Small rigid router - Design advise needed

[mitchejc]

@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?

[mekanik]

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

[Clive S]

@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.
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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.
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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.
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Does the free offer include the flights. only kidding. ..Clive

[EddyCurrent]

As I said earlier;

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

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.

[TonyD]

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.

[mitchejc]

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...

[Boyan Silyavski]

-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 . 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.

[EddyCurrent]

-About the fans-make them all not to suck. This is wrong, it sucks . 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.

[Boyan Silyavski]

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

[EddyCurrent]

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.