04/13/2019 at 00:02 •
The prototype uses axis made from 3 D printed parts and off the shelf components. I used the pancake type steppers on these but have designed mounts for other footprints. The printed parts are designed to self align, are fast printing and very rigid and stable. Here are the major parts for each axis:
After many designs the axis have never been easier to make. Here are things slipped together and ready for final assembly.
Not sure yet what the final design will be yet. This years contest leans heavily toward mass manufacture.
04/12/2019 at 15:05 •
The simplest of the machines functions is a plotter,graphics drawing application. I made the holder so it fits sharpie markers which are widely available and used frequently by lots of folks in making.. The pen holder is adjusted so just the weight of the marker itself provides ample pressure for drawing.
The colors for sharpie seem endless!
This attachment consists of two 3 D printed parts fused together. It bolts on the Z axis like the others using the two wingnuts.
I often use this before laser or routing on a piece of scrap paper to check the tool paths and make sure everything is a go.
04/10/2019 at 20:47 •
The router attachment simply consists of a motor in a cylindrical mount that attaches to the Z axis like the others. The motor can be of different sizes depending on what materials the user is working with. The motor has a collet type chuck and holds the bit securely while in sideload.
I have been using bits smaller than 2mm for most of my projects as they leave a nice smooth edge on woods and a super smooth edge in plastics. Here is a general look at the motor attachment:
This motor is about 2 inches around and 2 1/2 inches long with ball bearings on both ends I made several of these motor attachments including one with a very large shaft for use with a drill chuck. I must confess I never used it as a cnc driven head however it is handy to use a drill press by steering the X,Y axis with the joystick and then drilling with the Z. I have never had the need yet for drilling so many holes in a workpiece to set up a program for doing that.
I do use this to make a prototype PCB from time to time and the holes I drop in the router bit. Normally I mill pcbs on this with a .5mm to 1mm bit so it works out ok but does add wear to the bits. I have been buying these bits at a pretty good price though so I don't feel to bad about it. I also have been using more phenolic PCB material instead of FR4 and that also seems to help if I dig a little deep on the traces(sloppy setup on my part).
The nice thing about the smaller motor9if you can use it) is less noise and screaming from the machine running a part. I often use this machine in my house so noise can be an issue sometimes(cats hate it) But I have more horsepower available if I need it and the attachment swap fast and easy.
04/10/2019 at 19:50 •
I always liked the idea of laser cutting but the cost even as low as it has gotton was still not in my reach. I was cruising the ebay pages of laser products and started seeing laser engravers-thsy are basic woodburning type beasts that make really nice engravers but lack the power to actually cut. I first bought a 2 watt version and was going to settle for the engraver as an attachment but after using it to make some cool wood etches I wanted more power. I found a 7.5 watt version for around 45$ and bit the bullet and got it. I couldn't help but notice that this version would actually cut thin materials and really engraved well also. Again I ordered the next step up a ten watt version. This thing was pretty amazing for the cost and I quickly experimented to find its limitations. It is shown in the prototype photo.
Here is the 2 watt version:
It does etch/engrave just fine but will only cut very thin stuff-and not all that well.
If you just want to engrave-this is cheap and perfect. The final version of the machine will be able to accept the 15 watt version. I am underfunded right now and just can't afford it. all of my data and photos will reflect the ten watt version.
In order to save my table from laser damage I simply found a material that the laser could not cut through and did not burn well to make a smelly mess. under the material to be cut I place a small 3 D printed frame shown here:
This elevated the workpiece away from the table and allows space for the laser to pierce and safely absorb the beam without problems.
In the final version machine the table will have a laser safe shield to protect the user from laser energy. The shield will also function as a router shield from chips, etc.
useful tips on these laser modules:
Be careful when you hook up and test these things. The light will cook your eyes, your skin and anything,even across the room. You need a backstop, and some eyewear that is laser rated.
When you are purchasing the laser module of your power choice::
Buy from a reputable dealer with perfect feedback and good customer ratings. Many of the power ratings are NOT as advertised. The higher the wattage the more fudging they tend to do. My first ten watt laser module was only tested at 7.4 watts. I balked greatly and got another. The ten watt one measures at 11.2 watt.
So many China dealers are fudging the ratings on these modules. Beware.
04/08/2019 at 23:17 •
I made this as an accessory as many times I want a spray paint a one off stencil or want to cut out some designs in sticky backed vinyl. It can cut other thin material and cardstock up to 90lb.
It was a tricky little attachment to make as the knife blade must always stay in the direction it is cutting and on sharp corners the z axis must lift the blade, rotate the blade then lower again. It was an interesting set of problems to solve.
Here is the attachment mounted to the machine:
Note the servo which rotates the knife shaft. I fashioned the mount for use with an exacto penknife as they are widely available as well are the blades.
Here is another view of the mounted assembly:
I normally put a heavy pasteboard under the material to be cut. This allows an easy setup when mounting the knife and getting the blade pressure correct so it cuts perfect every time. The blade lasts a long time too!
04/07/2019 at 03:07 •
In trying to keep it simple I built the machine for minimal effort to operate. The lower set of controls consist of three pushbutton switches and a joystick. The joystick function is simple-it allows the user to move the X and Y axis manually. It is nice if you want to set up something on the table to avoid material waste and also useful to manually rip sheet stock into strips or just straight line cutting without any CnC control. A DB15 connector is also installed to allow the user to connect a large analog joystick for freehand cutting or engraving. The Z axis can be run up and down via 2 of the pushbuttons. A third pushbutton runs a built in table calibration if some table is alignment is suspected. Pushing in on the joystick sends all axis to the home position. The home position is part of every program and all axis return automatically home after each part is done,however of the joystick is used manually it can be done manually.
A pot control is installed to control router motor speed(markings show recommended settings for material/bit size and also laser power control.
The remaining pushbuttons shown on the upper left are imported part programs. These switches will be replaced with a 16 key keypad in the final version and the user can upload multiple designs and select from them when desired. An LCD soon to be added will display which parts have been uploaded and what button to press to make that part as well as show progress and inform the user which tool needs to be mounted on the Z axis to manufacture it. This will be a nice neat tidy solution that will allow first time users easy access to their part formation. In the end version all buttons may be moved to the keypad for simplicity and ease of manufacture with the exception of the joystick and power control.
I am pretty sure as this evolves it will get streamlined more for ease and simplicity of building it. This prototype has already yielded lots of new ideas for the next version.
04/06/2019 at 23:07 •
Quick demo of machine routing, laser cutting and pen drawing. Nothing fancy just a demo. The material is 1/4 inch on the motor router,two stacked 3/16ths thick wood on the laser and posterboard on the pen drawing.
On the laser cut I made a bit of a mistake-Instead of putting the beam stop under the 3/16ths material I stacked 2 3/16ths material on top of each other. The result was the top layer was cut fine but did some scorching as a result. All is well wood scraps are plentiful. The camera did not like the laser light as you can tell in the video....I wiil add the vinyl cutter and a few other accssories soon.
04/05/2019 at 02:21 •
The circuitry for this machine is really brutally simple. The controller is an Arduino, right now an Uno but soon a mega. A number of files can be flashed into the Arduino and accessed via some buttons(or a keypad) and of course with the SD card.
I had a board made at:https://jlcpcb.com/ and it was very well made, super fast in production and well worth the effort. I have used them before and you just can't beat the price!
The driver electronics are all mounted on a simple small Pcb an use the typical stepsticks.The power supply is 15 volt at 6 amps.The laser requires 3 amps and is not fussy about being tied to the motor driver power so a single supply runs it all easily.Laser power is manually selected depending on job requirements and range for simple etch/engrave to max power for cutting material. The same Pwm is arranged so it also powers the router motor also.
Endswitches are provided for each axis for safe travel as well as slot photointerupters for counting leadscrew revolutions. I sort of wanted some security past just step signals to keep track of the progress. The wiring on the 1st prototype is rather gangly looking but will be shaped into a nice neat harness when all the details of the machine have been satisfied.
This is probably the stupid simplest wiring and controller setup I have ever made...Finally!
I am hesitant to make an Arduino shield as many will scoff at the idea and want to go with another flavor of controller. More power to ya!
I am also entertaining the idea of adding an lcd to show status,progress etc. There may be some other items helpful to the user friendly aspects of the machine tossed in there as things move along.
04/04/2019 at 15:27 •
I have built a dozen or so 3D printed machines including lathes,mills carvers and duplicators for a variety of materials and each improved drastically as I learned what I could get away with and what the limitations of each machine would be being made of plastics.
This machine would make use of all the combined knowledge accumulated and produce the best that could be gleaned from previous designs. This machine uses a gantry design for the z axis, supported by two pylons at each end which allows excellent rigidity for the tools being used. The gantry pylons are joined with steel rods that the z axis itself can be moved on if needed and solidly supported to the base with ever widening pylons and affixed to a baseplate. The axis are also all 3 d printed as three durable blocks with a conventional 12 inch leadscrew affixed to the stepper and bearing placed throughout. I selected flat pancake steppers for this design but the axis have multimounts that can accommodate and form factor motor.
The table for this 1st prototype machine I made woefully small and can increased on the next version but was most helpful in establishing endstop switches and slot sensors for positioning. The table size will increase by 25% or more on the final machine. All the printed parts I produced from ABS and are solvent fused together to make modifications, extra holes etc in future versions. I am making files for this entire machine to be also fabricated from laser cut plastics as well as the 3 D printed stl files.
The steel rods are typical hardware store versions in 3/8 inch size and I opted for the zinc plated versions as they tend to be smoother and will not rust. All the mechanical hardware for the machine came to about 35$. I used a full spool of ABS printing this machine as it appears in the picture.
As far as best way to manufacture this machine: Still unsure. 3D printing the parts is an excellent way to allow individuals to build it for themselves, but to make a bunch...That is going to take some more serious looking into. I actually made a simpler version of a gantry setup similar to this out of wood with supporting rods and it worked well(not suggesting I would use wood). There are available options that will present themselves as this moves forward.