Thick panel, big ‘ole (metalwork)
« on: November 21, 2007, 05:55:40 AM »
I’ve been through the meta which contains a few bits and bobs on metalwork but haven’t found anything with regards to this, I need a 34mm hole in a 3mm panel for meter in a GSSL.

How do you guys get big holes into front panels? I’ve been looking at punches and they only seem to be good up to about 1.5mm thickness. Too big a for a drill surely?



Rob Flinn

Thick panel, big ‘ole (metalwork)
« Reply #1 on: November 21, 2007, 06:00:22 AM »
If it's aluminium then sometimes you can get a way with brute force & a punch, but it's not too good for the punch & the panel may distort a bit.

Other than that a stepped drill bit, but they can be expensive.

Or mark the hole.  drill a load of smaller holes round the edge & a round file to finish it off.
regards Rob


Thick panel, big ‘ole (metalwork)
« Reply #2 on: November 21, 2007, 06:54:49 AM »
I use a hand router (made for woodwork), 6mm bit, 30000rpm, lots of parafine oil applied - to cut 4mm frontplate aluminum.

If you're talking steel front at 3mm (ouch!), drill a row of 4mm holes, connect these by tilting the drill, and file for the rest

Jakob E.
..note to self: don't let Harman run your company..


Thick panel, big ‘ole (metalwork)
« Reply #3 on: November 21, 2007, 07:43:49 AM »
I would say, if it is steel, forget it.
"All PCB traces are curved to emulate the electrical response of point-to-point wiring" -Drip


Thick panel, big ‘ole (metalwork)
« Reply #4 on: November 21, 2007, 08:05:41 AM »
No, it is Al, should've said.

Thanks for suggestions guys. Yeah, stepped bits that size seem expensive (£55!) and I can only find up to 35mm (with 2mm steps, ergo no 34mm anyway). Could probably find proper size but at that sort of price I'm not inclined to try.

I have a dremel tool, I might try lots of small holes, cutting the shape with the dremel and then finshing with a rounded file. In the past I've used that method for square holes and it wasn't perfect; good enough though.

I'll make sure I have a bottle of Laphroaig to hand to keep the shakes at bay. :green:




Thick panel, big ‘ole (metalwork)
« Reply #5 on: November 21, 2007, 08:51:39 AM »
XLR holes i do it with a stepped bit untill 3/4 inch then i use a sawhole 3/4 but the diameter of the hole it does is fine for xlr. maybe you could try it!

maybe 1 inch 1/4 sawhole?

good luck.
Life is a path, death the destination.


Thick panel, big ‘ole (metalwork)
« Reply #6 on: November 21, 2007, 09:45:13 AM »
Good call!

I always thought hole saws were for wood but a glance at google tells me you can get ones which will work on metal (bi-metal). With bits costing less than £10 this will probably be a goer if I can find a 34mm bi-metal bit.

Thanks  :thumb:



Thick panel, big ‘ole (metalwork)
« Reply #7 on: November 21, 2007, 09:46:12 AM »
best results I ever got was with a step bit. Yes they are pricey but if you plan on doing lots of DIY, might as well just buy the right tool the first time. whats more costly, Doing the panel right the first time with an expensive bit or messing it up and having to redo the panel all over again?

If this is a one time thing then  might find a machine shop and have them do it for you. It would take no time at all and they would probably do it on the cheap.
You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is.

Freddy G

Thick panel, big ‘ole (metalwork)
« Reply #8 on: November 21, 2007, 10:25:56 AM »
Beleive it or not I use hole saws for all of my heavy guage steel chassis LA-2As :green:
Works like a charm :thumb:

Don't know about aluminum , I'm sure the trick is in the right drill press speed....also for steel I use lots of cutting oil :sam:
PRR wrote:
Use #18 wire for rock-n-roll, #16 wire for classical.


Thick panel, big ‘ole (metalwork)
« Reply #9 on: November 21, 2007, 11:00:05 AM »
For a Hole punch you could try here (UK)




Thick panel, big ‘ole (metalwork)
« Reply #10 on: November 21, 2007, 12:20:33 PM »
Hole saw should be considered over step bit if cost is consideration and you have a drill press.  I have a 2" (51ish mm) hole saw that has cut many thick aluminum cases for transformer mounting.  A little frightening to use on a drill press, but we like danger, right?

Doug Williams
Electromagnetic Radiation Recorders

"I think this can be better. Some kind of control that's intuitive, not complicated like a single knob" - Crusty

"Back when everything sounde


Thick panel, big ‘ole (metalwork)
« Reply #11 on: November 21, 2007, 02:14:38 PM »
The trick with holesaws is to go halfway through from one side then the rest of the way from the other side. Means that the work can lie flat on the bed of the drill press and there's a lot less deburring to do afterwards.
Lots and lots of lube.
Then there's always flycutters... (For real excitement try doing a 100mm hole with a flycutter in a drillpress :-)


« Reply #12 on: November 21, 2007, 03:12:43 PM »
with holesaw use lube, have drillpress bed all squared up and set toslowest speed you can and use clamps to keep it straight...I've had success with the wood holesaws.
"really fine players do not use stomp boxes or master volume, they match the amp to the room and turn it up to 11.  Stevie Ray, BB King, Albert King, Duane Allman, Dicky Betts, Louis Armstrong"


Thick panel, big ‘ole (metalwork)
« Reply #13 on: November 21, 2007, 08:24:37 PM »
Thanks folks, lots of useful stuff.  :thumb:




Thick panel, big ‘ole (metalwork)
« Reply #14 on: November 22, 2007, 09:24:14 AM »
bought my drillbit from this guy. Shipping to Europe is low and the product is really good, super easy to use even on metal.
I know it's 35mm but for the price, would 1mm change a lot?
and if you want the step before 35 is 33mm, you can file the rest...





Thick panel, big ‘ole (metalwork)
« Reply #15 on: November 22, 2007, 12:04:56 PM »
Thanks for the link Nicolas, that's good value. The drawing says 34mm Max. I may drill 33mm and carefully nibble away with my dremel until I get a nice fit.



Thick panel, big ‘ole (metalwork)
« Reply #16 on: November 24, 2007, 05:51:32 PM »
Chassis punches QMax thingies from Canford
Nearly ripped my elbow out of its socket but it worked - I drilled the hole in the front panel by mistake!
no warping worked fine


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