I thought how I could make it more sturdy: the big problem was the bolts/nuts put all the stress on the relatively weak plastic. I tried tightening it up, but there was a cracking noise: the plastic had broken. The final big problem was the crosspiece where the two sets of rods meet. ![]() It looks pretty nifty! Crosspiece Wobbles/Breaks I didn’t like the way the original design held the control board (and it didn’t fit mine), so I found this design on thingiverse which fit it exactly. The nuts holding the threaded rods on the base quickly loosen due to vibration, so I added some split ring washers to prevent this. Below is one of them: Threaded Rods Come Loose There are two retaining parts at each end of the device. I used a piece of 15mm thick plywood I had in the cupboard from refitting our kitchen floor, some 6mm recessed bolts and some butterfly nuts to attach the device to it. I designed some simple retaining parts to clip onto the threaded rods. Since the drawing arm extends so far, the entire device wobbles quite drastically during drawing: sometimes its actually supported by the pen itself. The complete redesigned pen assembly looks like this: Device Wobbles During Drawing This also means its a bit heavier, helping the pen to make contact with the paper better: I redesigned it completely to be much more robust, and also to cope with larger pens. The pen holder doesn’t cope with any sort of stress: Pretty much as soon as I tried to draw something, this happened. I wired them into the X/Y axis limit headers on the CNC shield. I designed retrofitted plastic parts to hold some limit switches I had in the cupboard and installed them. I always find this means it will immediately try and exceed one of its limits and start making distressing grinding noises. To fix this, I redesigned the “Yend” piece so it covered the rods preventing this: Lack of End Stops Once I put it under tension, the rods immediately popped out of the frame. However, it was quickly obvious there were some big design issues: Rods pop out the frame My 4xidraw svg to gcode is here on Github.Updated GRBL with servo support is on Github.Replacement 3D printed parts are on Thingiverse.I’ve posted the various parts mentioned throughout this post to various places: So I ordered the rest of the parts and set to making it one weekend. I already had a Keyestudio CH340 Arduino Nano clone and Keyestudio CNC shield v4 in the cupboard from a project I never got round to doing. ![]() However, I did some looking around and found this home-made version: I can definitely justify making one myself. GRBL Shield – excluding Arduino,Shipping)īuildlog.I quite fancied one of these AxiDraw drawing machines, but at the price they go for, I couldn’t really justify it. The Arduino CNC Shield is now available from our Ebay Store – ![]() Up to 1/16 micro stepper with A4988 and 1/32 with the DRV8825 drivers ) Compatable with Pololu A4988 type drivers including the latest DRV8825 drivers.(4th Axis can clone the X, Y, Z axis’s or run of the D12-D13 pins) Arduino CNC Shield – 100% GRBL compatible (USD25+ Exluding Arduino, Pololu Drivers, Shipping Included) Using GRBL (software) and these micro-controllers(Hardware) makes it very easy and affordable to build your own Computer Numerated Controlled Machines(CNC). GRBL is G-Code interpreter that is able to run on small Atmel Micro-controllers like the controllers used on Arduino Boards. The following are a few of the shield / boards that are compatible with GRBL.
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