As mentioned in the last post I’d created a batch of shapes on a piece of acrylic, only to pooch the lot by opening another Easel window in Chrome which reset the connection to my Shapeoko.
Easel appears to be the “Easy-Bake Oven” of the CAM world: You can make simple designs and indeed you can create more complex designs as well, but like creating four cups worth of cake batter for the easy-bake, you’re going to be sitting there a long time before you get through it all, and it’s faster to make things in small batches.
Here’s an arbitrary (though close to real) set of timed procedures to compare operations on the Shapeoko and two programs.
If you make a circle in Easel and tell it the material is 4mm thick (Z axis) and to plunge in 1mm per pass, your Shapeoko will cut the circle four times, 1mm at a time. That’s great – it cuts it, it does a fine job as long as your machine is set up correctly and you cut out a circle of material. [pic]
If you make four circles in Easel and tell it the material is 4mm thick (Z axis) and to plunge 1mm per pass, your Shapeoko will cut the first circle to a 1mm depth, raise the cutter, move to the next, cut the second circle to a 1mm depth, raise the cutter again, move on to the third, then the fourth. Fascinating as it is to see the machine move, the Z axis is about as fast as a slug on chamomile. So for each batch of four circles you’re raising your Z axis 16 times, lowering your Z axis 16 times, plus making your cutter move from one area to the next 16 times.
- Lower the Z Axis = 2 minutes x 16
- Raise the Z Axis = 2 minutes x 16
- Move the X/Y Axis = 4 minutes x 16
- Cut the circle = 3 minutes per pass x 16
- = 2.93 hours (176 minutes)
Let’s see what creating one circle at a time would consist of:
- Move the X/Y Axis = 4 minutes
- Lower the Z Axis = 2 minutes x 4
- Raise the Z Axis = 2 minutes x 4
- Cut the circle = 3 minutes x 4
- = 32 minutes
- Re-Zero the machine by hand = 3 minutes
- = 2.28 hours or 137 minutes
Save 39 minutes with “Human Intervention”? I thought machines were “labor saving devices”! Well, they are, when they’re used properly and the process is thought through.
Thinking through the four circles, a more expedient way to cut the four circles would be to
- Move X/Y Axis to circle 1 = 4 minutes
- Lower the Z Axis = 2 minutes x 4 = 8 minutes
- Cut the circle = 3 minutes x 4 = 12 minutes
- Raise the Z Axis = 2 minutes x 4 = 8 minutes
- Move to the next circle = 4 minutes
- Each circle = 28 minutes
- times 4 circles = 1.86 hours or 112 minutes
While Easel doesn’t allow this, other programs such as MakerCAM does, by way of MakerCAM.com, creating your files, then exporting the g-code (you can also save and import svg files). Bringing the g-code into your favorite computer based program (the next step for me is grbl-controller 3.61) and following the basic rules you hopefully learned in Easel:
- Machine is set to zero (0,0,0 on the x, y & z axis),
- spindle is on,
- safety glasses and hearing protection is on (okay, those aren’t in Easel but they should be)
An even more expedient fashion would be to cluster the circles as close as possible (in a four-leaf clover fashion) and cut through the whole pattern without lifting the Z Axis to go to the next.
- Move X/Y Axis to circle 1 = 4 minutes
- Lower the Z Axis = 2 minutes x 4 x 4 = 32 minutes
- Cut the circle = 3 minutes x 4 x 4 = 48 minutes
- Raise the Z Axis = 2 minutes
- = 1.4 hours or 86 minutes
These are my musings away from the machine, now for what I WAS able to accomplish:
http://www.makercam.com/tutorial.html – info to become familiar with MakerCAM
015-01-21 – In MakerCAM created 2 25mm circles and 3 14mm circles. Selected all 5 and selected “Follow Path” operation.
Started job 7:59pm
Ended job 10:23pm – 143 minutes
With this, the Z axis was found to raise to 0 every time before lowering back down to the next level. Step Down rate is at 1.5
2015-01-22 – Want to try again with separated toolpaths – created file called “MakerCAM 2-25 3 14mm 3 – SEPARATE PROFILES”
Ended 6:50pm 92 minutes
2015-01-22 Trying a third time with a 1mm safety height and a 1200mm/min plunge depth. The feed rate stays at 1500, same tool (diamond router bit that is slightly tapered)
74 minues – shaved 17 minutes off the time.
Things were going along as I thought they might, within an acceptable range, then I decided to cut some harder material…