You won't flex those mounts. If you are flexing those mounts you are mistreating your copter.
Mustang7302's Bat Bone Build Log
- Thread starter Mustang7302
- Start date
You won't flex those mounts. If you are flexing those mounts you are mistreating your copter.
Can you tell me the approximate distance from the geometric center of the Bat Bone out to the end of the arm? Mine arrives tomorrow and I'm going to make up my wiring harness tonight.
Thanks!
Thanks!
Mustang7302
Senior Member
Thanks, man! I really appreciate that! I'm excited to build this thing.
Now you got me wanting one of these. My AnyCopter Quad parts will start arriving next week.
Mustang7302
Senior Member
Boom Length: 10"
Front Arm Width (Left Boom to Right Boom): 23"
Geometric Center to Front Mounts: 15"
Overall Length (Rear Mount to Perpendicular with Front Mounts): 20"
Geometric Center to Rear Mount: 9.5"
Geometric Center is 1/2" forward of the rear screw location for the rear arm to the body.
For Just the Body:
Front Arm Width: 11"
Geometric Center to Front Mounts (10" Boom): 13.5"
Overall Length: 6"
Geometric Center to Rear Mount (10" Boom): 12"
All measurements are taken from the center of the motor shaft hole in each mount.
I like to enable people
.
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Make them at least an inch longer. You can always wrap them somewhere...
Boom Length: 10"
Front Arm Width (Left Boom to Right Boom): 23"
Geometric Center to Front Mounts: 15"
Overall Length (Rear Mount to Perpendicular with Front Mounts): 20"
Geometric Center to Rear Mount: 9.5"
Geometric Center is 1/2" forward of the rear screw location for the rear arm to the body.
For Just the Body:
Front Arm Width: 11"
Geometric Center to Front Mounts (10" Boom): 13.5"
Overall Length: 6"
Geometric Center to Rear Mount (10" Boom): 12"
All measurements are taken from the center of the motor shaft hole in each mount.
I like to enable people
Thank you!!!!
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Mustang7302
Senior Member
Update: An updated powerplant was used to eventually get this frame into the air. Please see the following post for details - http://forum.flitetest.com/showthre...t-Bone-Build-Log&p=82338&viewfull=1#post82338.
Update 3: Motors, ESCs, Props, and Servo arrive from RCTimer!
Ordered: Friday, June 28th, 2013
Arrived: Friday, July 12th, 2013
Order Total (with shipping): $119.16
The longest order to arrival wait yet! I did have a order from Hobby King's international warehouse come in on the Wednesday prior which was ordered the same day as the RCTimer parts, but that order had supporting parts like wire, heat shrink, XT60 connectors, three pin connectors, velcro, and a prop balancer which I am not going to track explicitly.
So on to the build! First thing I did was label both ends of the 10cm female to female servo jumper wires which will connect the receiver to the KK2 with nifty printed heat shrink tubing.
Next I put some velcro under the foam pad base of the FCB to keep it secured to the lower plate of the Batbone body.
Wanted to clean up the bundle of wires between the receiver and the FCB, so I put some mesh braid over them. The labeled ends make it easy to make sure connects are made properly once they're bundled together! Once it was prettied up, I put on some velcro to help keep things where they should be.
I moved on to putting some attention to the motors next; first by getting the 3.5mm three pin connectors soldered onto the motor's leads. I was planning to wrap the motor's wires with the mesh braid, but in my excitement I forgot to do so before I had started soldering; oh well. Helping hands are very handy when soldering!
The motors from RCTimer have a nice length to them; and to figure out where the ESCs would be mounted, I decided to get the motors mounted first. The first issue I ran into was the X mount that screws to the bottom of the motor and then to wherever you're mounting the motor too didn't line up correctly to the motor's holes! Upon further investigation I discovered the mounting pattern is indexed where one of the four holes is slightly closer to the center of the motor than the others, and the X mount matched. Cool, crisis averted, and on to getting the motors mounted to the rotor bones mounts.
That's when I discovered problem two. The X mount is considerably larger than the rotor bones mount, with no way to bolt or secure with zip ties. After looking at it for several minutes I decided to see if the hole pattern on the motor it self would match up to the holes in the rotor bones mount; sure enough they do!
And then there was problem three with mounting the motors. The screws used to mount the X brace to the motors is counter sunk for the tapered shank flat heat screws. The screws do reach through the thick G10 material to the motor, but only bite with a couple of threads. This wouldn't be strong enough and I considered taking the mounts out to the drill press to counter sink the holes, but I worried it might weaken the strength of the G10 mounts. Went to sleep and woke up this morning with the idea of seeing if I could find longer screws at the hardware store. After toiling around trying to figure out the screw's size, I discovered they were M3 screws and was able to locate enough M3-.50x6 screws to mount the motors (picked up some 4mm ID washers too)!
The build continues...
Turnigy 4000mAh 4S batteries, charger, power supply, a Lipo bag, and parts were ordered yesterday from Hobby King's US warehouse, which should round out the parts and supplies needed to get the Batbone build done. One last order was with Altitude Hobbies yesterday as well, for a watt meter and battery balancer to ensure things run within spec and stay healthy. Hope these two orders come in early next week.
Update 3: Motors, ESCs, Props, and Servo arrive from RCTimer!
Ordered: Friday, June 28th, 2013
Arrived: Friday, July 12th, 2013
Order Total (with shipping): $119.16
The longest order to arrival wait yet! I did have a order from Hobby King's international warehouse come in on the Wednesday prior which was ordered the same day as the RCTimer parts, but that order had supporting parts like wire, heat shrink, XT60 connectors, three pin connectors, velcro, and a prop balancer which I am not going to track explicitly.
So on to the build! First thing I did was label both ends of the 10cm female to female servo jumper wires which will connect the receiver to the KK2 with nifty printed heat shrink tubing.
Next I put some velcro under the foam pad base of the FCB to keep it secured to the lower plate of the Batbone body.
Wanted to clean up the bundle of wires between the receiver and the FCB, so I put some mesh braid over them. The labeled ends make it easy to make sure connects are made properly once they're bundled together! Once it was prettied up, I put on some velcro to help keep things where they should be.
I moved on to putting some attention to the motors next; first by getting the 3.5mm three pin connectors soldered onto the motor's leads. I was planning to wrap the motor's wires with the mesh braid, but in my excitement I forgot to do so before I had started soldering; oh well. Helping hands are very handy when soldering!
The motors from RCTimer have a nice length to them; and to figure out where the ESCs would be mounted, I decided to get the motors mounted first. The first issue I ran into was the X mount that screws to the bottom of the motor and then to wherever you're mounting the motor too didn't line up correctly to the motor's holes! Upon further investigation I discovered the mounting pattern is indexed where one of the four holes is slightly closer to the center of the motor than the others, and the X mount matched. Cool, crisis averted, and on to getting the motors mounted to the rotor bones mounts.
That's when I discovered problem two. The X mount is considerably larger than the rotor bones mount, with no way to bolt or secure with zip ties. After looking at it for several minutes I decided to see if the hole pattern on the motor it self would match up to the holes in the rotor bones mount; sure enough they do!
And then there was problem three with mounting the motors. The screws used to mount the X brace to the motors is counter sunk for the tapered shank flat heat screws. The screws do reach through the thick G10 material to the motor, but only bite with a couple of threads. This wouldn't be strong enough and I considered taking the mounts out to the drill press to counter sink the holes, but I worried it might weaken the strength of the G10 mounts. Went to sleep and woke up this morning with the idea of seeing if I could find longer screws at the hardware store. After toiling around trying to figure out the screw's size, I discovered they were M3 screws and was able to locate enough M3-.50x6 screws to mount the motors (picked up some 4mm ID washers too)!
The build continues...
Turnigy 4000mAh 4S batteries, charger, power supply, a Lipo bag, and parts were ordered yesterday from Hobby King's US warehouse, which should round out the parts and supplies needed to get the Batbone build done. One last order was with Altitude Hobbies yesterday as well, for a watt meter and battery balancer to ensure things run within spec and stay healthy. Hope these two orders come in early next week.
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Thanks for the pics and the detail.
Mustang7302
Senior Member
My pleasure.
Mustang7302
Senior Member
Update: An updated powerplant was used to eventually get this frame into the air. Please see the following post for details - http://forum.flitetest.com/showthre...t-Bone-Build-Log&p=82338&viewfull=1#post82338.
Update 4: 4000mAh 4S Turnigy batteries, Accucel 6 charger, Power Supply, LiPo bag, and HXT 4mm to XT60 adapters arrive from Hobby King's US Warehouse! Plus the Bat Bone Tricopter runs ... Technically.
Ordered: Thursday, July 11th, 2013
Arrived: Monday, July 15th, 2013
Order Total (with shipping): $142.09
A few hours of soldering and moving stuff about on the Bat Bone body later, I had everything together and the components more or less where they would be for the ride into the sky. So much time spent soldering, I cannot stress this enough. Motor leads, motor leads side of the ESCs, battery side of the ESCs, power harness to connect the ESCs to the battery, and adapters for batteries; so much soldering. I will be coughing lead/tin/flux fumes for a week.
I fell short on taking pictures of a lot of stuff during the final parts of the build; for two reasons. I was simply too excited to get it running and up in the air was most of it, but also because I was not certain of where things would end up staying on the frame. I will document these things later on, after I get a new motor and turn the rig into a V-tail quad; more on that at the end of this post.
Let's get to some picture for now:
Soldering the 3.5mm three pin connectors to the motor side of the ESCs. The plastic piece slides over the connectors, the "gold" terminals are soldered to the wires, and then the red plastic cover is pulled back over the connectors until they're flush with the front of the openings. Solder is introduced into the connector through a small hole on the back half (not pictured); the hole seen in the picture is the vent hole for when the connectors are slid together.
Moving on to the other end of the ESC, it gets the male end of the XT60 connector. It is a little cumbersome to get the iron on the terminal, the wire, and have enough room to get solder up into the cup; but it works out with some patience and burning the occasional corner of the plastic holder.
Just when you'd been through 24 solder joints between the motors and ESCs, there is still more soldering to do for the battery harness. The harness gets female ends of the XT60 connector, which has very shallow cups, until the last link in the harness which is a male to mate with the battery's female connectors. The shallow cups on the female ends makes it a bit easier to solder, but also has a greater risk of weak joins. Take your time, get a good amount of solder in there, and do not forget your heat shrink. Speaking of heat shrink 5mm tubes are a touch too big to fit into the cups in the plastic shield of the XT60 connects, but they're also -just- big enough to slip over doubled over 16awg wire. 4mm could be stretched to fit over the wire, but it might negate fitting into the cups if you did that. Four of five millimeter heat shrink, the choice is yours.
Finally everything is connected and I am ready to power up the whole rig for the first time. Started to tinker with the KK2 settings by setting motor layout, setting sub trims, setting the auto balance to the auxiliary channel, and calibrating the ESCs.
It was about time to make this baby fly, but took baby steps. First order of business was to get is a low hover. I found however that despite calibrating the sensors in the KK2, the rear motor was spinning noticeably faster than the front two motors which would cause it to want to flip over on its "face." This was alleviated some by checking the right orientation of the props, and sure enough they were backwards. Then I started checking on control input response and found I had the front two motors on the wrong output channels, so I switched them.
At this point I was able to get the rig up into the air mostly level with a quick jab of the throttle and lower it back down. However it was instantly spinning like a top in the air. Upon further investigation, I observed that the tilt for the rear motor was never getting back to level once a left or right direction was given. I found some slop in the pull/pull mechanism, and even trying to preload the tension on both sides it still had the same result. So to remove some variables from the system, I took inspiration from FliteTest's original Tricopter videos by mounting the servo directly to the pivot.
Screwed a servo arm into the two holes the control rods would of Z'd into, cut the mounting tab off the servo, put s spacer under the servo, zip tied the the servo to the arm, reversed the output in the KK2's mixer for the servo channel, and it was off to try again. But yet again, there was too much slop in the mechanics. What I have found is that the plate with the holes drilled into it for the control rods (or servo arm screws) has slop in the roll axis and the G10 plate the motor mounts too. Additionally, with that much weight sitting so far off the back of the pivot itself, it causes flex vertically. Tiny amounts of flex in the mount translates to about an inch of deflection at the ends of the 10" propeller. For as cool looking as this rotor bones tilt mount is, it just isn't up to snuff for my setup (or possibly any setup). I figured I would end up making this rig a v-tailed quad at one point or another, but dealing with the slop in the tilt mount just isn't worth the fuss and I figure I would move on.
Two last things I want to put out there for now: The additional thickness added by the velcro under the foam of the flight controller causes the corners of the PCB to -just- fit through the opening in the top of the Bat Bone body. It is pretty firm actually and negates any vibration dampening. I will be removing the lower wider layer of foam to reduce the height of the flight controller in the body and keep it under the top shell. This could have added to some of the erratic flight tendencies I was struggling with initially.
Lastly I was able to update the firmware on the KK2 to v1.6 today. I had found posts mentioning the original v1.2 firmware didn't handle a tricopter setup very well. I had been meaning to order a AVR programmer from Hobby King, but they have been out of stock for a very long time. I saw mentioned in the comments of the programmer's item page to an outfit that produces programmers originally marketed towards flashing the Turnigy 9X transmitters, and order it this morning. But me being me, impatient, I figured there must be a way to use my Arduino to flash the KK2 and found the solution with a little digging. This is the guide I used to help flash with an Arduino and it was pretty straight forward; download the kkMulticopter software package to use the AVRDude utility via command line, upload a native sketch to the Arduino to be a AVR flash tool, make four connections from the Arduino to the KK2's programming header, connect the Arduino ground to the motor 1 ground, and run the command line code found link the prior link.
Update 4: 4000mAh 4S Turnigy batteries, Accucel 6 charger, Power Supply, LiPo bag, and HXT 4mm to XT60 adapters arrive from Hobby King's US Warehouse! Plus the Bat Bone Tricopter runs ... Technically.
Ordered: Thursday, July 11th, 2013
Arrived: Monday, July 15th, 2013
Order Total (with shipping): $142.09
A few hours of soldering and moving stuff about on the Bat Bone body later, I had everything together and the components more or less where they would be for the ride into the sky. So much time spent soldering, I cannot stress this enough. Motor leads, motor leads side of the ESCs, battery side of the ESCs, power harness to connect the ESCs to the battery, and adapters for batteries; so much soldering. I will be coughing lead/tin/flux fumes for a week.
I fell short on taking pictures of a lot of stuff during the final parts of the build; for two reasons. I was simply too excited to get it running and up in the air was most of it, but also because I was not certain of where things would end up staying on the frame. I will document these things later on, after I get a new motor and turn the rig into a V-tail quad; more on that at the end of this post.
Let's get to some picture for now:
Soldering the 3.5mm three pin connectors to the motor side of the ESCs. The plastic piece slides over the connectors, the "gold" terminals are soldered to the wires, and then the red plastic cover is pulled back over the connectors until they're flush with the front of the openings. Solder is introduced into the connector through a small hole on the back half (not pictured); the hole seen in the picture is the vent hole for when the connectors are slid together.
Moving on to the other end of the ESC, it gets the male end of the XT60 connector. It is a little cumbersome to get the iron on the terminal, the wire, and have enough room to get solder up into the cup; but it works out with some patience and burning the occasional corner of the plastic holder.
Just when you'd been through 24 solder joints between the motors and ESCs, there is still more soldering to do for the battery harness. The harness gets female ends of the XT60 connector, which has very shallow cups, until the last link in the harness which is a male to mate with the battery's female connectors. The shallow cups on the female ends makes it a bit easier to solder, but also has a greater risk of weak joins. Take your time, get a good amount of solder in there, and do not forget your heat shrink. Speaking of heat shrink 5mm tubes are a touch too big to fit into the cups in the plastic shield of the XT60 connects, but they're also -just- big enough to slip over doubled over 16awg wire. 4mm could be stretched to fit over the wire, but it might negate fitting into the cups if you did that. Four of five millimeter heat shrink, the choice is yours.
Finally everything is connected and I am ready to power up the whole rig for the first time. Started to tinker with the KK2 settings by setting motor layout, setting sub trims, setting the auto balance to the auxiliary channel, and calibrating the ESCs.
It was about time to make this baby fly, but took baby steps. First order of business was to get is a low hover. I found however that despite calibrating the sensors in the KK2, the rear motor was spinning noticeably faster than the front two motors which would cause it to want to flip over on its "face." This was alleviated some by checking the right orientation of the props, and sure enough they were backwards. Then I started checking on control input response and found I had the front two motors on the wrong output channels, so I switched them.
At this point I was able to get the rig up into the air mostly level with a quick jab of the throttle and lower it back down. However it was instantly spinning like a top in the air. Upon further investigation, I observed that the tilt for the rear motor was never getting back to level once a left or right direction was given. I found some slop in the pull/pull mechanism, and even trying to preload the tension on both sides it still had the same result. So to remove some variables from the system, I took inspiration from FliteTest's original Tricopter videos by mounting the servo directly to the pivot.
Screwed a servo arm into the two holes the control rods would of Z'd into, cut the mounting tab off the servo, put s spacer under the servo, zip tied the the servo to the arm, reversed the output in the KK2's mixer for the servo channel, and it was off to try again. But yet again, there was too much slop in the mechanics. What I have found is that the plate with the holes drilled into it for the control rods (or servo arm screws) has slop in the roll axis and the G10 plate the motor mounts too. Additionally, with that much weight sitting so far off the back of the pivot itself, it causes flex vertically. Tiny amounts of flex in the mount translates to about an inch of deflection at the ends of the 10" propeller. For as cool looking as this rotor bones tilt mount is, it just isn't up to snuff for my setup (or possibly any setup). I figured I would end up making this rig a v-tailed quad at one point or another, but dealing with the slop in the tilt mount just isn't worth the fuss and I figure I would move on.
Two last things I want to put out there for now: The additional thickness added by the velcro under the foam of the flight controller causes the corners of the PCB to -just- fit through the opening in the top of the Bat Bone body. It is pretty firm actually and negates any vibration dampening. I will be removing the lower wider layer of foam to reduce the height of the flight controller in the body and keep it under the top shell. This could have added to some of the erratic flight tendencies I was struggling with initially.
Lastly I was able to update the firmware on the KK2 to v1.6 today. I had found posts mentioning the original v1.2 firmware didn't handle a tricopter setup very well. I had been meaning to order a AVR programmer from Hobby King, but they have been out of stock for a very long time. I saw mentioned in the comments of the programmer's item page to an outfit that produces programmers originally marketed towards flashing the Turnigy 9X transmitters, and order it this morning. But me being me, impatient, I figured there must be a way to use my Arduino to flash the KK2 and found the solution with a little digging. This is the guide I used to help flash with an Arduino and it was pretty straight forward; download the kkMulticopter software package to use the AVRDude utility via command line, upload a native sketch to the Arduino to be a AVR flash tool, make four connections from the Arduino to the KK2's programming header, connect the Arduino ground to the motor 1 ground, and run the command line code found link the prior link.
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I built my bat-bone with the recommended motor setup, the speed 300 motors from HK. I also had problems with slop in the tail pivot. For the small motors it was ok at first but after about 5 or 6 flights it started vibrating at power above 70% and got worse with each flight until finally I couldn't fly it at all. I ended up burning out the Speed 300 on the tail because the vibration was causing it to draw too many amps. The holes where the pivot shaft goes through were oval-ling out until it became unusable and it happened pretty quick. I'm now rebuilding the tail with David W's dual front wheel steering block mechanism, waiting on parts from HK to do so. I'm surprised I haven't seen more complaints about the pivot wearing out fast, maybe it's just me.
Mustang7302
Senior Member
The following quote is an exerpt from my Christmas 2013 iQuad build log and summarizes the lack of resolution to this thread. A little more detail about the various steps to get where I am today is included, as well as a nice detailed log of the build process. Be sure to check out the iQuad's build at: http://forum.flitetest.com/showthread.php?6530-Mustang7302-s-iQuad-Build-Log
However, thanks to a very surprising blessing from CranialRectosis, I have been given a unique opportunity to bring this thread to completion. CR started building multicopters shortly after I had started the initial Bat Bone build and was almost as disappointed as I was when the the final straw was broken. Six months later and a Bat Bone build of his own, he became determined that I should have a tricopter in my fleet and make "The Bat" fly, so he ordered a complete Bat Bone kit and had it sent to me. Once I discovered this turn of events I quickly set out to sort out the electronics.
Six months of building and flying tough me the biggest lesson was to keep the weight down as much as possible. Not only does less weight mean longer flight times because less power (therefore current) is needed, but it also is much less prone to breaking something in minor to moderate crashes. Having learned an idea of power range in mind for the FliteTest frames I chose the following components for the second Bat Bone build, "Retribution."
Motors: Turnigy D2822/14, 1450KV, 38g, 160W
ESCs: Afro 12A w/ SimonK Firmware
Props: Gemfan Nylon 8045 CW & CCW Pairs
Servo: Turnigy 380MG Micro Servo, 3.6kg, 15.6g, .15sec
Flight Controller: HobbyKing KK2.1 with LCD, 6050MPU, and Atmel 644PA
Battery: ZIPPY Compact 2200mAh 3S 25C LiPo
These Turnigy D2822/14 motors were chosen for their light weight and slightly faster RPM than the SK3 1275KV motors I used on my iQuad. Again weight being an important aspect, but I also figured the extra RPM would help offset the lack of the fourth motor and cope with the little extra weight with the Bat Bone frame. It also means I could share the same 8045 props between my two multicopters; even at the sacrifice of collets to mount props, which I thoroughly dislike.
Even though I liked the simplicity of using the Q-Brain 4 in 1 ESC on my iQuad build, it wouldn't be as practical on a tricopter. I went with the 12A Afro ESCs because I knew the current would be low enough to get away with it and it again helps to shave a little weight. Even though the 12A Afro ESCs were labeled as including 3.5mm bullet connectors on the battery and motor sides, they came with 2mm bullets. Luckily I order extra 3.5mm bullets for the custom power harness and was able to retrofit the ESCs with the larger bullet connectors; was really hoping to omit the tedious amount of soldering. I also took the time to dress up the wires on the ESCs with wire mesh, which required a lot of patience.
The Turnigy 380MG micro servo is a very beefy servo. It is 2mm or so longer and wider than typical 9g servos, which meant it didn't fit into the mount of the tail pivot. I took a file to the delrin material and made enough clearance for the servo to fit and re-drilled the mounting holes for it. After having centering issues with the servo I tried using on the first build, I found that this 380MG did the job well for the brief flight that the first Bat Bone eventually made before getting run over. A slight amount of extra weight, and expense, here ensured plenty of torque and a servo I knew I could rely on.
I used a 3 into 1 style harness with a twist; the three legs were put into one of the 3.5mm bullet pairs for one of the motors versus into the XT60 connector to the battery. Two of the three leg pairs went to the other two motors and the third leg pair was used for a 4"-5" extension to the XT60 connector. This allowed the power harness to tuck into the shell of the Bat Bone body very well and gave me more options of where to route the battery lead out of the frame. The power harness was made with 18AWG Red and 18AWG Black wire. This is thinner wire than normal, versus 14AWG wire, which I chose again for the reasons of weight and knowing my current load would be pretty mild.
I decided to go with a fluorescent orange and black color scheme for this Bat Bone build. The vertical spacers of the body were painted orange where they would be visible from the outside of the copter. I had also planned to paint the front booms orange and the rear boom black to help promote orientation. I had difficulty getting a good coat of paint with the fluorescent orange, which was very thin and needed many layers, and then was prone to cracking as it dried. Since we've had cool weather which wasn't ideal for painting recently, I decided to go with nature square dowels to get it into the air sooner than later. I will revisit colored booms in the future.
All up weight is 720 grams with a 2200mAh 3S battery, which 80 grams heavier than my iQuad and about 100 grams lighter than CR's Bat build. The 2200's provide about 12 minutes of flight with moderate maneuvering and swooping about; which is very respectable. As of writing this I have at least ten battery packs on this build in the air using the default KK2.1 firmware and gains; it flies very smoothly and exhibits no oscillation.
Here is some video of the second flight and still getting a feel for the airframe:
With that I can now finally consider this build finding completion. It might have taken six months and a generous blessing, but we're finally here. Will probably update this thread every so often with new pictures or video as well as answer any questions which are brought up.
However, thanks to a very surprising blessing from CranialRectosis, I have been given a unique opportunity to bring this thread to completion. CR started building multicopters shortly after I had started the initial Bat Bone build and was almost as disappointed as I was when the the final straw was broken. Six months later and a Bat Bone build of his own, he became determined that I should have a tricopter in my fleet and make "The Bat" fly, so he ordered a complete Bat Bone kit and had it sent to me. Once I discovered this turn of events I quickly set out to sort out the electronics.
Six months of building and flying tough me the biggest lesson was to keep the weight down as much as possible. Not only does less weight mean longer flight times because less power (therefore current) is needed, but it also is much less prone to breaking something in minor to moderate crashes. Having learned an idea of power range in mind for the FliteTest frames I chose the following components for the second Bat Bone build, "Retribution."
Motors: Turnigy D2822/14, 1450KV, 38g, 160W
ESCs: Afro 12A w/ SimonK Firmware
Props: Gemfan Nylon 8045 CW & CCW Pairs
Servo: Turnigy 380MG Micro Servo, 3.6kg, 15.6g, .15sec
Flight Controller: HobbyKing KK2.1 with LCD, 6050MPU, and Atmel 644PA
Battery: ZIPPY Compact 2200mAh 3S 25C LiPo
These Turnigy D2822/14 motors were chosen for their light weight and slightly faster RPM than the SK3 1275KV motors I used on my iQuad. Again weight being an important aspect, but I also figured the extra RPM would help offset the lack of the fourth motor and cope with the little extra weight with the Bat Bone frame. It also means I could share the same 8045 props between my two multicopters; even at the sacrifice of collets to mount props, which I thoroughly dislike.
Even though I liked the simplicity of using the Q-Brain 4 in 1 ESC on my iQuad build, it wouldn't be as practical on a tricopter. I went with the 12A Afro ESCs because I knew the current would be low enough to get away with it and it again helps to shave a little weight. Even though the 12A Afro ESCs were labeled as including 3.5mm bullet connectors on the battery and motor sides, they came with 2mm bullets. Luckily I order extra 3.5mm bullets for the custom power harness and was able to retrofit the ESCs with the larger bullet connectors; was really hoping to omit the tedious amount of soldering. I also took the time to dress up the wires on the ESCs with wire mesh, which required a lot of patience.
The Turnigy 380MG micro servo is a very beefy servo. It is 2mm or so longer and wider than typical 9g servos, which meant it didn't fit into the mount of the tail pivot. I took a file to the delrin material and made enough clearance for the servo to fit and re-drilled the mounting holes for it. After having centering issues with the servo I tried using on the first build, I found that this 380MG did the job well for the brief flight that the first Bat Bone eventually made before getting run over. A slight amount of extra weight, and expense, here ensured plenty of torque and a servo I knew I could rely on.
I used a 3 into 1 style harness with a twist; the three legs were put into one of the 3.5mm bullet pairs for one of the motors versus into the XT60 connector to the battery. Two of the three leg pairs went to the other two motors and the third leg pair was used for a 4"-5" extension to the XT60 connector. This allowed the power harness to tuck into the shell of the Bat Bone body very well and gave me more options of where to route the battery lead out of the frame. The power harness was made with 18AWG Red and 18AWG Black wire. This is thinner wire than normal, versus 14AWG wire, which I chose again for the reasons of weight and knowing my current load would be pretty mild.
I decided to go with a fluorescent orange and black color scheme for this Bat Bone build. The vertical spacers of the body were painted orange where they would be visible from the outside of the copter. I had also planned to paint the front booms orange and the rear boom black to help promote orientation. I had difficulty getting a good coat of paint with the fluorescent orange, which was very thin and needed many layers, and then was prone to cracking as it dried. Since we've had cool weather which wasn't ideal for painting recently, I decided to go with nature square dowels to get it into the air sooner than later. I will revisit colored booms in the future.
All up weight is 720 grams with a 2200mAh 3S battery, which 80 grams heavier than my iQuad and about 100 grams lighter than CR's Bat build. The 2200's provide about 12 minutes of flight with moderate maneuvering and swooping about; which is very respectable. As of writing this I have at least ten battery packs on this build in the air using the default KK2.1 firmware and gains; it flies very smoothly and exhibits no oscillation.
Here is some video of the second flight and still getting a feel for the airframe:
With that I can now finally consider this build finding completion. It might have taken six months and a generous blessing, but we're finally here. Will probably update this thread every so often with new pictures or video as well as answer any questions which are brought up.
Cyberdactyl
Misfit Multirotor Monkey
Awesome Mustang. And that's a perfect field right next door!
Mustang7302
Senior Member
Awesome Mustang. And that's a perfect field right next door!
Ironically that field of empty lots is where I lost the first Bat over the fence and getting run over in traffic. Luckily I have a bit more experience to keep that from being as much of a risk now.
I've been watching your thread. You've got that thing lit up brighter than the New Years Eve ball in New York! Enjoy flying it! The more docile nature of the larger span on this Bat is more enjoyable to fly than the small iQuad I built just before Christmas; I've got at least 12 flights in since Sunday morning.
sbman, I have a Bat Bone in the air and have for 60 days or so. There is no slop in the tail mechanism on my copter and no ovaling of the center line holes. Can you post a picture of your build and list the specs?
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