power for fan

[dpilott]

Hi there, i'm building my first cnc wood router, ive found the motors and controllers i want to use and i want to put them in a case, however if i put them in a case ive been told i need a fan in there too, my problem is what do i use to power the fan as all the case fans i can find are 12 v and my motor power supply is 50v ?

any help greatly appreciated

thanks

[Al_The_Man]

You could use a 240vac version, say a 6" across the incoming supply.
Or Put 4 in series across the 50v.
Or make up a simple 12vdc supply from a wall-wart.
Or if you have a toridal transformer for the PS. wind a small secondary and a small br.rectifer. to give you 12dc.
Al.

[martinw]

Originally Posted by Al_The_Man You could use a 240vac version, say a 6" across the incoming supply. Or Put 4 in series across the 50v. Or make up a simple 12vdc supply from a wall-wart. Or if you have a toridal transformer for the PS. wind a small secondary and a small br.rectifer. to give you 12dc. Al.

Dear dpilott,

I would definitely go for a 230v 50hz mains fan. For a start they generally do not cost as much as DC fans. IMHO, things to look out for are the free-air flow rate, and the noise level rating. Choose a fan with the biggest flow rate and the lowest noise. Also, find one with ball bearings rather than sleeve bearings. As an example, a 120mm square axial flow fan with a 120
m3/hr flow, and a 37dBA noise rating will cost you about £15, and probably less if you go to Maplin. The current consumption is utterly trivial compared to that of cnc stepper motor power supplies.

You should check to see what flow rate you need through your cabinet in order to keep your electronics at an acceptable temperature. I'm afraid that is not the easiest of things to calculate, but my rule of thumb is "go for over-kill". Compared to the cost of toasted electronics, fans are awfully cheap.

Best wishes

Martin

[dpilott]

thanks for the help guys, i'll look in to your suggestions,

cheers