Adam@SheekGeek, Author at SheekGeek

I just bought a GlowForge laser cutter and here’s why

December 17, 2018December 30, 2015 by Adam@SheekGeek

UPDATE 2017: I canceled my order for the Glowforge as life happens and I couldn’t afford to let them earn interest on my money anymore. I just had to get my money back for life reasons. I do still recommend you get one if you can. I’ve seen them in use in person at Charlotte Latin FabLab and it is really awesome!

Original article below:

So for the last 7 years or so, Jess and I have considered purchasing a laser cutter. My personal goal is to have my own FabLab. I’m partially there with Jess’s KNK Zing vinyl cutter and my Shapeoko/Xcarve CNC machine. The two main missing components are a 3D printer and a laser cutter. Being a FabAcademy alum and running a FabLab at work, I am intimately aware that lasers are the most used (and arguably useful) machine. They are definitely the most fun to play with. They are also the easiest to make money with (It’s always easiest for me to justify big purchases with the expression “hobbies that pay”). For the past several decades, laser cutters or laser engravers have been used in trophy shops and all sorts of companies. You can use a laser cutter to make products to sell on Etsy (as many people do), make the most amazing personalized birthday and holiday gifts, prototypes of ideas you have, or just make cool stuff for yourself.

I recently saw a new laser cutter on the market and I held back for a while before making the decision to buy it. That may have been a mistake. The GlowForge is shaping up to be a great machine. I’ve followed it since September, when they were offering 50% discounts on all models. At the time of this article, they have raised the price to 40% off retail price. And, if you use this referral code, both you and I will get $100 off our orders! (In full discretion, I have had no contact with Glowforge, nor have I actually use the machine myself yet. I’m just really stoked with this machine and its potential. I do have a PhD in Computer/Electrical engineering with Computer Science background and I run an official node of the FabLab network that was started at MIT, so hopefully I’m not off base here… )

There are lots of cheap ( <$15k ) 40-watt laser cutters on the market such as some cheap Chinese ones from Alibaba, or Full Spectrum. So why go in on a Glowforge? Well quite simply, it is the best designed laser cutter for FabLab/Makerspace/Hackerspace use. Unlike others in the price range, you don’t need a 5 gallon bucket of distilled water and a fish pump to cool the laser tube (yes that’s a real thing some other models at these prices require and it is ridiculous). It breaks the paradigm of how users interact with a laser cutter. It is following some of the latest research on user interface and user experience in the field of computer science. Honestly, those are project I wish I could implement myself but didn’t have the time. It brings together lots of great solutions from these projects and crams it all into a single package.

Paradigm shift #1: Unlike traditional laser cutters, where you print to the machine like a printer on a network or connected to your computer, Glowforge can be printed from practically any location in the world. This is because the software is cloud-based. I used to be wary of this kinds of thing, but since Glowforge also promises to make a version of the software open source, you can implement it yourself if you want.

Paradigm shift #2: Glowforge allows you to easily position your designs on your material using a live camera view of the material. This is a godsend for those who are familiar with the waste of laser cutters. To be able to make sure a design will fit on a scrap piece of material, you have to do some measurements, hold your tongue just write when pushing the cut button, and hope you remembered to reset the origin (0,0 point) on the laser before cutting. Sometimes this can be very hard depending on what was originally cut out of the scrap you are using, you might have a weird shaped area and it can be very hard to find out if you can use it to cut a new part. There are some ideas being researched to handle this kind of situation and other tools you can purchase that are very expensive, but Glowforge has it built in. Being able to literally move my design on top of a video camera image of the material allows me to use as much material as possible without the risk of mis-cutting and having to toss that piece of material and grab a new one.

Another great feature is to simply draw on the material you want with a pen. The cameras will read your design, vectorize it, then the laser will frickin’ cut it exactly as you’ve drawn it. This is worthy of some type of award because it will save a lot of time for people. I constantly have students who would benefit from simply being able to draw their designs by hand and quickly cut a part out. Again, this feature somewhat comes from newer research into user interface design of laser cutters I’ve been keeping my eye on for some time now.

Paradigm shift 3: Glowforge uses dual cameras inside the cabinet to not only allow you to place your design on the material, but it can conform and auto focus even on non-level materials. The example on their web video mentions etching a design on a macbook, but this is sooo much more powerful and useful than just that. Many materials you want to laser, such as a 1/8″ piece of plywood, have a warp to them. If you focus your laser on the low part of the warp, then keep that measurement to cut the whole part, you can end up with edges that aren’t exactly as you had designed them, or edges that are weak due to the wood not ablating and instead burning. This is bad for a couple of reasons. One it can start small fires, but more commonly your edge is brittle and ashy. This changes the workable dimensions of your parts and sometimes makes them unusable.

Also, the cameras can detect materials you put in the machine. There are barcodes on the materials you buy from Glowforge, but you can make them yourself, which tell the machine what settings to use for engraving or cutting the material. Settings are different for plastics versus wood, etc. Even different densities of wood matter, so this is a great solution to the problem of figuring out what power and speed settings to set the laser to use.

And finally on this point, it seems there’s also some image recognition. Put your laptop in there and you it’ll detect it’s a macbook and know what settings to use to best etch it. It can even bring up possible designed others have submitted online for you to use if you want.

Paradigm shift 4: The firmware as well as a simplified version of the cloud software will be made open source. This is great because I can hack on it (as I would have done anyway, but at least now I have a much better starting point) . I’m certain a community of hackers/makers will be adding features, which is exciting since this machine is already starting with an impressive set of features.

Paradigm shift 4: On the Pro version of the machine, you can open the front and back to be able to cut material that is 20″wide, but infinitely long. This comes from two places, the vinyl cutting machines that are in the market (which can cut a certain width, but practically an infinite length of material from a spool), the Shaper and the awesome Shopbot Handibot (Shoutout to our friends and fellow Carolinian’s; thanks again for the help this past summer in Pittsburgh Salley!), which can do large designs piece-wise. The cameras on the Glowforge can help align the previously lasered portion with your design and make adjustments as needed. This is incredibly helpful for making sure the finished product comes out correctly.

Glowforge will also host a libray of other peoples’ designs you can choose from if you aren’t the artistic type. This is similar to Makerbot’s Thingiverse or Ultimaker’s YouMagine for 3D parts and Inventables’s project section for CNC projects and file, which can be imported into Easel (Inventables’s cloud-based CNC CAD/CAM software for their line of Shapeoko, Carvey, or X-carve machines).

Words of Negativity: For the specs of the machine, the 20″ wide cutting area is slightly awkward and a 24″ width seems more practical. Also, since the Glowforge isn’t out yet, I have to wait. I have to wait to see if it lives up to these expectations, and also wait to play with it myself.

All that being said, the Glowforge sale at this point is a presale. I won’t receive my machine until summer 2016 or later, but you have until the time it ships to cancel your order and get a full refund. I expect any bugs in the system will be worked out before I get mine and if not, then I’ll have a good excuse to play with it in more depth.

Disclaimer: The only affiliate link in this post is for the Glowforge. All other links supplied in this post are to simplify your internet browsing adventure.

How to track your family history free and easy

August 27, 2015 by Adam@SheekGeek

A few years back, I got interested in my family history. My grandmother had been telling us all stories for years, but at some point, a switch flipped in my mind and suddenly I had an intense interest in stringing these stories together. I thought I’d write up my method for researching including some of the tools I use. Please excuse the verbose brain dump but I wanted this page as a reference to be a one-stop shop for myself as well as anyone who is interested in genealogy.

Click here to read the whole article

Installing a Kitchen Backspash

January 31, 2015January 4, 2015 by Adam@SheekGeek

Here is our kitchen before:

And, here is our kitchen after (even more appropriate that it is messier):

As I mentioned in my previous post about this, Jess came home with backsplash materials one day. We looked at a bunch of online designs and decided to have a go at it ourselves. In the first installment, we installed the extruded aluminum edging that boarders the tile. This time we will talk about the tiling itself.
The toughest part of this whole ordeal is figuring out a good pattern for your tiles. We spent hours trying to get a good random look in the tiles we used. We went with the glass and stone tiles that come on a 12×12 inch netting material. Most of these pieces are in a nice random pattern, but some are not. We had to manually cut out some pieces and replace them with other colors to keep the pattern pseudo-random.

Once we had our pattern laid out, we prepared the wall for the tiles. First, turn off all the breakers that power the light switches and outlets in the area you will be working. Remove the light switch and outlet covers and check to make sure the breakers have turned off the power to those areas. Breakers may be labeled incorrectly as I found out when it shocked the $#!+ out of me… so I highly recommend getting an electronic sensing pen like this one to use to make sure the power has been turned off. It works without having to be in the circuit. Just place it near the hot wire (black or red wires) on the sides of the outlet or light switch boxes. If an electric charge is detected, it will turn the tip of the pen red and beep at you. Once you’ve ensured the power is off, go ahead and cover these with masking or painters tape. When we go to grout these areas, we want to make sure they don’t get all clogged up.

It’s important to note that tiling isn’t as hard as it used to be. Instead of having to put layment on the wall to stick the tiles into, we used these sheets that are basically like 2-sided tape. The flat portion sticks on the wall and the other side had what looks like hot glue in a grid pattern on it. The hot-glue-looking stuff is a pressure activated adhesive so to place tiles you simply press them into place on this material.

You can see the glue in the background in these pics:

We started our tile design at the bottom of the wall, where it meets the counter top. this is a good place to start because people will see this part more than directly under the cabinet. In our house, the cabinet and counter are not perfectly parallel. Starting with a full-sized tile at the bottom where the wall meets the counter will ensure any half-cut tiles or extra space will be hidden under the cabinets. Also, we have about 1/4 and inch of play since we used the metal edging. This will allow us to fudge a little if we need to.

We began with the shortest wall we had as a test. We had a 2 x 1.5 foot section of the wall we wanted to test on. This was critical to the learning process! We learned how to lay the tiles so the ends match up with the corner of the wall well as well as how to hide the edges. We also figured out the best method for cutting the tiles around an outlet in the middle of this small section. I suggest practicing like this on a small area before doing a big area.

For cutting the tiles, we bought a tile cutter. (This little guy looks reliable too. There are lots of $20 options and in our experience, it did the trick. I don’t plan on needing a tile cutter often so I didn’t need a workhorse.) Don’t use a tile nipper if you are using glass tiles because they will shatter or crack unpredictably. It helped to cut draw out where the outlet met the tile sheet, then laid the entire sheet in the manual tile cutter. Scoring and snapping each tile separately produces the best results. We did find that sometimes the natural stone cracks on veins of impurities rather than the scoring line. In most cases that was OK since it can be filled in with grout later, but sometimes we ended up cutting that tile out and replacing it once the sheet was on the wall.

When using the sheets of tile, you need to make sure you grout it within 24 hours from when you set the tiles. Otherwise the tiles can fall off the wall due to their own weight.

Student Engineering Portfolios

October 20, 2023December 27, 2014 by Adam@SheekGeek

This past semester, we radically changed the curriculum for the Intro to Engineering course at the college where I teach. We are focusing more on competency-based learning via constructivism in this introductory practicum course. To track the student progress we used an online website portfolio. We tried to base this concept on the webpages we had to make in the FabAcademy. Here is what tools I used and what I’ve learned.

In the FabAcademy, students were required to make an HTML webpage each week chronicling their progress with that week’s project. This HTML page was saved in a Mercurial repository on the students’ computers, and synchronized with the FabAcademy server. At my college, the port for doing this was blocked, so it was impossible to synchronize the repository unless I did it at home.

Since we can’t run a Mercurial server (due to the port issue) at my campus, and I didn’t want to have to fix the problems of over 100 students creating multiple heads of the repository, I went another direction.

Instead of HTML pages, I created a multiuser WordPress installation only for students at my school. It was available online from any computer, and students can upload any code or design files in any format they wanted as long as it was a .zip. This worked marvelously. I had worked with WordPressMU years ago creating this exact type of environment but I couldn’t get an audience. In fact, I used the same domain name as my first site from long ago. the concept was supposed to be something like instructables.

WordPress was great due to the very low overhead for students. They didn’t have to install any funky toolchain, learn to use the terminal, or anything like that. They could focus on the assignments themselves. It did take a while for them to understand the concept of technical writing but eventually most students turned their website into a great portfolio. That was the main objective. The students last assignment was to export their website and import it into their own wordpress.com site to continue documenting their work to create an engineering portfolio they could show prospective employers. This is similar to the concept behind InnovationPortal created by Project Lead The Way and many other services of this sort.

In the end, just like FabAcademy, I wanted to scrape the pages and create a static HTML version of each student’s website at the end of the semester. This way our future students could benefit from previous generations and build upon their ideas and projects just like in the FabAcademy. being static HTML frees up resources on the server and reduces the chances of being hacked by reducing the number of live users and database entries. The static HTML copy of all the websites didn’t seem to be a hard task. I had found a plugin called Really Static that does exactly what I needed. I tested it on my own old senior project website.

While testing this plugin on a single site on our server, I accidentally activated it on all 100 blogs. This was a disaster! I’m still trying to figure out how to fix this issue. I emailed the support page and even emailed the author who stated he has used it on many multiuser sites, but I got no replies for help. I don’t really know PHP, just enough to hack on it to glue code snippets together (if I am lucky) so there’s no way I’d figure out how to fix it. Also the comments of the code for the plugin are in German, which I’m not great at.

A new solution appears

After this mess, I decided to look more into Static Site Generators (SSGs). This is a system that creates static HTML pages from the get-go. Users write pages and posts in a markdown language of some type in a plain text file, then the site generator turns this markdown language into a static HTML site. Some common ones are Jekyll and also Hyde. There are several large lists of Static Site Generators on google as it is the new fad in webhosting. The issue with almost all of these systems is that it is not user-friendly. For instance, a new post on wordpress is literally as easy as writing an email or word document. To use most of the systems I’ve seen for SSGs, you have to install a compiler (Ruby or python for instance) then some libraries, then you have to write your code in a text file, compile it into HTML, then manually upload these files to the server or to Github pages.

There is no way my students can handle doing all that without asking millions of questions, even if I make a how-to video showing each step (heck, they asked enough about wordpress as stupid-proof as it is…)

There are some relatively simple solutions out there already. Most notably is Dillinger which seems to be fully featured except missing a toolbar to help complete noobs. Having more features scares me since I’m not great at javascript. I just came across this one and had to mention it because it does integrate dropbox, googledrive, Microsoft onedrive, etc. I like it, but there are some drawbacks:

it is too complicated for me to work on until I learn javascript enough.
There doesn’t seem to be an index page that updates automatically (like Simple below) which is needed
There doesn’t seem to be multiple templates. you get what you get, though it does look quite nice.
There are no buttons to help noobs like I mention below in the RES.

While searching the list of SSGs, I found one solution I think is workable and stripped down enough that I might be able to wrap my heard around it somewhat. It is called “Simple” and it uses Github pages. It is very easy to set up and use and it has a web-based interface with a live preview of the generated HTML from the markdown language. Markdown is a very simple language to learn and is intuitive enough for freshman students to pick up quickly. So I forked Simple so I could hack on it. It has an MIT license, so it is fully manipulable.

While it has a simple interface, I wanted to make it easier for my students to use the Markdown language. I’m taking my cue from the Reddit Enhancement Suite (RES) Chrome plugin. When you make comments on Reddit using RES, there are little icons almost like a rich text editor. You have an icon for Bold, Italic, Strikethrough, quote, link, etc.

These icons make it dead simple to use markdown language, and especially if the user can see a live preview of the results using the “Simple” interface.

The template for Simple is currently hardcoded, but looks clean and easy to use. There are only a couple of issues:

Students must get their own Github account and host their site there, making it a bit tricky to scrape the content at the end of the semester…
Students must link images that already exist online somewhere. This means they will either have to upload the files to Github (yeah right, like I want to get 1M questions about using the sync app) or use their google drive from their school account. I’m almost 100% on them creating a folder in google drive to host the pics as long as I can guarantee I can scrape the images well enough. I haven’t tested this yet.
They cannot directly embed youtube videos into the markdown language. I can skirt this by making a button that links to the video with a screenshot of the video pretty simply. I have seen other people extend the Markdown language to be able to embed youtube and vimeo videos, but I’m not savvy with javascript, which is what Simple is written in.
There is currently only one template, and it is hardcoded.

Otherwise, it seems pretty darn good. I expect that it could be extended for use completely in google drive, but I’m not sure.

It is going to take me quite a while to implement the RES-style buttons due to my lack of javascript skills. If anyone wants to help, check me out here

Another strong contendor already has a simplified button interface and can be connected to google drive. This is called StackEdit. It has a great editor, fast previewer, and can export to several options as well. Since the buttons are a must, this is a good solution. It is too cocomplicatednot even sure if itis open source) for me to modify in any way, like Dillinger, but we can see how it goes. I haven’t played around with it enough to see if there is a variety of templates to use.

Shapeoko Software Adventures

January 4, 2015December 26, 2014 by Adam@SheekGeek

I finally got a little time to work on the Shapeoko V1 to V2 conversion. I made a video to document for my future self what settings I used for things with explanations of why I used those. I hadn’t previously made many notes so I had to basically start from scratch and I lost a lot of time redoing things. I tested some software and did a quick comparison. Details of my experience and links to the software are below. I also had a bit of trouble from the top software choice, Chilipeppr that I hope someone could shine some light on.

Software:

1. http://chilipeppr.com/grbl

UPDATE: John Lauer, maker of Chilipeppr , showed me the error of my ways and addressed most of my concerns with it. He made an update feedrate modification update that I have yet to test.

Chilipeppr seems to be the best interface by far with full 3D display, code simulation, and lots of neat widgets and macros. While testing my first milling job, however, I ran into some trouble. I haven’t really watched all the tutorials on this so it is probably something I’m doing wrong, but when I used the feedrate multiplier on the Gcode widget, I typed a value in by hand and hit “enter.” I entered 0.15 into the feed rate window, hit the enter key, and tested it out. This did not work at all. You can only modify the feed rate by clicking the up and down arrow buttons on the Gcode widget in Chillipeppr. You can verify the feed rate change by watching the lines in the Gcode change when you click the buttons. I noticed that if I watched these values while typing an input, they don’t change, unless I mouse over the Gcode line.

I ran a simulation to verify it would work. ~~The simulation was slow as expected since I was only going 15% of the full speed.~~ Simulations do not take into account feedrates. When I went to run the real job, I broke a bit almost immediately. The very first line it cut was at the feed rate I specified (15% of the default speed) but immediately on hitting the next line command in the Gcode, the speed went back to 100% breaking my bit.

Something I loved about this app was the ease of modifying the positions, zeroing and such. A couple of improvements might be to add options to only zero one axis at a time, and to add a custom offset to each axis if needed. This can be done manually by entering the appropriate G92 code with the wanted offset, but a button similar to the “Move By” would be nice. You can zero a single axis by clicking the little triangle next to the axis name (ie X, Y or Z) and select “Zero Out Axis”.

I would also like the “Move By” to default to 0 when you change from one axis to another. I mistakenly drove a bit 10mm into my workpiece after adjusting my Y axis first. I had used 10mm for Y, but meant to change it to 0.1mm on Z. That was totally my fault, but a “stupid-proof” option would be nice for that.

2. Gcode-Sender Chrome plugin

This neat little app is a chrome browser plugin. It is very basic. (this link is that video cued to exactly the point I’m testing this software). It autodetects and connected to my GRBL device instantly. I didn’t have to install any executable alongside this. An issue is that there is no visualizer for the gcode so you can’t really see what it is going to cut or graphically how far along it is in the cutting job.

3. Universal Gcode sender

You can see in the first video of this post (this link is that video cued to exactly the point I’m testing this software)that I detail this app. I couldn’t get to display correctly. I have java 1.8 and for some reason, none of the buttons or objects display correctly. I also couldn’t get the visualizer working at all. I tried version 1.04 and 1.07 with no joy. I was able to manually move the machine, but I couldn’t trust it with a cutting job since I couldn’t really see what the button said and couldn’t get the visualizer working.

4. Grbl Controller

Here is the video cued to this software. This is the software I ended up using in for my first mill job after I couldn’t get the chillipeppr feed rates to scale with its default Gcode. I created my own code quickly in easel.com and threw it into GRBL Controller to mill. I liked the simplicity of the interface.

I have a few gripes:

The serial terminal portion is really slow on my machine and I don’t know why. it takes 5 full seconds to connect to the serial port and print the GRBL stats. When I send commands manually, there is a definite delay of a couple of seconds before the machine moves.

The visualizer is good, and I love that it prints the extents of the design. I dislike that it is a 2D only viewer. While it is a good viewer overall, if it was 3D, that would make this tool much better.

The GRBL Settings under the “advanced” tab really messed up my settings. Since I am running GRBL0.9g, when I loaded this window, it populated the window with my GRBL settings, but when I changed a value ($110 for instance) in this window, it actually wrote it to the OLD GRBL setting number for that setting. This really confused me for a while. I’m not sure why this happened. I fixed it in a serial terminal and decided not to use that option again.

Other CAD/CAM tools I surveyed

Easel.com is the CAD/CAM software package from Inventables designed for their machines. It only works with GRBL 0.8c directly, but there’s a way to export the Gcode so you can use any gcode sender.

I ran a job I created in Easel. I had to make sure I selected the correct bit size and on Machine–>advanced I created, then exported the Gcode. I brought the Gcode into “Grbl Controller” to send the job. Since I milled with a 0.5mm bit, and I wanted to go 1.5mm deep, that takes 3 passes (rule of thumb is to only cut as deep on a single pass as the width of your bit). This worked pretty well because Easel generated the multiple passes without telling me anything about it. I had manually entered 30mm/minute as a feed rate into Easel.com, but it seems to have automatically calculated the feedrates based on either the Gcode it exported, or used the GRBL defaults for each axis because it cut much faster than that. I would have really liked to have some kind of stats or a note about the number of passes or the approximate mill time based on traveled distances and feed rates.

MakerCAM.com is kind of a precursor to easel. It allows you to import SVGs and do things like pockets or outlines. It then generates toolpaths based on your entered tool values. It is really easy to use and what is great is that you can download the whole things so you can use it with a device not connected to the internet. There are some great tutorials here.

GRBLweb is another browser-based gcode sender. I didn’t try it out, but the video on the webpage makes it look like a good tool.

JScut is a tool that GRBLweb and Chillipeppr use. JScut is a browser-based CAD/CAM package that helps you create toolpaths. It is similar to Makercam but being JS-based, other browser-based tools can interface and use it.

Miscellaneous notes about my setup and justifications:

I’m using GRBL 0.9g as I wanted to take advantage of the 4th axis in the future. this has a different pinout than version 0.8c. 0.8c Is what Easel.com uses when you click the “Carve” button on their interface (they use a server app to send the gcode to the machine from the browser, for some reason, I couldn’t get this to register correctly, even when I had 0.8c and the website kept telling me to download and install the server app. The settings I used for the 0.9g setup and justifications for these values are at the bottom of the post.

Grbl 0.9g [‘$’ for help]
$0=30 (step pulse, usec)
$1=50 (step idle delay, msec)
$2=28 (step port invert mask:00011100)
$3=2 (dir port invert mask:00000010)
$4=0 (step enable invert, bool)
$5=0 (limit pins invert, bool)
$6=0 (probe pin invert, bool)
$10=3 (status report mask:00000011)
$11=0.050 (junction deviation, mm)
$12=0.100 (arc tolerance, mm)
$13=0 (report inches, bool)
$14=1 (auto start, bool)
$20=0 (soft limits, bool)
$21=0 (hard limits, bool)
$22=0 (homing cycle, bool)
$23=0 (homing dir invert mask:00000000)
$24=100.000 (homing feed, mm/min)
$25=250.000 (homing seek, mm/min)
$26=250 (homing debounce, msec)
$27=1.000 (homing pull-off, mm)
$100=5.470 (x, step/mm)
$101=5.470 (y, step/mm)
$102=320.000 (z, step/mm)
$110=300.000 (x max rate, mm/min)
$111=300.000 (y max rate, mm/min)
$112=50.000 (z max rate, mm/min)
$120=250.000 (x accel, mm/sec^2)
$121=250.000 (y accel, mm/sec^2)
$122=50.000 (z accel, mm/sec^2)
$130=290.000 (x max travel, mm)
$131=290.000 (y max travel, mm)
$132=100.000 (z max travel, mm)

Here are the justifications for these settings:

Note: GRBL 0.9g runs at 115200 baud.

I needed to change the X and Y steps/mm based on the following:
Motors have 1.8degrees (200 steps/revolution)
MXL belt has 2.03mm pitch
My belt pulleys have 18 teeth on them
I’m single-stepping my stepper motors
I used these values in the following calculator: http://prusaprinters.org/calculator/#stepspermmbelt
= 5.470 step/mm for both X and Y

To test this, enter the following code
G01 Y-10 F300
Which means “Move Y axis -10mm at a speed of 300mm/min”
I confirmed this motion with a micrometer
My Z axis seems fine using the values from the shapeoko website (I meanured about 1mm when I sent it the command to move 1mm.)

I’ve had to invert my direction on a couple axes:
https://github.com/grbl/grbl/wiki/Configuring-Grbl-v0.9 ctrl+f “$2 – Step port invert mask:binary”