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Mini Tri Test Build

Twitchity

Senior Member
#1
Seeing the talk about mini tricopters lately got me wanting to build my own, so I sat down one evening and came up with a test design for a mini tricopter. The criteria I wanted to build the tri to was FPV capable, and just large enough to fit 6" rotors.

Once I got the design made and cut out I noticed the top and bottom frame plates closely resembled a manta ray :D although I forgot to take into account the bit I was using to cut the material was exactly at the size for the camera mount cutouts so it my CNC skipped over those cuts. Not a big deal as I can just use double-sided tape/Velcro to mount my 600TVL camera on this test frame. The arms were taken off of my FPV quad so they aren't the ones that will be in the final design, I'm just out of 1/8" G10 at the moment (on the bright side, I'll be getting my CF order today).



And assembled



I'm still not sure how I want to mount the tail motor tilt mechanism, or even what kind I want to use, but for now I'm using the landing gear style tilt mechanism since I had the parts for this laying around. Here's the beginning or the wiring and the arms temporarily attached to the tri. Electronics were also stolen from my FPV quad.



Just need to mount the tail servo, connect wires to the Naze, and program the Naze for a tricopter and I SHOULD be good for a maiden flight.





I looked some last night, but wasn't finding much information on programming the Naze32 for a tricopter. I followed the connections from Abusemark where the servo plugs into S1 (old M1) and motors plug into M3, M4, M5 for servo mode.

I also did not follow the rotor rotation from the manual where it shows all motors spinning in a CCW rotation. FL motor spins CW, FR spins CCW, Rear spins CW. If this will cause an issue, someone please let me know :)
 
#2
You don't need to follow the the prop directions in abusemark manual for Tri. I am running my Titan Tri on a Naze32 with the same prop rotations you mentioned and it doesn't seem to care.

The one thing you have to do is go into the CLI and change the mixer type to "TRI", I am trying to find the exact command right now.
 
#3
Looks great Twitchity! Ever since my Bat Bone, both of them really, I have always had a soft spot in my heart from Tricopters.

I sent you an email, but the way. Let me know what you can do with the request.
 

Twitchity

Senior Member
#4
I just sent you a reply Mustang. The quad is yours for that week if you'd like it. The email is more detailed though ;)

mpbiv, thanks for the correct configuration type. I couldn't seem to find anything on what to enter in the CLI for the type last night.

I started on a tri, and want to get back to a try. Just something about them that I've always liked.
 

cranialrectosis

Faster than a speeding face plant!
Mentor
#5
Been waiting for the Twitchity Mini-Tricopter. Armattan is too boxy and expensive.

I am almost desperate enough to cut down my BatBone ala FGA.

I think the CLI command is mixer = tri. Pull up the mixer list and it will show you they syntax.

Twitchity is fast becoming my preferred frame vendor for advanced builds. :)
 

jhitesma

Some guy in the desert
Mentor
#6
I like it...a little tall looking but you have to fit the FPV gear somewhere :)

I really need to try a tri one of these days...but I have a feeling I'm going to go bigger when I do a tri. Just still scared of servos, have heard too many horror stories about them breaking left and right on tri's unless you go with expensive servos.
 
#7
I like it...a little tall looking but you have to fit the FPV gear somewhere :)

I really need to try a tri one of these days...but I have a feeling I'm going to go bigger when I do a tri. Just still scared of servos, have heard too many horror stories about them breaking left and right on tri's unless you go with expensive servos.
I started with a couple tri-copters then built a really nice 450quad but still end up going back to the beater tri copter. Although I am absolutely loving this mini quad I just finished.

Like I said I started on a tri which meant ALOT of crashing and I have only gone through one servo. They are generally pretty well protected on most frames. Even that one servo I did have to replace was still working when I removed it. I was lucky I got 2 flights out of the servo before I noticed it looking like this.


I've had really good luck using corona 919 servo's they are (as you can see above)metal gear and digital and are under 7$. On the other hand I also bought a 28$ servo that never worked out of the box. I wouldn't let a servo keep you away from Tri's. I don't see it being any higher odds of a crash caused by the servo as opposed to whole extra motor/esc and all the connections associated with those.

and tricopters love being big check out this behemoth I just finished that is a pleasure to fly.



 

x0054

Senior Member
#8
Twitchity, you beat me to it! I was working in AutoCAD on a Tri design as well, same design specs, but you know, I had to figure out how to make it fold, to keep going with my theme :) I think I figured out an interesting tail servo mechanism using helicopter ball joint like these. I'll shoot you the design files as soon as I am done. Post some videos of the min Tri flying. Is it every bit as cool to fly as I suspect it is?

- Bogdan
 

Twitchity

Senior Member
#9
Thank you for the kind words, Cranial. It sounds like someone wants first dibs on a mini CF tri to me... ;)

Jhitesma, the tri does look a little tall, but it's the same height as all the other frames at 35mm. I think it's just the overall size of this thing is so small that it looks tall.

Bogdan, no videos yet as I'm still working on the tri. Something came up last night that required my attention so I wasn't able to work on the tri any. I'll be sure to post videos when I get it flying though, and I'm going to bet it'll be just as much fun as it looks. Can't wait to see what you made in AutoCAD. Mine was more of a I'm bored on Sunday and it's raining, lets see what I can get my self into kind of thing.
 

kah00na

Senior Member
#10
I like it...a little tall looking but you have to fit the FPV gear somewhere :)

I really need to try a tri one of these days...but I have a feeling I'm going to go bigger when I do a tri. Just still scared of servos, have heard too many horror stories about them breaking left and right on tri's unless you go with expensive servos.
Don't be scared of breaking servos. I started off buying the Hitec servo's for $30 but after breaking 2 of them, I tried this one from banggood and it has worked PERFECTLY for me on my big tricopter and my mini tricopter. The only time I've broken a servo is when I was trying flips and landed on it. Yeah, that will break about anything. This one is digital and has metal gears. You can see it in my mini tricopter video as well.

VWINRC TREX 450 Spare Parts Metal Gear Digital Servo MG90D

SKU080329--1.jpg
 

Twitchity

Senior Member
#12
Let me get one flying first before I look into selling them. I'm still not sure what to do about the tilt mechanism if I sell this frame. I don't have a 3D printer or else I could print some brackets for a tilt mechanism.
 
#13
Let me get one flying first before I look into selling them. I'm still not sure what to do about the tilt mechanism if I sell this frame. I don't have a 3D printer or else I could print some brackets for a tilt mechanism.
I don't know if you have considered it, but I've been really happy with the quality of the prints Shapeways has done for me so far!

You can also sell your printed hardware through their e-commerce setup.

Once you upload a model and have printed it once, they evaluate the printing success rate, and if you meet the threshold, you can sell the printed part using their e-commerce system through the website. It's not hard to meet the print success rate threshold if you follow their design criteria. All of my (4) parts have passed so far.

After a design is approved for sale you basically fill out some info to populate your webstore page, you can even attach pictures of the real part, or just use the rendering they supply from your STL file. Once it's live, people can search the site for your store or parts, and purchase directly from shapeways. You can also set it up so that if you want to offer the STL model to others so they can print at home, they can download it directly from your shapeways product page.
 

Twitchity

Senior Member
#15
So will we see plans, a kit, or a build vid? If so, when?!?
I can post svgs/pdfs/whatever as far as plans go if someone wants to cut out their own frame. I didn't know the demand for a mini tri was this high and this build was an I'm bored on a rainy Sunday experiment. This is another one I'd eventually like to sell, but I'd want to get one in the air first before I do.

Right now I'm currently having problems getting the tri flying properly. The tri is in a constant left yaw state, and the servo is constantly moving back and forth (slowly). I bumped down the Yaw P to 4 and it seemed to help out some but the problem still persists. I'm going to mess around with the tuning more today, and move the tilt mechanism over one tooth to hopefully eliminate the constant yaw.

Another thing it seems to be doing is overcompensating after I stop a yaw. I never thought I'd say this, but as of right now I rather have a KK2.1.5 board on a tri over the Naze32.
 

Twitchity

Senior Member
#17
I might take you up on that offer, Mustang. I have a few ideas for a tilt mechanism that would utilize the existing motor mounting holes I'd like to try.

Also mpbiv, I might take you up on your offer for help in Inventor Fusion. If I can send you the outline of the shape in a dwg/dxf format, and a drawing with dimensions of what it should look like, would you be able to easily create the STL file for print? I don't plan on making this complicated; it will more than likely be two simple parts.
 

Twitchity

Senior Member
#19
Perfect, and thank you. It will probably be sometime this weekend before I get around to it. I'm going to try to get at least one complete frame cut for you tonight after work and try to clean up my mess on the couch and coffee table so I have a place to sit again :D
 

x0054

Senior Member
#20
Twitchity, try reducing the looptime on the Naze and bumping the P on the yaw even further. It helped me out, but on a larger tri.