Cut a 16mm hole with13mm bit?

[PabloPicasso]

I need to cut a 16mm hole in a3mm aluminium plate to get an so239 plug in. Biggest bit aboard is 13mm.

Is it fairly easy to bore the 13mm and use the same bit to effectively ream out to 16mm. Or would this end up in a total bodge job?

 

[Norman_E]

Its a bit hard to explain but it can be done neatly if you have a round file to finish the job. Drill though, then angle the drill so that it enlarges the hole sideways and take the drill round in a circle so that the top and bottom of the hole are enlarged evenly all round. You really need a round file to finish the job neatly. Go carefully and slowly so that you don't make the hole too big.
A very useful thing to have on board is a step drill which will do what you want without drama.

 

[Jabs]

draw a 16mm hole so you have something to aim for.

Should be a doddle. 1.5mm either side is not a lot.

try to keep it round by going gently. too much speed and you will end up with a triangular hole.

good luck

Tony

 

[bbg]

Its a bit hard to explain but it can be done neatly if you have a round file to finish the job. Drill though, then angle the drill so that it enlarges the hole sideways and take the drill round in a circle so that the top and bottom of the hole are enlarged evenly all round. You really need a round file to finish the job neatly. Go carefully and slowly so that you don't make the hole too big.
A very useful thing to have on board is a step drill which will do what you want without drama.

Surely that would give an oval

 

[Jabs]

You take the drill off vertical and orbit it through 360.

 

[macd]

A very useful thing to have on board is a step drill which will do what you want without drama.

+1
Or even a couple, of different sizes.

 

[VicS]

I need to cut a 16mm hole in a3mm aluminium plate to get an so239 plug in. Biggest bit aboard is 13mm.

Is it fairly easy to bore the 13mm and use the same bit to effectively ream out to 16mm. Or would this end up in a total bodge job?

Drill it 13mm and file it out to the size you want!

 

[Norman_E]

Surely that would give an oval

No, as Jabs says you orbit the drill round so that the hole is enlarged in every direction.

 

[pvb]

Wouldn't it be easier to take the plug off the cable?

 

[VicS]

Wouldn't it be easier to take the plug off the cable?

ITYWF that SO239 is actually the socket. Presumably 16mm is the size of the mounting hole

The plug on the cable is PL 259.

 

[pvb]

ITYWF that SO239 is actually the socket.

I was obviously confused by the OP calling it a plug!

 

[PabloPicasso]

I was obviously confused by the OP calling it a plug!

Yes it was a socket, yes it is now done, but got the loan of a step drill bit from another boat.

Thanks for the advice, even the pedantic stuff

 

[sailor211]

Wrap some abrasive paper around a rod or drill and use this to open the hole. I have a bit of 6 MM. with a hacksaw slot for this Emery paper can be wrapped to 12 mm

 

[lw395]

I would probably dril lots of smaller holes then file.
3mm Ali is on the thick side for punching. Otherwise that's a good way.
Will probably distort if you angle the bit over.
13mm drill will possibly be messy in such thin plate.
A fly-cutter type of hole cutter is another alternative. Or a hole saw.
Emery paper and a slotted mandrel in a drill is a good alternative to files.

Cone drill or big taper reamer also options.

 

[lw395]

Or change the 239 series (spit) for something that fits a smaller hole....

 

[nigelmercier]

Or change the 239 series (spit) ...

Really? I love PL259/SO239 connectors, assuming you get the right one to fit the cable.