Intro: Aluminium Milling
I have been building a funky bike shed that I call a Bike Wardrobe and I needed to mill a slot in some 5mm thick aluminium sheeting for the locking throw bolt.
A quick search on YouTube taught me how to do it and I was amazed at achieving this for the very first time!
Come with me and I will show you how to do it as well...
Step 1: Bits That You Will Need
Aluminium [aluminum] sheet, mine was 5mm thick.
Off cuts of MDF or ply for jig
Electric router, I use a 1/2" router though a 1/4" should do also
High speed steel [HSS] router cutter for wood, I used a plunge cut one with cutter profiles on the bottom as well as the side, width to suit the milled slot.
Selection of drill bits + countersink
Step 2: Prepare Your Router
Remove the plastic base plate from your router.
Cut a piece of ply/MDF [I used 4mm thick] to a larger size than the base of the router to allow it to be screwed to the jig.
Cut a slot from it to allow the cutter to plunge freely and to enable you to see the progress of the milling.
Carefully mark the fixing holes from the base of the router and drill and countersink the ply for re-fixing back onto the base of the router.
Step 3: Make Your Jig
A jig is just a device that holds your tool [router] and guides the material [aluminium].
I required a strip of aluminium about 50mm wide which I cut by hand!
The jig design will be dependent on the shape and size of the piece of aluminium that you need to mill.
I cut two pieces of 6mm thick MDF and fixed them to a thicker 18mm MDF to hold the aluminium strip though allowing it to slide without any play side to side.
The router and its ply base was screwed to this MDF jig centrally as I needed the slot in the middle of the strip.
The whole jig was screwed securely down to the work bench, important that there is no movement in the jig.
Fix a screw at either end of the aluminium strip at the desired extent of the slot to act as stops.
I was fortunate to have a tapped hole that I inserted a bolt into to make the sliding of the strip easier, sticking a tab of duck tape to the aluminium strip should work as well.
Check that all is screwed down securely, that the router will plunge the full depth that you require and that the aluminium strip will slide.
Step 4: Mill
Please wear ear defenders and eye protection, you know it makes sense!
Switch on and slowly plunge until the cutter cuts into the aluminium.
I found that only a fraction of a millimeter was possible to mill at each pass.
Listen to the sound of the cutter to determine that the cutter was not being put under any strain.
Slowly slide the aluminium strip until it reaches the stop and return to the starting position.
Repeat the process until at the desired depth.
For my 5mm thick piece it probably took about 12 to 14 cuts to mill all the way through. Deeper milling should be possible up to the depth of the router cutter.
Release the plunge and switch off the router.
Step 5: Fantastic!
Remove the aluminium strip from the jig...
...and you have a perfect milled slot.
I love learning new skills and I am still amazed that within a few minutes of searching the internet and YouTube that you can learn enough to tackle something that you have never done before.
I hope that you have enjoyed this Instructable and maybe you will also learn a new skill! If you liked it, your vote in the Beyond The Comfort Zone Contest would be really welcomed. Thanks.
If you would like to check out the build of the Bike Wardrobe please click here to go to my YouTube channel, where you will also find my Its a Rubbish Challenge videos where I try to make interesting things out of the stuff that we throw away.