Machinist question??
 

I have a piece of 1/4" thick x 3" long x 2" wide aluminum. I want to cut a piece out of the middle that is 3/4" wide x 2" long.

I am working with scrap right now, trying to build Ogre's door wiring bracket/thing. Once I get this figured out, I'll build the real ones.

First, I drilled a series of hole in the corners, getting up to 5/16". Then I started with a Dremel with a cut off wheel, but it won't cut all the way through the aluminum, it does not have enough blade clearance between the aluminum and the handle of the Dremel to cut all the way through the aluminum. I have a scroll saw with a metal blade, but it is really hard to control on this small piece to get any accuracy, but I did get a piece cut out with the scroll saw, but it was a really inaccurate cut.

Then I started filing, but the file is clogging up with the aluminum.

So, what is the best way to do this? And what do you do to get aluminum out of a good file?

Thanks.

Re: Machinist question??
 

I'm not a machinist. A machinist would head for the nearest milling machine.

I'd reach for my 4.5" grinder and a worn to smaller diameter thin cut off wheel and some wd40 as lubricant, get as close to the end of the slot as you can, do both sides of slot from both faces, then finish with a fine hacksaw and file

I use a wire brush to clean files

Re: Machinist question??
 

Robert, Ive done similar when I didn't have access to a mill..
In this instance,
I'd drill a larger hole and use a jigsaw or hacksaw w/course blade, rough out the opening,
then use a file,,The courser the better for roughing it in..
With aluminium, lubrication is key,wd40,even brake cleaner works,if you don't have the good stuff
It's hard to clean aluminium out of a file...

Re: Machinist question??
 

Use a file card or a wire brush to clean the file, and next time before you use it, put a little bar soap on it to lubricate it.

I'd do what you're doing but I'd get an $11 die grinder from HF if you have a compressor.

The best solution is to buy your way out of it. Go to sendcutsend.com and order a few to play with https://sendcutsend.com/

Re: Machinist question??
 

Having been a machinist for the last 40 years, there is no substitute for having the right tools. I have a machine shop at my house and make little parts all the time. What type aluminum are you working with? It sounds like you have some real soft material. Sawing aluminum is much better than trying to grind it. when you get close to finish size get the file and use smooth stroke pushing then lift and push again, don't try to cut on the back stroke. then get a good file card and clean the file every couple strokes. You can make a good quality product, just take your time and go slow

Re: Machinist question??
 

hogfarm has it. a coupe of forward only file strokes and then file card iit. then, what I do, is soapstone the file when it is clean before filing again. it helps the aluminum not stick. some guys use chalk with some success. have used the jigsaw or recip saw as well but it creates heat and aluminum gets fatter with heat quickly so keep the blade lubed up with some soapy hand sprayer squirts.
what I have done in the past for aluminum is use a router with carbide bit. drill the corner holes inside the line so you can finish nicely. make the corner hole big enough for the router bit to fit into. then clamp the part down well, gear up with the safety equipment including a hat and ear plugs and simply router it with small bites at a time. if you have a bit with the bearing on the end you could make a template and end up with a nice looking part with no filing. a bit if wd40 for lube wouldn't hurt. dish soap in a hand squirt water spray would also work likely. it is gonna make a mess with small chips everywhere so work in as small a space as you can. hang a curtain or something, do the collar up too. the cuttings will also be sharp. a shop vac hose tied close would help.

Re: Machinist question??
 

I also have a burr selection for the die grinder and the aluminum ones have wide deep flutes. soap stone is what i use and don't be cheap with it. some machinist buddies of mine say solvent works too, good old varsol.

Re: Machinist question??
 

Thank you all.

Re: Machinist question??
 

this ogre doesn't have a lot of metal working tools either. i drilled two 1/4" corner holes in opposite corners and used a jigsaw to rough cut the opening and a file to clean up the holes.

when i drilled the roll pin hinge hole, i oversized the top and half the bottom to make it easier to install the tube. line up the holes and drop wiggle the pin in, once everything is 100% tap the last bit in.

note where the roll pin pivot goes, right inside the wall of the tube. i can send you a better picture if you'd like, though i believe this is pretty self explanatory

Re: Machinist question??
 

Ogre, thanks. I have another piece of scrap aluminum the right thickness and I'm going to try again on that one as soon as I get some more jig saw blades.

Re: Machinist question??
 

when jigsawwing I usually cover the material with overlapping rows of masking tape so the jigsaw doesn't scratch things up. that makes it easy to lay out as well. just know that it can be pushed around by the jigsaw so maybe don't totally rely oj the layout lines without checking.:devil: just a thought.
post up some pics when you get to it.

Re: Machinist question??
 

Not sure if appropriate but the custom fabricator and dies maker at the big boat shop uses a regular table saw with a wood blade to cut outside items from sheet aluminum. I tried it at home and it works!!

Re: Machinist question??
 

Yup, I've done that too. I use a carbide blade with lots of kerf. Again, all the safety equipment cuz you never know if the blade is gonna stick. Try some wax on the blade. Some of the aerosol stuff wood guys use on the saw table to keep it slick so it's easy to push the wood through.

Re: Machinist question??
 

you are cutting a small piece, hard to keep a saber saw balanced on that, maybe consider screwing or gluing it down to some scrap wood?

I glued some carpet to the bottom of a saber saw once to protect something, it worked well and tended to smooth out the saw, making it easier to handle on shiny surfaces, the carpet stayed on for years. Some of those stick on felt furniture feet would be easier to give a try. YMMV

Re: Machinist question??
 

Thanks guys. I am going to try some of this on my scrap material to try and figure it out.

Re: Machinist question??
 

I often use a jig saw or sawzall to cut metal for projects. For the 3/4" cuts I would drill a 3/8" hole near a corner. Then, using the jug saw, I would cut on a curve until the blade was cutting on the desired line. Once the blade is on the desired line I'd continue to cut until the blade reached the corner. Next, lift the saw, turn 180, place back in the existing cut and proceed in a straight line to the other corner.

Re: Machinist question??
 

Thanks 1project.

Re: Machinist question??
 

You can clean your files with a piece of 1/2 in copper pipe (I use 3/4 in) smash one end and push it across the teeth and it will clean your file. here is a short video. https://youtu.be/yzsn-E1YDgk

Re: Machinist question??
 

Thanks. I have some scrap copper pipe a x will try it