Video: DIY Milling of a rear panel

http://www.youtube.com/watch?v=uA0xwIE4xdI

Now, I just need to figure out ways to make the whole process run faster. But I'm pretty happy with it. I can do something else while it does it's thing.

looks very nice, why are you carving a spiral from the center out on the xlr holes? I'm sure you are aware--much time, etc. could be saved by not starting at the center of the hole-- or does that method make for a true, centered, round hole?

I'm just a newbie at this thing.

I had problems with bits breaking so I'm trying out different things... varying speed, depth of cut, etc.

I'll try just doing an outline on the XLR holes and see if my bits will hold up. But yes I agree, that would be faster.

I'll bet if you just cut the outline of a hole that the left over center of the hole goes flying across the room, or jams up your mill and snaps the bit.
Otherwise it seems like a good idea.
Kelly

I think using a 1/4" mill for the XLR holes would cut a big chunk of time. But that means I will have to manually change the bit, and baby sit it.

The smallest hole I need to do is 1/8" so I'm using a 1/8" bit. Then I just let it run and do something else.

But even if with the manual tool change I can cut down on time drastically, I may try that. (Need to buy a bigger bit though.)

Where's ptownkid? ... he might be able to give some insight on how to do this the professional way.

Owel, you wrote what I was thinking. spooky.
maybe it's faster to either use the cnc to drill a pilot for a step bit or drill the outlines and leave two tiny break off connections and you could pop out the slug...

K

So are you using it to engrave your front panels?

Hi,

For the NEUTRIK XLR holes : Greenlee Punch 15/16 !
Clean, neat, and very fast ! :thumb:

For all the rest : especially square holes or big holes for enormous meters, milling seems to be the solution !

I want one !

[quote author="Sleeper"]So are you using it to engrave your front panels?[/quote]

Not yet... but that's part of the plan.

For the NEUTRIK XLR holes : Greenlee Punch 15/16 !
Clean, neat, and very fast ! Heck Yeah!

Click to expand...

I hear ya... a step drill bit will also be faster... if it's a one-off piece.

But not for several panels. I'm after consistent quality, repeatable results, and automation. The higher the quality and the less work for me, the better :grin:

[quote author="owel"] I'm after consistent quality, repeatable results, and automation. The higher the quality and the less work for me, the better :grin:[/quote]

I understand... very well ! :green:

eD

EDIT : but you don't have neighbours do you ? Unfortunately, I live in an appartement ! :wink:

It's not terribly loud. Only when you're down in the garage.

When I'm in the office above the garage, I can barely hear it. I haven't checked outside the garage for noise levels.

My neighbor on one side is a famous country artist, and on the other side is a doctor. No complaints But we all get along well. Houses are spaced farther apart too.

I'm not expert, but I can definitely add some advice here. Other than the off chance of a piece flying out, it's much better to do the hole outline (inside contour) as it takes less time and adds less wear on your bits and motors.

As for bit sizes and manual changes, when you're doing holes as an outline instead of pocketing in that spiral pattern, just use the 1/8" bit. You're not going to save any time (or next to none) by using a bigger bit unless you're pocketing something that doesn't go all the way through. I use 1/8" bits for all holes 1/8" and up.

I hadn't noticed before, but those panels are steel aren't they...

Thanks ptown. I'll try that.

No, these are 5052 Aluminum.

Wow cool video!

A mill bit has a flat center and doesn't drill very well! So spiraling out is a good idea. Forcing a mill bit to drill makes it wander or break. So drilling a hole first is the machinist way to go.

I would suggest some lube for aluminum. Or you will clog the bit with melted aluminum and break them. You can use some great stuff that is a concentrated water soluble oil that you mix with water. Or 50% kerosene and 50% transmission fluid works great on aluminum. However it is flammable somewhat...

The water based stuff you can spray on with a spray bottle from the Walmart cleaning section. Mill bit's tend to melt aluminum on their leading edge and produce a rough cut and clog the bit. Of course the higher the rotation speed the higher the risk. And the larger the diameter of the bit the higher the external rotational speed. So speed is important...

An 1/8 bit will snap easy on any metal at the wrong speed or no lube to cool it and clear chips. I used my first Bridgeport when I was 12 lol... And it didn't have a cool touch screen like yours lol! Very cool. :thumb:

Having worked on quite a few CNC's may I add a suggestion: put a box around the thing, and organise some form of swarf catching. Otherwise some of the alloy shreds will get airborne, and the computers fan will inhale them, occasionally one will get across some vital connection and blow something, or cause strange intermittent faults.

One customer in Manchester brought me 2 big powers supplies to fix, they'd swapped them out when they blew. I found swarf in them both. When I checked the machine there was no air filter in the frame where one should have been. "It got blocked up and was overheating", they told me. I explained that my bill was rather more than a box of filters....

Now I got some brains to pick :grin:

SF, can you tell me where I can buy that oil? Right now, I'm just using WD-40 from a spray can.

I can't use lots of coolant because my T-slot bed is made of MDF. And not aluminum. Hmmm...I may need to upgrade my bed and use some 8020 aluminum to build a T-slot table.

So drilling a hole first is the machinist way to go.

Click to expand...

Smart. Not a bad idea. That removes any stress from the plunging bit.

put a box around the thing, and organise some form of swarf catching.

Click to expand...

Thanks for the suggestion ProfPep. I was originally thinking of building an acrylic cage but I may scale down my plans. I need to at least prevent those swarf from falling off the edge of the table and get sucked in by the computer fan.

Instead of a t-slot table, why not get a piece cut to the right size for your bed, and then have your machine make holes and then tap them...

[quote author="owel"]
I can't use lots of coolant because my T-slot bed is made of MDF. And not aluminum. Hmmm...I may need to upgrade my bed and use some 8020 aluminum to build a T-slot table.
.[/quote]

Now you're into bootstrapping territory: get a T slot cutter and use the mill to make a new bed for itself. T slot cutters do clog a bit, one of the more experienced machinists might have some pointers on that.

I have used this before http://www.lpslabs.com/Products/CuttingFluids/tapmatic.asp

And some other stuff I can't remember the name of. You just mix a little bit in a squeeze bottle with water. Lasts a long time. You can spray it on the bit to cool it and keep chips from flying around or melting into the flutes.

Real machinists call it "soup" when it is mixed!

My first full time day in a machine shop was when I was 12 on summer vacation... (My dad's machine shop) I worked 40 hours a day at 12! But I made $65.00 a week! I was a rich man with a shiny dirt bike and a used SG and L6S! Now in recording I work more. Go figure.

And the others are right. If your machine is powerful enough you could make a table with it. Machines make machines... Like Terminator :green:

Hey thanks... found a 18oz bottle of the DualActionPlus#2 for Aluminum. Not bad at $9.00 Will try those.

Great idea on making my own T-slot table. We'll see...