Striver mini VTOL 4+1 QuadPlane

Hi Alberto,

I am not an expert at flying at high altitudes. Hopefully, someone else will post some tips on doing that. In general, you will want to increase your prop size at 6000 feet.

I haven’t built my wings yet. Is there room for a larger prop than 18x5.5 for the quad motors? My guess is that one end already goes over the wing area. The easiest fix may be to try some 18x8 or 19x5.5 props if you can find them cheap.

Yes, I believe that you are correct on adjusting the Q_M_THST_HOVER parameter. It can also learn this value in QHOVER or QLOITER modes by enabling Q_M_HOVER_LEARN. Sometimes it is faster to just adjust it yourself.

Cheers and good luck!

Your Believer conversion looks great. Just wondering what motor/esc/props you are are using for your two cruise motors?

I have been considering a VTOL conversion for my believer so interested in your setup…

Cheers

Jeff

Hi, still working on my build. Last weekend I did some benchtest with the motors included in the kit, here are my results in case anyone finds them useful.motor1

motor2

Hey. Thanks for your interest.

The forward motors are sunnysky x3120-III and the forward props are 12x12 apc.

Previously I had been using t motors 3520 motors and 13x12 apc props.

The ESCs are hobbywing xrotor pro 40A. Pretty light.

I have a couple of believers so I have started to convert one to VTOL as a testbed.

Thanks for that. Good luck with your project.

Cheers

Jeff

1 Like




Mounted both vtol arms on the wings and front vtol motors.

Next step is to cut the vrol arms after determination of backward motors location based on CG.

I have a couple of questions:

  1. How much wing twist should be allowed? Currently, on application of approximately 3kg force on one side of vtol arm, the back side deflects about 2 to 3 cm.

  2. How do the front vtol motors effect the forward thrust motors when the front vtol props cover approximately half of the forward prop when viewed from the front? The current installation barely fits 12x12 inch APC props.

I apologise for hijacking this thread but it seems trivial to start a new thread when all the great minds are already in this thread. If im out of line, kindly let me know so I may move this to another thread.

1 Like


Started wiring up one of the wings.

Currently, its a test setup for testing hover soon.

Planning to use 6s7p LG HG2 Li ion battery first.

I have kept the motor spacing for 18 inch propellers. That might bw an overkill but considering the voltage drop, i think it is best to start with a larger prop first.

Any recommendations regarding the wing twist in the above post?

A bit of an update on my Striver Mini 4+1. I’ve done 6 flights now, and the plane is performing nicely with 4.1.x firmware. I’ve done both a VTOL tune and fixed wing tune.
I’ve also updated the default MakeFlyEasy parameters for 4.1.x, you can find the parameters here:
http://uav.tridgell.net/MakeFlyEasy/
Apart from normal tuning, the key thing I needed to adjust was the Q_A_THR_MIX parameters, which needed to be much higher than normal in order to handle gusts of wind while landing. My flying site has a rising slope where I land, and the wind up that slope can destabilise the aircraft in the stage before it has weather-vaned around to nose into the wind.
I ended up needing a Q_A_THR_MIX_MIN or 0.4 for good stability in landing, which is above the max allowed in 4.1.3 and before, so in the 4.1.4 release I increased the allowed maximum to 0.5.
Overall the striver mini 4+1 is a really nice aircraft to fly!

7 Likes

Completed Some initial setup.

H mixing induced yaw and lots of wing flex, hence shifted to X Mixing.

Tried Hover at a non-ideal place. About 10 to 15 cm off the ground in Qstabilize mode as the GPS environment was not ideal.

A video of the short hover is here: X Mixing QStabilize First Hover - YouTube

Attaching bin log for any comments or suggestions on how to take it from here.

Should I move to follow the VTOL Tuning page in the WIKI?

Today, I had another flight in Qstabilize mode followed by QHover Mode.

One thing I have observed, the quadplane tends to move forward with no pitch input. Maybe it can be adjusted by Q_TRIM_PITCH as stated in the quadplane tips here: QuadPlane Tips — Plane documentation.

If the aircraft tends to move forward, then Q_TRIM_PITCH will be positive, right?

The quadplane also has calculated the hover throttle to be about 0.25. I am using 18 inch props at the moment which are surely an overkill and there is room to reduce the boom lengths by decreasing prop sizes. which will essentially also reduce wing flex. Is it recommended to go this route?

I seriously hope I am not spamming this thread. If I am, kindly let me know so I can move it to another topic.

For the wing flex, I was following the tuning guide at Tuning Process Instructions — Plane documentation, where after step 6 and a bit of manual decrease of D term, the flex is almost all gone. maybe it was due to the control loops overcorrecting. Either way, a significant decrease in wing flex is observed.

Step 7: Re-tried QHover which also performed much better.

Step 8: Yaw Bias while QHover is a mean of -0.04 with a peak variation of up to -0.12 at takeoff. Documentation states it should be less than 10%. Does that refer to peak-to-peak variation or should it be read as ±10%?

Hi @tridge Thanks for sharing your Striver parameters. I would be updating to 4.1.5 today and this would help considering that the default MFE parameters are out of date with the 4.1.x.

1 Like

Hi Tridge,
Thanks for your updates on the Striver which I too am about to complete. I also got a Freeman 2300 tilt VTOL and loaded the MFE parameters. Have you flown your Freeman 2100 and done any updates on the MFE params so it will be compatible with the latest Arduplane stable firmware?

yes, I did an update in the Freeman2100 thread:

@tridge @Michael_Oborne Hi there! I had a strange behavior on a Striver flight today. I am not sure what caused the Striver to skip VTOL takeoff (WP1) and head from the ground straight to WP2, which is 1.4km away @ 360m AGL. I have no idea why it skipped the VTOL takeoff altitude and attempt to ramp up to WP2. It was pure luck not hitting the roof and poles.The test mission proceeded for about 45 minutes and landed later without incident. After landing, i used the simulator to check and found that the mission planner was activating WP2 instead of VTOL takeoff WP1, each time AUTO is clicked. The only change I have had is upgrading mission planner. So, I re-installed Mission planner 1.3.76 and this behavior got resolved. Is there a way to force a minimum safety altitude and prevent ramps towards a waypoint from ground?

Plane: 4.1.5
Video: MFE Striver VTOL_Arduplane_4.1.5_Mission-Planner_1.3.76 near crash - YouTube
Telemetry log: Microsoft OneDrive - Access files anywhere. Create docs with free Office Online.
DataFlash Log: Microsoft OneDrive - Access files anywhere. Create docs with free Office Online.

Thanks for the help.
Sunday.

what happened was this (in sequence)

  • the GCS uploaded a mission with a zero VTOL_TAKEOFF altitude:
    2022-01-25 01:04:35.86: MISSION_ITEM_INT {target_system : 1, target_component : 1, seq : 1, frame : 3, command : 84, current : 0, autocontinue : 1, param1 : 0.0, param2 : 0.0, param3 : 0.0, param4 : 0.0, x : 47374063, y : 70295143, z : 0.0, mission_type : 0}
  • the plane was switched to AUTO and the first mission item was loaded and the wait for completion code was started. It didn’t complete the first item as the plane was disarmed
  • the GCS then uploaded a replacement for the takeoff waypoint that had an 80m target altitude
    2022-01-25 01:10:57.60: MISSION_ITEM_INT {target_system : 1, target_component : 1, seq : 1, frame : 3, command : 84, current : 0, autocontinue : 1, param1 : 0.0, param2 : 0.0, param3 : 0.0, param4 : 0.0, x : 47374063, y : 70295143, z : 80.0, mission_type : 0}
  • the replacement was in mission memory, but did not replace the existing WP at zero alt that it was already working on. We don’t replace WPs that are still being processed when you upload a mission
  • the place was armed, and the zero alt target WP immediately completed, so it moved to WP 2

we could avoid this by re-reading the mission when you arm. I’ve noted that for discussion

1 Like

Thank you so much @tridge for the quick response. This is very clear to me now. In the meantime, I will simply avoid uploading missions on the ground while in AUTO mode. Once again, I appreciate your feedback. Thanks.

Hola Rollys, pudiste armar tu VtBird?

No, not yet. Too many things going on at the moment. Hopefully in a few months when things settle down, I’ll start on it.

Google translate:

No aún no. Demasiadas cosas pasando en este momento. Con suerte, en unos meses, cuando las cosas se calmen, empezaré con ello.

Me encuentro armando un Vtbird 4+1, quería saber si me podrías indicar cómo realizar el cableado a una controladora Cuav v5 nano?