Acceleration Settings = Scary Machine

I’ve been cutting things rather slowly here for the last couple of months. I set it up to make some small basic shapes, set it to go and monitor it as I’m doing other things. It’s been going okay and I’ve set up and saved several files I have gotten back to and reused, tweaking them to move them along incrementally faster – it’s a consumer machine after all, right?
After experimenting with a rather complex engraving and nursing my decaf while I watched the machine methodically go through it’s motions, making a mental note to lower the z-axis travel point to 1mm instead of 2.5, I poked around further on the internet, knowing I’d seen Shapeoko’s move faster than mine. Sure enough, people were stating they were breaking bits, having to lessen the depth of their cuts, etc.
Over a cup of tea in the morning (I’d run out of caffeinated coffee and was not going to placebo myself on a Saturday morning) I searched for Shapeoko 2 seek speed, finding posts over speed tests, youtube videos of machined going crazy fast and more. Figuring they’d used upgraded motors I pined for the day I’d be able to step up to the machines I’d seen. Looking further, there were “Hello World” races going on. Finally I ran across one post: which stated “I’ve been running my ShapeOko with default GRBL values. Well, last night I decided to try speeding things up. I found that a single change ($8=50 instead of $8=9.8) made my ShapeOko run better than twice as fast.”
Looking into my settings, I found that my acceleration was at a way beyond conservative 0.000…
Setting it to 50 and having it seek on the x and the y axis using Grbl Controller my eyes damn near fell out next to my dog who was crossing his legs and whimpering for me to take him out for his morning editorializing (he likes to read and reply to the post, and the tree, and the stop sign…).
Rerunning the engraving I went from 4 hours and 25 minutes to 12 minutes and 26 seconds! a 20 fold increase or there about if it were to accurately do what I intended it to. It didn’t take long for the memories of people’s stories of broken bits to invade my creative cranium’s one-seat cinema: this machine has gone from an interesting little oddity to a dangerous machine sitting in my living room next to the haunted coat closet (don’t run the machine if the clock strikes 12!).
Weekends were made for this! Experimenting, updating, scheming and dreaming – and garbage… and doing the paperwork I’d put off, and the other paperwork… At least my breaks will be more interesting!

Shapeoko Beginnings: MacGyver ‘d Dust Shoe

Left: Black and Decker Rotary Tool, Right: Washing machine drain hose, Center: bottom of oblong shampoo bottle upside-down, bottom: "dust skirt" made from an old transparency

Suave shampoo bottle gets a second life as part of a dust shoe for a Shapeoko

It’s snowing outside, but there’s an accumulation of white powdery stuff inside as well that I can see on the keyboard and other surfaces – it’s the dust from the Shapeoko that has “escaped” the from the aging dustbuster, sending a cloud of powder into my face as I was clearing the cutting area. 

I’d seen a lot of creative individuals that had used their Shapeoko to create their own dust shoes and was impressed, but I needed one immediately. I also had the challenge of having a different Dremel-like tool – a Black and Decker RTX B3

I’d gone back to the rotary tool that came with the Shapeoko but quicky returned to the Black & Decker being so much quieter since it’s in the living room what with the sub-zero temperatures and the need of a computer keeps it out of our “damp” cellar.

I like a lot of the designs that are out there, especially the ones that have a hose and shoe removal system,  The RTX 3 has an odd shape to the handle that’s great to grip but difficult to shape and connect a shoe onto.  Fortunately the bottom collar unscrews and there is enough room to attach something thin – about 1-2mm into it and have it hold. 

One of the many benefits of living with people with more hair than me is they prefer special shampoos and conditioners which means there are a wide variety of plastic containers in the recycle bin to choose from.  An oblong shampoo bottle worked out well for the rotary tool, but then there was the vacuum hose…


As many home-moaners will attest to, when you’ve lived in a place for any length of time you will accumulate “spare parts” over time: things you didn’t need, other things you meant to return for a refund, and yet other things that disappear in the moment of need, only to reappear days and sometimes minutes after you’ve replaced the missing piece.  In this case it was a flexible washer drain hose we had bought from our neighborhood hardware store.  It just fit the other side of the shampoo bottle  turned dust shoe.

Using the rotary tool and a tile cutting bit I cut through and fit the pieces easily, the collet ring securing the boot nicely and the hose snugly fit into the hole right beside.


With LCD displays sending old overhead projectors to the recycling center (and to ebay in various forms such as some really great fresnel lenses for cheap pyrotechnic fun), “transparencies” – the clear sheets of acetate used for the overheads and some double-sided foam tape made a nice skirt for the shoe to contain the flying bits of plastic and foam, also creating a confined area for the vacuum to draw the dust from.

With everything in place all that’s needed is a vacuum device.  The dust buster is a loud little beasty with a bad seal, so that was out, but thanks to other surplus items we were able to create a small liquid based dust collection system that is not very loud, and surprisingly efficient…

Shapeoko Beginnings – harder material was NOT the issue…

The material I was cutting next was a harder plastic so I slowed the feed rate down some from the previous settings but the machine seemed to be moving in a jerky fashion, especially the Y (toward and away from you).  Looking at the material afterward It was definitely not as smooth a cut as the initial material. I had moved the machine but everything looked fine, then I checked the Black & Decker tool – it’s a great and quiet little hand tool, but it had some spindle issues, so I moved it to the tool bin of often used hand-tools and pulled out the whiny arbitrarily variable speed spindle that came with the Shapeoko (not a slight on Inventables – the price:machine ratio was just right, and their description: “ recommended for hobbyists who see building and upgrading the machine as part of the fun.” is what I committed to) and set that up.  The machine cut through the material, but it was jerky and certainly not the circles I had been cutting before, so I knew something else was wrong. It was back to looking over the wikis and trying to figure out what was going on which is where I found the “Diamond Circle Square” test…

Shapeoko Beginnings: – Make a Cookie, not a Batch of Cookies

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
    • times 4=128 minutes
  • Re-Zero the machine by hand = 3 minutes
    • Times 3 = 9 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, 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:

  1. Machine is set to zero (0,0,0 on the x, y & z axis),
  2. spindle is on,
  3. safety glasses and hearing protection is on (okay, those aren’t in Easel but they should be)
  4. Begin!


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: – 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”

Started 5:18pm
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…

Shapeoko CNC 2015-01-19: Start Small

After a couple of hours of running one project and getting 95% through the first of four passes, I reset the program by opening another window in easel. This could be my computer (if you think my dog is a mongrel, I’m running windows 8.1 in 32 bit mode on a dell laptop).

running a couple:of smaller projects now, going to test easel against easel’s g-code export into grbl controller 3.81.

So far, 2:25pm on the easel 4 25mm circles to 4:30pm – several more lessons learned:

  • Don’t pack too much into a small area – trying to be too frugal will waste more than if you leave reasonable tolerances between them.
  • either shut off the tabs completely on all of the parts (using adhesive to hold the parts instead of the tabs), or overcompensate by a couple  mm in the setting on the thickness of the material (it is a waste board after all).


Big Box Store LED Bulbs

UtilitechAfter a long DIY well pump replacement, extra parts I didn’t need went back to one of our big box stores.  Since we needed a carbon monoxide detector replacement (they don’t all last forever), I poked around through the lighting aisles and found a wide variety of LED replacement bulbs.  What I also found was the wattage ratings are creeping up to the CFL equivalent of 13W for a 60W equivalent bulb.  Not that I would buy a CFL bulb that needs replacing every seven months when the LED bulbs are carrying up to a three year replacement (and I have several that have lasted longer than that), but the concern is the Total Cost of Ownership (TCO) compared to what could be achieved.  It’s also called “comparisonitis” in some circles, (others call it penny pinching among other things).

Back to the bulb and some “standard” comparisons they like to write about:

  • Brightness
  • Lifetime
  • Wattage (compared to web)

The Utilitch Pro Warm White 60W Replacement bulb (indoor) part #0424722 is a glass and metal LED bulb that replaces the standard A19 base (screw in base normally found in the states). Distributed by FEIT Electric, this  UL listed (yay!) bulb is 800 lumens, and has a 270 degree light distribution.  Previous lights that have a “half-dome” exhibit shadowing that can make them inadequate for table lamps, casting most of the light upward.  The other issue with the upward facing configuration is the heat will concentrate on the glass, possibly shortening the life of the bulb. the curvature of the heat sinks may help alleviate some of this but I don’t have the equipment necessary to test such things; I’m a “home-moaner” not a scientist.

According to the packaging, the bulb consumes 9.8W.  The Kill-A-Watt measured 8.0W, measured after it had been on for about one hour.  On there is a similar bulb with the same box displayed advertising the bulb as a 13W, with the specifications stating it is 9.8W. There is also a similar bulb from utilitech that is a 65W replacement where the numbers in the picture and the specifications do match (this is part #0338931). Note: the big box store had them advertised at $10.98 US, so it was worth the drive compared to $15.99+ $5.49 shipping.

Aside from these discrepancies, there is the “Estimated Yearly Energy Cost”:  to reach the $1.18/yr cost based on $0.11/kWh, you would have to run the bulb for three hours per day average.  Also the 22.8 yr lifespan is based on this same use per day.

Factoring in a more realistic $0.20/kWh (since we’re not just paying for the electricity, but also the “line charges”, the “transmission charges” and probably the “utility worker driving by to electronically read our meter from the comfort of his cab at thirty miles per hour” charges, it still compares nicely at – okay, I just looked back at several of my posts: seems my calculations are a bit non-standard too…

So I’ll be going back and trying to “standardize” my measurements as well, starting now:The Utilitech Pro #0424722 run for 1000 hours will cost you $1.96, based on $0.20/kWh.

An equivalent 60W bulb run for 1000 hours would cost you $12 based on $0.20/kWh.

  • To figure out how much it will cost you to operate for 1000 hours, find your utility bill and figure out your actual cost per kWh
  • multiply the cost per kWh by the wattage of the bulb (in this case 9.8)

That makes about 2.74 hours per day for the bulb. Too low? You leave the lights on 8 hours per day? take the total from the 1000 hours and triple it for a close estimate.

Indoor Salad Garden – April 27, 2013

4.5 oz loose leaf lettuce

4.5 oz loose leaf lettuce.

Lettuce and chives under the LED flood light

Lettuce and chives under the LED flood light

Lettuce and Chives under the Philips LED Bulb

Lettuce and Chives under the Philips LED Bulb

After three + weeks of neglect – or should we say “no maintenance”, the lettuce and the chives just keep growing.  In fact, the letuce under the LED Flood light has come a long way, and may have outgrown the Philips bulb if they had started at the same time, but neighboring plants, the actions in the soil and other factors may have contributed to its growth as well.

Starting to get bitter though, so we cut down the lettuce and will be starting some tomatoes from seed.  Since all I have is Roma and Beefsteak, those will be what will go in.  The best tomatoes for indoor gardening are the dwarf and the cherry type, which I will be choosing for the next set of experiments. The soil was dry down to about one inch, but there was no drying of the leaves on the lettuce.  A couple of strands of the chives were brown but the plants continued to send out new blades.

All cut, we had 4.5 oz. of lettuce leaves from what turned out to be four plants, not just two, and 1.4 oz of chives or onion greens (chives are actually smaller that these greens, as these were “pearl onions that had started to grow, so I placed them in with the lettuce).

Once the tomatoes start and I remember to check on them, we will update the site again, unless we begin dabbling with something else.

If you are interested in performing your own experiments, the lights we used were the Philips 12.5W LED bulb, and the LEDwholesalers 10 Watt LED Waterpoof Outdoor Floodlight, found in big box stores as well as Amazon.
Note: using the links above cost you nothing extra and help fund our continuing dabblings.  Thanks in advance for your support.

Cut and Come – Two Weeks of Neglect

harvest of 1.25 oz after two weeksIt’s been a couple of weeks since I checked on the lettuce in the silos – only had about five minutes to make a salad and go, so here’s the pic of the picking – 1.25 oz from one lettuce plant, and enough for a nice salad. Included a couple of sprigs of onion greens, a hard-boiled egg, some ham and a vinaigrette made a satisfying salad. Still more than enough to pick another salad or let it grow, the leaves are crunchy and not the slightest bit bitter. Over at, you can see the latest of our non-cellar endeavors: lettuce grown in potting mix held by “steamers” – microwave utensils that are typically used once and recycled.

Cut and Come – Pick Your Salad and Let it Grow

Lettuce as of 2013-03-16 before picking

Lettuce as of 2013-03-16 before picking

Since the lettuce under the Philips bulb is doing so well, I decided it’s time to harvest a bit of it.  Picking the outer leaves, I was able to get 0.75 oz of lettuce leaves and still have plants that dwarfs the other two, though they are continuing to grow.  “Cut and Come”, “mow and grow”, “plow and chow” – you don’t have to pick the whole plant and start new every time.  We’re going to see how many “garden salads” we can get from these plants before they start getting woody or just decide enough is enough and give up the ghost.  Meanwhile, we are starting some more lettuce plants elsewhere under traditional fluorescent bulbs to see how they fair.



2013-03-16 Lettuce after picking

2013-03-16 Lettuce after picking

0.75 oz of lettuce from under the Philips 12.5v bulb

A nice garden salad.

Similar scales can be found here.

New Experiment – Let’s Play Catch-up!

Lettuces under LED Flood and Philips bulbLED Flood and box from LEDWholesalers -

Removed the “Miracle-LED” lights from the left-hand silo and replaced it with an LED Flood light.  Shown on Amazon as a 10W flood, the box says 12W.  Have to bring the “Watt-Miser” down to check the actual power consumption.  The LEDwholesalers 10 Watt LED Waterpoof Outdoor Security Floodlight 85-264v Ac, 3701WH comes with tinned bare wires and a wire clamp so you can tap it in – this is supposed to be wired by a certified technician.  Fortunately, the color coding is easily found on the net, and armed with shrink-tubing electrical tape and Gorilla tape, we were able to connect it to an unused three-prong grounded plug with little difficulty.  Nice bright white light and barely warm, it will be interesting to see how the plants respond.  I had gotten a second one from a different vendor that was unfortunately a 12V version which will be going back to Amazon.  Amazon makes it easy to return products – just an explanation and a printout of a return label and away it goes.  I’ve bought from LEDWholesalers before and like their products – this is no exception.

May harvest the lettuce on the right and transplant one of the smaller ones to do a better a/b split test against the Philips LED bulb.  The eventual plan is to use two of these floods to grow some tomatoes and cucumbers to see how they fair in the cellar with little to no regular sunlight, but that is a future experiment.