Do you prefer chassis punches or hole saws for cutting your tube socket holes?

[mort]

Just wanted to hear some of your preferences on cutting out your chassis. Also any tips on cutting out PT slots would be appreciated. Thanks

[jbltwin1]

I prefer hole saws because I HAVE a bunch of them. Square holes that size, I use Jilson snips or a sabre saw. Depends on how thick the chassis is and what it's made of. Up to 18 gauge, I'll use the jilsons. The hole saws are a LOT cheaper too but they do have the byproduct of cuttings that you have to account for. Mike.

[soundguruman]

Chassis punch of course.
If you have a drill press, I suppose you could use hole saws.
Well, most hole saws won't even last long enough for ONE hole in a steel chassis...

PT slots- milling machine.
You need to find a fabricator machine shop that will help you for a reasonable rate.

Using hole saw hand drill files, etc
It's going to turn out a bit sloppy.
Depends on if you are just doing it for yourself...or doing it professionally.
If you are doing it for a customer, it probably should be neat and clean as possible, machine shop.

[ric]

I've found machine shops to be expensive here in a MI factory town. To the tune of two grand as an estimate for some fret scale templates. That was with an offer from the VP, whom I know to program the CNC himself NC & pay the guys to run the parts. Then again, for a chisel I wanted bent for guitar work, they annealed it, bent it, retempered it and sharpened it for ten bucks. At a different place I wanted a radio chassis milled and it came back looking like they probably just used a sawsall. Your results may vary. Nice thing about chassis punches is if the drill wanders, if you're oversize on the bit, you can set the punch back on your line and you're golden. I've found the Klein electricians nibbler, available at any home center, to work fine for square holes for my one-off hobby stuff.

[hylaphone]

Punches are cleanest for the tube socket holes, always center punch and pilot everything first, anything under 1/2" I just use a step-drill.
Always do the tube sockets / PT bell cutout before you drill their mounting holes.. without a milling machine it's hard to locate those precisely..
The PT cutout is short work when you drill the corners and jigsaw in between.
Large round and bastard files are really helpful too. Also a nice big sharp drill bit for deburring your holes by hand..

I find the layout far more time consuming than the actual machining.

[imaradiostar]

Chassis punch whenever practical. Often use a step drill. Small rectangular cutouts are done with a series of holes and a file.

Jamie

[tubeswell]

Punches. I got a whole heap of assorted sizes.

[mort]

Hi Tubeswell !!

[wyatt]

I've been buying old Greenlee radio chassis punches on eBay for years, I must have four sets of some. I pair them with a modern, ball-bearing drive bolts. The punches are self-sharpening as they cut, so if they were taken care off, with no amateur attempt at sharpening them by hand, they'll usually work like new.

The radio chassis punches are true-to-size...a 1-3/16" punch cuts a 1-3/16" hole. The modern Greenlee punches are knockout punches for conduits and cut oversized holes.

The "BIN" asking price for old radio punches is usually outrageous ($50 a punch), but you can often by a batch of them (with a few common sizes) for $15-20 in an auction.

[Tom Phillips]

...The punches are self-sharpening as they cut, so if they were taken care off, with no amateur attempt at sharpening them by hand, they'll usually work like new. ...

I've always wondered if my Greenlee punches would ever need to be sharpened. And, if so, how it should be done. This self sharpening information is very interesting to me. Really! Can you tell me more? Does Greenlee mention this in their instruction manuals or other literature? My old punches seem to work fine. I just always wondered if they could / should be better.
Cheers,
Tom

[cminor9]

I use a bimetal hole saw. Seems to work fine with the relative light steel and aluminum boxes I use for my builds.

Greenlee punches would be nice, but unless you're gonna use them a LOT, it's hard to justify the cost IMO.

[Alan0354]

I use this kind. I was surprise how fast it drill. You start a hole with drill bit, then use this and takes like 20 seconds to drill a 12AX7 hole in a Fender Bassman 100 chassis.

http://www.amazon.com/Neiko-Titanium...hole+drill+bit

You can find different sizes to cover the whole range of holes. All I used was a cordless drill. So this is cheap and small if you have any drill at home.

[pdf64]

Yes, step drill for round holes and a nibbler NEW Supercoup NR1 Sheet Metal Nibbler Cutting Shears : Amazon.com : Home Improvement for drop through PTs.
Pete

[Alan0354]

Yes, step drill for round holes and a nibbler NEW Supercoup NR1 Sheet Metal Nibbler Cutting Shears : Amazon.com : Home Improvement for drop through PTs.
Pete

Nice, I was just thinking how am I going to enlarge the PT hole!!! Nice.