Friday, July 30, 2021

Modded trailer for hauling the Onex

 Got a 2.5 mm "walking plate" aluminium and some bolts. Cut two plates to shape and fastened them with two bolts. The trailer is made so the rear lights swing to the side when the airplane (or boat) is carried.

For the tail wheel I just used the existing bow rest. Removed the rubber to buffer the bow, and inserted two poly-carbonate plates cut to shape. With those plates the tail wheel gear fits like a glow in between and is held secure against swaying to the sides, in the same manner as the bow buffer rubber when a boat is hauled.

With this mod I can simply exchange bow buffer with the plates and I can haul my boat or the Onex as I wish

The aircraft is fastened to the trailer using ropes through the tie down loops in each inner wing.

Tuesday, July 27, 2021

Trailer and moving

Family affairs has finally settled. As a result this means moving to a new house and making a new shop to build in (from scratch yet again). First things first, I need a trailer to move the plane, and later to use it to haul the plane to/from the airport. I bought a boat trailer that seems to work, way more than enough weight can be carried, and it is long enough.

I just have to add a couple of plates for the wheels and a different fastening system for the tail wheel. The plane will be travelling in reverse on the road, which should work just fine keeping the speed moderate.

Wednesday, October 14, 2020

New propeller

 Got the new propeller from Prince some time ago (in Mars). It took some time, but it is nice indeed.


Re-built the throttle quadrant

The throttle quadrants from Sonex are reverse throw, and not all that long throw. The ULPower engines are set up for positive throw, and longer throw. Took apart the throttle quadrant, made a new hole, one new friction fix stop member and "mirrored" it. Now it should work also for the ULPower.

Tuesday, July 09, 2019

The engine mount from Kaolin arrived today

Got the mount, and it seems to fit like a glow, at least on the fuselage side. Included were also an NDT test which showed no cracks in welding.

Sunday, April 21, 2019

Electrical System ULP V06

After several comments/mail and reading books about this stuff, I think I'm finally converging to something usable.

The primary system is taken straight out of the ULPower manual. I have added the fuel pump 2 and manual switches for fuel pump 1 and 2. The isolation switch is a manual one installed with the battery (this may change, not sure yet).

The Mascot 8660 is removed. The reason is it will be impossible to isolate all the components from the common ground. The RDAC needed for EGT, CHT and MAP must be grounded to the engine, or it wont be able to read anything, and so on. Ideally all the RDACs should be in the primary system, and communications should be optical (fiber), maybe in 100 years. With a common ground, all isolation is gone. The 8660 would really only function as a current limiting device. Another reason is the 8660, when taking into account the efficiency (81%) will be too small. This could be fixed by dividing the system and install another ECB, but then things gets too complex for this little aircraft.

Friday, April 12, 2019

Pondering on fuel system

I think I found a good fuel surge tank. It's a "universal" version with 6 AN8 connections. There are several manufacturers of similar devices, and they can be had for 1 to 4 L sizes. A 2L tank seems to be suitable for me. It's simply an aluminium box with 6 holes in it.

Looking a bit closer at these tanks, it should be very easy to make an inverted system, with no moving parts, no flop tube. I may do that later on, it shouldn't be more to it than installing two tanks in series, like the sketch below.

Normal flying would cause no change. Gravity fills up both surge tanks.

When inverted, the inlet line will eventually be evacuated, while the vent line will close due to the gravity valve (also off the shelf racing part). The first tank will then gradually empty, while the second tank remains full.

When applying positive G again, the second tank will gradually empty while the first tank gets filled up. When the first tank is filled up, fuel starts flowing into the second than and they both eventually gets filled up. It should work I think, but should probably be tested in the shop first :-)

There are a few snags here, like what will happen if the aircraft goes inverted again, before the second tank is filled up completely? but nothing that can't be fixed by positioning the outlet to the EFI pumps vertically down towards the middle, and sizing the tanks correctly. The first tank should be smaller than the second. It would probably be better to build them as one single invertible surge tank.