Official Skynetic Bison XT STOL Discussion Thread

[Atrix]

Hello, Can anyone please answer this question? Thanks in advance.

Prop 15X8 or 16X8 for 6S lipo?

15x8 - 6S
16x8 - 4S

They shared this during yesterday's stream

[Denc23@comcast.net]

Small prop for 6s larger for 4s. According to MRC latest video.

[Atrix]

A couple hiccups, but I got her put together. Still gluing the tires so I stuck some foam tires on to complete the look.

Also, I can confirm that the light controller does not like 6S, it gets burning hot. I pulled it out and will just direct power the lights with my own regulator or a separate battery. For anyone interested, the light controller puts out 6V.

[2much2do]

Boo for linear regulators. Might go find a small 2s pack for the rare times i want lights.

[MJ4RC]

Small prop for 6s larger for 4s. According to MRC latest video.

Thank you very much.

[MJ4RC]

15x8 - 6S
16x8 - 4S

They shared this during yesterday's stream

Atrix,
Thanks for the prop info and confirming the issue regarding the light controller. I submitted a trouble ticket to Motion RC support. I will probably use a 2S lipo for now to power the light controller. Thanks again.

[Atrix]

I maidened the Bison XT this morning at my local field (asphalt runway) on 6S. I went with disconnected slats and threw a FT Aura 5 board in there just to be safe. I started on full manual, passthrough control and full rates (20% expo all around), and ground looped on the first take off attempt, got some road rash on the outside edges of the wings/ailerons. On the next attempt, I was able to power it into the air without flaps. I took it around the field and had to do quite a bit of trimming, especially (oddly) in rudder. Landings were very bouncy and tricky to control on the hard runway, and ground control is almost nil because of the relatively soft springs between the tail wheel and rudder. I got through three batteries without destroying the plane, which is a success in my book. Here are a couple notes:

• The road rash from the ground loop also tore both aileron hinges. The unreinforced foam hinges here are a bit of a disappointment for a bird so beefy everywhere else. Luckily I had hinge tape and was able to field repair. If you get this kit, I would reinforce the aileron hinges before maiden.
• I lost a lock nut in the landing gear, which was surprising, but easily remedied.
• I lost one of the wing light assemblies, despite bending the pins as suggested. The issue was that the light assemblies get pretty hot which shrank the double sided tape and made them loose. As I mentioned in a previous post, I swapped the included light controlled for a regulator, so this may be on me. The regulator is set at 6V, and I am not sure if that contributed to the heat in the wing light assembly. No other LEDs got hot. I removed the other wing light before it fell off and will experiment with different voltages on the desk to see about heat. In any case, use some other means to secure these lights, just as back up.
• Tires and landing gear worked great, despite being tricky on the ground.
• The Bison is pretty power hungry. Even at full flaps (which I set at 30 degrees) I would lose altitude below 50% throttle.

So, all in all, I am happy with the Bison XT.

[2much2do]

wow...that sounds immensely disappointing. I really hope Motion doesn't have a complete flop on their hands.

[Atrix]

I played around with the remaining wing light unit. It still works all the way down to 3.5 volts and consumes less amps at lower voltages, which may be obvious to those who are better than me at electronics. I was getting 0.4A at 6V, 0.3A at 5V, and as expected 0.2A at 4V. Lower voltages/amps means less bright lights but less heat as well. 4.0 volts seems to be a good compromise between brightness and heat, I was able to leave it powered for 10 minutes while only getting a little warm.

[Warlox]

Anyone know what these are?

[Atrix]

Anyone know what these are?

They glue to the end of the wing. I used Foam-Tac glue.

[Gilatrout]

Has anyone noticed it had problems with the control rods being too long?

Both the flap rod and the slat rod are too long. I'll need to cut the flap rod in order to center the servo. The flat spot on the slat rod extends well past where the grub screw meets the rod as well.

[Atrix]

Has anyone noticed it had problems with the control rods being too long?

Both the flap rod and the slat rod are too long. I'll need to cut the flap rod in order to center the servo. The flat spot on the slat rod extends well past where the grub screw meets the rod as well.

I have not attached the slat rod yet but I did not have an issue with the flap rod once I moved the servo to the one extreme. Here is a picture of what I have:

[2much2do]

I have not attached the slat rod yet but I did not have an issue with the flap rod once I moved the servo to the one extreme. Here is a picture of what I have:

I'm confused that picture makes the Flap rod look WAY too long. You set the servo up that way with the flap flush?

[Gilatrout]

I'm confused that picture makes the Flap rod look WAY too long. You set the servo up that way with the flap flush?

Yeah, that's the way mine looked before I cut down the rod.

The next issue is the manual calls for 2.6 x 12 screws for the undercarriage. The bag labeled with these are a set of self tapping screws that will not connect the undercarriage to fuse.

#edit#
It looks like the whole undercarriage instructions are incorrect. Using 9.1.2021 instructions

[Atrix]

I think the long rod provides a large range of flap movement.

I was also missing the screws that mount the landing gear to the fuselage. The manual says 2.6 but the part they screw into is actually an M3 thread. I used some extras I had laying around.

[2much2do]

I hope Motion is Watching, this seems a large number of complaints, without any flight reports coming up good.

Mine Arrives tomorrow. I'm trying to still be hopeful

[Gilatrout]

Tail wheel assembly is going to need some work. There is so much slop in the springs that the wheel hardly moves even though the rudder is moving to full deflection.

All in all, this is going together much more like an ARF instead of a PNP foamy. Little things here and there that need adjustment or fitting.

Im taking a break for today and making some wing bags for it.

[Atrix]

Tail wheel assembly is going to need some work. There is so much slop in the springs that the wheel hardly moves even though the rudder is moving to full deflection.

Yeah, at the field yesterday I was hardly able to control it on the ground, turns are super wide on pavement and non existant on grass. I had to hand wheel it out to the runway. I ordered a set of assorted springs off Amazon with the idea that stronger springs will help keep the wheel and rudder connected.

[2much2do]

I have not attached the slat rod yet but I did not have an issue with the flap rod once I moved the servo to the one extreme. Here is a picture of what I have:

Umm...Your photo would give you nearly 0 flap deflection. You get a couple of degrees before your rod bangs into your servo. That's why gilatrout cut his down.