Updates before OSHKOSH

In no particular order:

This is how the fuel and cooling plumbing will look. Blue is cooling. Green is high pressure fuel. Red is low pressure fuel return line. All these hoses are custom molded to our 3D shapes and dimensions. Super easy to install. No other fittings besides a handful of clamps. This makes for a clean, effective, light, and simple fuel/cooling system. Not to mention it looks great!

Here are some photos of how these silicone hoses are made. The tape is actually shrink wrap. A steel mandrel of our CAD-generated shape was fabricated then inserted into the silicone then wrapped in the heat shrink and baked. After the baking process the heat shrink and mandrel are removed and we have perfect fitting hoses.

Here is a video just posted by our friend Brain from Columbus. He is waiting on his Merlin kit and close enough to come visit us on occasion in Dayton. And pretty good at making videos. Maybe I can bribe him into making one from Oshkosh.  https://youtu.be/Olz_a9yU3nA

Speaking of Oshkosh, we will be in our usual space just north of Building C in the main display area. We have only one Merlin and don’t have any Merlin Lites to show but we will have plenty of updates on the finished Merlin Lites that didn’t arrive on time. And we will show 3 tents full of our innovations and technology. DEPOD, RAES, HYBRID, Hyper-STOL, Amphibs, to name a few. Plus, the Vtwin with all this nice plumbing should make the stand.

For those future Merlin owners, we will likely have a small price increase AFTER Oshkosh. This has little to do with inflation but a lot to do with all the technology we keep adding to this build. For those builders waiting so long to get the parts they need to finish their Merlin’s it won’t be much longer as plenty of parts are coming in soon. Thanks for your patience and I trust it will be worth your wait.

Builder Don has finished the right-side circuit board. Panel status:

  • Left-side circuit board Revision 1 has been ordered and should arrive in time to show at Oshkosh. This is the production version so plenty of boards are ordered.
  • Right-side boards are recently ordered and will likely arrive shortly after the show.
  • The final dimensions are now known so we can have panels laser-cut. We will bring the first panels and bring them to the show also. One will be anodized and laser-engraved and have the EFIS and maybe the left-side panel installed.

Here is Don’s description of the new ‘fuel-control’ right-side panel:

The holes for the switches and LEDs are on mechanical layer 2. There are five mounting holes but those are not part of mechanical layer 2. The tank-select switch is three-position: Left, Auto, Right.

The AUTO MODE SELECT switch to the right of the tank-select switch allows for automatic tank selection based on “TIME” or “BALANCE”.  With the Tank-Select switch set to “AUTO” and with the mode select set to “TIME”, the tanks will switch automatically every 10 minutes (or whatever interval we decide to program into the microprocessor).  When “BALANCE” is selected, then an (as yet to be determined) balance will be maintained automatically between the tanks.

Setting the tank-select switch to either “LEFT” or “RIGHT” will always disable automatic tank selection.

The four green LEDs are (from left-to-right), Pump 1 ON, Pump 2 ON, LEFT TANK, RIGHT TANK

The two red LEDs illuminate whenever either pump is turned on and the respective fuse has failed.

Alright so what does this mean?

  1. With a fuel-injected engine one pump must always be on. We install 2 pumps for redundancy. The pilot can choose to run either pump. Or both for take-off and landing if desired. Just make sure one green LED is lighted.
  2. The electronic fuel selector has a horizontally mounted switch. Simply choose left tank or right tank. Switch tanks whenever you like. When flying cross country, I usually will fly 1-1/2 hours on one tank then finish the flight on the other tank. Then I know how much fuel I burned and how much remains. Good to know if you don’t trust your fuel gauges.
  3. But wait, there is a middle position? Yes. This you might find in your friends’ Gulfstream. If you choose the middle position, then the fuel tank selector will automatically change from left tank to right tank based on a time interval or a fuel level interval.
  4. The toggle on the right side gives you the choice to have the tanks balanced automatically by time or by fuel level. You choose. We will have to decide what those intervals are and will program the microprocessor to follow those intervals.

Note: The Merlin is not out of balance with one fuel and one empty tank. The tanks are close enough to the center not to make much difference. Having this automatic fuel balancing option is a convenience and also a safety feature. Not everyone remembers to switch tanks on time.

See you at the show!