This is the Super EZ Graver project documentation. If any of the documentation doesn't make sense or links are broken etc please let me know and I'll do my best to fix it.
I started engraving early in 2019 after coming across some engraving videos by Shaun Hughes on YouTube. I started off with some push engraving while I ordered up the parts for Shaun's "Home made hand engraving machine". I built one of these and proceeded to hack my way through some brass and copper practice plates and I also enjoy making jewellery with enamel. I have now aquired a microscope which has had a marked effect on my engraving, previously I used an optivisor with an added loupe but it is not adequate for my old eyes.
Shaun had the idea of a solenoid powered engraving system over 2 years ago and posted a video on YouTube and one of the engraving forums. He wasn't the first to come up with the idea, as far as I can find out that was Steve Lindsay back in 1979. So its nothing new although the availability of cheap electronic components and the advent of 3d printing has enabled me to put these together to make the Super EZ Graver. He also has tinkered with a Rolson engraver uses an AC driven laminated solenoid and power is regulated using a fan speed controller YouTube. Jerry Moralles uses a similar tool to engrave coins very effectively: YouTube. He also has made some additions that allow for the mounting of small abrasive stones to mechanise sanding and finishing very effectively.
Prior to this the McShirley power mallet utilises very similar technology by using a solenoid with presets for power and speed and a number of potentiometers which are used for fine control, you can view their 1975 patent here. There is also a video showing the McShirley Power Mallet in action
The Super EZ Graver that I have built is based around a XRN-13/30TLS solenoid. This is a small tubular solenoid that is 13mm in diameter and 30mm long. It will not plow its way through all materials put before it. You may find that for your purpose it does not pack the punch that you want but it suits me. I've had to adapt my engraving so that it is a bit more refined, which I think is an improvement for me, I no longer bury the tool and break tips. There may be a solenoid out there that will give all of the power and finess that everyone needs in a small package but I doubt it, I suspect that more than one toolpiece will be required and hopefully I'll add more designs and information to this project when it becomes available.
The controller and power source can handle much more powerful solenoids but I've only tried out a couple, I've made a list of the ones I've tried and added some comments. If you've tried others let me know and I'll add them to the list.
Some of the links are to google searches, this is because actual products will become unavailable at some point so a list of products that you can select from is probably better.
Arduino Uno, this is a link to the official Uno page. You can get unofficial versions much cheaper. Other Arduinos can be used but this is a cost effective board which can be run off the same 12VDC power supply so makes it very convenient. Ebay arduinos
Mosfet Link to google search for appropriate mosfet. This is used by the Arduino to send a pulse of electricity to the solenoid.
PWM power controller Link to google search for appropriate PWM opwer controller. This is used to control how much power is sent via the mosfet to the solenoid.
Power Supply Link to google search for appropriate 12VDC power supply. The XRN-13/30TL solenoid draws a maximum of 23w which is around 1.8 amps so a 5amp power supply will be ample.
Foot pedal - potentiometer Link to google search for potentiometer foot pedal. I use this for control of the PWM power controler. It is not absulutly necessary as you can use the potentiometer that comes with the PWM controller. It does add some flexibility to allow alteration of how much power is transmmitted while engraving. If you want to use one of these you will need to remove the potentiometer on the speed controller and wire the foot pedal in. I removed the extra stuff in the pedal and wired straight to the potentiometer in the pedal. There is a you tube video of the insides of the pedal
Foot pedal - hall effect Link to google search for hall effect foot pedal. I use this foot pedal for controling the frequency of the pulses that are sent to the solenoid. You could use a further potentiometer foot pedal for frequency control. The Arduino code will require appropriate parameter changes to use the potentiometer foot pedal.
Solenoid Link to google search for XRN-13/30TL 12vdc solenoid. This is the tubular solenoid that I've used to power the fabricated and 3d printed handpieces
(I did cut off the screw thread and the piston needs to be cut down. I also removed the label from the solenoid so that it's not so tight in the handpiece. Once you have cut off the screw thread from the solenoid and cleaned it up with a file this can be installed into the handpiece. Screw in the inner sleeve add the spring and the piston. Press the piston in so that it's hard up against the solenoid body, then offer up the QC toolholder. You should be able to take a measurement for how far it is protruding from the handpiece. The measurement needs to be for the part which can move inside the handpiece. Subtract 3mm from that measurement and that is how much you should remove from the end of the piston. What you are aiming for is, when the piston is fully depressed the QC toolholder protrudes no more than 3mm from the flat area of the handpiece. Taking off less is better than taking off too much; you can always cut off a bit more but it's much harder to add material back. 2.5mm protruding is probably optimal with the piston fully depressed.)
Cable connectors Link to google search for cable connectors. For connection of the arduino to the other components.
connectors - male Link to google search for connectors. I use these for connection of the foot pedals to the PWM controller and Arduino. These are optional you can solder the wires together or use connector blocks.
connectors - female Link to google search for connectors. I use these for connection of the foot pedals to the PWM controller and Arduino. These are optional you can solder the wires together or use connector blocks.
Cable Link to google search for speaker cable. I've used a cheap speaker cable which seems to work fine.
Heat shrink tubing Link to google search for heat shrink tubing. If you are soldering cables together the assortment packs are useful for insulation once they are soldered.
You will also require a box to put everything in. I use a clear plastic storage box.
The code for the arduino can be found in the src directory of this github project.
Arduino programming setup guide Link to the guide for setting up the programming environment for the Arduino.
Arduino setup YouTube Link to the video guide for setting up the programming environment for the Arduino.
Mosfet and Arduino background This is the background to mosfets for power control using the arduino. I've used a mosfet module that has the mosfet, diode and resister in a package so its much easier to connect the components up.
I've created two 3d modelled handpieces in the open source 3d modelling application Blender. The blender source files are available to download as well as the stl. There is a YouTube video on how to setup the handpiece and also the Mk2 version which has a brass sleve insert. This was first produced using petg but it may be better to use a more heat conductive material such as ice9 for better heat dissapation. I've not tried this yet.
Anarasha had a problem with the blender version of the 3D model as the blender model has tolerances built in to it which causes problems with his slicer(I think). He has kindly produced a fusion360 model of the handpiece which has the stl and STEP files if this suits you better.
The first handpiece that I made was fabricated from brass and delrin. A YouTube video is available for the handpiece along with a video on the handpiece design refinement