[fdm_guy]

Hi Folks,

I have a 6040 machine with black box from YooCNC, no major changes on it as all seems to work OK for Wood. I did not try to machine Aluminum yet but I intended to do some small metal work and have coolant system / atomizer (Sommer ZN) installed.

Now I would like to manufacture Heated Print Bed for 3D Printer, the part would have following specs:

* 230x230mm size, T6082 Aluminum, raw sheet is 250x250mm
* Level surface, I plan to take off ~1/3mm from each side for that.
* 200x200x2mm pockets on both sides, pockets can have round corners.

Big question is: This is a big part, much bigger then pieces I initially thought to do. Will my 6040 be able to perform the task with reasonable quality?

If yes, what about tooling? What would be the optimal mill type, diameter and coating for this kind of job?

Will this be a good choice: Maritool 3mm 3 Flute Carbide End Mill 38 Deg Helix 12mm loc ZrN?

Thanks!

[SigLover21]

Make sure your stepper couplers are the correct type for aluminum. There are three types Flexible, simple, and plum. Each has it's own max speed velocity mm/min. Flexible less than 1500, simple 2000, and plum 2500. The lst two are for milling aluminum. That is all I can say for sure. Good luck.

[tgdavies]

I've done a little bit of Aluminium cutting with my 6040 -- I have an 800W ER11 spindle, what do you have?

I would be inclined to use a larger diameter cutter for facing the plate.

I have been using a 0.2mm step down with a 1.5mm cutter.

Please let us know how you get on.

[Palmhoej]

Attachment 232360

I have made this with my 6040Z-S80 from carvingcnc.com. Its made out of one solid 10 mm aluminum sheet. I have not tried anything thicker than a 20mm aluminum sheet, but it might be possible. I use my CNC mainly for cutting aluminum.

You have to understand that when you do aluminum cutting on one of these types of machines you are really ridding them on their limits. This is why it is very important to use the right parameters (feeds, speeds, depth of engagement etc.).

I only use single single flute cutters. This is the only way i can run the spindle at almost full speed, ensuring maximum torque. I use these:

5pcs 6mm Carbide CNC Router Bits Single Flute Engraving Machine Tools 22mm | eBay

or similar... its chinese, so you don't always get the same, when ordering from ebay. I have manage to run one of these bits for 10 hours straight without any sign of it getting dull. But usually you run one for 2-3 hours, then you break it because you make a mistake, which is why its great that they come cheap

Settings are as follows:

Diameter: 6mm
Feeds: 800-1000 mm/s
DOC: 0.8-1 mm (Depth of engagement)
Speed: 22k-24k rev/min

I also use a DIY mist spray, thats spray alcohol on the bit. This keeps the work piece clean and ensures that the bit stays cold. You can see mine in operation in this video:
https://www.youtube.com/watch?v=Ff2NVm_vJEc

One last thing: I secure my workpiece with screws into a piece of wood. The good thins is that it is fast and if you cut to deep, you just use another piece of wood. The bad thing is that the piece can vibrate, if reaching the perfect resonans. If i for example use a big heavy 20mm plate of aluminum, there are no problem, because the weight alone kills the vibrations. But as the plate gets smaller and smaller, the vibrations starts to show and then i can't use as deep a DOC as i could in the beginning. The vibrations are very audiable and sometimes a little notch on the Speed button or a slower/faster feeds can dampen the vibrations.

These machines are soft as butter, so you need to make a final finish pass, for every 5mm of DOC if you want good tolerance. Doing this i usually can keep it within 0.05-0.01 of a mm.

Good luck

[Alantron]

800 mm/s? Wow that's fast lol. I've been testing out different speeds, feeds I do mostly profiles and at 1mm doc 12k @400mm/min the 2 flute 4mm endmill I was using started making crazy noise towards the end. I'm cutting shapes out of 6-7mm aluminum btw. I think a smaller doc would've yielded better results. I'm using vcarve for cam. What are you guys using for aluminum projects? Also any links to that homemade a mister setup you have there? I really need one