Chassis Punches

taskerc · « **on:** 4 Jan 2010, 01:47 am »

Hi All,

When building my cornetII, I struggled with getting good chassis holes punched - and ended up buying a series of dedicated punches. So here is a chassis punch kit for those so interested....

http://cgi.ebay.ca/Chassis-Hole-Punch-Knockout-Tube-Amplifier-Vintage-New_W0QQitemZ120513590535QQcmdZViewItemQQptZVintage_Electronics_R2?hash=item1c0f2b7507#ht_764wt_1165

I hope this helps someone and no, it is not my listing

Chris

JimK · « **Reply #1 on:** 4 Jan 2010, 02:51 am »

Have you used them yet? I ask because I had a very similar set for punching holes in electrical panels (back when I had a blue-collar job and a strong back), and the dies always left marks on the metal. If you haven't used them yet, I would strongly recommend protecting the casework with some heavy tape or similar so that you don't mar the finish.

But other than that, they do work slick!

taskerc · « **Reply #2 on:** 4 Jan 2010, 06:11 pm »

Hi JimK,

Yes, used them during my CornetII build last year and they were very nice to use - I made sure I but the marking side of the punch on the inside but even there I saw no real issues - but they did make it easier than my first attempts by far - the build looks very good which from my handiman skills is something of a mystery and a surprise

Chris

jaevans · « **Reply #3 on:** 4 Jan 2010, 06:23 pm »

You should post some pix of the project. FYI, I have a brake and sheer for bending steel and aluminum for chassis' and have used pasteboard from cereal boxes to keep the surface from being marred by the brake - it works well, plus it is plentiful and cheap. I haven't tried this with my punches, but I suspect it would work as well as tape.

john

taskerc · « **Reply #4 on:** 4 Jan 2010, 06:27 pm »

Hi John,

Funny, I never got around to posting the final result - good reminder. I have been trying to find a reasonable way to do DIY slikscreen on the CornetII to do it some justice as it looks, er, kinda plain.

Am thinking of a thickish piece of acetate, the half-sticky photo glue stuff (like post it notes glue only a bit better and sprayable), the CornetII logo pack, a very sharp exacto knife and an airbrush to see what happens. The I will do the same for my piccolo and my Cinemag SUT and my Lenco TT project and .......

Too many projects, too little time for it all.

Chris

david62 · « **Reply #5 on:** 4 Jan 2010, 07:10 pm »

As an alternative,would hole saw work well?I have seen metal drills that have a center twist drill and a lateral scribe that cuts out the hole.
David

taskerc · « **Reply #6 on:** 4 Jan 2010, 07:37 pm »

Hi David,

I looked at using a hole saw and a stepped bit but for me they did not work out very well. But remember, my metalworking (or related) skills are not exceptional. That is why the punches were such a good option for me - here is the process:

1) decide size of punch to use
2) drill pilot hole to size of chassis punch centre spindle
3) place chassis punch inner section on "good" side of metal to be punched
4) place chassis punch outer section on "no so good side required" of metal to be punched
5) use wrench/spanner to make chassis hole

Super easy and very good result and I did an entire ConrnetII chassis (except IEC power outlet on back) in under 30 minutes.

Chris

Wayner · « **Reply #7 on:** 4 Jan 2010, 07:49 pm »

These punches are used throughout the electrical trades to put holes in electrical boxes (usually 18 awg or thinner) and are clearance holes for the usual pipe fitting sizes (1/2, 3/4, 1 and 1/ 1/4). These punches are probably not meant for stainless steel or any kind of tool steel as they are all too hard for the punches. Mild steel or galvanized steel is OK if the gauge isn't too thick. I wouldn't go any thicker than 16awg.

These were sometimes refered to as "greenfield" punches in the old days (greenfield being a water-resistant flex conduit) and the set is very handy when a fairly clean hole is needed in a panel. A hole saw will never deliver the quality of hole that these punches will.

Wayner

jaevans · « **Reply #8 on:** 4 Jan 2010, 08:06 pm »

Most of the time, however, they were referred to as Greenlee punches and are still available and pricey.

john

taskerc · « **Reply #9 on:** 4 Jan 2010, 08:10 pm »

Quote from: jaevans on 4 Jan 2010, 08:06 pm

Most of the time, however, they were referred to as Greenlee punches and are still available and pricey.

john

Yes they are a bit expensive (which was why I sent the eBay link). I think I paid about 70 GBP for three punches and have used them for about 4 projects now so they have ALMOST paid for themselves in lost time, knuckle scrapes and general inconvenience

Chris

david62 · « **Reply #10 on:** 4 Jan 2010, 08:16 pm »

It sounds like the punches might be a good alternative to a hole saw for light ga. chassis steel.

Wayner · « **Reply #11 on:** 4 Jan 2010, 08:28 pm »

Quote from: jaevans on 4 Jan 2010, 08:06 pm

Most of the time, however, they were referred to as Greenlee punches and are still available and pricey.

john

John, you bumped some old, really old brain cells on this one!!!! Wasn't GreenLee a manufacturer of these style punches?

Wayner

jaevans · « **Reply #12 on:** 4 Jan 2010, 08:31 pm »

Yes, Greenlee was the major manufacturer a long time ago - they still make them, too, as documented here: http://tinyurl.com/ybeplpp

john

JimK · « **Reply #13 on:** 4 Jan 2010, 08:40 pm »

"Greenlee"! Dang it, for the life of me I couldn't think of that name last night! I mean, it's not like I didn't use them almost every day for about 10 years....

Wayner · « **Reply #14 on:** 4 Jan 2010, 08:40 pm »

Thanks John!

I bookmarked this page. As I also fear, the quality of the punch set on ickbay may be questionable, but if you are doing thin gauge or just a few holes, that maybe the ticket for you. Way better than a hole saw.

I need to find a set for myself as these are handy from time to time.

Wayner

jaevans · « **Reply #15 on:** 4 Jan 2010, 08:44 pm »

Indeed - memory is the second thing to go and I forget the first

I purchased a set of about 5-6 punches back in the late 60s from Lafayette Electronics - cheap, made in the orient set, but they've come in handy and done well for my non-production use.

john

Wayner · « **Reply #16 on:** 4 Jan 2010, 08:47 pm »

I never see them for sale in partsexpress or other ecatalogs. I wonder if homey depoty has them?

W

taskerc · « **Reply #17 on:** 4 Jan 2010, 09:22 pm »

Quote from: Wayner on 4 Jan 2010, 08:47 pm

I never see them for sale in partsexpress or other ecatalogs. I wonder if homey depoty has them?

W

I recall looking in Home Depot for them and drawing blank stares .....

nameci · « **Reply #18 on:** 4 Jan 2010, 11:44 pm »

Harbour Freight Tools has them. I bought my set from HFT locally and it goes on sale once in a while.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=91201

david62 · « **Reply #19 on:** 5 Jan 2010, 12:33 am »

so would punches be the best way to go?Do you need any special tools to use the punches?Thanks,
David