AndyUK's Build - 1.2x1.0m Gantry

[AndyUK]

Promised an update when I ventured into Aluminium; its only the smallest of steps, but I'm pleased with the results.

The "client" has requested a lampwork beadmaking tool which could form the molten glass into a heart shape. This is the first in a series of tests; the eventual product will need to have two identical sides to squish the bead into shape, but we've just started with a single side for now.

Tried two shapes, a 3D heart and a 2D heart. I pocketed and roughed with a 4mm single flute endmill at 18k RPM and 1.5m/min. Kept the DOC very low at 0.5mm as this is my first time, but the router wasn't phased in the slightest. Then finished with a 3mm Diameter ball nose, 24k RPM 1m/min. Very basic tool paths from aspire, nothing fancy. Went a bit overkill and gave it lots of air blasts to clear the ships and plenty of WD40 in between!

To give an idea of scale, these hearts are designed to fit within a 15mm diameter circle. Very small.







My thoughts are slowly turning towards the 4th Axis that I'd like to add to this machine, but I haven't come across any dedicated build threads yet. Anyone got any initial recommendations / suggested reading?

[JAZZCNC]

Nice Job Andy, very rewarding isn't it when you get results like these. Don't be araid to push the machine, I'd be inclined to lower the step over on the ballnose so you get a smoother finish, it could be the pictures but it looks a little scolloped which comes from too large a step over. I use between 3 - 5% diameter on cutters 3mm or less and 10% on anything larger. Takes a little longer but get a nice smooth finish.

[AndyUK]

Thanks Dean - I used Aspire's default step over, so no idea what it was set to! I'll look into it tonight and get it into that range.

Out of interest, what would you expect to see DOC wise on a router like this with a 4mm single flute? APT suggests slowing down from those parameters once you're over 1.5 D, but I assume that advice is really for mills; 6mm felt like quite a big chunk to be taking.

[JAZZCNC]

Thanks Dean - I used Aspire's default step over, so no idea what it was set to! I'll look into it tonight and get it into that range.

Out of interest, what would you expect to see DOC wise on a router like this with a 4mm single flute? APT suggests slowing down from those parameters once you're over 1.5 D, but I assume that advice is really for mills; 6mm felt like quite a big chunk to be taking.

Ye aspire is mostly based on wood which is a little less forgiving so any small scollops can be sanded away but in Ali you want a smaller stepover for the best finish.

Difficult to say because every machine is different, spindle power and rigidity plays a big part. If it was me I'd start at 50% D and feel your way down. Or just go for it turn the spindle up to full RPM so you are getting Max torque then go with 1.5xD and play with feeds n speeds.