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View Full Version : The dude butchered my aluminum extrusion :( !!!



Fancy
15-12-2018, 03:07 PM
So i had some length of aluminum extrusion that i wanted cut and i went to a near by shop for it to be cut on a miter saw now the extrusions' ends aren't square and aren't the same length +0.5-1mm from one another. i really hate delegating stuff to others but unfortunately i don't have the tools :(. does anyone have suggestions on how to solve this ? i am okey with trimming up to 5mm as long as they match and squared.

spluppit
15-12-2018, 04:02 PM
Unfortunately a chop saw is only as good as the idiot in control of it... this applies to all machines unfortunately. To a general company that will be about right squareness and length wise... different people and different trades have different idea of what is right.

If you go to a proper machine shop and you tell them what you want then you should get what you need. Again the job is only as good as the information you give them, make sure you specify what you actually need rather than leaving them to their own devices and deciding for you. This should have been done against a dead stop which in saw terms could still be + or - .25mm pending the saw and the guy in control of it.


I think your best option is to find someone with a mill and get them to square the ends up against dead stop. Mill one end and debur... rotate 180 and repeat against a dead stop. You will get accurate and square ends that way if you need them that good. I use this process a lot for getting repeatability on longer parts.

John McNamara
15-12-2018, 11:36 PM
Some extrusions have a central hole, if yours has one you can turn the ends between centers if you have access to a big enough lathe. obviously there will be a small pip left, that can be removed with a countersink or filed off.
This method will produce close to perfect 90deg end faces.

Being Aluminium I don't think a half centre would work well.

magicniner
16-12-2018, 12:22 PM
If you had a square and a scriber you could mark it out accurately and cut it with a hacksaw then finish with a file.
Everyone seems to forget completely about the importance of good bench work once they've seen a machine ;-)

Ger21
16-12-2018, 03:22 PM
A sliding table saw with a very sharp blade will also work.

cropwell
16-12-2018, 03:29 PM
Everyone seems to forget completely about the importance of good bench work once they've seen a machine ;-)
I have a piece of my late father-in-laws work from his pre-war Army training in the Signals. It is a test piece, a steel plate with a 1" square hole and in the hole is a friction fit 1" steel square. You can put that inner square into the hole in any rotation or turn and the fit is the same - perfect. All this was done with a drill, a file and a micrometer. My bench work is crude and impatient by comparison.

Boyan Silyavski
02-01-2019, 08:40 PM
The way to do it is go to butchers with a small precision square in the pocket. And politely check their machine before cutting. Once they see the precision square, they will understand you mean it square... I have been laughed at but at the end i achieved mine, in terms of precision...

Better to know you as the Precision Loco. In Spain we say : El que no llora no mama, meaning if you don't cry there is no a tit for you :hysterical:

Clive S
02-01-2019, 09:38 PM
Or you could say: yo solo habla catato

Fancy
06-01-2019, 06:35 PM
I read your comments and I've decided to go to a machine shop with a mill to trim the ends. Hoping to get away with trimming 2mm total. Also I am gonna keep you posted on my build log. Thanks for the help guys.