fault signals in parallel so if any drive faulted it turned on the relay. The relay NO or NC contacts would be used to control other things like E-stop relay and send signals to control saying fault happened.!! . . . Much safer.

Thanks for the advise, Jazz. Keep in mind we rely on computers for safety all the time, in fact in some cases we use computers to make mechanical things safer :-) I do not really agree with you comparing an arduino with a pc as they are worlds apart in terms of complexity and things that can go wrong etc but its not a topic I want to labour.

I believe what you are trying to get across is that the relay solution is ultimately more reliable and I'd still like to get that working if possible. I thought this was going to simple as pie and its not like I did not try and I spent more than a full day to get it working and failed to do so reliably. My challenge is the following: Fault output on the driver is a sinking type output. I connected it as per the manual with a simple little 5V circuit containing only a current limiting resistor and I got 0.7V on the driver fault output pin when in fault and 4.7V when not. I can swap these around in the driver setup when I set fault to "active high". I used this setup with a small relay board that basically contains a transistor and a diode but it switches even at 0.7V and its at that point where I started fiddling and burning time and eventually chucked in favor of the simple arduino setup which I got working in 30mins. So what's the right way to do this? Can you perhaps please help me out with a description or diagram or close-up pick of your fault signal setup if you are using Leadshine drivers?

Quote:

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Originally Posted by mitchejc

Thanks for the advise, Jazz. Keep in mind we rely on computers for safety all the time, in fact in some cases we use computers to make mechanical things safer :-) I do not really agree with you comparing an arduino with a pc as they are worlds apart in terms of complexity and things that can go wrong etc but its not a topic I want to labour.

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Well if your so sure it's safe then you don't need any other system so why waste each others time.!. . . . Carry On.