Month: February 2017

I worked on the design of the machine this week.  I will probably replace the mechanical limit switches with optical sensor from digikey - I feel they will be more precise and reliable I received some shipments over the week for the CNC Mill project From TNutz.com : Received t-nuts for the Series 15 extrusion along with double inside corner angles.  I planned to saw / drill the corner angles from strock aluminium angle but at the price tnutz sell them... From CPIAutomation.com : Received a 65lbs worth of extrusions!  Quite happy about the quality of their product.  I was worried about the X axis not being rigid enough but now that I received the 3x3 extrusion, lets just say I don't think this is going to be an issue Linear rails / leadscrews ship...

Added most screws and limit switches.  I like the fact that the limit switches on the sides are under the frame and protected.  I may eventually switch to optical barriers as I feel this would be more reliable / repeatable (at least for the home). I also confirmed that MACH3/4 support Axis+/- limit switches.  I also started to think of a safe way to mount the electronics inside the frame.  I'm planning to use either rubber mounted or spring suspension in order to keep vibrations away from the electronic.  Also planning to put at least one fan to ensure proper airflow.  I'm also looking at putting the VFD right up in the mast and water pump/tank(s) under the bed which would allow for a totally standalone machine (just need to feed power and air)

What a week... I started to place the order for the extrusions at OpenBuilds.com and found out the shipping cost to Canada would be 218$usd  + customs.  I then found a local supplier in Montreal and called for 3 days in order to get a quote.  I finally gave up on this supplier and looked at imperial extrusions instead, which are way easier to find in north-america.  I found a distribute for 8020 inc in Ontario and then decided to change the current design to use imperial extrusions. While modifying the original design, I also spent some time trying to identify possible ways to make the design / construction easier.  I then decided to change the bottom frame of the machine for one that would be easier and cheaper to construct. Specifications : 7" Z clearance below the beam...

Today, I 3d printed a bunch of parts that I will later machine out of aluminium.  I also placed the order for t-nuts and will probably order the extrusions tonight or tomorrow.  I'm having a bit of an issue with the rails supplier (china) due to holidays there.  Worst case, I'll find another supplier! I set my 3D printer to the fastest print / lowest quality (0.35mm / layer, 120mm/s)  as these parts will be discarded anyway.  I also had a 'spaghetti' incident where one of the supporting rods for the head disconnected (magnetic) and the head simply sprouted plastic in the air.

Progress update Over the last few days, I added all missing screws, normalized screws lengths and started to build my orders for material.  I'm going to start with the rails / extrusions in order to build the frame.   Printing the plates using my 3D Printer I've finally decided to print all parts that can fit on my 3D printer. Pros: Faster than manually cutting / drilling the parts Allows for inexpensive test-fit / changes Allows to use the machine itself to machine the parts using aluminium Cons: Not sure about the rigidity of the printed parts : will the machine be stiff enough to machine its own aluminum parts ? Will require complete disassembly / reassembly to replace the parts   Here's a teaser of some motor mounts, limit switch holde...