How to Do Pushbuttons Right

[Tim Ganz]

Using the tools in this link http://www.alliedelec.com/Images/Products/Datasheets/BM/GREENLEE_TOOL_CO/70160434.pdf

To make 22 mm and 30 mm holes for pushbuttons how is the keyway tool used? I think this key is where the tang of the legend plate fits and keeps it from rotating?

Are all the 22mm and 30mm knockout tools oil tight? What is the difference in oil tight? I guess I have never seen an oil tight button.

How would you keep the keyway punch lined up and square as you only get one chance with a panel door.

 

[TConnolly]

If you are referring to the 602XX or 601XX punches, the punch typically has 4 scribe marks on it at 0°, 90°, 180°, and 270° that you line up with scribe marks on your panel This centers the hole and key slots.

If you are referring to the 720 key way punch tool you line it up with your hole after the hole is punched and use it to nibble in a key way.

 

[jimtech67]

the manufacturer will supply hole dimensions.

A 22mm and 30mm knockouts are standard sizes

http://www.ab.com/en/epub/catalogs/12768/229240/229244/2531083/Approximate-Dimensions.html

 

[Tark]

Using the tools in this link http://www.alliedelec.com/Images/Products/Datasheets/BM/GREENLEE_TOOL_CO/70160434.pdf

Holy cow that 30mm punch is nearly $500!!!

 

[califflash]

I'm not surprised. The 720 keyway tool is over $400 list by itself and that's a two step operation which requires a $65 hole punch. The all in one seems like a money saver at that point. I have never used and of those. I use a 30.5 knockout and a file, very carefully. I've never seen a price on the draw stud type keyway knockout. I'd be interested to hear how they work.

I find buying a push button enclosure to be more economical if you look at the cost of labor for layout, knockout, keyhole, debur plus the cost of the panel. I think you come out ahead if you just add a precut box. I don't do a lot of doors with push buttons. If I had more than a couple I would definitely look into waterjet.

 

[Bit_Bucket_07]

Why do you think that control system designers love graphical interfaces? ;-)

 

[TConnolly]

Yeah, those punches are expensive. I have a 720 keyway tool but the only time it gets used is if a button has to be added to an existing panel. All new panels are laser cut. Its actually very economical, and most laser shops do plenty of panels and have the cutouts pre-programmed, you just need to give them the locations (get a quote, you may be pleasantly surprised).