Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => AmpTools/Tech Tips => Topic started by: plumcrazyfx on April 16, 2017, 04:37:39 pm

Title: Which Knockout Punch for 9 Pin Sockets?
Post by: plumcrazyfx on April 16, 2017, 04:37:39 pm
I bought a Greenlee Knockout set 1/2 to 1 1/4 only to find out they are talking about the conduit size not the hole size.  I think I have the one I need for Belton 8-pin sockets but I need to know what is the one for 9-pins (3/4 hole).  I hear people talk about them in threads but I can't find them.  A link or model number would help.  Doesn't need to be Greenlee, just not junk.  I'd rather not drill (especially in steel).
Title: Re: Which Knockout Punch for 9 Pin Sockets?
Post by: sluckey on April 16, 2017, 04:51:39 pm
I bought a Greenlee Knockout set 1/2 to 1 1/4 only to find out they are talking about the conduit size not the hole size.  I think I have the one I need for Belton 8-pin sockets but I need to know what is the one for 9-pins (3/4 hole).  I hear people talk about them in threads but I can't find them.  A link or model number would help.  Doesn't need to be Greenlee, just not junk.  I'd rather not drill (especially in steel).
You need a 3/4" chassis punch, not conduit punches. Greenlee calls theirs a Radio Chassis punch and the advertised size will actually be the size of the hole. Here's one...

http://www.ebay.com/itm/Greenlee-Fine-Tools-for-Craftsmen-No-730-3-4-Radio-Chassis-Punch-Box-Paperwork-/292085993620?hash=item4401ae9094:g:cs0AAOSwSlBYv51B (http://www.ebay.com/itm/Greenlee-Fine-Tools-for-Craftsmen-No-730-3-4-Radio-Chassis-Punch-Box-Paperwork-/292085993620?hash=item4401ae9094:g:cs0AAOSwSlBYv51B)

I use this small Greenlee step bit for anything up to 7/8"...

https://www.lowes.com/pd/Greenlee-3-16-in-Step-Drill-Bit/3122175 (https://www.lowes.com/pd/Greenlee-3-16-in-Step-Drill-Bit/3122175)
Title: Re: Which Knockout Punch for 9 Pin Sockets?
Post by: PRR on April 16, 2017, 07:24:41 pm
+1 on using a step-bit. Marvelously more controllable than punches, fly-cutters, spade-bits, and cheaper than a set of GreenLee punches. I now won't use anything else until I get over 1.5" (I need 1.9" for large electric fittings, I do that with a 2" hole-saw and a lot of scrap oak backing).

Also:

> for 9 Pin Sockets?

Tube sockets cone in various sizes for the same base-type. A complete set of punches would be absurd. A good close-step step-drill will give you a right-enough size pretty sure.

Step-drills fall down when your stuff is much over 1/16". If you can go from both sides, or don't mind round-filing, 1/8". Of course radio/amplifier chassis stuff is normally thinner.
Title: Re: Which Knockout Punch for 9 Pin Sockets?
Post by: plumcrazyfx on April 16, 2017, 07:38:58 pm
I started with a Unibit for pedal building - drilling aluminum boxes but found I prefer regular bits.  I just hate drilling steel no matter how thin.  I tend to like the Belton socket so I think I can get away with 2 sizes and maybe drill for the pots, etc.  Now if someone just made a IEC punchout.
Title: Re: Which Knockout Punch for 9 Pin Sockets?
Post by: kagliostro on April 17, 2017, 04:28:27 am
Quote
Now if someone just made a IEC punchout.

I've never think about that tool, seems that isn't very difficult to be find

but the price is really an obstacle  :sad2:

http://www.auberins.com/index.php?main_page=product_info&products_id=511 (http://www.auberins.com/index.php?main_page=product_info&products_id=511)

http://uk.rs-online.com/web/p/products/0543614/#header (http://uk.rs-online.com/web/p/products/0543614/#header)

Franco
Title: Re: Which Knockout Punch for 9 Pin Sockets?
Post by: DummyLoad on April 17, 2017, 08:24:19 pm
Now if someone just made a IEC punchout....

they do! (http://www.homedepot.com/p/Dremel-4000-Series-1-6-Amp-Corded-Variable-Speed-High-Performance-Rotary-Tool-Kit-4000-6-50/202713349?cm_mmc=Shopping%7cTHD%7cG%7c0%7cG-VF-PLA%7c&gclid=CPblqOTrrNMCFQUQaQodbSAC4g&gclsrc=aw.ds)  :icon_biggrin:


--pete

Title: Re: Which Knockout Punch for 9 Pin Sockets?
Post by: MFowler on April 18, 2017, 05:35:37 am
I use a 18.6mm for the Beldon 9 pin and 30mm for the Beldon octal socket.


The ceramic type sockets (22mm) I think the Greenlee conduit punch works for them but I rarely use ceramic sockets.


My collection of Harbor Freight step bits get a lot of use since 2008 and they still work great.
Title: Re: Which Knockout Punch for 9 Pin Sockets?
Post by: PRR on April 18, 2017, 09:50:32 am
Nobody uses a nibbler (https://en.wikipedia.org/wiki/Nibbler)?

Radio Shack used to have a low-price one. I did a lot of aluminum with mine. Around the year 2000 there was a fad for custom PC case cut-outs, and nibblers were a thing for many madmen.

The classic nibbler makes straight/square cuts; curves are awkward. Round-corner cutouts, you naturally drill the corners first then connect them with the nibbler.

I just got (have not tried) a 'Bad Dog Biter', a nibbler which goes in your power drill. It can be set to cut semi-straight or fairly freehand. It has marvelous reviews on Amazon (many real). It is hardly cheap. I have not been brave enough to try it yet.

Eastwood Tools has air nibblers at $40 and $180. Probably aimed at larger work than an IEC inlet.
Title: Re: Which Knockout Punch for 9 Pin Sockets?
Post by: shooter on April 18, 2017, 10:17:33 am
Quote
Nobody uses a nibbler?
I just found an old nibbler as I was cleaning up the barn, they are beyond useful any more - RUST!
I used the heck outta them throughout the '90s, mainly for D type holes and they worked well, touch up with a dremel.
Title: Re: Which Knockout Punch for 9 Pin Sockets?
Post by: sluckey on April 18, 2017, 01:03:28 pm
Quote
Nobody uses a nibbler?
I have one and used it quite a bit back in the '60s and '70s. I could nibble some decent looking holes but I always followed up with a set of jeweler's files. My Dremel has made my nibbler obsolete.
Title: Re: Which Knockout Punch for 9 Pin Sockets?
Post by: Sonny ReVerb on May 20, 2017, 05:42:14 pm
Now if someone just made a IEC punchout.
I bought one of these (http://www.newark.com/duratool/974-0010/rectangular-hole-cutter-28mm-x/dp/55T8294) which is the correct size for an IEC cutout. It's not cheap, but it is compared to a Greenlee ;)
Title: Re: Which Knockout Punch for 9 Pin Sockets?
Post by: Sonny ReVerb on October 08, 2017, 10:30:39 pm
Step bit
Title: Re: Which Knockout Punch for 9 Pin Sockets?
Post by: lego4040 on January 07, 2018, 06:12:27 pm
I use a few different step up bits I have and a dremel cutting wheel for the IEC

Title: Re: Which Knockout Punch for 9 Pin Sockets?
Post by: Diverted on February 12, 2018, 02:28:54 pm
These are great. Best to use with a drill press, but you can use by hand too. Drill slowly.
I always start a hole by pre-drilling a 1/16" or 1/8" hole. That way the stepped bit stays where you want it. As someone mentioned above steel will tear them up, but if you're slow and don't force the bit they'll do the job.

https://www.harborfreight.com/3-piece-titanium-nitride-coated-high-speed-steel-step-drills-91616.html