Not exactly the submission I was hoping to do, wanted something more “artsy” but just hadn’t had the time. So, I figure from seeing @BartK’s post, it encouraged me to just post what I have been doing, as it is 2D plates, that assembly in to a “3D” part. I have already shared the design files of my SO3 linear rail adapter plates but never really went into the CAM and workflow I go through. This is also the first time designing and using fixture plates (not just vises and drilling holes into my HDPE spoil board) to help develop faster and repeatable setup time (Typing this now, I am wondering if there is going to be a “fixturing” contest in the future from @Julien )
Originally, I wanted to be able to machine two pieces of stock for the 4 (Y Axis) or 3 (X Axis) assembly parts, however I miscalculated how large of a fixture plate I would need and had to improvise a little. So I decided to move forward and just have the fixture plate multi purposed and machine the first set of parts, then re-setup with new stock to mill the second set.
There was at least three setups I needed to do, the first setup was the stock in its rough cut form (5.5" x 9") using fixture pins and side clamps to get access to the top for boring tolerance and threaded holes along with other features (dado joint and motor through-hole).
Second setup required getting access the sides to clear the stock down to shape. Using the existing features of the part, I created M4 thread holes that align with them on the fixture, so once features were cut they expose the mounting points to my next setup.
Third setup is to support chamfering the parts on either side, I used index pins to locate the part in its final form while still using the M4 threads to clamp the parts down, removing the pins before starting the g-code op.
When it came to tolerances, I really don’t have them defined, as for one, I’m not a professional (I don’t know the best method to define them), and in a way it’s in the hands of the SO3 rail lengths and how precise the linear rails are mounted; let alone there is slop designed into the system. However I try to do my best to get as close as possible (<0.005") in the critical areas. To do so, I use gauge blocks and Fusion 360’s “Stock to Leave” to dial in the dado joint. I end up surfacing the Y plates (being typical 6061) to increase flatness and parallelism (indicating on the dado) using a fly cutter on my benchtop mini mill (hope that’s not disqualifying :P). ATP-5 stock would help alleviate this process (though I believe it’s flatness spec is 0.015" at this thickness). I then surface the joining plate until they fit into their paired counter part.
All said and (almost) done, it was quiet the journey filled with frustration, pain and eventually love and happiness
The Y fixture and CAM was my first attempt and just is a mess with weird setups from in-progress fixes, etc. The X fixture is a better example too look at and base off
Linear Rail Carriage Plates
Y Extrusion Plate CAM
Y Carriage Plate CAM
X HDZ Plate CAM
X Motor Spacer CAM