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mpbiv's 3D Printed Folding Tricopter: a work in progress

#61
Back from the dead!

I got tired of waiting on parts, in particular a 4in1 ESC from RTFQ. I am aware of the poor service reputation they have, but up until now this would be my first poor experience with them out of probably 6-7 previous orders.

So I went ahead and ordered some ZTW Spider 12A ESC's to complete this build because I was tired of it sitting on the bench. I also had to add a couple 5V regulators and PDB to complete the power setup.

But I digress, so to start off the wiring, I decided to un-case my Futaba R2106GF Receiver and remove all the header pins that the servo connectors normally attach to in an effort to save some room. Below you can see the power and ground wires soldered directly to the RX
IMG_0691.JPG

Unfortunately this turned into a much harder task than I intended, and on the signal side of the board, two of the solder pads lifted and tore off. If you look closely at the gray and yellow signal wires (for channels 4/5) you'll notice they don't appear to be attached to a solder pad. I ended up soldering these directly to the "via" holes in the PC Board, and I checked them for continuity with my multi-meter. After everything checked out with the meter (I also double checked in cleanflight and all my channels seem to work), I covered all the connections in 5min epoxy to ensure they stay.
IMG_0692.JPG

Decided to go with the Lumenier 4-Power PDB, simply because it was available and cheap:
IMG_0690.JPG

I also chose it because I figured it would package well:
IMG_0689.JPG

Installed a Pololu 500mA 5V regulator on the PDB to power the Naze32 and the Futaba RX
IMG_0693.JPG

To prevent power issues like brownouts, I opted to use a separate Pololu 1A 5V regulator inline with the yaw servo:
IMG_0696.JPG

I had to reprint the tail section, and the new design incorporates a large pocket for the ESC and 5V regulator for the servo:
IMG_0697.JPG

At this point I sort of gave up trying to document the rest of the wiring. It became a really tedious project trying to place the other two ESC's but I did come up with a mounting solution that will suffice. Trying to place the ESC's for the arms was difficult because I needed enough room for the motor wires to loop a little bit so that the arms could still fold. In order to do this I ended up designing an extra A-frame style bracket which I heat shrunk the two ESC's to. I also had to remove the large capacitors for the front ESC's and I mounted them remotely so that they wouldn't stick out of the frame.

Below are just a couple pictures to kind of show how the ESC's are nested in the frame:
IMG_0698.JPG

IMG_0699.JPG

And here she is ready for some maiden flights:
IMG_0700.JPG

I didn't get done wiring until late last night so no test flights yet. But I did get everything setup and tested in cleanflight, and I also checked (and corrected) the motor directions, so she is ready to fly. Lastly, I am still waiting on an LC filter to hookup the FPV gear. This was also something I ordered from RTFQ's and have not received, but I went ahead and ordered another one from a different source which will hopefully arrive by the weekend.

If I have to redo this build, I will probably switch to Lumenier 12A ESC's because they have better cap placement and they also have built in BEC's which would have simplified the wiring.

When I have a chance I will have to pull the bottom plate and take a picture of the wiring........it's not my finest work, but I would like to show how I mounted the ESC's and also where I placed the remote mounted caps.
 

cranialrectosis

Well-Known Member
Mentor
#64
Sorry about RTFQ. Still, I like my ZTW Spiders on my Twitchity Mini-Tricopter. I think they fly very well.

Funny how we so often finish our builds when it is too dark outside to fly. I find myself having trouble sleeping just as if I were 10 years old and it is Christmas Eve...

Beautiful copter. Excellent build. I think this is the finest 3D printed copter build I have seen yet.
 
#65
Sorry about RTFQ. Still, I like my ZTW Spiders on my Twitchity Mini-Tricopter. I think they fly very well.

Funny how we so often finish our builds when it is too dark outside to fly. I find myself having trouble sleeping just as if I were 10 years old and it is Christmas Eve...

Beautiful copter. Excellent build. I think this is the finest 3D printed copter build I have seen yet.
Thanks!

I don't have any real complaints about the ZTW Spiders, they seem to work well so far, I just didn't anticipate how to package them properly when I designed this thing. I have a bad habit of designing around specific components and specific placements, and in this case I was relying heavily on having a 4in1 to keep things simple. So maybe I need to go back and re-think some of the design, because it's more likely anyone else who is going to build this from my files later will be using these ESC's (or Lumeniers, or Rotorgeeks, or KISS ESC's, etc.) and most likely won't be using a 4in1.

It's true, I almost always finish my builds when it is dark out too......

......and the sad part is I usually set whatever I am working on, on my night table, so I can admire my hard work before I fall asleep :eek:

But I did manage to fly it last night after work. Still needs a lot of tuning, and this is my first time tuning on Cleanflight using PID Controller 3 (MultiWii 2.3 with rates uncoupled). I was using Baseflight and the standard PID Controller 0 with the coupled rates on the last mini-tri I built. This one hovers fine, but I am having an issue with tail oscillation under rapid throttle inputs. If you keep the inputs smooth it flies nicely. If I was just putting around this would probably be ok, but when I tried a couple flips and rolls it didn't work out so well because it couldn't handle the quick throttle input on recovery. I ended up running 4 batteries through it slowly tweaking the PID's before crashing after doing several test flips/rolls on the last pack. Didn't break anything, not even a prop, so that's good.

I plan to fly it some more this weekend and hopefully dial out the tail oscillation issue.
 
#66
Below you can see the part I designed and printed to hold the ESC's. It is basically an A-frame which also bolts in between the PDB and FC and acts as a standoff for the two boards. Wiring is very tight and there is just barely enough room for the motor cables to wrap around to the top of the ESC. I'm suspicious that this setup will eventually break the wires due to strain. Lots of things to consider in a re-design, but I think I am going to upload these files to Thingiverse this weekend so others can play around with it and also just let it be a living project.

Not my neatest wiring job but it works:
IMG_0701.JPG

Part of the difficulty in getting everything soldered was that I used two different gage wire sizes between the ESC power wires and the remote mounted caps. So it was a bit challenging to get the iron heat settings right to melt all the solder without melting the insulation on the smaller wires. As you can tell, I still managed to melt some of the insulation on the smaller wires:
IMG_0702.JPG

Crash #2:
FullSizeRender.jpg

So I got the LC filter installed and all the FPV gear powered up. That all works great and this is my first time using the Sony 600TVL board cam and I am liking it. Last night I used up one battery playing with the yaw tuning. Still having major issues with the oscillation under heavy throttle. Currently I have set very low P and I values, with D set to 100. Extreme changes in P or I don't seem to improve the issue, so I am wondering if maybe the servo is underpowered. Maybe it needs a 2-3A BEC, or maybe it is just too weak in general to deal with the torque the motor creates at high load. It flies ok team nana style though and as long as I don't try to punch out real quick it's ok. I also have the roll/pitch rates high enough (.90) that it can do flips/rolls nearly in place. Running 60% expo to make it manageable.

So I went ahead and took it out the empty neighborhood nearby and flew some FPV with it. I should have put an SD card in my Dominator V2's so I can record the flights, but none the less I flew 2 batteries through it before crashing. The 200mW transmitter I am using is good, but not nearly as good as my 600mW Immersion VTX's on range. I ended up flying a little too low, and behind a concrete drain pipe, and lost signal long enough to cause the crash above. Luckily I wasn't going that fast nor was I very high, so no damage. Just have to clean the motors out and check the props.

Now that I've been flying with the goggles, my FPV flying has been getting better and is becoming more enjoyable.
 

jipp

Senior Member
#67
lots of people are having issues with tri and servos. im starting to wonder if a better servo could be develop just for it.

chris,
 
#68
Well it's getting plenty of crash testing!


Still haven't managed to reign the tail in completely. Only lost one prop from this experiment.
 

narcolepticltd

I unbuild stuff regularly
#70
Lookin good man! I think I may have sorted at least some of my issues I was having... I'll get a better idea at the field tomorrow or sunday weather permitting.

Does your FC sit right dead center of all 3 motors or is it moved forward from center?
 

jipp

Senior Member
#71
i think you can be proud of your design, and since you have uploaded its cool to know many more will take to the air :D
seems to take a crash too.

chris.
 
#72
Lookin good man! I think I may have sorted at least some of my issues I was having... I'll get a better idea at the field tomorrow or sunday weather permitting.

Does your FC sit right dead center of all 3 motors or is it moved forward from center?
Good to hear!

Yes the FC is centered in the thrust circle of the three motors.

I am wondering if maybe a 1A power supply is not enough. I have this same servo on my other Hybrid 3D Printed/G10 tricopter, and it works a lot better, but the difference is the BEC on that copter can do 3A. So that might be something I go after.
 
#73
Cost

I absolutely love this design. Wondering how much it would cost to have it printed? Are there sites/members that would print this at a reasonable cost?
 

jipp

Senior Member
#74
I absolutely love this design. Wondering how much it would cost to have it printed? Are there sites/members that would print this at a reasonable cost?
i have no idea. but id be happy if someone could print the drawings to a PDF, his software does not support it.. if i could get them in a pdf or a picture 1 to 1 so i could trace them onto some hobby grade plywood.. id be happy with working with that.. id have to change the design a little but i think i could make it work.. i may not be very competent with all things RC.. but i know my way around lumber, and my wood working tools.

looks like a 3d printer cost around 800.00 i was looking at this solidoodle thing. http://www.solidoodle.com/
it seems the makerbots are over priced compared to everyone else.. of course i was just looking out of bordom.. i do not see my self ever owning one. even tho i can not ride my recumbent trike anymore, which if i sold it could pay for one.. but yeah, its pretty neat technology to look at and learn about.. owning one.. dunno.
chris.
 
#75
looks like a 3d printer cost around 800.00 i was looking at this solidoodle thing. http://www.solidoodle.com/
it seems the makerbots are over priced compared to everyone else.. of course i was just looking out of bordom.. i do not see my self ever owning one. even tho i can not ride my recumbent trike anymore, which if i sold it could pay for one.. but yeah, its pretty neat technology to look at and learn about.. owning one.. dunno.
chris.
Hey dude, I just want to let you know, all of the parts I have shown here were printed on a $540 machine:

Printrbot Simple Metal (6x6x6" build area)
http://printrbot.com/shop/simple-metal-kit/

I have a couple upgrades, like the heated bed and LCD controller, but I could have printed these parts even before I had those upgrades. Prices of printers have dropped quite a bit, so keep looking for the next few months and something enticing may come along that better suites your price range.

Honestly, I didn't think I was going to get one for a long time. Twitchity bought his Printrbot Simple (which is even more affordable, but with less build area than what I have), and when I saw a couple parts from his printer, I was super impressed with the quality for the price point. That pretty much solidified my decision to get the Printrbot. Beforehand I was skeptical of the quality of 3D printer roughly $500 would buy.
 
#76
Hey dude, I just want to let you know, all of the parts I have shown here were printed on a $540 machine:

Printrbot Simple Metal (6x6x6" build area)
http://printrbot.com/shop/simple-metal-kit/

I have a couple upgrades, like the heated bed and LCD controller, but I could have printed these parts even before I had those upgrades. Prices of printers have dropped quite a bit, so keep looking for the next few months and something enticing may come along that better suites your price range.

Honestly, I didn't think I was going to get one for a long time. Twitchity bought his Printrbot Simple (which is even more affordable, but with less build area than what I have), and when I saw a couple parts from his printer, I was super impressed with the quality for the price point. That pretty much solidified my decision to get the Printrbot. Beforehand I was skeptical of the quality of 3D printer roughly $500 would buy.
mpbiv,

Do you have the heated bed sold by Printrbot? I also have a printrbot simple metal and love it. Been using it for about 6 months. I have some issues with PLA warping for big flat parts and was hoping the heated bed would help. I was worried since it only goes to 60 deg C that it may not work so well for ABS.

BTW, love your tri design. It is going to be my next multirotor project.
 

jipp

Senior Member
#77
Hey dude, I just want to let you know, all of the parts I have shown here were printed on a $540 machine:

Printrbot Simple Metal (6x6x6" build area)
http://printrbot.com/shop/simple-metal-kit/

I have a couple upgrades, like the heated bed and LCD controller, but I could have printed these parts even before I had those upgrades. Prices of printers have dropped quite a bit, so keep looking for the next few months and something enticing may come along that better suites your price range.

Honestly, I didn't think I was going to get one for a long time. Twitchity bought his Printrbot Simple (which is even more affordable, but with less build area than what I have), and when I saw a couple parts from his printer, I was super impressed with the quality for the price point. That pretty much solidified my decision to get the Printrbot. Beforehand I was skeptical of the quality of 3D printer roughly $500 would buy.

thats pretty crazy how low prices have gone down ( i was looking a the spool material, and that is about 24.00 ). i mean 500.00 yeah that's a lot of cash for me but its plausible if i saved for a bit. also i was planing on spending 150.00 on my next frame.. if i took that 150.00 i was considering spending and put it into a 3d printer.. i guess the only real issue i would have is software, is the free stuff ok?
( off topic, but i think its cool how guys are able to use there 3d printers to print arms for kids.. for around 200.00. compared to what it wold normally cost for something they would out grow.. plus you can print it in all kinds of colors which kids would dig, or i would of if i had to have a 3d printed arm _
i have a recumbent trike i an no longer ride.. i was considering selling it.. that be a quick grand.
yeah i know you can get regular bikes brand new for a 100.00 that will get the job done.. but if you are a crippled and need special capability's for the bike, they start off at about 1300.00 i paid 2k for my trike 5 years ago.
chris.
 
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#78
mpbiv,

Do you have the heated bed sold by Printrbot? I also have a printrbot simple metal and love it. Been using it for about 6 months. I have some issues with PLA warping for big flat parts and was hoping the heated bed would help. I was worried since it only goes to 60 deg C that it may not work so well for ABS.

BTW, love your tri design. It is going to be my next multirotor project.
I do have the PrintrBot heated bed. Is that 60C what you are setting it to? Or is that the actual measured temp you are getting? Also do you have the upgraded power supply?

Mine used to max out around 74C measured at the bed surface with a infrared temp gun. I now have the insulating kit upgrade installed on the bottom of the bed, and the surface temp will max out around 90C which works better for ABS. If you don't have the insulation kit, you should order it because PrintrBot is basically giving it away free to those who have the heated bed upgrade already.

Also on prints where there is not a lot surface area sticking to the bed, I use aquanet hairspray to help things adhere.
 
#79
I do have the PrintrBot heated bed. Is that 60C what you are setting it to? Or is that the actual measured temp you are getting? Also do you have the upgraded power supply?

Mine used to max out around 74C measured at the bed surface with a infrared temp gun. I now have the insulating kit upgrade installed on the bottom of the bed, and the surface temp will max out around 90C which works better for ABS. If you don't have the insulation kit, you should order it because PrintrBot is basically giving it away free to those who have the heated bed upgrade already.

Also on prints where there is not a lot surface area sticking to the bed, I use aquanet hairspray to help things adhere.
Thanks for the info, I Dont have the heated bed yet, going to order it today. Have not tried aquanet yet.
 
#80
Thanks for the info, I Dont have the heated bed yet, going to order it today. Have not tried aquanet yet.
Ahhhh ok. I misunderstood.

Actually between printing on blue tape, and the using the heated bed, the heated bed seems to have less PLA warping issues. Especially if you manually turn it on and pre-heat it a couple minutes prior to printing. The aquanet hairspray is an extra layer of adhesion which is not really required for PLA, but it helps. I never tried hairspray on the blue tape, but I would guess if would be too messy and cause the tape to rip when removing parts.

If you are purchasing the current heated bed upgrade I am pretty sure it includes the insulation kit I mentioned earlier, and it won't have a problem doing ABS. But with ABS, hairspray is pretty much required to get proper build platform adhesion.

I've only printed a couple things in ABS. It's definitely more sensitive to warping, so getting the platform up to temp and heat soaked, along with a good layer of hair spray is a must. Some people also use an ABS/Acetone slurry on the build platform (instead of hairspray) to help adhere the print.