Tuesday, March 19
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Electronics

Designing a cool smart doorbell for my house

Designing a cool smart doorbell for my house

CNC, Electronics, Uncategorized, Woodworking
Introduction Our doorbell's button stuck in the pressed position and caused the electromagnets coils to melt. I decided to use this project as an opportunity to design my own door bell using off the shelf hardware for the electronic and custom wood / acrylic case. I was also looking at a small project to try resin coating wood in order to get some experience for my upcoming computer desk project. Requirements: Fit with the decor - approx 10'' x 5'' x 2'' Play a mp3 / wav file when the doorbell button is pressed Include addressable led strips for lighting effects Use off the shelf component for the electronics Easy to program so my kids can help Use existing wiring (2 wire power + 2 wire button) Hardware Raspberry PI 3b + Raspian OS I wanted to use ...
New Power Panel for CNC mill/table machine

New Power Panel for CNC mill/table machine

3D Printing, CNC, Electronics
New Power Panel It's been a while since my last post here. I've been quite busy added a new workshop to have a nice plice for all my toys... I finally moved my CNC mill/table from my basement to my new workshop. I made a steel base, which I'll cover in another post to replace the wobbly wood base I used in the basement. I also re-wired most of the circuits : Added contactors to control power to the computer, control boards, motors drives and spindleAdded a hard-wired emergency button to physically cut the power to motors / spindle. The temporary emergency was software only which wasn't that great from a safety point of viewAdded an software controlled relay to turn the spindle cooling pump on/offAdded a flow sensor on spindle cooling line to ensure proper coolant flowAdded ...
Start / Stop buttons

Start / Stop buttons

CNC, Electronics
I finally wired and configured Mach4 to use the start / stop buttons that I installed along the emergency stop button a while ago.  Moving all the home / limit / probing switches to SmoothStepper Port 3 freed inputs on Port1 than I was then able to use for the buttons.  The start button that I used is recessed, making accidental activation less likely. I had to change the screen script to call CycleStart / CycleStop on inputs activation. All in all, I'm pretty happy : The buttons allow me to look at the machine instead of mouse / screen to start / stop the machine
Limit and homing switches

Limit and homing switches

3D Printing, CNC, Electronics
In order to use my newly added tool touch pad, I needed to be able to move the machine to a known (absolute) physical position.  So it was time to finish my half-wired limit / homing switches system. I did a bit of cleanup in the schematic and added a quick and dirty 'breakout' board for the SmoothStepper Port 3.  This also allowed me to regroup all limit / homing / probing inputs on the same port I used cheap 6 pins / 4 pins round connector to make it easy to disconnect the wiring (I'll move the machine in my upcoming workshop this summer).  I actually used the machine itself to machine the connector openings in the board (non-circular holes)   The 'switches' are actually optical barriers.  I decided to use optical switches due to easier installation, ...
Add a tool touch sensor

Add a tool touch sensor

3D Printing, CNC, Electronics
A few weeks ago, I made a wooden plate using my mill machine and decided to time how long it would take to mill the whole plate.  I found out that I spent 25 minutes out of 67 doing material Z measurement (zero) and Tool Z adjustement after each tool change (I want a toolchanger!) I realized that a few thing that I could do to streamline operations (and prevent small tool breakage) would be : Automated material height sensing (Z).  must work with both conductive and non-conductive materials. Automated tool length measurement before and after a tool change in order to automatically adjust the current Z position 3 axis touch sensor (I already have it, just need to make connection easy to do) I decided that the biggest time saving would be #2 - Automated tool length...
Spindle Coolant Flow Indicator

Spindle Coolant Flow Indicator

3D Printing, Electronics
Ok, it's been a while since I posted, doesn't mean I stopped working on the machine! One thing that I found is that I often open my coolant bucket to ensure the coolant is flowing.   So I decided that designing and machining a flow indicator would provide a good opportunity to experiment with full depth cuts / adaptive cutting vs slotting and multiple side machining.   I already machined the part last Sunday and will post the finished pictures tonight along with comments
Designing a dust collector

Designing a dust collector

Electronics
After working with wood and MDF, I quickly realized that I needed something to collect all the dust.  I couldn't fix a ready-made design so I grabbed some good ideas in existing design and rolled out my own. Requirements: Transparent enough to be able to see the spindle / work area Clamp-on spindle Removable vacuum hose - store away when not used Allow for long / short tool lenght Flexible bristles so as not to snag into the material Magnetic dust shoe to allow quick access to work area and different bristles lengths Cheap! " template="default" order_by="sortorder" order_direction="ASC" returns="included" maximum_entity_count="500"]
CNC Mill (late) Update

CNC Mill (late) Update

Computer, Electronics
it's been a while... I worked quite a bit on the machine and it is currently operational.  I'm still missing the cable chains (lost in the shipping - replacements underway).  The first parts that I machined with the machine where the aluminium parts needed to replace the 3D printed plastic parts. I have videos of the machine in operation that I'm currently editing to make a nicer video / presentation Here a pele-mele of pictures that I took lately " template="default" order_by="sortorder" order_direction="ASC" returns="included" maximum_entity_count="500"]
Z axis assembly

Z axis assembly

Computer, Electronics
I spent the last two evening finishing the plates for the Z axis and drilling missing holes on the backplate for the newly designed limit switches.  I also decided to use connectors for the limit switches and designed a bracket for it https://youtu.be/4MC9gMEZO4k I also received 2 replacement flexible coupling for the motors, this did solve a problem I had with the motors 'wobling' on their mount : the hole I had to enlarge on the coupling was not straight... I assembled the Z axis tonight and I was glad to see how everything went together without a hitch.  I will do the proper wiring of the motor over the weekend along with the limit switches.  Meanhwile, here's a short video of the Z axis moving (sorry for the audio, I will make a proper video so...
Z axis limit switches

Z axis limit switches

Electronics
I finally settled on using optical photo switches for all limit switches.  My reasoning is that optical switches should be more accurate and reliable than mechanical switches and there is no wear caused by friction as there is no contact. After a bit of research on digikey, I settled for https://www.digikey.ca/product-detail/en/tt-electronics-optek-technology/OPB472N11/365-1646-ND/1636911 which are small, inexpensive and can be used for all axis (different orientation needed).  I then designed a base that I will glue the switch in    Followed by adding the switches on the Z axis backplate and tweaking the Z nut adapter plate to provide barrier for the switches   I then proceeded to print the support and placed the order at Digikey....