Giving the laser scribe a workout

The other day I posted about a laser scribe I purchased. I think I have gotten the hang of it. I’ve found that the wireless connection from Android via Bluetooth is sufficient for most of the things I tried. The following is a picture of the device in action.

I used a lens filter to help protect the camera on my phone, that is why the picture is all green.

Now for a couple simple designs, I have tried. The first is the design from the South Carolina state flag burned into a hickory cutting board:

That design is about 40 mm square and took about 20 minutes to complete. The board just needs some mineral oil to finish it off. See that large crack across the bottom of the board? It is filled with mint green epoxy, to salvage the board and keep the crack from continuing – that is why my wife gave it to me to experiment on!!

The second design is a picture from my son’s wedding. Since they have an anniversary coming up, I thought I would burn it into a piece of poplar I had laying around. This design is about 170 mm by 70 mm (if I remember correctly). It took about 8 hours to burn into the plank.

Now I just need to trim it up and put some finish on it to protect it.

On to my next woodworking adventure… Dum spiro spero (While I breathe, I hope) Another South Carolina state moto.

Getting Deeper into using a Laser Scribe

For over a year now, I have been using a small laser scribe (a version similar to the NEJE DK) to burn images into wooden medallions.

NEJE DK

I place these into wooden items I’ve made to essentially ‘sign them’. There are cases where I can’t use a forstner bit to create a 1” hole so I can insert one of these coins, that is why I’ve been looking for other options.

I recently purchased a NEJE Master 2 3500. This engraving and cutting device is essentially a 3.5 watt laser mounted into a portable CNC machine. It can burn a design into an area of 170×170 mm.

NEJE Master 2

NEJE Master 2 is equipped with 2 processors and can support 2 types of firmware at the same time, allowing it to talk with Windows (or a Mac) PC using USB or an Android phone via Bluetooth. You design the image to burn on the computer and download it to the laser scribe. It will take the process from there.

So far, I’ve created a small cat design (using one of the provided images) using my phone and burned a larger picture from my son’s wedding into a board. Both seemed to work well.

Next, I am going to try burning images into some less standard objects, like a pen or wooden box. The key will be positioning the item securely since it cannot move during the burning process.

The feature I like most about this laser is that I can place it physically on something I’ve made (e.g., cutting board, table) and burn a design into it without the concern about the size of the object I had with the old tool. The older device had to have the item placed inside its enclosure.

I ordered the Master 2 a little over a month ago and it arrived directly from China in the most impressive packaging I’ve ever seen. I could have dropped that box off the top of a two-story building and the impact would have had no effect on the contents.

To get the scribe working, there was only some minor assembly (all the tools were included). I then hooked it up to my device, loaded the drivers & software and started burning.

Creating a wooden table from scratch

Since I’ve been working on teaching others how to use Fusion 360 and have also continued to develop my woodworking skills, when my wife said she wanted a new table for our porch I thought why not…

I asked her to look around and find some designs that she liked. I took the features I liked out of them and created a design:

The table design

Progress so far:

I am making the table out of hard maple, starting with rough sawn lumber. Once complete, it will be finished with a weathered grey stain and Spar urethane, since the table will be out on our screened in porch exposed to the weather. I will probably have $120 in it by the time I’m done, plus a few hours of my time, of course.

I did learn something in getting the construction to the point shown above. Build the least constrained assemblies first and work to the more constrained ones where possible. I was using a biscuit and glue assembly and did not make ‘the ladder’ first.

Since I didn’t do that, I now will need to use some screws or other fasteners to assemble the ladder. The table is too tightly constrained at this point to put it together any other way. I was originally stiving for a no fastener solution.

A beginner’s mistake – which proves I am still a beginner.   

Actually wrote a game in Python

I mentioned a while back that I was using the Covid lockdown to learn Python. I thought I finally had enough understanding to write something interesting…

I wrote an implementation of a Settlers of Catan Dice Game in Python. Sure it is just a text based game, but it is still playable.

First Four Moves Example

I usually end up writing a game to learn a new platform or language. I’ve done this on the Apple II, HP 1000, VAX, Macintosh, Windows, Palm and Android. There may have been a few more but I am probably repressing them. I’ve used Algol, C, Pascal, C#, Basic, Lisp, Java and now Python for my game development efforts.

Thinking back, I bet there were at least 30 different games. Most of the games were graphic in nature, this is the first text based game I’ve written this century (at least that I can recall).

The one thing I learned about Python in the process of writing this: there is so much more to learn and it is way too easy to fall back and write code the way you would on a different platform. I am sure a real Python programmer would cringe at my technique.

Now I need to let my daughter try it out and comment on my user interface design. Oh well, on to something else.

RF Safety and the Radio Amateur

With the advent of Covid, clubs seem to be looking for more content that can be presented remotely. Our club was looking for a presentation on RF Safety and I threw this presentation together. Hopefully, it may be useful for others. It goes through a bit of the history of RF safety and the FCC and what the current expectations are of the US Amateur Radio Service (ARS).

History of RF Safety and the ARS

Expectations of the Radio Amateur to do an RF Safety review

Details about the regulations

What does 97.14 say

OST/OET Bulletin #65

Educational requirements

A RF Safety Calculator

Example

MPE limits by frequency

Other resources about RF Safety

Tools to assist with compliance

A PDF version is also available to review (that should have working links).

A process for creating Topographical Designs in wood using Fusion 360 and your CNC

A while back I wrote about a project I had done to create a map using my CNC machine. The Technology Special Interest group in our woodshop asked me if I could put together a high level presentation about the technique used. For the map I used information about the area around Hilton Head, SC. The rest of this post is a copy of those slides:

A high level summary of the process

There are numerous mapping resources out on the Internet. I found Snazzymaps as of the most versatile tools for creating designs that can be used with minimal manual effort.

Finding a map for your design

There are also many options for raster to vector conversions. Inkscape is the best open source alternative I could find. It may take you a bit of practice to understand the user interface… but there are many examples available.

Converting the raster data into something the CAD system can understand

Loading the correctly formatted SVG file into Fusion 360 is one of the easiest steps in the whole process.

Loading the map data into Fusion 360

In this example I used a 2mm flat bit for the contour cutting and a 60° V-bit to engrave the edges.

Creating the machining data for the CNC

Cut the design

Putting a finish on the design

In this post only the basics were covered. The possibilities are nearly endless.

Other options and designs

Musical summary of 2020

I had a friend share the following on their Facebook page:

2020 key signature

I thought that was funny but for me it has really been more like:

2020 song

Yesterday, I thought about it a bit more and this might be more approriate:

2020 song version 2

For those musically inclined, you’ll figure it out…

Finishing the cartography experiment

Way back in March, I wrote a post about an experiment in cartography using my CNC machine.

I never did get around to finishing it, until now. I happened to be in Hobby Lobby the other day and they had all their wooden craft boxes on sale. I picked one up for about $3 and then cut my wooden map down to fit inside of it.

I whitewashed the box and then epoxied the map to the bottom. There were a few bubbles that kept coming up off the map, so I swirled those into a cloud effect and then put a final coat of epoxy over the top. This is the result:

It is not perfect, but as an experiment I thought it came out fine.

Making your own pen blanks (yes, it is possible)

Epoxy Pen Blanks

One of the projects you can do on the lathe that has near instantaneous gratification is making a pen. You can easily create a pen in an afternoon. In order to do this though, you will need pen blanks and a pen kit.

Pen blanks are pieces of material that are usually about 5” x ¾” x ¾”. They can be made from nearly any kind of wood as well as acrylic. These blanks can be purchased on-line or at your local woodworking support shop.

Cutting them out of a single piece of wood or out of scrap that you have glued together is a straight-forward process. You can figure that out on your own, but…

Recently, I have been experimenting with making my own epoxy pen blanks. These polish up to a glass like finish and are relatively easy to create. What is required is:

1. A silicon mold – I was able to find some ice cube trays that fit the bill perfectly. You can order 3 trays for about $15. This would allow you to create 12 blanks at a time or you can give them to your woodworking friends.
2. Epoxy – To make the blanks, I used clear epoxy that I purchased for about $65 a gallon on Amazon (this used to be cheaper before everyone started crafting with Covid). Epoxy can be used for a range of woodworking finishes, tabletops, jewelry making… so do not think of it as only being used for making pen blanks.
3. Mica pigment – I was able to purchase 50 colors of pigment for about $30. The mica pigment is useful for a range of woodworking and other activities. Only a tiny amount is required for each color, so the small packets purchased will last a lifetime for most of us.

You can purchase these products in smaller quantities. I already had everything except the molds lying around and knew I was going to use them for other projects, so I purchased the larger sizes to get the volume discount.

There are many videos on YouTube about how to mix the epoxy and tint the epoxy with mica pigment, so I will not go into detail here. The blanks take about 12 hours to harden and I would not work with them on the lathe until they have set for 24 hours. One thing you always need to watch out for when working with epoxy is bubbles and trapped air pockets. These are easily addressed with a heat gun or torch, since heating the bubbles before the epoxy hardens will cause them to expand and pop.

The blanks I made turned very easily. In fact, I believe they were easier to turn than the commercial blanks (probably because they were still not quite totally set, which probably takes at least 48 hours).

You might wonder if making your own blanks is cheaper than just buying the blanks commercially. Acrylic pen blanks are in the range of $3.50-$6.00, depending on the color and pattern.  I was able to create my blanks for about $1.50 each, in colors of my own choosing. It may not be worth the effort. It is not always about the destination, but the experiences developed along the journey.

A black and gold pen made from an epoxy blank

Caught a computer virus and took my machine to bare metal

I don’t know about you but on the rare occasion my computer catches a virus, I wonder if I can ever trust it again. Fortunately, the Windows 10 security tools notified me off the infection, so I hope the security compromise wasn’t hanging around long.

In this case, I decided I could not risk it (since the virus was listed as a fairly serious issue. Since I hadn’t rebuilt my computer’s OS in over 4 years, it was probably time to start over anyway and get rid of off the chaff floating around my machine.

At the same time, I decided I would go through almost every account and password of any importance and change my login information as well. Needless to say this took quite a number off days.

Replacing the operating system with a new start was the easiest part since Microsoft provides a Windows 10 Installation tool. If you want to start over, the installation tool does require 8GB of free space (at least).

Next comes the tedious process of reinstalling (or even remembering) everything that you use. Over the years, I have put together a fairly reliable list of tasks to do before starting the rebuild like:

1. Backup any Outlook rules
2. Backup outlook contacts local to the machine
3. Make sure the system backups are up-to-date
4. Take a screenshot of the start menu layout
5. Print out all the programs installed, from powershell:
   Get-ItemProperty HKLM:\Software\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall\* | Select-Object DisplayName, DisplayVersion, Publisher, InstallDate |Format-Table -AutoSize
6. Export your favorites from the primary browser into a file (this is just a backup since the browser sync should take care of this)
7. Backup the user AppData files

I have a detailed list of things to do to perform the install as well, like:

1. Install the OS
   1. Create personal account
   1. Create admin account
   1. Reduce privileges for personal accounts
2. Install graphics control panel and latest graphic drivers
3. set the fixed swap file size in the This PC properties
4. set the name of the computer
5. reboot
6. Set up network
   1. set fixed IP address (if necessary)
   2. set the DNS info (if necessary)
7. if the system is on an SSD run program to make sure the system knows it’s an SSD
   1. Run ‘Winsat formal -V’ to config SSD from an ADMIN CMD line
   2. Fsutil behavior set disabledeletenotify 0
   3. Disable indexing on the SSD
   4. Look at ‘windows 10 OS running SSD’ on the browser to get the latest information
8. check to make sure that system restore is turned on (computer settings -> system protection)
9. Check for updates
10. Install programs…

And it goes on and on

Now I have a machine that is running again accessing all my development tools, ham radio and 3D printing software. I need to try my CNC machine connection next. Oh well that’s a couple days I’ll never get back.