I have been busy since my last update, and wanted to share some modifications as well as progress on my vacuum work holding and temporary control panel.
New tool rack cover
I have designed a new tool rack cover that no longer relies on sensor controlled pneumatics. It is a clear acrylic cover held in place with two long springs. When the gantry moves into the tool change area, the X axis blocks hit two rubber bumpers attached to the cover, and it is pushed back with the movement of the gantry. See images below:
Here is a short video of it working: New tool rack cover and pneumatic air MQL nozzle - YouTube
And it working during a tool change: Example of ATC sequence - YouTube
New pneumatic MQL nozzle
I designed an auto-retracting nozzle for my MQL system. It is used cooling and chip evacuation and can provide air, liquid, or both. When the spindle moves to the tool change area, a sensor triggers the air cylinder’s solenoid so that it remains out of the way of the tool holders. See image below:
Here is a video of it retracting during an automatic tool length calibration using the tool setter:
Vacuum work holding
I have been planning a vacuum work holding system for quite a while now, and have progressed to the point where the main components are complete and have been tested.
It consists of a large block of 6061 aluminum which will act as the vacuum base. It has been machined at the top of each side to allow future probing to align (I will describe its control in the control panel section at the end).
Here it is attached to the aluminum table:
The bottom right hole is the vacuum inlet. My idea is to keep the base block flat, and use a series of customized vacuum fixture plates - these will have the gasket grooves, as well as any clamps specific to the work being done/product being produced.
Here are pictures of the fixture plate bottom, showing the gasket, and it in place on the vacuum base:
The vacuum base also has 6 drilled and tapped holes that I will use to attach my non-vacuum SMW fixture plate and mod vise. See image below:
Machining aluminum
Since my previous update I had been developing various toolpaths and strategies that I would need for machining my vacuum plates, as well as practising the cuts on scrap aluminum. Below are some videos showing a few of these (I apologize for the quality of the videos/lighting. I am still experimenting with video formats and video editors. Because I plan to continue to video my machining, I think my next big investment will be in a new camera and lighting sources. Although I enjoy sharing the videos, I find having them as a record benefits me as I continue to learn and archive recipes that work):
Facing the vacuum base: Surfacing aluminum vacuum base plate - YouTube
Drilling the 5 mm holes: Drilling 5 mm holes in aluminum vacuum base - YouTube
Slotting the 3 mm gasket groove: Milling 3 mm gasket slot in vacuum plate - YouTube
Temporary control panel
I have slowly been adding to and modifying a control panel, which when complete and finalized, will be mounted at the front of my table - similar to what you will see in the images that follow. My goal was to have easy access to useful controls, that allow for both manual and automatic control, and that support or enhance what I can do with my nearby touch screen (I have a 3rd party touch screen and Masso touch screen addon software giving me basically a ‘Masso Touch’). I will break it down into categories:
- Tool changes
I have a manual toggle switch that controls the tool release and one as well for the air return function. This is very useful, for example I can drop in my probe whenever I want, or put in a newly purchased holder/end mill. These of course are also controlled automatically by Masso and the tool change logic. I also have a toggle switch for an air blast which cleans the inner spindle taper, but I may remove this in the final implementation. See image below:
- Tool setter air knife
Although this is also controlled automatically by the Masso too setter logic, I added a manual control in case there was ever excessive debris build up on the tool setter plate. Since this should not happen because of the tool rack cover, I may remove this from the final panel design. See image below:
Vacuum fixture
I described the basics of my vacuum system in an older post. I have completed it now by adding automatic control of the vacuum by connecting the output of my digital pressure sensor to a SparkFun IoT power relay. When the vacuum drops below 20 "Hg the output triggers the relay and the pump turns on. When the switch sense maximum vacuum , 25 "Hg for my pump, it shuts off the relay and pump. I chose this IoT relay because it could be controlled directly from a Masso output, but since there are no inputs/outputs dedicated to a vacuum system I am happy with sensor controlling it. In my testing it has been flawless, and the pump rarely comes on.
The other part of the vacuum control on the panel is a manual push-pull valve. This allows me to lock the vacuum in the reservoir tank, while I open and close the valves of the manifold when releasing and replacing fixtures on the base. See images below:
MQL cooling/lubrication/air chip evacuation
For the chip evacuation air, I have an on/off switch for the solenoid, as well as a valve dial to control the volume/pressure. I also have the solenoid controlled by the Masso output assigned as Flood Coolant (More on that below under *F360 PP mod). See image below:
For the MQL, I have a switch that powers the peristaltic pump/stepper motor that doses out the liquid. It has a manual setting for on/off, as well as an automatic setting. The automatic setting is controlled by a relay connected to the Masso controller Mist Coolant output. The dosing rate is controlled by a dial, which is the PWM for the stepper driver controlling the pump. There is also a manual/automatic switch for controlling the solenoid for the pneumatic retraction of the MQL nozzle. See images below:
*F360 PP modification
One problem I wanted to solve was to be able to have F360 control both the air chip removal and the mist coolant. When milling aluminum and plastics I wanted to have F360 turn both on at the same time. The problem is you can chose only one of mist or air cooling at a time, and on top of that, Masso does not have an output to control air cooling, just mist and flood. Through the help of a Masso forum member, it was suggested that I modify the F360 PP to allow both mist and flood cooling to be turned on when mist cooling is selected. Then, connect the Masso Flood Coolant output to the relay controlling the air chip evacuation solenoid. This worked perfectly, particularly since flood cooling is a system I will never use on this current build. I now have a new F360 PP to use when I want to machine aluminum and plastic, as it controls the on/off of both MQL air and liquid automatically - I also learned a new skill which may get me started on more PP modifications. Here is the code snippet that is modified(see bold lines):
var coolants = [
{id:COOLANT_FLOOD, on:8},
{id:COOLANT_MIST, on:[7, 8]},
{id:COOLANT_THROUGH_TOOL},
{id:COOLANT_AIR, on:8},
{id:COOLANT_AIR_THROUGH_TOOL},
{id:COOLANT_SUCTION},
{id:COOLANT_FLOOD_MIST},
{id:COOLANT_FLOOD_THROUGH_TOOL},
{id:COOLANT_OFF, off:9}
VFD control
I purchased the Operator Interface Panel for my Hitachi VFD, and it will be mounted on my control panel. Connection is via RJ45 cable from the VFD enclosure. See image:
Masso keyboard shortcuts
Along with my touchscreen, I had purchased a mini keyboard and tray that attached it neatly to my touch monitor mount. After using it for a while, I realized that I wanted something closer to the table and the work I was needing to look closely at and focus on. Because my touch monitor is mounted on a swivel arm, I can get it quite close already, but it was also the need to correctly ‘touch’ the small areas on the screen that was adding to a less than ideal result.
The programmable keyboard that I discussed in a past post has solved this and is working very well.
Currently I have easy access to a key/button that switches between the F12 (RPM)and F13 (Feed rate) over ride functions, as well as a knob to adjust their values. These can otherwise only be accessed on two ‘F’ screens, or a keyboard, and having them right in front of me on my panel has been invaluable. I do not have to look away at all as I watch and react to the machining in front of me. I have gotten so used to the location and function of the keys on the pad that, like my pendant, I do not even have to look down at the controls. I also have keys/buttons for Cycle Start, Feed Hold, and the F2 and F3 screens. The latter are proving convenient in many scenarios, for example, you can only use the pendant when on certain F screens, and instead of having to stand up and use the touch screen (it is often not on the correct jog screen), I just need to hit the F3 key which is right in front of me. See image below:
Other functions
Of course I have my big red E stop button on my panel - front and (not) centre. Too many times I accidently hit E stop when my body leaned forward over the table. I also will add buttons for the other common functions I will use, namely rewind, home, park, etc…
My next goal is to use my single form thread mill to cut some M6 threads - machine wax first, then plastic, and finally aluminum. After that, I will start machining various parts and projects I have been designing.
Until my next update…