Just wanted to shout out, I received my OF. Setup was amazingly simple and straightforward, from unboxing to first cut. I spent most of the time in getting the brush strip into the dust boot.
I now want to gauge the precision and accuracy of the OF a bit better, to see where things are. The most precise measurement device I have is a 1 inch dial gauge, so I’ll have to be a bit creative. One idea was to cut slots in 1 inch increments and measure the actual end-to-end cut distance, see the gcode below for a 1/4 flat cutter.
Until next time!
#101=1.0 (step)
G90 ; absolute pos
G20 ; inches
G1 F51; semi-fast
G1 Z0.25; raise Z to safe
G1 G90 X0 Y0; go to zero
G1 G90 Z-0.1; go to cutting depth
G1 G91 X0.25; move a bit right
G1 G90 Z0.25; raise Z to safe
G1 G91 Y#101 X-0.25; move measure step, reset x
G1 G90 Z-0.1; go to cutting depth
G1 G91 X0.25; move a bit right
G1 G90 Z0.25; raise Z to safe
G1 G91 Y#101 X-0.25; move measure step, reset x
G1 G90 Z-0.1; go to cutting depth
G1 G91 X0.25; move a bit right
G1 G90 Z0.25; raise Z to safe
G1 G91 Y#101 X-0.25; move measure step, reset x
G1 G90 Z-0.1; go to cutting depth
G1 G91 X0.25; move a bit right
G1 G90 Z0.25; raise Z to safe
G1 G91 Y#101 X-0.25; move measure step, reset x
G1 G90 Z-0.1; go to cutting depth
G1 G91 X0.25; move a bit right
G1 G90 Z0.25; raise Z to safe
G1 G91 Y#101 X-0.25; move measure step, reset x
G1 G90 Z-0.1; go to cutting depth
G1 G91 X0.25; move a bit right
G1 G90 Z0.25; raise Z to safe
G1 G91 Y#101 X-0.25; move measure step, reset x
G1 G90 Z-0.1; go to cutting depth
G1 G91 X0.25; move a bit right
G1 G90 Z0.25; raise Z to safe
G1 G91 Y#101 X-0.25; move measure step, reset x
G1 G90 Z-0.1; go to cutting depth
G1 G91 X0.25; move a bit right
G1 G90 Z0.25; raise Z to safe
G1 G91 Y#101 X-0.25; move measure step, reset x
G1 G90 Z-0.1; go to cutting depth
G1 G91 X0.25; move a bit right
G1 G90 Z0.25; raise Z to safe
G1 G91 Y#101 X-0.25; move measure step, reset x
G1 G90 Z-0.1; go to cutting depth
G1 G91 X0.25; move a bit right
G1 G90 Z0.25; raise Z to safe
G1 G91 Y#101 X-0.25; move measure step, reset x
G1 G90 Z-0.1; go to cutting depth
G1 G91 X0.25; move a bit right
G1 G90 Z0.25; raise Z to safe
G1 G91 Y#101 X-0.25; move measure step, reset x
G1 G90 Z-0.1; go to cutting depth
G1 G91 X0.25; move a bit right
G1 G90 Z0.25; raise Z to safe
G1 G91 Y#101 X-0.25; move measure step, reset x
G1 G90 Z-0.1; go to cutting depth
G1 G91 X0.25; move a bit right
G1 G90 Z0.25; raise Z to safe
G1 G91 Y#101 X-0.25; move measure step, reset x
G1 G90 Z-0.1; go to cutting depth
G1 G91 X0.25; move a bit right
G1 G90 Z0.25; raise Z to safe
G1 G91 Y#101 X-0.25; move measure step, reset x
G1 G90 Z-0.1; go to cutting depth
G1 G91 X0.25; move a bit right
G1 G90 Z0.25; raise Z to safe
G1 G91 Y#101 X-0.25; move measure step, reset x
G1 G90 Z-0.1; go to cutting depth
G1 G91 X0.25; move a bit right
G1 G90 Z0.25; raise Z to safe
G1 G91 Y#101 X-0.25; move measure step, reset x
G1 G90 Z-0.1; go to cutting depth
G1 G91 X0.25; move a bit right
G1 G90 Z0.25; raise Z to safe
G1 G91 Y#101 X-0.25; move measure step, reset x
G1 G90 Z-0.1; go to cutting depth
G1 G91 X0.25; move a bit right
G1 G90 Z0.25; raise Z to safe
G1 G91 Y#101 X-0.25; move measure step, reset x
G1 G90 Z-0.1; go to cutting depth
G1 G91 X0.25; move a bit right
G1 G90 Z0.25; raise Z to safe
G1 G91 Y#101 X-0.25; move measure step, reset x
G1 G90 Z-0.1; go to cutting depth
G1 G91 X0.25; move a bit right
G1 G90 Z0.25; raise Z to safe
G1 G91 Y#101 X-0.25; move measure step, reset x
G1 G90 Z-0.1; go to cutting depth
G1 G91 X0.25; move a bit right
G1 G90 Z0.25; raise Z to safe
I’m about to follow this calibration routine as I cut some 20mm ‘dog’ holes in must spoilboard last weekend and I now find that they are actually 19.95mm … just a little tight for my 20mm dogs so hopefully I can calibrate to something a little bit closer.
Don’t expressly fault the 1F, I’ve started using a micrometer on my bits…and surprise! Many are just close on their size, found about 3 of 9 that are off by 1 or 2 thousandths of an inch. When you double the diameter of a hole hogged out, well it doesn’t take much for it to be tight.
Also bear in mind the controller converts circles and arcs to line segments when cutting with the tolerance controlled by the max deviation setting. Also some post processors will not output G2 and G3 but will instead output line segments with their own tolerances. This could also lead to under or oversized holes. When I created my dog holes I had the same problem, the dowel pins I had did not fit. Using Fusion 360 I used a negative stock to leave value on my toolpath increasing the value by -0.01mm until the dowel pins fit properly. This is not an ideal long term solution for all projects but might make sense for ones requiring greater accuracy.
I tested repeatability accuracy on all axis, the biggest deviation I measured on mine was on the Y axis of less than 0.001" (after a little adjustment of the ball screw). The X axis was spot on 0" deviation (for now).
I used a dial indicator to measure start and return points when moving in all axis. There was no measurable deviation with repeated movements in the same direction, therefore it’s all backlash related. Repeatability of the motors, software and other components is spot on, at least at this scale. I played around with the retainers on either side of the ball screw shown here to tighten the Y axis a little:
Thanks to all of you for sharing the tips, experiences and discussion! I followed @pootaholic 's link and @Pleased2fly 's advice on the bit wear. These are my current observations:
Measured backlash with dial gauge by approaching arbitrary zero with and without reversing direction first. Backlash should show up as difference in measurement. The actual difference was below 1 thou in the X axis, haven’t measured Y yet.
Measured accuracy over 20 inch distance via the ruler method. This is somewhat limited by eyeballing the correct position and my eyeballs ain’t round. It appeared that the accuracy was short by around 1/64th (15 thou) over 20 inches in both X and Y. I adjusted via the “mm traveled” motor setting (setting it to 20.015 / 20 * 10). I’d be curious how much thermal expansion already plays a role at this scale.
Measure my spiral downcut bit to be 0.245, instead of the nominal 0.25 (shoutout to @Pleased2fly ). Constructed a tool path in Fusion 360 to mill a 1x2 rectangle with adapted bit diameter to 0.245. Measured milled rectangle to 0.997 x 1.996 with cheap digital caliper.
Accidentally drilled a hole through the table, must have forgotten to zero Z properly.
Great idea. I have made some modifications to my 1F, and may experiment with them if my backlash consistently indicates above 0.02-0.03 mm. Are there two per ball screw(one hidden inside the mount?
I calibrated my Onefinity today. Not bad - XAxis: 0.5mm over 1000mm travel and YAxis: 0.25mm through 650mm travel. I’ve adjusted for both and will check again over time. (I have to trust my ruler, fresh out of the packet and intended for creating MFT tables)
