After all these years I finally made a decision to use 0.090″ 6061T6 aluminum to cut my instrument panel out of.  Using this specific aluminum offers 2 benefits over the 0.063″ 2024 aluminum that I had been planning on using for quite some time.

First off, plasma cutting 6061 is cleaner than 2024 since 6061 is better at rejecting heat (6061 can be welded, whereas 2024 cannot).  Also, a thicker panel has less tendency to warp during heat-producing operations such as plasma cutting.

Next, the 0.090″ thickness will allow hiding the panel switches’ anti-rotation keyway holes, which coincidentally need to be 0.063″ deep.  Below, the blue arrows denote 8 of the 10 anti-rotation keyways (on the panel backside) –which were once all through-panel holes– that were removed from the front face of the instrument panel once I thickened the panel from 0.063″ to 0.090″.

Below is a more “3D view” to better see the switch anti-rotation keyway holes at an angle, again, on the backside of the panel.

Meanwhile, over on the front side of the panel: no visible switch anti-rotation keyway holes!

Here is just a quick annotation of all the anti-rotation keyway holes that I was able to remove (hide) off the panel front by going with the thicker 0.090″ 6061 aluminum panel.

Once again, back to some CNC Tooling Up: Today I was able to install all the major Centroid Acorn CNC hardware components into the Lathe CNC Controller Box.  

I started off by installing the 24V/5V power supply into the back left corner of the box. With it situated as it is in the pic below, it will provide decent access to install/add/manipulate wires as needed.

[NOTE: The screw in the middle area on the floor of the controller box is for the X-axis’ 36V power supply that will get mounted on edge just like the current one installed].

I then focused on the component installs on the removable plastic tray.  First up was determining the location of the Acorn relay breakout board.  Critical in choosing a location for the relay breakout board is that the flat wire bundle that connects it to the Acorn main board must not be twisted in any way, but remain flat… as per a warning in the Acorn CNC manual.  

To achieve the non-twisted routing of the Acorn relay breakout board’s wire bundle to the Acorn main board, I utilized the opening in the plastic tray to run the wire bundle through and then above the Acorn main board by the gap created with the standoffs used in securing the main board to the underside of the plastic tray.

Here we have the Acorn main board installed on the underside of the CNC controller box’s plastic tray.  

If you look closely, you can see the wire bundle from the Relay Breakout Board attached to the main board at the very bottom of the main board– where the red wire is hanging off.

I have a 92mm x 92mm 5V cooling fan on order that I will install once it arrives.  Besides the fan (and associated vent), I have one more hole to drill that will use a grommet to protect the wires for the E-Stop switch and both Home/Limit switch wires.  Finally, I have one more board to install that will allow me to control the spindle speed and direction (primarily to facilitate tapping operations) and then I’ll be pretty much done with the planning, design and component install for the Lathe CNC Controller Box.

In one of our conversations my buddy Marco asked if I had cut out the panel yet, so I sent I sent him this . . . Yep! (yuk-yuk) 

Of course this is the cardboard panel cutout… that I drew up in Fusion 360 CAD and then Marco precisely drew out for me on cardboard using his plasma cutting machine as a high-end plotter.

As a point of note, I’ve made a final decision to go with 0.090″ thick 6061T6 as my panel material.

Back to some CNC Tooling Up: To help organize some of the myriad of parts I have on hand, I decided what better way to keep track of them other than simply install them?!

So I took a few hours to do some final design work, then some drilling and Dremel Tool cutting to add some of the loose components to my Lathe CNC Enclosure (AKA “Tool Box”).

I started with with each end, and below is the left end as facing the front of the tool box.  

From the lower left hand corner, going clockwise, we have the power plug compression mount, a fuse holder with 10 A fuse, the spindle encoder cable compression mount, the lighted ON/OFF switch, and the CAT5e port.

So far on the right side I was only able to get the X-axis and Z-axis stepper motor compression mounts installed.

Towards the middle of the right end of the Lathe CNC Control Enclosure will be a large cooling fan, and also another wire entry port(s) for the E-Stop Switch and the Home/Limit switches wires.

Back upstairs –under some very harsh lighting– I grabbed a couple shots of the interior of the box where I drilled the mounting holes to vertically mount both 36V power supplies and both Hybrid Stepper Motor Drives (blue components).

Tomorrow I plan on drilling one more set of holes on the floor of the Lathe CNC enclosure to mount the Centroid Acorn 24V/5V power supply, then I’ll work a bit mounting the Acorn main board and relay bank on the upper removable shelf of the Lathe CNC enclosure.

Before I pack up and haul my new CNC components down to NC, I needed to do an operational function test on each part to ensure it works.  For each closed-loop stepper motor setup this includes the motor itself, the drive (blue units) and the associated power supply.

Since one of my power supplies was back ordered, I only have 2 on hand to test out 3 motors.  I could have connected two motor setups onto one power supply, but I decided to keep it simple with one power supply to one drive and one stepper motor.

The closed-loop stepper motors I have on hand is an 8.5 Newton Meter (Nm) Nema 34 (mounting size) for the mill’s Z axis, a 4.5 Nm Nema 34 for the mill’s X axis, and a 3.0 Nm Nema 23 for the lathe’s Z axis.  I also have a 4.5 Nm Nema 34 for the mill’s Y axis on the way.

I started my ops test with the 8.5 Nm Nema 34 and 3 Nm Nema 23 stepper motors.  Prior to the actual ops check I connected up a data cable to the respective motor drives and changed the drive alarm circuit parameter from Normally Open (NO) to Normally Closed (NC).  This is rather important in identifying any drive fault in that a NO circuit would not indicate if the actual circuit was, say, cut.  Conversely, if a NC alarm circuit is damaged or cut it will result in an alarm…. clearly better (IMO) to have a NC alarm circuit.

Since this was my first go at real-world spinning of the stepper motors, it required a 2-hour period of research and digging in the manuals to educate myself after I got power to the motors to actually allow the Acorn CNC controller to control the motors.

Here’s a ~25 min video showing my efforts:

I still have the 4.5 Nm motor to test, but I think all the above is enough excitement for one evening!

Since arriving back home from my latest NC/Virginia Beach trip I’ve been in a mad dash to finish up some of the tasks I started while on my journey.

One such task was to finish sketching out the mounting base for my Solid State Starter Contactor –the Lamar Superswitch– that I’ll be using in my Long-EZ.  

If you’re curious why I’m using this rather esoteric component, it’s because it has no moving parts to weld to each other or simply wear out (as mechanical contactors tend to do) and, more importantly, it weighs in at around 1/3rd of a pound vs. its hefty 1-pound mechanical cousins.

[NOTE: These are no longer available nor sold through Aircraft Spruce]

The one slight downside to the Lamar Superswitch (which, as an FYI aside was used extensively by Lancair Aircraft) is that it is open in the back to the innards which is essentially a bunch of potting material and the internal side of the 2 big cable studs.  With a flange with 2 small holes, there’s not a convenient way to mount this contactor without making up some type of lightweight aluminum mounting bracket, which I’ve done here.

So here’s my spec’d and designed Starter Contactor mounting bracket that will secure the Lamar Superswitch onto the sidewall of my battery compartment.

The version above actually had 4-40 screw holes as one of my tasks this morning was to determine the size of the two screw mounting holes located on the contactor’s aft/lower side (bottom/back <unseen> in the pic of the unit at top).

Determining that the mounting screws need to be 6-32 screws, I then reset the diameter and threads for all the mounting screws in the mounting base to this correct size.  I also moved the holes a bit farther up.  These updates are shown in the CAD sketches below.

The original mounting holes for the contactor unit are to the left in all the depictions of the mounting base shown here.  The new mounting holes, which I’ll have to drill into the contactor housing (top edge in pic at top), are the ones located to the right in all these depictions. 

Below is the back side of the Starter Contactor mounting base that is actually shown in the 180° reverse position to how it will be mounted in the battery compartment of the plane.  

The cylindrical channel with the slot is for 2 hardwired small diameter red & black control wires (behind, right and top in pic at top) that will be channeled through the mounting bracket to then safely exit out of the unit/mounting bracket combo for subsequent connection into the electrical system.

Of course I’m glad to get this component lined off of my CAD sketch to-do list, but it of course wouldn’t be complete without a fancy rendered version of it!  I chose green not because it will end up green, but just to shake things up a bit.  

Again, the silver-colored Phillips-head screws are #6 sized screws, while the Cadmium colored mounting bolts are #10 (AN3) sized.  I may go down a size to #8 on the mounting bolts, but I’m still assessing that option.

Regardless, I’m calling the CAD drawing and design for the Starter Contactor mounting bracket complete!

After departing NC on this last trip to clear out my #3 storage unit and consolidate nearly all the airplane build stuff in the hangar, I headed up to Virginia Beach to spend a couple of days with Marco and Gina.

While at Marco’s, I updated my Instrument Panel CAD diagram with all the dimensions I had taken off the actual panel while down in NC.  With Marco’s help, I then shared the CAD file to a shared online folder and he was then able to convert it into CAM to be drawn out on his plasma cutting table with a Sharpie onto cardboard.  

This may seem like some underutilization of a fairly expensive plasma cutter to merely use it as a plotter, but not only did it test & confirm some limit capabilities of Marco’s plasma cutting table (better than we initially thought), but obviously it will allow me to cut out the cardboard panel, test it in the actual airplane, and then make any required tweaks if need be before we do an actual plasma cutout of the panel with actual expensive aluminum.

In fact, the pics of the crazy bearded guy below (me!) is with plotted panel version #1, which afterwards I realized that I had forgotten to update some dimensions I had gathered relating to the panel’s upper corner longeron notches . . . 

Although I’d like to say it was fairly easy to update the CAD file to redraw the dimensions on the panel longeron notches –and subsequently the top panel contour– it actually did take a bit of drama-filled machinations to get it done.  But, with Marco’s help I learned a few new tricks regarding Fusion 360 and was able to update the panel drawing to the correct dimensions.

We then embarked on plotting out Instrument Panel version #2 on Marco’s plasma cutter with no hiccups.

In fact, I took a short video of the last little bit of the panel plotting effort on the Plasma Cutting table.  We didn’t film the entire event since to draw the separate circles and rectangles in the panel we had to lift the Sharpie up slightly in its holder (which Marco cleverly designed and 3D printed) after each drawn component to allow the assembly to relocate to the new spot that the next component would be drawn, then slide the Sharpie down in contact with the cardboard.  

This pen lift/drop cycle is shown in the video, as is the entire drawing of the Instrument Panel perimeter.

After the instrument panel plotting was done on Marco’s plasma cutting table, I then labeled the components on the cardboard to grab this shot here.  Most of the larger component holes will get cut out, which I’ll show in a subsequent blog post.

I’m extremely pleased with how the cardboard panel mockup came out, and am excited about dialing in the panel CAD drawing to enable Marco and I to plasma cut my panel out of a piece of aluminum.  I will say that Marco and I (and a few others) are discussing the pros and cons of 2024 vs 6061 and what thickness the panel should be (0.063″ to 0.090″).

Ok, so Mission Complete on getting cleared out of storage unit #3…. with most all Long-EZ project components, materials and tools out of storage units #2 & #3 and transferred to the hangar.  Then, I consolidated the remaining NON-airplane-build stuff from storage unit #3 into unit #2…. did you get all that?!

While down in NC I once again took the time to flip the engine upside down to allow the camshaft, etc. to bath in oil for a few days.   I then recharged the desiccant both in the Engine Dehydrator tub and in the individual cylinders’ spark plug dehydrators.  In the next trip or two I’ll hit all the cylinders with preservation oil . . . hopefully for one last time before I fire ‘er up!

On my last day in NC, I stopped by the hangar to do some much needed cleanup on my motorcycle and lathe, both which had some minor surface rust showing up here and there.

I also found my starter contactor which allowed me to get the dimensions off of it (again) to draw up a mounting base for it in CAD.  

I also took a bunch of measurements on the panel to verify that my panel dimensions were correct since I was going off of both memory and my very first panel cutout from 2012 to create the recent CAD sketch of the instrument panel.  Specifically, I wanted to get the new numbers since the top of the panel lost a good 3/8″ in height when I added the sub-glare shield base to the business side of the panel.

Here’s a closer shot of the fuselage in the hangar . . . also note the winglets leaning against the canard and the cowlings stored on top of the shed behind the fuselage.

And a wider angle shot of nearly my entire hangar.  Note that the boxes to the left of the fuselage are all specifically Long-EZ project related.

I also pulled out some non-aviation related wire and terminals –that I normally use for just testing purposes– to use on wiring up and testing the machining CNC stepper motors and drives.