I'm going on a holiday to Spain next month and I decided I want to take some FPV gear with me. My Micro Apex will be great for quick freestyle rips but I also wanted to take an airplane for longer range exploration. I've had a lot of fun with my Twin engine LIDL Glider but it's too large and fragile to put in a suitcase...

So while looking around for smaller airplanes with detachable parts I found the Hee Wing T1 Ranger, which has individual detachable wings and a detachable tail! It all comes in a box that measures only 39 x 22 x 14 cm...



There's a KIT version with just the frame but in my opinion it's a bit expensive. The PNP version is a much better deal because it comes with 1404 motors, 20A esc's and the necessary servos. This version also comes with special quick release connectors for the wings, and programmable LEDs in the wing tips.

I ordered the PNP version on AliExpress last month but due to Chinese New Year there was a lot of delay and the order got canceled. But I got very lucky because PaiRaN from the rcgroups.com thread (also known as JustFPV on YouTube) hooked me up and I could buy a spare one from him - yay!

I threw in a Matek F405-WSE controller, Matek ELRS-R24-D diversity ExpressLRS receiver, Beitian BN-220 gps module and a Rush Tiny Tank VTX. Only a nano sized FPV camera fits in the nose (unless you cut it up) so I chose a Caddx Baby Ratel, which has a very nice image in my opinion. I also put a Caddx Peanut action camera on top of the nose.

The airplane's foam is exceptionally dense and strong, but I still reinforced it a little by putting clear packing tape to the front of the wings and the front of the stabilizers. This should protect it a little against damage if I hit a branch or something like that. I also reinforced the action camera bracket in the front, and the flimsy handle on top of the canopy.

Instead of the provided 3830 propellers, which feel a bit cheap, I'm using Gemfan 4024 props. They are slightly larger and slightly lower in pitch, which should theoretically make them a little more efficient.

   

Last but not least I made some 3S li-ion packs with 2600 mAh Sony VTC5 cells. They can handle up to 35 A, which is much more than this little plane will ever demand.

For the INAV settings I copied most of what I learned from the LIDL glider build. Just two weird things:

1. After flashing the ESCs with Bluejay (for 48 kHz efficiency) I had to change the ESC protocol to DSHOT 300. DSHOT 150 worked for the normal BLHeli_S firmware but not for Bluejay
   
2. I could not get all advanced telemetry information (such as GPS position, heading, battery level) through the ELRS link until I completely disabled the SOFTSERIAL feature (even though I wasn't using it, the F405 has plenty of real UARTs)
   

It's been a little windy lately but I couldn't wait to do the maiden flight. It all went exceptionally smooth, it flew great from the first second 

I bought one as well! Do you have a couple of pictures on the inside and cables layout?

Awesome! You're going to love it 

Actually I crashed my T1 the other day and the battery plate got ripped apart, but I can still walk you through it;


The F405-WSE is almost completely in the back. It's not screwed down now because of the crash, but you can see how I used servo headers only for the servo's and LEDs. The RX, VTX and CAM wires are just soldered to the pads.

I put an extra LED (top left) in the wire going to the right wing so it's programmable in a different color (see https://youtu.be/ItRgwActlHQ?t=1). But honestly you can't see the LEDs while flying anyway so it wasn't really worth the effort.

The ELRS-R24-D is in the middle (without heat shrink now because one antenna came loose after the crash). The (Prodrone) antenna's are stuck to the sides left and right of the battery, both at a different angle. I considered putting the antennas outside but I can reach 7 km with this setup so no real need to make extra holes in the fuselage... Yet?




Next you can see a power lead on the left going from one of the servo headers to the magnetic plug for my Caddx Peanut in the nose. The wire from the XT30 battery plug goes under the controller to the back. In the middle there's a long wire for the analog camera and on the right are the wires going to the little extension board of the controller. There's supposed to be a little 6-pin plug on that board but it got ripped off in the crash so I soldered the wires to the pads on the back. I'll stick this board back to the side of the fuselage when I assemble it again. The sticker helps me remember which way the switch enables and disables the beeper.






The BN-220 GPS fits nicely in the back. I always get a fix in less than 3 minutes, so it seems like a good spot away from any interference.




For the VTX antenna I put a pigtail with an SMA connector in the back hatch. For the first few flights I had the Rush Tiny Tank just dangling inside the fuselage (with heat shrink), but it got way too hot and I lost video a few times. Instead of making extra venting holes in the fuselage I just made a square hole to fit a little heatsink, strapped it to the VTX with tiny zip ties and glued everything in place with hot glue. Even though the heat sink only sticks out for 2 mm it keeps the VTX perfectly cool.






Hope this gives you some ideas! Everybody does it a little different, so do share some pictures when you've finished your build

Had a motor failure yesterday but I managed to get home without too much trouble. This is why I love flying twin motor airplanes!



I'll be replacing the motors soon with T-Motor F1404 3800KV motors. They should be more reliable and I'm also hoping they are slightly more efficient with the strong, curved magnets.

(27-Jun-2022, 10:45 PM)L0stB1t Wrote: Had a motor failure yesterday but I managed to get home without too much trouble. This is why I love flying twin motor airplanes!



I'll be replacing the motors soon with T-Motor F1404 3800KV motors. They should be more reliable and I'm also hoping they are slightly more efficient with the strong, curved magnets.

Good test indeed! The T1 doesn't really glide, but 1 motor seems to be enough for a gentle descent. Luckily, you were close enough.

(27-Jun-2022, 10:45 PM)L0stB1t Wrote: Had a motor failure yesterday but I managed to get home without too much trouble. This is why I love flying twin motor airplanes!



I'll be replacing the motors soon with T-Motor F1404 3800KV motors. They should be more reliable and I'm also hoping they are slightly more efficient with the strong, curved magnets.

Hey mate, a quick update on my latest test:

4s VTC6 3000mAh
1507 2800Kv t-motor
APC 4.1x4.1
INAV Throttle scale at 70%

Throttle at 40/45% - 65 km/h - 2.5/3Ah
Full throttle (capped) - 100 Km/h - 9Ah

So far, this is the best combination I found.

(11-Jul-2022, 07:25 PM)andreab Wrote: Hey mate, a quick update on my latest test:

4s VT6 3000mAh
1507 2800Kv t-motor
APC 4.1x4.1
INAV Throttle scale at 70%

Throttle at 40/45% - 65 km/h - 2.5/3Ah
Full throttle (capped) - 100 Km/h - 9Ah

So far, this is the best combination I found.

Hi Andrea!

Thanks for sharing the details. That's some very impressive efficiency! Do you have the patience to go for a 1 hour endurance test?

I just had my first test flight with the T-Motor F1404 motors today and they perform nicely in combination with Gemfan 4024 props. To cruise at 60-70 km/h I need 60% of throttle which draws 8 amps. At full throttle it draws almost 20 amps. With the original motors I needed more like 75% throttle and 9 amps for cruising, and the top amp draw didn't get much higher than 16 amps. So it seems the T-Motors have slightly better efficiency for cruising and a bit more top end when needed.

With my 3S VTC5 (2600 mAh, 2200 mAh real usage) packs I could squeeze out 22 minutes of flight before. I'm very curious how much longer I can fly with the new motors, and even more curious how long it can last with the bigger P42A cells.

I tend to fly wings more for long-range with some freestyle at the end. I don't always need 1 hour flight time, but it's good to know I can do it if needed. So far, I've done 48 minutes on a single VTC6 pack.

I swapped between several 1404 motors, and they all perform slightly better than the originals but not that much (even due to the same kv in your case). I also built a 3s P42A pack, and I got about 20% more time on cruising around. Not that much with freestyle due to the additional weight. If you want to fly longer, the way to go is 4s as you can drop the amperage by 25%. If you want to fly faster, the way to go is the APC 4.1x4.1. Unfortunately, APC doesn't make any t mount prop, and there is not much choice of bi-blade with t mount connection.

I just got a PNP kit and was wondering what you guys think of running bigger props on 2s. Like 5" props. I don't care about speed really as I have other wings to cover ground. Just would be nice to get some decent flight time and still have enough thrust to get out of a tricky situation. I have some molicel 4200mah cells I would make into a 2s2p setup.

(12-Jul-2022, 02:18 PM)Lukeman Wrote: I just got a PNP kit and was wondering what you guys think of running bigger props on 2s. Like 5" props. I don't care about speed really as I have other wings to cover ground. Just would be nice to get some decent flight time and still have enough thrust to get out of a tricky situation. I have some molicel 4200mah cells I would make into a 2s2p setup.

The lower the number of cells, the higher the Amps you need. The larger the prop, the higher the Amps you need.
There is no perfect formula, it's a trial and error process. Install a prop and go to the field for a test. A grassy field is preferred 
HOWEVER, fly around for a few mins then land and check the motors' temp. If they are hot, it's not good.

IMHO 2s are not enough for this model.

(12-Jul-2022, 02:18 PM)Lukeman Wrote: I just got a PNP kit and was wondering what you guys think of running bigger props on 2s. Like 5" props. I don't care about speed really as I have other wings to cover ground. Just would be nice to get some decent flight time and still have enough thrust to get out of a tricky situation. I have some molicel 4200mah cells I would make into a 2s2p setup.

You'll need much bigger motors to run 5" props. I've tried Gemfan 5126 props on my LIDL Glider before and it nearly instantly brought the F20 (1408, 3250 KV) motors to a boiling point. Ok that was on 4S and maybe it could work on 2S, but you definitely need to do some short tests at home and check the temperature.

To get the best flight time it's clear to me that you're best off with something like Andrea's 4S setup. 3S is good enough for me but 2S doesn't make much sense. A pack with four 21700 cells probably won't fit and is really heavy for the little Ranger.

(12-Jul-2022, 03:01 PM)andreab Wrote: The lower the number of cells, the higher the Amps you need. The larger the prop, the higher the Amps you need.
There is no perfect formula, it's a trial and error process. Install a prop and go to the field for a test. A grassy field is preferred 
HOWEVER, fly around for a few mins then land and check the motors' temp. If they are hot, it's not good.

IMHO 2s are not enough for this model.

Yeah it's a balancing act for sure. 2s on the same 4" prop is less amps than 3s on that prop. So going up to a 5" prop and going down to 2s voltage should theoretically be the same current draw with the benefit of more thrust from the bigger prop, but could be a wash for efficiency depending on how much throttle is needed to cruise. 

I'll do some static thrust tests on the bench with some different props and see what happens. I'll see if I can find a magic combo for efficiency. My goal is to find the best combo for the most thrust with as little current draw at 50% throttle.

I guess I'm just wondering if there's ample clearance for a 5" prop or is 4" the max? I haven't opened the box yet.

(12-Jul-2022, 03:32 PM)L0stB1t Wrote: You'll need much bigger motors to run 5" props. I've tried Gemfan 5126 props on my LIDL Glider before and it nearly instantly brought the F20 (1408, 3250 KV) motors to a boiling point. Ok that was on 4S and maybe it could work on 2S, but you definitely need to do some short tests at home and check the temperature.

To get the best flight time it's clear to me that you're best off with something like Andrea's 4S setup. 3S is good enough for me but 2S doesn't make much sense. A pack with four 21700 cells probably won't fit  and is really heavy for the little Ranger.

Yeah I guess I wasn't thinking about all that weight. I could probably get by with just a pair of cells in series for 4200mah 2s but will it balance with that pack? Should be around 140-150 grams. 

What size pack are you running?

(12-Jul-2022, 04:37 PM)Lukeman Wrote: Yeah it's a balancing act for sure. 2s on the same 4" prop is less amps than 3s on that prop. So going up to a 5" prop and going down to 2s voltage should theoretically be the same current draw with the benefit of more thrust from the bigger prop, but could be a wash for efficiency depending on how much throttle is needed to cruise. 

I'll do some static thrust tests on the bench with some different props and see what happens. I'll see if I can find a magic combo for efficiency. My goal is to find the best combo for the most thrust with as little current draw at 50% throttle.

I guess I'm just wondering if there's ample clearance for a 5" prop or is 4" the max? I haven't opened the box yet.

I run my mini zohd planes with a similar motor, 1406/2800kv all day on 2s with a 5x5 prop on a 2s1p with no issues. For what it is worth, i really don't get that much more endurance on that set up than with the 3x5x3 props on a 3S 1100mah battery, probably mainly due to wind. Plenty of thrust either way.

(13-Jul-2022, 12:36 AM)burkeomatic Wrote: I run my mini zohd planes with a similar motor, 1406/2800kv all day on 2s with a 5x5 prop on a 2s1p with no issues. For what it is worth, i really don't get that much more endurance on that set up than with the 3x5x3 props on a 3S 1100mah battery, probably mainly due to wind. Plenty of thrust either way.

Thanks for the insight! I think I'll be trying some of the ultra light 5x3 hq props on 2s vs the stock 3.8x3 props on 3s. I may have some ultra light 4" props I can try on 3s as well. Maybe I'll do a smaller 3.5" 3 blade prop on 4s just to try everything. 

Yeah peak efficiency is a tough formula on for any aircraft. Like you said, just a change in wind can affect your performance overall. I'll have to try both 2s and 3s to see what works best for for this plane/motor combo.