Official Skynetic Bison XT STOL Discussion Thread

[Denc23@comcast.net]

I hooked b/w wire to RX, black on ground, white in signal, lights flash, switch does nothing , reversed lead, lights now on study, nav lights and side lights on fuse, switch still does nothing. On gear ch. Removed jst connector from esc to light controller and connected to a 600mah 2s battery, 7.4 volts. Don’t know why they didn’t just use the 5v from esc instead of the full 22v and 18v from pack?? Runs a lot cooler but runs battery down pretty fast, one flight probably, will test a 1300mah 2s when I get connector changed to jst. Maybe use a external BEC like some did.

[Evan D]

Seems like a couple days. I have had reviews, even good ones not show up.

[2much2do]

Anyone know how long it should take for a review posted to MotionRC to be visible? I posted one about 2.5 hours ago, I wouldn't expect them to be suppressing reviews.

[Evan D]

Have you, or anyone, tried polishing the side (or top) windows on this? My assumption is it's not the type of plastic that will polish out to decent optical clarity.

[2much2do]

Thank you. And for the two sets of wires coming from the tail? I plan on running 4s with the 17x10e prop on my bison. I’m using it for fpv and want scale handling. Hoping to not have the heat issues experienced with 6s

Those 2 just run off rx voltage

[Warlox]

Thank you. And for the two sets of wires coming from the tail? I plan on running 4s with the 17x10e prop on my bison. I’m using it for fpv and want scale handling. Hoping to not have the heat issues experienced with 6s

[2much2do]

Anyone have a diagram or tips for the lights? Does the black and white signal plug go to my rx for switch use? I have two power wires coming from the tail and don’t know where they go. Apologies in advance, I’ve never messed with nav lights before.

Yes i put black and white into a spare channel, it turns the nav/beacons on and off. Definitely do not run full 6s voltage into the controller though, lots have damaged them. I stepped it down to 6v before the controller and i get unlimited runtime.

[Warlox]

Anyone have a diagram or tips for the lights? Does the black and white signal plug go to my rx for switch use? I have two power wires coming from the tail and don’t know where they go. Apologies in advance, I’ve never messed with nav lights before.

[Starck Mad]

Same issues on mine, looks like a drop of CA same spot..

I don't think thats ca fellas. Same thing on all of them I've seen...its the point of injection (for the plastic) of the window molds. Also for anybody that wants to polish them for fpv...use automotive polishing compound, a soft cloth, and low pressure.

[gerbilstrom]

Just got mine today. I noticed that the windows look like they have overspray on them and the very top one looks like someone dropped CA on it. Also there are not enough y harnesses to plug all the lights in. Also the esc was disconnected from the motor, and just laying loose in the battery tray.. Was anyone else's like this or did I get one that was returned by someone.

Same issues on mine, looks like a drop of CA same spot..

[asesso]

It’s interesting, if you measure the CG from the leading edge of the wing and mark it at 57mm, it is the same spot if you measure back 70mm from the front of the slats. I think when the manual says “behind this line” they mean wing leading edge

[2much2do]

The manual appears to show the CG at 57mm from the front of the slats. It seems like it should be measured from the leading edge instead. Which is correct?

The manual appears to be wrong, please see the post directly above yours. 70-77mm behind the slats seems to be where everyone is landing.

[asesso]

The manual appears to show the CG at 57mm from the front of the slats. It seems like it should be measured from the leading edge instead. Which is correct?

[Starck Mad]

Great video Stark! Where are you mounting your battery at in relation to CG? I feel like if I measure back 57mm or even further back like others have....that battery wont be anywhere on the mounting plate and too far back to even throw the straps around. Could you post a pic for reference?

With the 4s packs (5000's) I have it to where the front strap just does go around the battery. With the 6s packs (3700's and 4000's) I tuck them under the tray slightly and the front of the pack is clear of the front strap...I just use the rear strap. I think our balance point is 77mm from the front of the slats. Our full set up is in our first video. Thanks for watching! Sub...we have much more coming!

[skiervh]

Ok guys! Our update video is up on Youtube (Model AV8R). We show how we fixed the tailwheel issue and show some taxi tests. We do some watt meter readings on 6s and 4s and show how to maximize the power on 4s, and show some maximum performance flight footage with both 4s and 6s. Check it out!

Great video Stark! Where are you mounting your battery at in relation to CG? I feel like if I measure back 57mm or even further back like others have....that battery wont be anywhere on the mounting plate and too far back to even throw the straps around. Could you post a pic for reference?

[Starck Mad]

Just an update from my weekend exploits with the Bison. We had an event at my local field, and I got some more eyes on the Bison from the crew of experienced pilots. Everyone was a bit flummoxed by the tail wheel and its tendency to not track very well (especially after some rudder input), making take off from the paved runway very tricky. There were a good number of failed take offs and ground loops and unfortunately the ends of my wings are bit beat up as a result. Once we switched to takeoffs in the grass, things improved quite a bit, but I am not entirely sure why, maybe less traction on the rear wheel meant less likely to be taken off course 🤷♂️

In any case, once I could take off with some regularity, I got through about 5 packs without too much trouble. In the air, I am still having to trim rudder, but other than that it was well behaved. I was doing low, slow passes all day with a few rolls and loops tossed in here and there. I have flaps mixed with elevator, but I have to tweak that a bit because I still pitch up on half flaps and pitch down on full flaps. Despite all the interesting challenges, I am still quite happy with the Bison and really enjoying it in the air (less on the ground).

Some things in the works. As you may have seen above, I am working on a springless tailwheel setup. I will report back how that goes this weekend. Also, I am designing 3D printable custom wing/aileron skids to help with my tendency to chew them up on ground loops. I am going to try and have them connect with a joint to help reinforce the foam hinge. I will certainly share them here for anyone interested.

Atrix the issue taking off...and landing from pavement is mainly due to the tires. They grip really well and since they are so much softer than say the Du Bro Big Wheels (which I run with no air...they are rigid enough) and require air...its really hard to get the pressure equal on both sides. I have the same issue from our geotextile runway. I do run mine with less air for less bounce which makes this worse...more air/stiffer would make it easier. That said I prefer the grass with a bush plane anyway.

[Starck Mad]

Ok guys! Our update video is up on Youtube (Model AV8R). We show how we fixed the tailwheel issue and show some taxi tests. We do some watt meter readings on 6s and 4s and show how to maximize the power on 4s, and show some maximum performance flight footage with both 4s and 6s. Check it out!

[FlyinTime]

Something i was told after i did it was to add a ring of soft foam inside so that even if they go flat you have something to roll on other than the plastic rim.

When I was watching some YouTubes on gluing tires for RC cars, They had what looked like foam inserts in them. Good idea, thanks

[2much2do]

Any tips on gluing the tires on the wheels? Never had to do it before

Go slow and use one of the little pipet tubes if you have it. Then just go over it again without leaks. Something i was told after i did it was to add a ring of soft foam inside so that even if they go flat you have something to roll on other than the plastic rim.

[FlyinTime]

Any tips on gluing the tires on the wheels? Never had to do it before