Wednesday, February 20, 2013

Makerbot News

Just a few things on the 3D printing front...

Ordered this upgrade kit, designed by wphthomas and packaged up (with permission) by scvette.  Looks like a lot of people (including Bre) are saying nice things about this.

tldr: more reliable filament feed.!topic/makerbot/-8PWUKprZ6g

And notes from one of our resident printmasters:

I recently experimented with some different print settings and thought I would share my findings.  Mostly with black PLA, though the final part was in red. 
240 deg / 60 extruder speed - the print starts getting messy.  I can see the extruder pushing around a lot of mush.  Too hot, IMHO. 
240 / 80 - filament gets very thin.  Feeding seems to be struggling to keep up.  No bueno.
Ended up going with 230 / 60, my tried and true settings for print you see in the attached picture.
If anyone else is making large, flat prints, you know they can be really frustrating to get off the build plate.  So I picked up a plastic putty scraper at Home Depot.  It now lives by the printer.  Go slow and keep the putty knife flat to the plate to avoid snapping your part in half (not that I would know). 

Wednesday, February 13, 2013

Things of Beauty

 At last night's meeting of the Concord Model Engineers, Ding presented a model he was working on, and gave some pointers about how to cut spars and assemble wings.  He cuts a template from aluminum with snips and files it to shape, and then cuts around the template.
 He brought this model he was working on, building from scratch without plans.  It was so nice looking I took a couple of snaps with my phone cam.  I was so struck by not just the impeccable craftsmanship, but the beauty of the frames.
 The final model will be in a contest where the minimum weight is 40 grams.  Ding is shooting for 35 grams, so that there will be some leeway for repairs.
There's some pretty impressive modellers in the CME, many with decades of experience.  Ding gets a lot of respect from these guys, as you can imagine.


Monday, February 11, 2013

Adding some LEDs to the ArctiBaby

 I put some LEDs onto the ArctiBaby, hoping to make orientation a bit more visible.  Here's the 2S connector for attaching to the battery. I put an 82 ohm on the wire, which split to 4 power wires to each of the LEDs.  I'm using 28 gauge servo wire.
 Here's my mockup to make sure I was getting the circuit right.  I put one resistor in series with four parallel LEDs.  I'm going to ask some gurus if that's the right thing to do, but it seems to be working.
 Here's how I attached the wiring.  I zip-tied the end of each wire (where the LEDs are) to the end of each arm, with the LEDs pointing out.  The front had two 5mm frosted amber LEDs, and the back had two 5mm clear reds.  I put some scotch magic tape over the reds to get some frosting effect. It didn't work very well.
 Here's the final result.  I'll give it a try tomorrow and see how the visibility is.  Right off the bat I can tell you that amber/red is a pretty poor color combination for orientation differentiation.
I was using my jumbo 500 random LEDs for $2 package.  About 90% of the LEDs are red, and most of the other 5mm LEDs were amber.  There were a few tiny (2mm?) green LEDs.  So that's how I picked the color scheme.  I've ordered some 5mm frosted blue LEDs; I'll replace one color or the other and see if that makes it better.

Saturday, February 9, 2013

Notes on proposed Drone Legislation

Media Certified Drone Hobbyist!
Here's some notes I'm putting together on the legislation being proposed in Texas by Rep. Lance Gooden (R, Terrell) [1], but I think they're applicable in other cases as well.

It's interesting to note that the citizens of Terrell, Texas and Berkeley, California seem to have a pretty consistent set of concerns regarding this issue. [2][3] (and as a personal aside, I used to live near Terrell in Garland, Texas, and now live just down the road from Berkeley in Piedmont, California.  In many ways so different, and yet surprisingly similar!)

I'll be updating this posting periodically.  Please add your comments below if you think there's some use cases, thought, ideas, etc, that might be useful.

My goal is that this will be a useful information/idea source for Representative Gooden in particular, and others interested in drone legislation in general.

My emphasis will be on hobbyist, non-commercial, and "emerging commercial" interests.  I'm assuming "Big Drone" will be capable of speaking for themselves (but hey guys, if you do need some help, give me a shout!)

Background and Disclosure

I'm an RC plane pilot and self-described "drone hobbyist."  I've been featured as such by the Wall Street Journal, NPR, the AP, and CBS (details here [6]).  I don't have any financial ties to the industry, other than as a customer and beta tester for several RC products.  I blog both here at and at By day I'm a software engineer.

One thing that started me thinking seriously about the legislative aspects of drones was when my AP story appeared on both the Fox News and Huffington Post websites.  People's concerns were almost identical across the political spectrum!

Text of Legislation

Some Use Cases

Here are some use cases that may serve to clarify some of the goals of the legislation.  My emphasis, it bears to repeat, is on the "small" user.

(in progress)

1. Hobbyist flying in neighborhood, with camera.

It will be hard to engage in recreational flight without having people's private property in the background.  In general, this is incidental and looks about like what you would see on Google Maps. This should be a protected use.

Question:  at what point/altitude does the FAA cede authority?  It's clear that flying a private plane over a neighborhood at 500 ft isn't considered a problem by anybody.  How about flying an RC drone at 400 feet? 100 feet? 10 feet?

2. Peeping tom spying on neighbor's swimming pool for non-commercial use.

It seems obvious that few people will approve of this usage.  The tricky part will be in getting the right language that catches this, while not catching up someone innocently flying a small copter in their own back yard.  How does the law handle someone standing on a ladder in their own yard, peeping over a fence at their neighbor?

Is there a useful distinction between having a video downlink, and making a recording of that video? Or sharing of that video?

3. Paparazzi taking pictures/videos of celebrity's swimming pool for commercial use.

Again, this seems pretty obvious.  We don't want paparazzi doing this.  Since they will be selling the pictures, it seems this easily falls under the current prohibition on commercial use.  If commercial use is licensed, that would be the proper place for regulations to be specified.

It may be the case that a blanket requirement that the aircraft be flown in a safe manner and within the guidelines of a generally accepted flight organization could take care of most of these cases, since remotely flying a quadcopter (for instance) close enough to snap pool bikini pics is probably flying too close for safety.

4. Pro or semi-pro drone pilot taking aerial photos or video of house for real estate advertisement.

This seems like a reasonable thing to do.  Would licensing be necessary?  I would imagine so, in order to ensure proper insurance coverage.

It seems to me that licensing on par with a Ham license would be appropriate.  A license on par with a private or commercial pilot's license would be overkill -- both too expensive, and covering a lot of unnecessary information.

5. Pro or semi-pro engaged in product development base on flying models.

It would be a shame to accidentally block a new high-tech industry, especially as Texas seems a prime area for development -- lots of open, flat spaces, many potential customers in the farming, ranching, resourcee management fields, etc., and a good business environment for small companies.

It would be great if the regulatory environment for small commercial-use drones were such that it encouraged innovation and growth in this sector.

It seems that requiring a commercial "small drone" license with appropriate insurance would cover the case of most small businesses.  Is there a gap caused by the hobbyist working on a potential product in his garage shop?

6.  In general, flying over someone's property.

This might be broken down into the types of property.  Flying over someone's open field (say for example at a large church on a weekday) is different than flying next to someone's window.

My Analysis of This Legislation

Googling didn't reveal the text of the proposed regulation. I've contacted Rep. Gooden for a pointer, but if you know where it might be please leave a comment!  For now I'm going by what has been reported in several venues. [4][5]
update: Rep. Gooden's office has provided a copy of the text.  It's online here: [1]

(in progress)

Suggested Language

Based on the previous sections, here are some suggestions for how to clarify the proposed legislation.

(in progress)



[2] Erk. My home town, Berkeley, wants to establish a "no drone zone"
[3] Berkeley rejects proposal to ban drones

[4] Lawmakers Aim to Limit Drones and Safeguard Privacy

[5] Texas "Anti Drone" Laws Would be Toughest in USA
[6] Press coverage

Thursday, February 7, 2013

MakerBot Replicator 2 Notes

Very exciting, I was able to try out the new MakerBot!  Here's some notes on getting things set up.

Note: Replicator 2 uses only PLA.

I'll come back and revise some of the missing parts (e.g. the menu instructions) after  I get a chance to go through the steps again.

Power on (switch on rear right)

Load Filament

  • snake the filament through the clear tube, from the back
  • detach clear tube from printhead
  • select menu:  utilities/filament/load (left arrow is back)
  • feed filament into head
  • you will feel the feeder take over
  • let filament go until it touches the baseplate
  • push the M button to stop filament feed
  • attach clear tube to printhead
Printing from computer
  • attach usb cable; usb cable falls between the two tables, fish out through the middle
  • run makerware, get your model ready
  • click "The Replicator 2" button
  • advanced parms:  set feed travel to 60 cm/min (default is 80) for better results
  • select raft and supports if you need them
  • see notes below on detaching
  • do something to disable sleep or you will blow your print.  on our macs, push the mouse to the bottom left corner.
  • click print.
  • when the unit starts, it will draw a line of filament from the front left corner to the start of the model.  watch for that, if this filament line is bad cancel your print.  

Printing from SD card
  • fiddle with your settings as above
  • we're still pre-7 firmware, so save as S3D
  • use an SD card of 2G or less
  • put your card in the slot
  • menu: utilities/filament/unload

To Detach
  • the baseplate will detach, push the rear tab back
  • blue painters tape can be put on the baseplate to ease detachment
  • lightly sand the tape for better adhesion, so the melted filament doesn't move around
Wrapping up
  • log piece(s) in logbook
  • unfeed filament (menu:)
  • power off
And here's my first test piece!  It's a sizer for metric nuts and bolts.  No numbers printed in this version though.  Next up:  camera carrier for Bixler 2.

Monday, February 4, 2013

Turnigy 9XR Programming Cable

Here's the programming cable you need to hook up your 9XR to your computer's USB port.  It's actually called an "AVR programmer" and can be useful for other things -- some quadcopter boards and microcontrollers will use this instead of USB.

USBasp AVR Programming Device for ATMEL proccessors

Sunday, February 3, 2013

er9x: uploading firmware

Here's how to flash the er9x firmware to your Turnigy 9XR.  Basic steps:

(note: after you write the firmware, you will get a throttle alert message.  this is normal, since the calibration settings have been cleared from writing the new firmware.  recalibrate your sticks and all will be well.)

  • attach data cable.  You might need to download some drivers -- some notes on this are upcoming.
  • download a copy of the firmware from this page:
  • download and install the eepe software on your computer:
  • in eepe, use the "write flash firmware to transmitter" option
  • reformat eeprom memory (radio does this automatically)
  • recalibrate your sticks and voltage meter