Protos Flybarless development thread

[ping]

A thread to dump all my work on converting the Protos to Flybarless. So far here is my head progress using stock parts.

I've been doing some research on V-bar head designs. Swashplate travel needs to be reduced by about 80 percent (source V-bar forum 80% is quoted as perfect). The only ways to reduce swashplate travel is to move the ball link on the grips out with standoffs or move the ball links on the servo arms in. Apparently it's best to move the grip links out.

I will reduce the length of the servo arms to 14mm, this corrects some geometry interaction with my servo of choice (JR Z3650). All the arms are 90 degrees to the swash at 14mm.

The swash driver is the stock washout assembly. I removed the opposite ends of the arms with a dremel tool. I drilled and tapped for a grub screw to lock the washout in place. My only concern currently with this setup is stripping the delrin washout.

More as I continue my setup.

[rcman]

Looks good so far. By looking at mine I know you need to move the balls out away from the head. I have been thinking about doing this for a long time now you may just spark my interest again

David

[rcmarty]

i saw a post the used a trex500 gri ball standoff for the grips , it increases the distance to the center of the head.
I'd also assume you could use a mikado standoff with a bolt if you wanted to keep with mikado stuff.

I would think you can move the servo ball in on the servo arm , it might cause the links to be not vetical but if there even on eother side of the arc radius then it would have the same geometry on both sides. You will get a bit of a boost or buck situation but one could dial that out in the tx if it bothered you. This is the same idea as the t500 uses on there setup.

I can find the pic if needed after work

MArtin

[ping]

You can't dial it out in the transmitter. Think of it like a gyro, you need as much resolution as possible through the hardware linkages. The v-bar unit works best when the servo travel is at 60-80 percent to 100 percent pitch movement. You achieve this by moving the ball links on the servos in, and the distance from the mainshaft to the ball links out on the head. I have 3 sizes of stand offs to try on the head I'll post the setup that works best.

You can't go shorter then 14mm on the servo arms without hitting frames with my servos. Also 14mm for some reason gives 90 degree linkage on my servos also. The stock 16mm made an inverse teepee like the Trex 500 links. I'll be testing different setups to find the best resolution with the least amount of interaction.

[Roadrune]

I used at first trex500 balls, but later Gaui's for a 500-size FBL head, since they have loose balls, and the possibility to mount a washer preventing the links to pop off (thats a bad thing )

I also moved my servo arms to 14mm, but found that i could not get enough pitch without binding, so i moved back to 16mm, which barely gives me 12 collective, and 10 cyclic, which is about minimum recommended.

[JaggedEdge]

Why not use grip stand offs/extensions?

[Roadrune]

Originally Posted by JaggedEdge

Why not use grip stand offs/extensions?

??? I think you misunderstand me, thats just what i did, or do i misunderstand you?

[ping]

Finished my setup I await test flights this weekend. With Trex 500 grip ball links and 16mm servo arms I get +-13 collective and +-8 cyclic. I can get way more cyclic but I get binding on the frames at full negative. I'm going to fly it and see if 8 is enough cyclic.

My modified swash driver is OK for now however it binds in the corners at full collective. I'm going to try the new Gaui swash driver or the Mikado one.

The swashplate needs to be moved up a bit from the stock position. I set my swash height with flybar arms on my original protos. For the V-bar setup I wanted to center the swashplate in the anti-rotation bracket.

RTF weights!
1710g - 7S a123
1560g - 6S 2600

With TWO 6S lipo packs on the scales I'm only 20g more then my fully blinged out T500.

[jamesotron99]

Corrado, when are you going to have a flybarless head and swash driver available for the protos?

[ping]

First flight success! The V-bar is AWESOME this is the first time I've ever flown a flybarless setup and it's amazingly smooth and responsive. The tail was rock solid from the moment of lift off, I never got a chance to try the Spartan but the tail gyro on the V-bar unit is the best I've tried to date.

I've still got a lot of setup optimization to do, I'll post my V-bar file when I'm complete. I also need to upgrade some of the hardware. The swash driver I made has to go I can't get hardly any throws without binding. Also some of the rod lengths need adjustment, I'm barely hanging onto a few threads on the ends of the links at the moment!

Here is a list of all the parts you need for the conversion:

H50094 Main Rotor Linkage Ball TREX 500 - Long ball links for grip arms
2x MSH51022 Head Rods Set Protos - You need longer links for your servo to swash linkages
8mm shaft swash driver either Mikado or Gaui......or some sort of official solution from MSH (hint hint)
A swash leveling tool - EXTREMELY helpful in programming the V-bar unit. My first flight required 0 trim!

Edit: You can size up the MSH stock ball links with a regular sizing tool to fit on the Align long rotor linkage balls. First size them up as much as possible with the stock MSH sizing tool. Then carefully snap them onto a normal ball link sizing tool. I used a JR ball link sizing tool. The link may snap in half at the top if you haven't sized it up enough with the MSH tool first. It takes a good number of passes with the JR link sizing tool to get them large enough to fit. Keep sizing and checking until you get silky smooth links.

I'll be posting more as I proceed in my setup tuning. At the end I'll be making a PDF guide for converting and programming the V-bar for the Protos. Stay tuned!