Drill jig advice

[MrStab]

Last time I wanted to drill a few aligned holes I ordered an aluminum "PCB" with guide holes. It was $2 or $4 from JLC, I don't remember. I used it as a jig:

Wouldn't the rigidity of the press and the vice mean any misalignment would just end up in the jig being drilled through, though? I use this: https://www.clarketooling.co.uk/product/clarke-cdp102b-bench-drill-press-230v/
JLC's prices for small quantities of less-common board types went way up earlier this year, btw! Meanies.

Gang Drill

Before that, back in the old days, we had a layout department. They used blue dykem layout fluid.

Omgomgomg, seriously hoping this is something I can retrofit! I'll need to take a while to comprehend the rest of your post, as these concepts are new to me.

just use a punch spot so your bit doesn't walk.  Drill everything a bit oversized so you have some slack. 

I do make a punch spot, but even a millimetre's error can cause things to go awry. The screw holes are very close to the edge of the main hole, so I'm apprehensive about making it too big. Am I being paranoid? Is there a standard imperial measurement which fits between 22 and 23mm?



I wonder if something to precisely guide and create two punch spots/pilot holes in one blow would be a good approach.

Thanks to everyone for the input!

[Phend]

[MrStab]

My old man's a marine engineer and just suggested a cross slide. Hmm...

https://www.aliexpress.com/item/1005005497082638.html

[marcelomd]

Last time I wanted to drill a few aligned holes I ordered an aluminum "PCB" with guide holes. It was $2 or $4 from JLC, I don't remember. I used it as a jig:

Wouldn't the rigidity of the press and the vice mean any misalignment would just end up in the jig being drilled through, though? I use this: https://www.clarketooling.co.uk/product/clarke-cdp102b-bench-drill-press-230v/
JLC's prices for small quantities of less-common board types went way up earlier this year, btw! Meanies.

I'm not sure I understand the question.

The idea is you use the jig to position the piece in relation to the drill bit first. Lower the drill into the guide hole, _then_ secure it in place.

I'm not recommending it, but it's possible to hold the piece with one hand, and let the drill "pull" the piece into place.

Maybe, if the alignment isn't perfect, it can "eat" the sides of the guide hole in the jig. That won't be a problem for a small batch.

just use a punch spot so your bit doesn't walk.  Drill everything a bit oversized so you have some slack. 

I do make a punch spot, but even a millimetre's error can cause things to go awry. The screw holes are very close to the edge of the main hole, so I'm apprehensive about making it too big. Am I being paranoid? Is there a standard imperial measurement which fits between 22 and 23mm?



I wonder if something to precisely guide and create two punch spots/pilot holes in one blow would be a good approach.

Thanks to everyone for the input!

I honestly think you are being a bit paranoid, yes =)

Drill the screw holes first, then the big one.

Just use low power and go slowly. Aluminum is "easy" to work with and you can course correct. Touch the surface of the piece with the drill and check. Adjust if you need it. If it's mostly right, use a file for the final touches.

The XLR connectors all have a bezel, so it will hide any imperfections.

And, lastly, try doing it in a piece of junk, discarded enclosure, etc. before you try with the real one.

[Phend]

You will need a VICE and or clamps.
Your hands are NOT a vice.
The one you have left after using your hands as a vice, will be the only one you have left.
ALWAYS clamp or vice your work piece down.
Old timers will "medium tight" clamp work down and then rubber mallet TAP the clamp/work or vice or locator edge so the work piece hole location "mark" is perfectly under the drill. Then tighten securely.
And drill.
Time, accuracy and patience is involved (not to mention skill), but the outcome is satisfying.

[MrStab]

There is no chance in Hell I'd even consider doing a 22mm hole with such a large chunk of metal without a vice Don't ask me how I know the risks there! It's more than just my mitts I'd potentially lose!

Neutrik XLR sockets don't seem to have an imperfection-covering bezel.

Thanks, Marcelo - I think I'm understanding more that the jig isn't meant to force the drill bit into position, but more of a visual guide. I had it in my mind that they were for hand drills and the likes, and would literally guide the bit where it's meant to go.

I'm more optimistic now than I was when I first posted. Better understanding of jigs, post-fact soldering, cross slides and less pessimism about deliberate oversizing leave me hopeful.

[MrStab]

If I go for "shoot first, solder later", do you think I should expand pad holes slightly from Neutrik's recommended footprint? Or could that decrease reliability over time?

The sockets have plastic notches to reinforce against plug insertion force, so that makes me a bit uneasy about this approach. Though I'm not sure how much benefit these have on the vertical-mounted variants, as opposed to the horizontal ones.

[mozz]

Also as was mentioned, Greenlee hole punch. Not the conduit ones, the chassis punches. I have a few different sizes for tube sockets and a 15/16th is .9375. I also would punch the larger hole first and drill the outside holes second.

[MrStab]

Aren't punches more for sheet metal, though, as opposed to 2mm-thick die-cast? If they can be used for die-cast, would there be some advantage in ensuring easier alignment of the 2 holes?

[PRR]

no chance in Hell I'd even consider doing a 22mm hole with such a large chunk of metal without a vice

I have done it. And still have two hands.

BUT this was a hole-saw. In a 20+ inch fusebox. And I had oak blocks on both sides. And a very powerful slow drill which would scrape steel rather than get bound-up.

You are trying to center the large hole on a small triangle of PCB pads. All I can see is to make a 4th center hole in the PCB, clamp PCB to case, drill the pilot for the hole-saw. And common drill bits hog-out triangular holes, not counting homogeneity and sludge in the cheap pot-metal.

There are XLRs with long "wire-wrap" leads, usually bent, for remote PCB mount. These tolerate misalignment. But eat space. And it sounds like your space-budget is spent-up. And they are not widely stocked.

[davent]

I didn't notice whether anyone suggested just laying out the big holes and drill to size, insert socket and drill the screw holes with the socket as the drill guide using a hex shank self- centering bit. Could do the screwholes with a handheld drill.

[MrStab]

That's quite a cool idea, Dave - my metalwork-deficient brain can make sense of self-centering bits. Still trying to figure out what you mean, Paul!

My drill press is dumb and fast only. I think. If I half-understand properly, the male XLR socket has a neat triangle of PCB pads, but the combo jack is a bit more complicated.

Reasons why I'm not just using independent panel-mounted sockets: Female combo jack necessitating 7 connections and male needing to be switched by the TRS socket, meaning either 17 offboard wires for signal (or a bit less with some awkward jumpering), including XLR screen. Or an excess of PCB$ and interconnect$.

[Elektrojänis]

As it stands, I can't reach the solder joints as the sockets are horizontally-mounted, but I may redesign to be vertical-mount (as standoffs allow reinforcement when plugs are inserted, albeit with added risk of board flexing). So post-insertion soldering is an option which makes sense to me.

From looking at your pic: How about redesigning it with the horisontally mounted sockets, but turn it upside down. I mean, instead of the IO-board sitting in the middle of the enclosure, it would sit right next to the baseplate/lid and you could solder the sockets in the box easily.

Hmmm... Usually people propose to think outside of the boxand here I'm very much doing even more inside of the box thinking.

Edit: And again I failed to pay attention and missed that there is another page on this thread... I was referring to the photo on the first page.

[bluelagoon]

Stop trifling and get one of these CNC machines, Would solve all your troubles.

[bluelagoon]

or you could use a 22mm Forstner bit, Im sure a sharp one would get through the alloy box easy enough, so long as you clamped down the box and used a drill press.

[bluelagoon]

[MrStab]

While I'd love a room-sized CNC machine, the biggest risk is that my 5 year-old would instantly commandeer it to satiate his obsession with YouTube crafting videos.

There's no real reason why I can't do the board upside down, and it'd probably put less strain on the filter cap. I'm exploring possibilities and have a couple of versions of revised board at the moment.

Thanks for the Forstner bit suggestion. I'll look into that. I think a big issue with all of this is the slight inaccuracy of my punch/pilot holes. That's why, at least intuitively, in my mind and spatial awareness it makes sense to somehow have an accurate means of doing both punches at the same time.

Gah! This seems so stupid and simple. Maybe sleeping on all the advice for a while will help.

[bluelagoon]

That CNC machine, Your 5 year old son might get lost inside of it. maybe not a good idea 

[Phend]

Caution with that paddle bit, it will break your arm when it breaks thru.
Caution with the X Y table, the backlash will probably be great if it only costs $30.00.

[marcelomd]

This specific one was drilled with a handheld power drill. I let the jig guide the drill. Turned out ok. (I don't have a drill press. Yes, the enclosure was safely secured =) )

Whatever you decide to do, it's better to start with a small guide hole, like 3mm and then use a step drill. No need to start  big.