Testing credit card charges with Stripe in a simple Rails app

Following up on suggestions from the board meeting to look at Stripe for charging member dues, I found a couple Rails tutorials and deployed via Heroku… it works with a few lines of (rails) code! The reason to maybe not use “gravity forms + stripe” just yet is because I think it is $200/yr — you need a Gravity Forms Developer License according to:
Yikes. Is that right? Different sites report different $$ so until someone at Hive tries it we may never know!

Well, we can just make our own embedded form, and Stripe can also deal with subscriptions painlessly, apparently. Try it with the herokuapp link below:
*****WARNING: it will actually charge your CC $1. I promise to deposit it back to Hive*********

Heroku is great, you deploy via github so we could also make the forms public (our private Stripe key is configured only in heroku and is NOT in the github repo). Here’s the rails app on github so we can collaborate; I put all the details for how I did this in the README.md:


Some more to think about:

1) Let’s make a member application fee of $1.00. This will ensure prospective members have Stripe setup BEFORE they become a member! Much better than if they are voted in but never actually pay…!

2) I think we should charge the Stripe fees *to the member*. This way we have dependable operational costs. You can see attached that a $5 charge results in only a $4.55 net gain because of the stripe fees, but this is still low cost and dependable for now (Stripe charges 2.9% + $0.30 per transaction). So we would need to charge users fee*1.029 + $0.30 (rounding up by cents; Stripe only charges whole cents) for each fee we designate. Then if Stripe changes fees in the future we just update this amount and Hive still has dependable operational costs.

3) Stripe is nice! Your CC will properly process whatever we write into stripe, here’s how it shows up on my card statement:

4) Right now funds get deposited into my personal checking account (!!) since I don’t have the Hive76 bank account number. Does someone want to give me that? Or I can coordinate this with the treasurer. Again, I promise to deposit your test charges back to Hive.

5) Obviously it needs beautification, choice between member rates, a way to subscribe, etc. But that’s all optimization for later, this rapid hack was about feasibility. It’s feasible to use stripe!

Here’s what you see in the Stripe Dashboard:

Apply Now: AMRI Summer 2014 Fellowships

We have an open call for Summer 2014 Fellowships at Advanced Manufacturing Research Institute (AMRI), hosted at Rice University in the department of Bioengineering.

We are soliciting applications for the following projects:

Project 1: e-NABLE 3D Printed Prosthetic Devices

In collaboration with the worldwide e-NABLE group, and Gloria Gogola, M.D. at Shriners Hospital for Children, Fellows will aid in the design, 3D printing, testing, and refinement of open-source prosthetic hand and finger designs. This unique fellowship will bring 3D printing into the clinical setting, working closely with Dr. Gogola and her patients in need.

Project 2: Selective Laser Sintering (SLS)

Fellows will augment and refine the open SLS design pioneered by Andreas Bastian last year. SLS machines typically cost $50k or more, we built ours for under $15k. This year we will focus on powder manufacturing and powder handling, as well as characterization of SLS parts via scanning electron microscopy (SEM) and mechanical testing.

Project 3: OLED 3D Photolithography of Living Tissues

Related to Anderson Ta’s exciting digital light projection (DLP) photolithography last year, Fellows will investigate and program organic light emitting diode (OLED) screens as a light source for 3D photolithographic printing of living tissues. Chemical functionalization of glass surfaces will also be investigated to passivate the screen surface and aid in detachment and 3D printing from the light source surface.

Project 4: Open Source Ink Jet Printing of Bacteria

A continuation of Steve Kelly’s inkshield augmentation of RepRap motherboards to print living bacteria, Fellows will investigate fluid mechanics, python scripting, and multicolor printing to create interacting bacterial colonies on top of and within agar gels. Fellows will also learn how to insert genes of interest into bacterial colonies for protein production. Steve’s 2013 AMRI Presentation is available here.

Check out all the details, and be sure to apply by May 15th:

Questions can be directed to amri@rice.edu.

Diagnostics by Design Workshop and Hackathon

Hot on the heels of their wildly successful Build My Lab contest (still 5 days left to enter!!), our friends at Tekla Labs are putting together another breakthrough event to unite DIYers and the science community (NOTE: These events are happening in Berkeley, CA).

Julea Vlassakis writes:

The Point of Care Diagnostics IdeaLab, Tekla Labs, and the Center for Emerging and Neglected Diseases is excited to announce a series of coordinated events to promote global health design and innovation.

January 9, 2014 Diagnostics by Design: A Workshop on the design, development, and implementation of Global Health Technologies (details/registration here)

January 10, 2014 The 6th Annual CEND Symposium. Academia and the Global Health Pipeline: Basic Science Innovation and Translation (register here)

January 11-12, 2014 Diagnostics by Design: A Hack Day for Global Health (register here)

The Diagnostics by Design workshop is an interdisciplinary forum for discussing the challenges and lessons learned in developing and implementing global health technologies, specifically at the point of care. Through interactive talks, a panel discussion with experts from industry and academia, and a hands-on build session, we will explore the challenges associated with translating technologies beyond the lab. This workshop will draw on the expertise and experience of individuals from across disciplines to explore collaborative solutions to global health issues. The workshop will feature Columbia Professor and mChip inventor Samuel Sia as the keynote speaker. See our eventbrite page for a full list of speakers and panelists and for registration.

The Diagnostics by Design hackathon is an interdisciplinary effort to bridge the gap between makers and do-it-yourself innovators and the sphere of global health. The event is posed as a challenge to participants: with minimal materials or through innovative coding, tackle a technological or informatic need in the space of point-of-care diagnostics. These can range from generating DIY lab equipment alternatives for medical clinics with limited resources, informatics for disease monitoring, or redesign of diagnostic tools for resource-limited settings. Attendees will be given a kit with some materials and have access to 3D printers, laser cutters, mills and more. Visit our eventbrite page for more details and to register.

T.E.R.A. Incognita at The Hacktory

Our friends over at The Hacktory (Repurposing Technology, Making Art) are running a Kickstarter to raise matching funds for an excellent project to unite artists with the latest technology to empower new designs. From their Kickstarter page:

Electronics and digital technology can infuse works of art with an element of magic. At The Hacktory we have literally put this magic in people’s hands, through classes and large public events. We want to do more though. We want to make our classes available to artists. We’ve found that they are usually the most excited to take our classes and play with technology, but usually the least able to pay for our classes.

The Hacktory is creating a program called T.E.R.A. Incognita: Tech Education and Residency for Artists. Our goal is to support artists who want to create new work and experiment with technology such as cameras, projectors, sensors, robots, software and circuits. The name “T.E.R.A Incognita” is part acronym, part vision for the program. We want to give these artists an opportunity to learn and explore at the edges of technology and art, literally in unchartered territory, to create new experiences and new possibilities with code, hardware and creative expression.

The Kickstarter ends on Monday, so go check it out and consider making a pledge! Some great rewards are being offered too.

Delaware RepRap Prusa i3 Mendel Build Class

Our friend John Abella (of the Maker Faire 3D Printer Village and Delaware Makerspace Barrel of Makers) is running a two-day RepRap build workshop in Wilmington Delaware, October 5th and 6th.   Attendees will be building Prusa i3 printers with all top-shelf parts:  milled frames from Josef Prusa, genuine J-head hotends from Hotends.com, stainless threaded rods and hardened chromed smooth rods.

The workshop is being held at the Wilmington DoubleTree Hotel, and will have catered food for attendees.   Every person attending will leave with tools and basic supplies to maintain their printer and get started printing.   The workshop fee – all inclusive –  is $999.

Click here for the official flyer for the event

More info and class registration can be found here:  http://botbuilder.net/classes/

FREE EVENT THIS THURSDAY: Through the Looking Glass

This Thursday, please join us at a FREE exhibition of the work of Cornelius Varley (1800-1860) put on by the venerable American Philosophical Society. It is a fantastic exploration of the life work of this fellow tinkerer and inventor who’s insight and explorations reminds me a lot of our Hive76 members!

A few of us will also be presenting at this event! We will have live 3D sugar glass printing, exhibitions of Brendan’s boom cases, Dan’s 8 mm RockBox, PJ’s electronics, Corrie’s textiles and artwork, Chris Terrell’s wood burning, and maybe a few more things.

We hope to see you there! Deets and directions below.


Free Refreshments (wine, food, music) will be provided at the event!!
APS Requests your RSVP HERE: museum@amphilsoc.org
Thursday, June 6th, 2013
5:30-7:30 pm
APS Museum in Philosophical Hall
104 S. Fifth Street, Philadelphia, PA

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Getting Raspberry Pi to control your 3D Printer

We got some Raspberry Pis and began jumping through some tutorials. Adafruit has a particularly thorough and easy to follow series. We’ve had good luck with the Raspbian Wheezy distro and it works just like familiar Ubuntu since it’s based on Debian. Remember to run:
sudo apt-get update
sudo apt-get upgrade

upon first launch. That will make things a lot easier since the release is rather old by now.

I got some time to explore the Raspbian distro.


After seeing all of my efforts, Morfin couldn’t wait to give it a shot.


Eventually we got my favorite light-weight print controller github.com/kliment/printrun running an active 3D print. It really was incredible to have a $40 computer connected to the interwebs and sending gcode with a full GUI over python->USB-serial. It’s a bit too slow for computational slicing, but would probably be GREAT for a bot-farm. Note that you should also use pianobar instead of full-blown pithos for pandora audio. Note that the audio worked great after we ran the apt-get upgrades mentioned above.


And remember to grab our desktop background! It’s only 1.2 MB.

ShopBot as a 3D Printer: controlled by a RepRap RAMBo

suggested by Kliment via IRC (/ht), the way to have a heavy toolhead moving about in 3D with high speed AND precision is to modify a ShopBot instead of a Rostock. Recall, the Darwin suffered this design challenge which led to the Mendel.

With RAMBo bypassing the stock motherboard we can drive the ShopBot to scary speeds (10x faster in XY and 100x faster in Z.). Precision should also be ~10x better than belt-driven motion, but needs more fine tuning.

and did i mention it was freaking awesome?

My ShopBot RAMBo Marlin firmware branch is available via GitHub (of course). Follow along in the GitHub log to understand our process.

Thanks to ShopBot and Ultimachine for all your help and schematics!!

Render your next Logo Design

Blender, the awesome open-source do-everything model/rig/render/animate program continues to be an important part of my toolkit. The Artist Community is definitely a huge bonus. So check out this excellent tutorial over at BlenderGuru.com

So…I put Sean’s Harrow through it’s paces, and here are some of my newest desktop backgrounds.

First you get the basic render down. I use 32-bit color with OpenEXR file format, saving z-buffer info too, just, you know, in case you need it later. You should get something like this… kind of flat when viewed on a crappy computer screen, but i assure you there is a ton of color info there for fine tuning later.

With all that extra color depth, you can easily fine tune the contrast, like so.


Then you need to come up with the shadow version… Andrew Price from BlenderGuru does this in a new Scene. I like the stark contrast… when you look carefully the sharp edges tell you that you are looking at a perspective view.


Put it all together, and you get a softly-back-lit Logo. WIN!