Ok, folks… yes, I’ve been out of it for a bit.  As some of you may be well aware, we had a good little cold spell here.

During the cold weather I was digging in deep to get spun up to get my lathe CNC online.  I got a good ways before realizing that I need to upgrade my lathe software to do the CNC I need to do, so that will be another week or so.

Meanwhile, in needing to use my truck I had some issues with it that I needed to tend to, including installing both a new battery and alternator.  Moreover, I’m fairly certain that this last round of really cold weather was the straw that broke the camel’s back in regards to my well water pump dying.  Another near 2 days in sourcing a new one and getting that installed.

I would say that I’m ready to jump back into the Long-EZ build —which I am— but I’m heading out for a long weekend that I surprised Jess with, so I’ll be back on it for another day or two before heading out on another short trip, just for fun.  Next Monday I plan on digging back in hard core on the build (whew!).

As for today’s build shenanigans: a number of days ago I added a little meat around the edges of the wing leading edge light mounting bracket (in Fusion 360 CAD) … about 0.05″ each side for more space for the 3 mounting screws to secure it.  I then 3D printed a thin mockup of the new bracket version to allow me to use it more as a template for marking the aluminum stock for cutting.

Looking around the shop for exactly what stock I was going to use, I settled on 0.025″ thick 2024.  Here I’ve marked up the 2 pieces that I’ll machine to make up the wing light mounting brackets.

I then cut the 2024 pieces…

And did my favorite blue tape and super glue hack to secure them to a scrap 2×4 for milling (yep, you can’t take the Neanderthal out of a Neanderthal “machinist!”).

I then prepped and machined the first landing light mounting bracket …

then did the same thing for the second one.

Here we have the 0.025″ thick 2024 wing lights’ mounting brackets, after I cleaned them up just a bit.  In the next day or so (weather dependent) I’ll clean, prep and paint them.

My immediate goals are to finish up the aft lower engine baffling, and also get the stainless steel compression-style EGT probe mounting bungs trimmed down on the lathe (for weight) so I can get them welded into place and operational.  Over the next few weeks I’ll be working to finish up the engine stuff to get it finalized, including the firewall.  When the weather warms up enough to start slathering up the bird with micro to finish it in prep for paint, I want to be ready to get that ball rolling.

Today was one of those days where the amount of actual work accomplished was maybe 45 minutes while the amount of research and prep to do that work was half the day.  But I got ‘er!

Again, through a ton of research I was able to figure out the wiring to my just-installed Lathe CNC spindle control board (from Little Machine Shop).  This board, along with swapping out a chip on the lathe main control board, allows the CNC control software (I’m using Acorn CNC) to start and stop the lathe’s spindle, control the spindle/chuck RPM, and provide directional commands for either forward or reverse.  This comes in real handy not only during normal lathe ops, but especially during creating threads and tapping.

Here’s the lathe side wiring.

The main thing I needed to figure out inside the Lathe CNC control box was wiring up the two relays that control the forward/reverse direction of the spindle.  Here is that wiring.

The main issue I had when I went to test it was not any of the wiring I had just completed, but remembering how to use the darn software.  At first I thought my wiring was wrong but then I realized I wasn’t inputting the right commands… doh!  It’s just been so long working these functions in the Acorn CNC software.

That being said, when I did finally get it fired up, the control was spot on… and that 4″ chuck was very smooth, vibration-free and purred like a kitten.  I still have some final dialing in to do, so I’ll make a short video when it’s operational.

Again, after I do some test lathe ops on some scrap stock, I’ll be chucking up the compression EGT probes’ stainless steel mounting bungs to trim those suckers down a good bit to knock off some weight.  Those bungs are an excellent excuse —while the weather is still fairly chilly— to get the lathe up and running since I’ll need to use it to make a number of other airplane parts as well!

Today I continued my work to finally finish the CNC conversion on the lathe… it’s way overdue.  I’ll also again highlight that with the weather colder it’s a good time to do tool upgrades and implementation since big epoxy-based tasks are a non-starter currently due to low shop temperatures.

I’d say the primary hole in my plan for integrating this new CNC spindle control board into the lathe control system is analogous to my GRT rant a while back: documentation. While the install docs that came with the control board have the basic install covered, they don’t go into any detail on how it integrates with the CNC control system I have, so I will be diving deeper and making a few phone calls over the next 2-3 days.

Thus, the main goal today was to simply get the new CNC spindle control board, housed in its nifty 3D printed case, mounted to the side of the lathe’s electronics box.

The blue wires connect the CNC spindle control board to the lathe’s AC power mains.

I said the space was tight inside the lathe’s electronic box… too tight to mount the new CNC spindle control board inside there.  But even the connecting cable from the new externally-mounted board to the existing interior board takes up a ton of space.  It’s the big black cable that looks like an oval race track.

I then closed up and re-mounted the lathe’s electrical box.

I incorporated a reinforced hole on the side —in my design of the CNC spindle control board’s case— to allow for mounting a wire-securing Adel clamp.

As a reminder, here is the CAD model of the case I designed for this new control board.

A front view of the freshly mounted CNC spindle control board housed in its 3D printed case.  The front of the case is open to allow for installing the control board into the case, but also so that when the lathe cover is installed  . . .

… as it is here, then the end cover serves as the de facto front wall of the CNC spindle control board case.

Since I am clearly getting the lathe up to snuff to use it, I also pulled the 5″ chuck off the lathe to swap it out for a new 4″ chuck.  The 5″ chuck is simply to big and heavy, causing way too much vibration for this size lathe to handle.

Here is the new 4″ lathe chuck in the box… which I bought over 6 months ago?

And here is the new 4″ chuck installed on the lathe.

Inching closer to have the lathe ready for real world CNC ops!

Well, between the still quite chilly weather, a good day and a half storm (causing a bunch of tornados inland that killed some folks), helping a friend using the trailer and knocking out a few other household tasks, I haven’t been as focused on the build over the past week as I want to be.

I’ll start off with reporting some good news.  I received the billet aluminum (or so it was advertised… it IS aluminum) threaded dipstick cap.  I immediately took it out to the shop and checked the fit: spot on!  It threaded in nice and smooth.

Here is the top face of the cap.  I’ll be drilling a 3/16″ hole in the center of this cap face to mount the dipstick rod.

This dipstick cap has an o-ring seal just like the Lycoming ones.  But unlike the Lycoming/Superior dipstick caps, this one is LOW profile to avoid clearance issues with the top cowling.

In other news:

I’ve also been doing some research to FINALLY finalize my lathe CNC conversion to allow me to get some parts made and tweaked (e.g. the EGT probe threaded mounting bungs).

I’ve had a kit from the Little Machine Shop in my possession for almost a year now that will convert my lathe to allow for the CNC system to control the lathe’s spindle speed and direction.  To do this, I have to add another board into the mix and tie it in to the existing electronics via a cable.

The first task in converting my lathe’s control board to allow adding in the new CNC control board was to swap out an integrated circuit (IC) chip one of the existing boards.  The removed original chip is in the Styrofoam block resting on the cables.

In addition, I needed to find a home for the added CNC control circuit board inside the lathe’s electronics housing.  The problem is that there is simply no room for this new board with how things are configured inside the housing.

After doing a good bit of measuring and assessing the setup, I decided to mount the new CNC control board outside of the electronics housing and simply run the cable in from outside.  It will be mounted to the left outside wall of the electronics housing under the left end spindle cover.

To minimize any dust or debris from dirtying up the new CNC control board, I designed up a protective box in Fusion 360 CAD.

I kicked off the 3+ hour 3D print on this new protective box, but about halfway through the ABS/polycarbonate filament I was using didn’t do well at all in printing out the box, so I switched to a standard ABS and restarted the print.   We’ll see how it turns out in the morning.

Since the weather over the next 6 weeks will most likely remain too cold for me to the major micro finishing on the remainder of the plane (unless we get a multiple day warm spell), I’m going to focus on all the other tasks —including cutting and mounting the firewall— that I can do until I can get to micro finishing.  Up next is still finishing the aft lower aluminum engine baffles.

I started off today by placing a strong LED light under the engine and searching for gaps in the CF inner baffles… I then slowly and carefully filled any gaps I found at the seams of the CF inner baffles.  With this task complete, it finalizes the install of the CF inner baffles.

Last night I worked a good bit on adding hexagons to the sides of the wing light mounting bracket…

Today, after finishing the gap sealing on the CF inner baffles, I then got back to work on finishing up the addition (in CAD) of the hexagon grids on the ends of the wing light mounting bracket.  The hexagon grids around the perimeter of the mounting bracket are not only for lessening the weight, but for air flow as well to aid in heat dissipation.

I then 3D printed the wing light mounting bracket.

Here we have a couple more shots of the wing light mounting bracket with the new hexagon grids added to each end.

I then test fitted the actual light unit into the wing light mounting bracket . . .

and it fit very nicely.

Now, with all that work done on the 3D printed wing light mounting bracket, there was one final check I needed to make: weight.  Here I checked the weight of the 3D printed wing light mounting bracket (15g) vs the 2024 aluminum wing light mounting bracket (7g).  Clearly the ABS mounting bracket is twice as heavy as the aluminum one, so my plan going forward is to stick with the aluminum wing landing light mounting bracket.

In other news, I received the oil sump mounted oil pre-heater from Anti-splat Aero to help heat up the engine on those cold flying days.

Here is the spot where I will mount it: the front right corner of the oil sump on the vertical sump wall.  This spot is right at the lower corner of the oil sump so the heater will “hover” just over the bottom of the oil pan, which will be a great configuration for heating the oil up.

I plan on running the electrical cord up over the top of the engine to allow me to gain access to the plug through the oil dipstick door.

Tomorrow I plan on jumping back on the aluminum engine baffles to get those knocked out.

Pressing forward!

I started off today doing a good bit of research on my oil dipstick, to either buy one outright that would work or gather more info on making one myself.  In my research I stumbled upon a post on the VANs air force forum that contained information about a billet aluminum knurled oil dipstick cap with the thread size and pitch that I need (my old Lycoming dipstick won’t work since the thread size is incorrect for the new Superior oil level tube).

With this cap being WAY cheaper than buying a Lycoming or Superior dipstick outright, I went ahead and pulled the trigger on it.  Moreover, with its low profile design this oil dipstick cap already works much better in my configuration in regards to required clearance with the top cowl/oil check door than the taller stock caps.  I’ll assess this cap after it’s delivered to see if it will work for me (some mods required!)… I’m cautiously optimistic that this thing will fit the bill.

I then spent a good little bit of time aligning and drilling the through-hole in the cross shaped left inboard inter-cylinder baffle before adding a grommet and then installing it.  As I did on the right side, I also installed the 90° right angled tab using both glue and the 1/4″ bolt that secures the fuel injection distribution “spider” bracket.  Also note that I did the final install of the -4 fuel line to the fuel spider.

Knocking out these left side inter-cylinder baffle pieces finishes off the installation of all the CF inner baffles.  I will have some minor gap fill tasks to complete, but for the most part I’ll be heading back to finish off the aluminum baffle installs.

I then knocked out a task I’ve had on my to-do list for quite awhile: machining the wing leading edge light mounting bracket, or at least a test bracket to check out both its weight and functionality.  I’ll also remind everyone out there that these wing light installs are a prerequisite task to micro-finishing the wings.

Here is the freshly machined wing leading edge landing light mounting bracket which I milled out of some scrap 0.032″ thick 2024 (from the aluminum baffles).  The aluminum stock wasn’t a perfect specimen size-wise (a hair short in width and on height at one corner), but definitely close enough to provide a good working test bracket.

Here is the cleaned up newly machined wing leading edge light mounting bracket along with the previous 3D printed initial test bracket.

Finally, here is the machined wing leading edge light mounting bracket with an LED landing/wig-wag light test fitted into the bracket.

Tomorrow I plan on starting on the lower aft aluminum engine baffles.  I’ll also be working on finalizing the trimming and final configuration of the exhaust pipes as well.

Well, I’m back from all my holiday travels.  Time to dispense with fun and frivolity, and get back to work on the bird!

As I was cleaning up the open browser tabs on my computer, I ran across a stainless steel bung that I had assessed for the compression style EGT probes.  It was a bit more expensive than the ones I purchased, and is a bit simpler in that it eliminates a component by combining the compression fitting with the threaded bung… essentially a compression fitting with a bung on one end for welding it to the exhaust pipe.

The vendor’s website thankfully included CAD drawings of their parts for sale, so I simply downloaded that and within minutes had 3D-printed a version of their EGT probe mounting compression fitting/bung (I didn’t 3D print the internal sleeve or cap).

This new EGT probe stainless steel mounting compression fitting/bung (right in pic) is considerably smaller than the compression fitting + stainless steel mounting bung combo that I currently have on hand.

One critical factor that I needed to check with both these EGT probe mounting bungs is the positional depth of the EGT probe inside the exhaust pipe.  Although there is a little wiggle room, I pretty much want the compression style EGT probe inserted fully into the compression fitting/bung… and this issue revealed itself while testing out the possible use of this new combined compression fitting/bung, as the EGT probe ends up nearly touching the opposite wall of the exhaust pipe (pic 1).  While my current compression fitting + mounting bung has the EGT probe positioned more in the center of the exhaust pipe.

Clearly this new combined EGT probe compression fitting/mounting bung was too small to allow for good internal exhaust pipe positioning of the EGT probe.  Thus my test was successful since it showed me that I simply need to press forward with what I have on hand, albeit still throw these rather chunky stainless steel bungs on the lathe for some needed weight reduction diameter wise, but leaving the height as is.

I then got busy with the somewhat tedious process of fine tuning the fit of my cardboard template for the cross shaped right side inboard inter-cylinder baffle.  After a good half hour of iterative fitting machinations, I finally had it in place with minimal daylight showing around its perimeter.

I then transferred the final shape of the template to the actual CF right cross shaped inboard inter-cylinder baffle and trimmed it up.  I then glued the CF cross shaped baffle into place and let it set with some slight weight on it for a couple of hours.

While the initial cure took place on the right side cross shaped baffle, I trimmed off the curved lower cylinder baffle wraps from the forward VAN’s aluminum wall baffle segments… since with the CF inner baffles in place these were now redundant (sorry, no pics yet).

I then removed the weight from the curing right side cross shaped CF inter-cylinder baffle —tacked at this point— and installed/glued in place the 90° right-angled tab that secures the cross shaped inter-cylinder baffle in place (since it clearly has a good amount of upward traveling air to retain).  I trimmed the top side of this right-angled tab in a pleasing curved shape and also added some Loctite to the screw before threading it into place.

With my “practice run” of getting the top inboard inter-cylinder baffle installed on the right side of the engine knocked out, tomorrow I’ll tackle the left side… which will be a bit more challenging given I have to account for the fuel line that travels from the fuel spider to the fuel injection servo.

Inching forward!