XLR Punch

[gemini86]

All I did was tape the template to the work piece, center punch each hole, then leave the template on to drill the pilot holes and punch, then removed to drill the small holes, since the small bits don't usually have a long enough point to find the center punch mark without tearing up the template.

Ideally, I would get a 2 ton arbor press and make a fixture to hold the punch, so I don't need to drill pilots... but that's a big much for a few holes. (if I start doing them regularly, I'll invest)

 

[Gold]

All I did was tape the template to the work piece, center punch each hole, then leave the template on to drill the pilot holes and punch, then removed to drill the small holes, since the small bits don't usually have a long enough point to find the center punch mark without tearing up the template.

Ideally, I would get a 2 ton arbor press and make a fixture to hold the punch, so I don't need to drill pilots... but that's a big much for a few holes. (if I start doing them regularly, I'll invest)

Marking the holes hasn't been the problem. It's been centering the stepper bit on the scribe.If you are a few mil off you are screwed. I am looking for a ruler straight row of 12 xlr's on a back panel with spot on even spacing.

 

[sr1200]

Can you just kinda use something like this as a template and build a jig?  Im thinking if you have this thing suspended above the piece youre drilling, with some kind of a guide bit (15/16 bit) that would centeritself in the hole, you could just drill down as long as the jig is secured... i can picture it in my mind, but cant find the words to explain it...

http://www.bhphotovideo.com/c/product/143699-REG/Raxxess_S12F_Single_Space_Connector_Panel_.html

 

[Gold]

Can you just kinda use something like this as a template and build a jig?  Im thinking if you have this thing suspended above the piece youre drilling, with some kind of a guide bit (15/16 bit) that would centeritself in the hole, you could just drill down as long as the jig is secured... i can picture it in my mind, but cant find the words to explain it...

I spent big bucks on a 15/16" bit. It doesn't make a round hole using a standard drill press. Maybe it would with a Bridgeport.

 

[Gold]

Can one use stepper bits for this purpose using a hand held power drill, or does one need a drill press?

It depends on how picky you are about looks. If you are looking for accuracy like you would get with a mill then no way can you use a hand drill. At least I can't. Maybe an experienced machinist could. If you are just looking to mount them and having them ruler straight doesn't matter then the answer is yes.

 

[david-p]

The problem I have found with a template or other methods involving measuring and scribing is that the drill size for the corner mounting holes is smaller than the tip of the stepper bit. It's then crucial and difficult to make sure the stepper bit is centered to the pilot hole. You could use a larger bit to drill the center pilot hole but this is three tool changes for each xlr. Very time consuming. Maybe I'm missing something.

I'm essentially using the connector as a template. Even a template would need to be squared. I'm talking about packing a bunch of xlr's close together. For a couple on a big back panel it doesn't matter as much (unless you are particular about looks).

Your method of making the big hole first and then the other two is one that I have always followed.  However, the last time I made a power supply in a US 18Ga  steel box I wasnt sure that my punches would be man enough for the job, and just used drills up to 1/2" and filing thereafter.  That's why I am interested to know whether others have successfully used allen key punches on steel.  I have to add that I got a good workout with the filing, so it wasnt all wasted effort!

In any case, having used a center punch it is good practice to start the hole as small as you can (1/16 or 1.5 mm) in order to ensure an accurate centre.  Then I proceed to to increase the size of the drill gradually, in 1/64" steps.  This is tedious, but accurate.  You can cut a corner by drilling all the small holes first and then increasing the size on all of them, stopping at the appropriate size for those that dont need to be too big and continuing with the rest.

David

 

[Gold]

This is tedious, but accurate. 

I like accurate. Tedious, not so much. Hence my quest.  Give the method I outlined a try. It's quick and dead accurate. 

I have been using centering/countersink bits which have very little runout. Next best thing are the short bits.
http://www.mcmaster.com/#combined-countersinks-and-drills/=gkaslk

 

[sr1200]

I usually drill a centered pilot hole with a 1/8" bit, then use a stepped bit to 3/4" and Dremmel out the little notches for the XLR chassis using a little metal grinding bit. 
The 1/8 pilot holes can be done together, as can the stepped cuts, but the nice thing is, the 1/8 hole centers the stepped bit, since the first step on mine is 1/8" it just pulls the material centered.

Once the XLR fits, i too, drill thru using the xlr as the template (usually tape the pieces down so they dont slip at all).  Its really a matter of getting to the habit of doing it.  The first few take a while, after 3 or 4 you can pop em out in a couple min no problem.

 

[Gold]

It seems like we are basically doing the same thing with a few differences around the margins. You get extra credit for cutting out the XLR notches. That's too fiddly for me. I get to 'close enough' before that. I use an all in one nut and lock washer with a dab of Locktite to secure them. They stay put enough for me.

 

[dirkwright]

Can you just kinda use something like this as a template and build a jig?  Im thinking if you have this thing suspended above the piece youre drilling, with some kind of a guide bit (15/16 bit) that would centeritself in the hole, you could just drill down as long as the jig is secured... i can picture it in my mind, but cant find the words to explain it...

I spent big bucks on a 15/16" bit. It doesn't make a round hole using a standard drill press. Maybe it would with a Bridgeport.

do you mean a 15/16" stepper bit? I'm not sure those are intended for this application. I think those are mostly for electricians to adapt and existing hole to a slightly larger size.

I use a paper template, center punch each of the large holes for the XLR, remove the template, mount the piece on a wood support in the drill press, drill the holes for the Green Lee punch, punch out the holes, then put the XLR on the piece and center punch the #4 mounting screw holes, remove the XLR's and drill those small holes. A better approach for me would be to use a Vix bit for the #4 mounting screw holes with the XLR in place. I don't know if they make a really small Vix bit though. I don't have huge experience with this, I'm not extremely picky about straightness, and I'm just a hobbyist playing around in my basement.

 

[sr1200]

No, he probably means a 15/16" bit.  I have one too and it just makes some god aweful S shape cut since the helix angle is ridiculously steep.  I have titanium step bits that work great and make a great clean hole.

 

[ksor]

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Let Google do the translation for you - set it up once and for all !