Chassis punches

[K1JJ]

Once had a 2 3/4" Greenlee punch for Western round meters. Paid $40 in 1974 dolllars. Worked FB for many years. Eventually it got dull. The wrench extensions got longer and longer.  Tried to sharpen it. BIG mistake. That thing never worked since.   Even the local machine shop didn't want to try.

Since then I use hole saw bits. At Home Depot they have an assortment that use the same hub assembly.  Just did three round holes for the new 10M amplifier. Looks great.  If careful, a hole saw drill bit works FB.   Even works on my favorite material, Plexiglas. Clamp the work down real tight or pay the price...

T

[KA2DZT]

I'd love to have a milling machine; i have looked at them on eBay but even used they are pretty expensive and then you have to go get it, sort of like going and getting a bc rig.  I'd have to keep any one i got in my garage.   

Milling machines are fun to have.  I had five, but I'm down to four.  You will be keeping them in the garage, as they are usually very heavy pieces of equipment.  3-4K Lbs is the norm.  Bridgeport millers are not that heavy, about 2K.  Problem is that sometimes it can take longer to set up the machine just to do one operation, it can be faster to cut meter holes with hand tools.

I have a complete set of Greenlee punches, including the meter punch.  The punches will cut through 1/8 aluminum panels easily.  Steel and heavier aluminum can be too much for the punches.

Most of the time I cut meter holes (aluminum) by drilling a ring of small holes just inside the desired diameter.  Then cut out the center with dikes.  Then it's just filed out to the correct diameter.  This method takes a little time and good files.

Cutting meter holes on a milling machine can be difficult unless you have the correct tooling.  Then you would need a jig to hold the panel to the table without having the cutters hitting the table.  Not all that easy, unless you were setting things up to cut lots of meter holes.  You would also need to square up the panel on the table if you were cutting a row of meter holes.  All this can take a lot of time.  Then consider that in order to affix the panel jig to the table you have to remove the milling vise.  Not a good idea, as reinstalling the vise back on the table can be a PITA.  Squaring up the vise (using dial indicators) on the table can take some time to get it exactly square.

Fred

[The Slab Bacon]

Oh-Yea, I also forgot to mention another handy contraption- - - A nibbler!
they can make life sooooooooo much easier when drilling and blasting out a chassis. I'll often Nibble the opening out as close as I can get it, and then file it out to a precision fit. The file is still your friend!!

[W2PFY]

A nibbler

Ok I'll bite, what does it look like?

[The Slab Bacon]

A nibbler

Ok I'll bite, what does it look like?

C'mon, Terry, you've never seen a nibbler    

It's a small hand held gizmo with a grip something akin to a pair of pliers. It has an extended end on it that you either put through a hole or start at the edge of the metal. When you squeeze the grip it bites little hunks of whatever you are cutting out. The nibs are little rectangular pieces about 1/4" wide and 3/32" long.
They will cut aluminum, steel, phenolic, etc very cleanly once you master it's use.

I have 2 of them and I am lost without them. They do, however give your hand a workout when you do a lot of cutting with them. Great for strengthening your grip as well. Especially on steel. You can cut just about any shape with them, and they are great for making square holes! !  

[N0WEK]

A nibbler

Ok I'll bite, what does it look like?

C'mon, Terry, you've never seen a nibbler    

It's a small hand held gizmo with a grip something akin to a pair of pliers. It has an extended end on it that you either put through a hole or start at the edge of the metal. When you squeeze the grip it bites little hunks of whatever you are cutting out. The nibs are little rectangular pieces about 1/4" wide and 3/32" long.
They will cut aluminum, steel, phenolic, etc very cleanly once you master it's use.

I have 2 of them and I am lost without them. They do, however give your hand a workout when you do a lot of cutting with them. Great for strengthening your grip as well. Especially on steel. You can cut just about any shape with them, and they are great for making square holes! !  

The handheld Adel nibblers work great and you can now get powered nibblers at a reasonable price. The ones with the rotating head allow you to sign your name in any metal it's rated for. I cuts in the direction you apply pressure.

http://www.amazon.com/Neiko-Tools-Pneumatic-Nibbler-Cutter/dp/B002GQ8OJK/ref=pd_sim_sbs_hi_1

http://www.amazon.com/Klein-Tools-76011B-Nibbler-Tool/dp/B0000CBJCT/ref=dp_cp_ob_hi_title_4

[W1RKW]

I've used the hole saw in a drill press routine.  It works FB when the metal is clamped to a piece of flat wood. The mandril of the whole saw bit has to be of good quality as well and the drill press of course too.  I don't have the best drill press so  I planed the surface of the wood with a planer at 1 degree so that it was slightly slanted and not perfectly perpendicular to the hole saw blade.  This eliminated blade chatter and allowed a smooth cut.  Final touch up was done with a half round file or rat tail. 

[K5WLF]

I used to build panels for ultralight aircraft. The image shows one of the finished panels in a GoldHawk. The big holes were done with a flycutter. Just make sure you clamp the workpiece down securely to the drill press table and use a slow feed. Advantage to the flycutter is that "one size fits most". But be careful. If it's not clamped down good, it'll toss the workpiece clear across the hanger. Don't ask how I learned this. Panel in the image is 1/8" Al.

[KB3DKS]

  I still have a Sears Craftsman flycutter bought in the 70s for meter cutouts. Doubt they sell them now. Drill press is a must! Can cut up to about a 4" hole. For nibblers it helps to put some thin wall rubber or neoprene tubing over the handles. Cuts down on the blisters. Good unsplit hole saws are OK but a drill press helps. Keep the drill bit set so the smooth shaft is at the cutter point to keep the pilot hole true. lube helps. Yea, a couple dozen 1/8 inch holes around the circumference and a half round file works. Done that too when there was no drill press available.
  Wish there was an easy way to work with 1/8 steel panel.
Someone told me about a programmable CNC type cutter or a Laser head.
Not too many machine shops around anymore.
Bill

[The Slab Bacon]

I don't own one, but I have access to one anytime I need it. (About 7 miles away from my home) A Bridgeport will do all of the above if you can come up with a way to fasten the work to the bed. You would be amazed what you can do with a milling machine. A boring head will allow you to make any sized hole / slot you need.

I WILL own one before they shovel dirt on my face! ! ! ! !
They can be had used fairly reasonably, they are just unbearable to move!

[aafradio]

I'd love to have a milling machine...

Problem is that sometimes it can take longer to set up the machine just to do one operation, it can be faster to cut meter holes with hand tools.

Cutting meter holes on a milling machine can be difficult unless you have the correct tooling.  Then you would need a jig to hold the panel to the table without having the cutters hitting the table.  Not all that easy, unless you were setting things up to cut lots of meter holes.  You would also need to square up the panel on the table if you were cutting a row of meter holes.  All this can take a lot of time.

I guess I've had a different experience, but I've only been running Bridgeports and K-T mills for forty years or so, so I probably just have beginner's luck...  Mark the panel where the center of the hole(s) will be with a fine scriber.  You have to do that for any method anyway.  Slap the panel on a piece of plywood or other sacrificial material on the mill table with one of the meter holes roughly centered under the spindle.  Clamp in two places (a mill with its long table slots has a much easier system for doing this than a drill press, IMO.) Center the scribed mark under a small center drill and drill a pilot hole.  (Centering takes maybe twenty seconds with the X-Y table screws, and you can get within .005" in a heartbeat...that's certainly close enough for visual symmetry.)  Swap the center drill with a hole saw and drill through the panel.  (How many drill presses allow you to slow the peripheral speed of a large hole saw down to the recommended figure for cutting steel?)  Unclamp and slide the panel over to the next hole, reclamp, and fine tune its location per the previous process.  Deburr and you're done.  It's a lot faster than using a punch or drilling a zillion holes and filing to fit, at least for me.  Sometimes I clean up the hole saw cuts with a boring tool set for .010" larger to make it "look purty", but that's not essential.  Takes about as long to describe it as it takes to do it.  I disposed of my drill press to gain some extra room in the shop...they're handy for some things, but you can't mill with them...

Then consider that in order to affix the panel jig to the table you have to remove the milling vise.  Not a good idea, as reinstalling the vise back on the table can be a PITA.  Squaring up the vise (using dial indicators) on the table can take some time to get it exactly square.

I think that's why Kurt and the other vise makers sell slot keys for the bottom of their vises... 

Craig's List seems to be one of the best places to find an old mill, but you have to be patient.  Also visit some machine shops in the area - sometimes they dispose of their older equipment locally to save the cost of moving.  You may not be able to achieve the original accuracy with an old mill, but for garage hobby work, that is not usually an issue.  The one caution I have is that they can become a secondary collection temptation for tooling to go with them...

[K5UJ]

you can still get circle cutters at sears hardware, i have one.   I am hesitant to use it though, except maybe on plastic.  I'd much prefer a hole saw.  The sight of the cutter zipping around and what would happen if it came loose and flew off in the basement gives me the willies.  It's not just me either--i'd have my face covered and have on other protective clothes--it's also the idea of the thing hitting the front panel of some gear or smashing a 4-1000A or something.     

[KA2DZT]

I don't own one, but I have access to one anytime I need it. (About 7 miles away from my home) A Bridgeport will do all of the above if you can come up with a way to fasten the work to the bed. You would be amazed what you can do with a milling machine. A boring head will allow you to make any sized hole / slot you need.

I WILL own one before they shovel dirt on my face! ! ! ! !
They can be had used fairly reasonably, they are just unbearable to move!

A Bridgeport is not that heavy, about 2000Lbs.  Easiest way to move one is with a flat bed car carrier.  But this operation can be very tricky if you don't handle the machine correctly.  Once it is on the driveway, you can put pipe under it.  They are easy to pry up, a 3ft crow bar will work.  You then use a come along to pull the machine.  You need a solid anchor for the come along.  My Bridgeport was easy to move compared to my Van Norman miller which is closer to 4000Lbs.  My other miller is a K-T which I think is about 3300Lbs.

I use the Bridgeport most of the time.  I have a boring head for the Bridgeport which can bore holes to any size.  I have lots of tooling for all three machines.


To answer aafradio,

Thanks for your input.  The machine shop is just a hobby for me.  I've been using these machines since 1984.  I'm well aware on how to use the machines to make parts to within .001" but sometimes I just find it easier to do some operations the old fashion way.

Your method of using a hole saw and then boring out the last bit is certainly a very good way to cut the meter holes.  I think the largest hole saw I have is 2".  Maybe I should get something around a 2-3/4" hole saw and try your method as I do have an adjustable boring tool with a R-8 shaft to fit the Bridgeport.

Fred

[k4kyv]

For a real adventure in sheet metal work, try cutting out several 3½" diameter meter holes in a ⅛" thick steel panel by marking a circle and drilling a small hole every few degrees, then filing out the steel bridges between the holes and finally smoothing the jagged rough-cut meter hole to a smooth circle using a half-round file.

A big part of the fun with this method is drilling the holes as close together as possible without overlapping and having the drill bit slip off into the adjacent hole (and probably break).

"I carved this transmitter out of solid steel with my bare hands." - K1AJL (SK)

[KC9LKE]

A Bridgeport is not that heavy, about 2000Lbs.  Easiest way to move one is with a flat bed car carrier.  But this operation can be very tricky if you don't handle the machine correctly.  Once it is on the driveway, you can put pipe under it.  They are easy to pry up, a 3ft crow bar will work.  You then use a come along to pull the machine.  You need a solid anchor for the come along.  My Bridgeport was easy to move compared to my Van

Fred
[/quote]

A vertical mill is one versatile piece of eqpt. As some say, the only machine that can make itself. 

Yes they can be a little top heavy when removing from the flat bed. I like to drop the table and fold over the head to lower the CG. Easier on the heart. The pipe works FB for moving. For the last few feet or into a blind corner I throw some sand on the floor and once in place dust it out with compressed air. There are some videos or pictures on the web of a gent cribbing one down into his basement. Being a rigger would be an awesome job. Lots of forethought, talent and experience to move a huge item slowly but surely into position.

Collecting the tooling can become an obsession. 

Best regards

Ted / KC9LKE

[The Slab Bacon]

Collecting the tooling can become an obsession.  

Yowsa, AINT THAT THE TRUTH! ! ! ! ! !  I dont know why, but collecting the tooling becomes an addiction.  

I have several lathes, one engine lathe and a jeweler's lathe. I tend to buy every piece of tooling and/or accessory for them that I stumble accross! ! ! ! (that I can afford) I guess I'm just a tool junkie  

I became a hobby machinist around 35 years ago when I started making parts for my antique gas engines. I'm now comfortable working to .0005 or so, which aint too shabby for using aincient machine tools. The tooling can become an addiction, as well as keeping all of the gizmos and jigs and adaptors that you made for doing that special job. You know, the stuff that you will never do again, but you keep it around just in case you need it again.....................

The next quest will be for a Bridgeport. Used 3 phase ones can still be had pretty reasonably. It will just cost me a king's ransom once the tooling addiction kicks in  

[aafradio]

Thanks for your input.  The machine shop is just a hobby for me.  I've been using these machines since 1984.  I'm well aware on how to use the machines to make parts to within .001" but sometimes I just find it easier to do some operations the old fashion way.

With four mills I figured you did, Fred, but I have noticed that a lot of mill owners unwittingly make the process too hard - precisely because they think in terms of a thou about every workpiece.  I approached everything that way for a long time, too.  Then it dawned on me that I was spending way too much time in setup when it didn't need all that much care.  When you only need +/- 1/16", then the setup becomes a lot quicker and I can just use an old fashioned eyeball and a small drill or pointy tool to indicate centers.  If I need better than that with a panel, I'll chuck a centering scope into the drill chuck to adjust the table, but a scratch on a panel to provide location has its own variables associated with it, so I try not to obsess over it.   

BTW, I dearly love the Kearney&Trecker or Cincinnati machines - the Bridgeport is such a toy compared with them.  The Bridgie's only saving grace is its flexibility - it's the Shopsmith of the milling trade...heh.

Your method of using a hole saw and then boring out the last bit is certainly a very good way to cut the meter holes.  I think the largest hole saw I have is 2".  Maybe I should get something around a 2-3/4" hole saw and try your method as I do have an adjustable boring tool with a R-8 shaft to fit the Bridgeport.

Well, it would be a bit slow to enlarge it by say, an inch in diameter, but it's certainly doable.  The boring tool is simply a fly cutter with a precision leadscrew (which makes it a lot safer than the flycutter), but it doesn't like being pushed too far on each pass.  At least you know it won't slip like the flycutter...those scare me too...

[KA2DZT]

My K-T machine is a Milwaukee, it's a model H, not a huge unit.  It's a horizontal mill with a #40 spindle.  I have the universal vertical attachment that IIRC has #7 B+S spindle.  The Van Norman is a model 22M with a #50 spindle.  It can be used as a horizontal, vertical or any angle in between. I have a lot of attachments for both machines.  Dividing heads, spiral-gear-cutting attachments (I'm not going to be cutting any spiral gears) .  Many different adapters for the #40 and #50 spindles.

All this stuff gets real heavy, makes ham radio stuff seem like featherweights.

Frank,

Try to find a Bridgeport with a single phase motor, they're around.  With the other two millers I had to change the motors to single phase.  These are called Old Frame motors but Leland Faraday made them new, 3hp 225 frame.   The Van Norman uses two motors, one motor ran at 1200RPM 1-1/2hp 224 frame.  I had that motor made special.

Fred

[KB2WIG]

"  For the last few feet or into a blind corner I throw some sand on the floor and once in place dust it out with compressed air "

Ice werks well also.

klc

[W7TFO]

Getting back to punches, I have successfully used them in my 30-ton press to pop 2-3/4" meter holes in 1/4" T-3 aluminum.

I started with a 3/4" drilled hole for the pull screw as a guide only.

Sure beats the screw & wrench method, even with ball-bearing pull screws.

73DG

[KM1H]

I have a couple meter punches and one is 2 and something 64ths used for a certain brand which escapes me at the moment.

The step bit here gets a lot of use and half round and rat tail files are for cleanup and perfection.

I have most regular Greenlees for 1/2" to 1 3/4" but always seem to misplace the 5/8 and 9/16

Carl