Good news, ok news

The good news: the Y-axis plate checks out fine. All 8 holes line up with the 80/20 50mm by 100mm extrusion, the holes for the motor mounts look aligned, the holes for the eccentric nuts fit exactly, and when the wheels are attached they are correctly spaced for the marker slide.

When the 11 year old was screwing in the screws for the 80/20 extrusion we both noticed that some of the screws were loose.

That's the ok news. The screws were loose because I tapped the axis with an M5 tap, and I should have used an M6 tap. Fortunately, a problem that is easily fixed.

Successful 5052 .25" aluminum milling run

Settings:

Feed rate: 300mm/minute
RPM: 30,000 RPM
Plunge rate: 60mm/minute
Depth of cut: .2mm
Lubrication: I used some WD40 at first, but it just seemed to make the aluminum flakes bunch up around the bit, so I stopped. I did run the ShopVac constantly.
Bit: Niagara Cutter N61442 Carbide Square Nose End Mill, Inch, TiCN Finish, Finishing Cut, 45 Degree Helix, 2 Flutes, 1.5" Overall Length, 0.125" Cutting Diameter, 0.125" Shank Diameter



I had to do a second pass where I went from -6.3 to -6.55.

Fans and pots

I've turned the potentiometers for the X and Y axis all the way up, and expanded the Lego case to include two fans.

So far everything looks good. 

Except that it turns out I have a 90 watt power supply, and when the potentiometers are turned all of the way up the power supply can't supply the full load.

Upgraded to x-carve z-axis

Last week the coupler on the z axis slipped during a run. 

I then ordered the x-carve z-axis plate, pulleys, and closed loop cable and swapped it in this week end. 

Grbl settings, for the next upgrade

I upgraded the firmware to 0.9, but forgot to save the Grbl settings.

Here are the input parameters used for the Grbl settings calculator:

X/Y belt pitch (inches): 0.0787402
X/Y motor (steps/rev) 200
X/Y pulley teeth 20
X/Y microsteps 8

Z threaded rod pitch (mm) 1.25
Z motor (steps/rev) 200
Z micro steps 2

Skipping problem solved

I've had two jobs where the router went off program and started plowing through wood along the Y axis. Both times this happened as the router was cutting a curve.

Last night I realized that router wasn't getting extra instructions, or firing erratically. Instead, the X-axis was stalling. Since it was cutting a curve, the stall showed up as a move in the Y axis. After looking around for a bit, it looks like a heat related problem and adding a fan to the setup would help.

I ordered a small 24V fan, and made plans to build a wood box to house the fan and the gShield/Arduino Uno combo.

I was going to wait for the fan to arrive, but then I realized I didn't need to. I already had a very large fan in the room that I could use to cool the gShield. My shopvac. I hooked the shopvac exhaust up so that it would blow over the gShield.

I had no stalls on the next, larger and longer run. I had one problem where it lost some steps on the X-axis, but I'm going to assume for now that's because I had upped the cutting depth to 3mm.

Successful run

I've been working on a dresser for my daughter, and using the CNC for some of the curves that will go on the dresser's bottom.

Last week I had an unsuccessful run where the CNC router suddenly decided to diverge from the path. I'm not sure if it was a user error or something else; it happened as I was preparing to hand things off to another operator. One of the things that I noticed was that the router had no problems going through the oak, even though it was already about 10mm deep.

But this week I had a successful run. The parameters were: cut depth of 2mm (up from 1mm), feed rate of 197.302 mm/min. The full file is available at http://a360.co/1NOrm5Y. 

One of the reason this run was a success was that none of the plunges happened in the wood; they all happened slight off to the side.