Since we were down to 1 car, I wanted to build up a nice electric bicycle for running errands and possibly commute. So, I've been keeping an eye open for a cheap conversion kit. I found one on ebay being sold by local guy, and picked it up for 107 bucks. this is homcom 48v setup and was rear wheel with speed controller. The bicycle converted was my old Specialized FSR freeride setup that I had for 20 years with maguro hydraulic rim brakes and full suspension. Since I didn't want to mess with the brakes, I decided to set this up just with thumb speed without brake cutoff. the part also included PAS feature but I decided to keep it simple. There were two main challenges to this conversion. One is power pack, and the other was figuring out way to mount it to the bike. The conversion kit came with tires and tube as well as 7 speed gear set. my original was 8 speed, shimano shifters but works fine . in most cases, gears won't get used much unless I am in assist mode.

The guy selling it was going to convert his bike until he found out what the battery cost were going to cost. this wheel setup typically sells for about 140 bucks on ebay. but most 48v lithium packs cost 200+ . those prices were unacceptable to me. On ebay though, there are these 36v 4.4ah 18650 based pack for about 35 bucks shipped. these have Samsung cells and have great review. These cells comes with balancing/charging board, which simplifies...Continue Reading

After living in Oregon for larger part of my life, we have moved to sunny and much warmer arizona and finally settling in. it has been crazy move, but thing went quite smooth since selling my old house and making the large change in my life. I do want to apologize to those in Oregon where I just didn't have time for proper farewell, but I do hate goodbyes and I hope my abrupt departure didn't cause too much problems. Still We are settling in nicely and loving the warm weather. I think we made the right move and are happy at our new place.

As part of my move, I finally picked up a Spark recently and been doing some light flight testing. What I am most impressed about, is its capability to produce very good 12mp still images. While video is pretty impressive considering its size, i do find it bit soft due to its use of center part of sensor not to mention it is only 30fps. While I don't mind having 1080only, I do wish I had 60fps, but combined with tripod mode, you can get decent video even doing pan.

One of the test that I like to run, is creating a simple pano manually. I just run timed shutter and do a slow pan. I stitch this using microsoft ICE software and I am quite happy with how it came out. not bad for single pass 15 image stitch pano. I have pretty nice backyard now . Overall, I am pretty impressed with the unit and would make good backup and pocket drone.

here is link to the full image as well

https://www.dropbox.com/s/kjwxddodqb...h%201.jpg?dl=0

I haven't been upgrading my computer for last few years but as I've been doing more Image processing, I found myself needing more processing power with multiple GPU. The only thing was that my pocket book would allow me to purchase much of an upgrade over what I already had. (i5-3570k based ) Recently, I've been seeing used Xeon Processors for low price on Ebay. Xeon E5-2650 is sandy bridge CPU with 8 core and 16 thread running at 2.0ghz (upto 2.8ghz turbo) and I found one on sale for 25 bucks shipped. I've also recently picked up an E5-2670 for 70bucks shipped. basically going from 2.4ghz to 3.0 ghz with all the cores (3.3ghz with single core) cheap 20% performance upgrade!


These Xeons are lifecycled out of server farms, but they have been ran conservatively and have lot of life left in them. They also uses DDR3 Registered ECC Ram, which are also available used. The only problem is that these processor requires certain motherboard. I have found new motherboard with X79 chipset , but they were 160 bucks or so. Because I wanted to run at least 2 or 3 GPU, I could not use pre owned server motherboard which are about 100 bucks with First gen E5 xeon, you couldn't run X99 board (which can only run with 3rd gen I believe)

After some careful research, I ran across used HP workstation that could run E5 chipset. HP Z420, Z620 and Z820 were originally sold as high end...Continue Reading

We finally received this printer and my son did a video review on this.

He3D-K200 3D Printer Review (3 min 39 sec)

We paid 199 shipped during christmas sale, but currently it is bit more. still, it is good quality printer if you have some knowledge and willingness to fix issues. anyway, take a look and enjoy. My son wants to start a 3d printing service as well. so we will have more information soon on that.

With cleaning up of my shop, I wanted to convert my emco compact 8 lathe/mill to CNC. I wanted it to be low cost conversion that did not require modification of the machine. I just wanted to be able to machine basic stuff as cnc mill or lathe without doing threading. I also wanted to keep it low cost.

Using a 3d CAD, I drew up a simple mounting plates. I printed them in my newly acquired 3d printer out of PLA. due to space available, I went with belt driven nema 17 motors for Y and Z axis (cross way and mill head) that are belt driven (using MXL pulley at ratio TBD while nema23 motor will drive the lead screw for X axis using the half nut already in th emachine. I did add thrust bearing on the z axis and dual bearing ( delrin) on the X axis. delrin bearing can easily be changed out to ball bearing if desired. once the design is tested and finalized, I will have the STL files available for the 3d printer parts. it should be easily to adapt it to mini lathe or 9x20 lathe. So, 2 x 84oz nema 17 stepper and 1x 280oz nema 23 steppers were ordered off ebay. (about 50 bucks total shipped) See the last blog post for mount pictures.


While I've been waiting for the stepper motors to show up, I've started working on the electronics. For many years, I've used mach3 using parallel port, but on this project I wanted to move to USB or better yet , having ability to run by itself without computer while keeping cost low. Mach 3...Continue Reading

3d printers has been available for few years, but it has been mostly DYI effort or pay 500 bucks or more. This year, we have seen many lower priced printers becoming available and some under 200 bucks. I've been playing around with 3d printer for many years. When I was working for Xerox, I helped support 3d system with their first 3d FDM/UV printers that was using Solid Ink printhead developed by Xerox. (formerly tektronix cpid). My foray into personal printing was with purchase from kickstarter. Phoenix eazy 3d printer was purchased for 400 bucks plus shipping and it was not very reliable and needed lot of work to get it to print. Because of all the problems, I really never used it much and eventually sold it for part. Because of my access to having cnc routers in my shop, I really didn't feel the lack of having 3d printing, but when prices start to hit 200 bucks, I decided to check out the available printer.

After thorough research, I decided upon Monoprice Select Mini 3d printer. This printer is capable of printing in 120x120x120mm size and can print in various filament upto 230deg in the nozzle and 60 deg in the hot bed. This does allow ABS to be printed, but PLA is still the preferred choice. (ideally, you need 100 deg bed for abs) This printer runs closed firmware based on STM32 microprocessor, and is fully functional out of box. I paid 199 bucks shipped via ebay, but was also available on amazon for 190 shipped during black...Continue Reading

I've been working with Deep Learning software called Torch for last month or so and had to setup a computer to run this software. Torch is based on AI software developed by Google called tensor flow that was open sourced last year. Deep learning software is very flexible and can be used in many application, especially with image recognition.

just take a look at this video.

NeuralTalk and Walk (3 min 44 sec)

This field has been advancing fast and I wanted to get into it. Torch itself can run in any machine, but many of the newer libraries uses Cuda GPU to speed up the process . So, with almost no knowledge deep learning, I jumped in.

Torch requires either an Linux computer or Mac. It is also possible to run under VM using dockerized version of the code, but it will be more painful to get it going. So, I got an old 2008 Mac Pro with dual Xeon quadcore and 32gb of ram as a base. The code library that I wanted to run required Nvidia GPU with compute index of 5.0 or higher. This meant that I needed fairly new GPU that I didn't have. So, I purchased GTX-750 ti with 4gb for 100 bucks. Once I had all this on hand, I had to install everything and make it work. (which was pain in itself) Not having used unix or linux for a long time, it was bit of learning curve to get everything setup.

Why old Mac Pro?. well, they can be purchased really cheap and with dual 4 core xeon at 2.8ghz, it...Continue Reading

I've been doing lot of work on Near IR aerial photo this year, but finally I have had time to play with making composite Near IR photo that gives different perspective on images. Most of the NIR conversion uses form of infrablue conversion that gives pinkish cast to the image and make the image unusable for normal viewing. This happens due to swapping of channel of color that happens due to filter that is used to capture NIR.

just by swapping the channels, you can create very nice looking images that looks surreal. the first image attached didn't have good white balance, third picture was done during summer with better white balance. With NIR, white balance is critical for good imaging. I retook the 1st image this morning with better white balance and it looks tons better.(second pic)

I've been making these for a while for my own use, and have decided to share how I made them

it is very inexpensive and economical way to may a retract for your multicopter

you need

2 giant scale retract (screw drive type) similar to below
http://www.himodel.com/m/plane/Giant..._PZ-15096.html

1/4-20 screw (1.25" length) I used aluminum, but steel will work

1/2" OD nylon spacer 1" long with 1/4" hole.
http://www.mcmaster.com/#94639A506

for tube, you can use

.515 ID tubing (5/8 OD) from goodwinds. (they have various length)
https://goodwinds.com/20983.html

or 13mm id carbon fiber tubing with 15mm OD.



step 1: take a retract and you may have to remove the shaft that is in the LG. otherwise, rotate the retract so that leg is down

step2: use 1/4-20 tap and tap the hole as seen on the pic

step 3: mount the nylon space using the 1/4-20 1.25" long bolt . tighten it well. you may want to use locktite on the bolt, but not a requirement.

step 4: cut tube to length

step 5: The tube will fit very snug onto the spacer, (.515" tubing) you will need to tap it in to the spacer. CF tubing may require thick CA or epoxy to hold it in place.

now, you have a working retract ready to fit onto the multicopter.

While I do love my RC, I also have deep love of music. Most of you probably don't know, but i played highland pipes for near 20 years and irish whistle, flute for almost as long. I've gotten into uileanne pipe (which mean Elbow pipe) last few years, but I just updated my practice set to half set and wanted to share with you.

Anyway, Uileanne pipe consists of Bag, Bellows, Chanters(first 3 makes practice set), add Drones (which makes it a half set) and Regulators(which makes it a full set). I had my practice set for a few years and it was put something I put together. The chanter was made by David Daye, who has pioneered a brass tube penny chanter. This one was one of his first apartment chanter with delrin body. Apartment chanter is narrow bore and bit quieter than concert type (commonly known as taylor style) The bellow was something I got off ebay that I refurbished. The first bag was something I made out of vinyl, but recently upgraded to elkhide bag from kelleher tradition.

I've always wanted to have a half set, and was going to make a drones for it, but never got around to it due to time and sheer procrastination. My recent move back from canada has allowed me to clean up my shop and catch up with all my old projects. anyway, during this cleaning up, I ran across a set of half set from pakistan for 200 shipped on ebay. Pakistani made pipe sets are notorious for being poor, but cosmetically ok. Drones are...Continue Reading

Last few weeks, I've been very busy trying to improve efficiency of multicopter while retaining good wind performance. I've spent lot of time on ecalc and real life testing using my y6 with 2216 motor. I love how well Y6 flies and handles wind, but it has efficiency penalty . Ecalc is also great tool for finding rough estimate. I wanted to set this unit to fly about 10min with reserve carrying my gimbal. Coaxial multicopter generally has 10-30% efficiency loss compared to flat multicopter From what I've been studying though, slower prop rpm is generally better for efficiency drop . One test I've seen seem to see 10-15% drop at 3000 rpm. (can't find where I saw that test though when I looked for it again. I've also used higher pitched prop on the bottom which has been shown to help efficiency a bit.


The key to efficiency has been Larger Prop turning relatively slow (2-3000rpm) with at least 50% throttle level. My test multi had sunnysky 2216-800kv motor on my Y6 using 10" prop and 4S 5000 pack at about 3kg. I have lot of experience with this setup. Using Ecalc, you get 8min hover flight time at 6.5g/w. with Y6 having bit of efficiency penalty, it corresponds well to my near 7 min actual flight I used to get out of pack. (normally flew for 5min for 3500mah) Going to 13" prop and 3S5000 pack. ecalc basically gave me same 8 min flight time at 2870gm (smaller pack weight difference) at 8.5g/w...Continue Reading

Several of us were discussing the portable multicopter for long duration flight with gopro gimbal. I've always flown quads, hexas and y6 but never a tricopter. just somehow, I never managed to build one mostly because I've always thought servo was added complicaton and my favorite multies were y6 anyway. one of the motivation was that I really like y6 and I was hoping that i would gain some of the benefit of Y6 without too much penalties

In the past, tricopter was popular because it could be built using cheap rates gyro without any special board. Also, motor/esc was more expensive compared to servo. After some research, may tricopter owners also stated that tricopter flew more like airplane or heli compared to true multicopter which tend to be very axial in turns. As long time heli flier, I really like how smooth heli can be flown, so, I decided to go for building a 15min flying tricopter with gopro gimbal and video downlink system using APM 2.6 flight control using 3.14 firmware.

I had few Dualsky 5010-9, which is 390kv motor with 15-4 prop, tunigy trust 6S esc flashed to bs.fet (simonk) , Tower Hobby TS160 servo (standard size digital cheap servo mostly because I had a new one and wanted to try cheaper, just to see if it will fly ok with it. had some nicer servo as backup just in case ) initially setup to run at 5v, but since changed to 6v. Since portability was desired, I needed the arms to be foldable. anyway, it took...Continue Reading

unlike lot of part of the country, we don't get a lot of snow in my neck of the wood, so when we had our big winter storm, I couldn't resist but get a video of it.

winter storm 2014 from air (2 min 59 sec)

Myself and my friend Kenji had a great pleasure of being able to do a indoor aerial video shoot of the Oregon State capitol building with permission from the Legislature.

This event got its start with pending UAV/UAS laws that were being debated by the state senate. While we were at the hearing (which both of us testified) we also presented them with sample videos that we shot. Soon after, Kenji did a nice outside video of the capitol building, which we presented to the legislatures and they gave us permission to also do an indoor shoot. This following is the product of that shoot. Kenji did a great job of editing the footage.
This was shot mostly in 1080p60 medium mode. We ended up with about 30min of footage in about 2 hour shoot. distilled down to what is in this video.

Tour of the Oregon Capitol (2 min 57 sec)

We managed to make arrangement with the facilities to be able to shoot on saturday when building was closed to public. Initially, the facilities managers were bit concerned but after nice discussion about the capabilities of the gear and a walk through, we allayed any fear that was present. Being professional, knowlegeable and experienced really is important in managing with people. Due to nature of this being indoor, we limited ourselves to smallest rig we had available. I was the indoor pilot as I had much higher experience in flying.

On the day of the flight, I brought my phantom with 3 axis stablized gopro...Continue Reading

I get contacted for yaw/roll coupling issue of gimbale a lot. there are couple solutions:

1) Do a 6point calibration of accelerometer. this usually fixes this. Earlier version of code required this everytime you upgraded firmware.
2) in 2 axis gimbal, you can connect flight control gimbal output to the input of alexmos. this is not an option for 3 axis though.


Alexmos issues

1) move the imu wire away from the motor.
2) add ferrite cored to the imu wire
3) I've had several people have issue with input connection causing problems. for pitch, remove the power wire . verify setup is correct




Video Downlink:

I've been having lot of fun and use out of my pirate eye setup. This is single eye solution for video downlink which I prefer as I can keep an eye on the vehicle LOS. I use 200mw 5.8ghz with simple osd (just voltage and time)
I have mounted the receiver and battery (velcro) to my outback hat for simple compact setup. even with stabilized video only, I can fly safely as I can watch the vehicle via LOS

this is video of my phantom with 3 axis gopro gimbal and video downlink with video out from stablized gimbal.(1295gm and 7 min on 2200mah 3s pack) I would have issue with doing this completely via goggle as I would lose the vehicle orientation. DJI OSD has small artificial horizon but they weigh more and cost more. with gopro, you get video on time so all I needed was voltage on my osd.

3axis phantom gopro black 1080p medium mode (5 min 53 sec)

To get peak performance out of AG DD gimbal, ,you will need good setup and possibly tweaking of the tuning. I will be using this blog to update the latest setting and setup technique. of course, be sure to read the software setup guide from tppacks, which will be updated in the future with more information.


as stated in the guide good performance is all about
1) good balance
2) friction free setup
3) good balance.
4) tuning

without near perfect balance and smoothness, you won't get good performance. first sign of improper setup is bad buzzing. this occurs when motor is trying to compensate for small positional error, but can't and create a fine oscillation. The main cause is either due to balance or friction. (and rarely resonance oscillation caused by motor vibration)

Mechanical friction:

let talk about friction first. In most adjustable gimbal, you get friction when things are out of parallel. for example, the yoke arms is not parallel in both vertical and horizontal view. the gimbal should move freely and easily. this should be fairly easy to test and fix. mostly visual and moving the camera plate should give us clue.


Balancing

I start with roughly balancing the roll with camera on. lock the roll down once this is done.

I do the pitch balancing next. Pitch balancing is critical with camera at all the angles that camera will face. I start by setting up the camera balance with lens facing down....Continue Reading

Lately, there has been lot of new gimbals with Direct Drive, thanks to work done by people like Alex and others. Of course, the first group that made DD servo available to mass has been DJI. They truly deserve accolade and they are still the performance champ.

First of all, I would like to clarify that Servo is nothing more than motor with positional feedback. Even the DD gimbal using motors gets its positional feedback via IMU that is mounted on the gimbal. Whether they are DD or not, they are all Servos. I know that people like to equate servo with typical hobby servo, but that is not true.

At least in hobby realm, for long time, we were limited by available motor (brushed), size requirement and available voltage(typically 5v due to transistors) While speed was nice, it was not as critical as torque and smaller size, so highly geared servos were made, has become standard. In greater motion control industry, servos are used to control many machinery. lot of them are direct drive, while most are belt or gear driven . Some uses screw drive to achieve higher torque/gearing effect. In fact, it is very rare that servo is used in direct drive application unless you need speed more than torque. In our application though, we do get pretty good assist from gravity by having perfectly balanced system, we reduce the inertia down to its frictional component.


anyway, as we all know, acceleration of starting motor depends on...Continue Reading

It seems like wind is our nemesis when it comes to doing AV/AP especially with multicopters. I seem to get lot of questions about this, So lets talk about ways to optimize high wind flying.


Like any other RC flight, the key to wind flying is wing loading, or in case of multicopter, disk loading. for high wind, flying wing works really well for airplane while glider type does poorly. In case of multicopters, we need to get our diskloading up for best wind performance. For this, we need to use smaller prop that is really rigid for best performance. You may also need to go higher voltage to gain back some of the loss in lift. The downside is loss of flight time, but if getting that shot is very important, flight time loss can be acceptable tradeoff.

Now, I get asked about what is the best frame for windy flying. My answer is that Y6 is the best. Stacked coaxial props behaves best for yaw, and has apparent reduced disk area so handles wind and high speed the best. You do want the frame to be rigid. The downside of Y6 is reduced flight time of 10-15%. To me, that is acceptable loss of flight time. For smaller multi, I do think quad is definitely better than hexa .

Of course, if you already have to frame, you can maximize windy performance.
1) Smaller prop (that is rigid) at higher rpm is better than bigger prop. Going from 10" to 9" reduces disk area by 21% and will require higher...Continue Reading

Let me begin by stating that I am not a video editing expert. but I have had to learn and setup a new machine dedicated to video editing and learn all about it over the last 12 month. I want to at least give basic idea on equipment and software it takes to get reasonable results.

Computer requirement::

Lot of people run Mac/iMac and they do work pretty well at a premium in cost. In general, more cpu power you have, better off you are. First of all, i would recommend Intel processor for video editing. Even latest AMD fx-8350 seems to lag behind core i5-3570 in terms of rendering speed and price is similar to i5-3570k. Just know that editing HD video takes lot of computing power. When I started, I used my old laptop with amd A6 fusion chip (quad core) and it has been really too slow. for example, running video stabilization using mercalli averages 5fps. If you want decent performance, I would recommend minimum of intel Core i5 with 16gb of ram. Luckily, video editing really does not need high power graphics card, so build in 4000hd graphics is adequate. But if you do like to decent preview performance, and run CS/6, it is wise to have decent nvidia card. luckily, cheaper card like gt640 seem to give good result with cuda implementation of cs6. . Dual SSD drive in RAID 0 configuration would be nice, but if cost is an issue, I would recommend dual Western Digital RED 1tb hard drive in RAID 0 configuration as minimum. RED series...Continue Reading

Happy New year everyone.

It has been almost a year since I've restarted building selling camera gimbals and now multicopter AP specific frames. it has been good run and we have made lot of progress. We have been very open in our development work and we are continually making improvement to make our products the best it can be.

As we get better result, we've always want bit more performance. It seems like never ending push for performance.

Key to Performances:

1) Use proven system and camera. Unless you are into fiddling and testing different stuff, you can save lot of head ache and issues with using proven setup. This goes for camera, gimbal/controller and multicopter. (as well as props and motors) use multicopter specific esc if you can, as it will help give extra stability.

2) vibration control, vibration control, vibration control. I cannot stress this enough. Especially if you are using camera that is more susceptible to vibration. Early CMOS cameras are really bad for rolling shutter and jello issues.


3) Practice, Practice, Practice. whether it is flying, taking picture or editing, you need so many skills for success that practice is paramount.

4) pick a right tool for the job and practice safe flight rules. sometimes small quad with gopro may be better tool than full rig. Use good common sense.

Now, I will talk a bit about setup. since most of us use DJI controllers, I will...Continue Reading