3D printed enclosure for 16 channel OpenBCI system with rechargeable battery

djfletch42djfletch42 USA
edited April 2017 in Cyton
Hello all:

I've been working with a friend to develop a small enclosure for my OpenBCI 16 channel system and I think it came out pretty nicely. I have space for a 3400mAh Li Ion battery, a Powerboost 500C charging board for USB recharging and power, an LED lighted external power switch and a cutout for access to the SD card slot. I installed touch proof sockets on one end for electrode attachment. I'm pretty happy with how it came out:



image

If anyone is interested in printing on of your own, I'm happy to share the STL files. Just thought it might be of interest to someone.

All the best,
Dan

Comments

  • wjcroftwjcroft Mount Shasta, CA
    Dan, the first image is not showing for some reason...
  • djfletch42djfletch42 USA
    Hmm. Let's try again.

    image
  • SkalbeSkalbe Latvia
    I need this! :D
  • wjcroftwjcroft Mount Shasta, CA
    I'm imagining this could be a welcome form factor in university labs using OpenBCI in clinical or research environments. Where the bare boards would be too exposed to shorts or liquids, etc.

    Dan, this might be something that could actually be sold by some type of 3D contract print shop. @Conor or Joel @biomurph might have suggestions on firms that do this type of assembly work. Would I'm sure depend on volume.

    Then again DIY is the way to go with a tight budget.
  • dralvesdralves
    djfletch42 Would it still be possible to share the STL files? I'm curious how much someone like voodoo manufacturing would take to print a few of these.
  • djfletch42djfletch42 USA
    Hey Folks. My friend who did most of the designing is happy to share the STL files. He'll upload them to Thingiverse (I wanted him to upload it under his account since he really did the lion's share of the designing). Once he gets it uploaded I'll post a link here along with links to the other parts you need to put it all together. Stay tuned!

    FYI, I did check out what it would cost to print at Shapeways. Looks like about $75 for the box and $38 for the lid. Frankly I was quite surprised by that. If you have a 3D printer it takes very little filament to print it. I used PLA and it prints pretty easily. You can theoretically print the model without supports (at least I could on my Lulzbot Taz 4), but the cutouts print better with supports, so I'd recommend using them. So if you (or a friend) have a 3D printer, print it yourself! It's a pretty simple model.

    Stay tuned!
    Dan
  • armz12armz12
    edited January 2017
    This is awesome, nice work!! Where did you get those touch proof sockets from?

    Also, where did you get that battery and battery holder?
  • djfletch42djfletch42 USA
    Here are the parts you need to build this.

    3400 mAh Li Ion Battery (this is a pack of 2): Amazon link
    Battery holder: Amazon link

    Lighted pushbutton switch: Adafruit link (we tapped 5V off the OpenBCI header and used a voltage divided resistor to make it less bright)
    Powerboost 500C charger: Adafruit link (you not use the included USB connector, but solder to the power points on the board)

    Panel mount touchproof connectors: Link

    These 20cm female-female jumper cables were the perfect length to connect the OpenBCI connectors to the touch proof connectors: Link

    I also used M3 screws to attach the lid by embedding these knurled threaded embedments into the posts in the box: Link

    Once the STLs are posted (hopefully soon) I'll post some photos of the disassembled system that will make assembly easier. Stay tuned!

    Dan
  • wjcroftwjcroft Mount Shasta, CA
    Dan, cool. Your M3 nuts link needs adjustment, is a duplicate of the jumpers.
  • djfletch42djfletch42 USA
    Oops. Sorry about that. Here it is:


    All the best,
    Dan

  • dralvesdralves
    djfletch42 curious: what are the dimensions of the box? have access to an old 3d printer but it can only handle small volumes...
  • djfletch42djfletch42 USA
    It's 12.5cm long x 9.5cm wide x 4cm tall. Hopefully it will fit!

    All the best,
    Dan
  • dralvesdralves
    djfletch42: any news on the stl files? Bought all components you mentioned  and eager to put the box together :D
  • djfletch42djfletch42 USA
    STL files are posted! Here's the link:

    Let me know if you have questions.

    All the best,
    Dan
  • dralvesdralves
    djfletch42 awesoome!
    already ordered the print (couldn't fit my printer after all).

    thanks!!!
  • dralvesdralves
    Btw ordered this from voodoo manufacturing. 2 whole boxes cost around $95.

    djfletch42: Thanks so much for posting this! Is there any way that you could post the pics of the disassembled system? or would that be too much work now? Some more detailed pics of the assembled system would already be pretty useful.
  • biomurphbiomurph Brooklyn, NY
    dfletch42,

    Yikes! I hope you're not connecting to and plugging yourself into the wall outlet through your USB connection! This is something very serious that you're doing, and I want you to know that it is not at all recommended in any way. 
    Also, The OpenBCI boards are designed to isolate the digital and analog power supplies, but there is not really enough isolation to prevent power supply noise from mucking with your signals. Be wary about signal quality if you are indeed trying to read data when connected to USB. When you say you 'tapped 5V off the OpenBCI header' are you taking that from the Analog side? There's no reason you can't light an LED from the 3V3 side of the board. 
  • wjcroftwjcroft Mount Shasta, CA
    Joel, I understood he only plugs into the USB for charging the battery. And does not hookup the EEG during charging.
  • djfletch42djfletch42 USA
    Hi biomurph. The USB connector is to charge the Li Ion battery (the large green one!) in the case. The 5V header is easy to get to and making a little voltage divider was no big deal.

    Thanks for being so concerned about my welfare! :)

    All the best,
    Dan
  • pwilliamspwilliams
    Dan and others,

    Regarding vendors for 3d printing, for anyone in the States I would suggest taking a look at www.3dhubs.com for anything that can be printed on a consumer-grade printer (especially FDM printers). I have used Shapeways and Sculpteo quite a bit, but they are generally a lot more expensive and have a slower turnaround than getting a job printed locally (or even not-so-locally) by a member of 3dhubs. For some jobs that have complex or unsupported components, or if you need a special material, the big commercial services are the only way to go. But anything that could be printed "at home" doesn't require them, and in my experience, some pieces that are designed specifically to be printed using FDM may actually print worse when another method such as laser sintering is used.

    Thank you for sharing this, Dan. It looks sharp!
  • dralvesdralves
    Thanks for posting this Dan.

    I successfully assembled the box.
    The one different thing I did is that I pulled power for the switch led from the powerboost directly and not from the cyton board (still needed the resistor, obviously since it's 5V).

    Dan: question, what do you use the 17th wire for? That is I have the 16 channels plus bias and ref, but there are 19 touchproof connectors. I assume it's the wire you have on N8P on the daysy board. What do you use it for?
  • djfletch42djfletch42 USA
    Hey there. Glad you got it working. I am collecting 15 channels of EEG (common reference SRB2) and one channel of ECG (bipolar input), so 15 EEG inputs, reference, ground, and two for ECG.

    All the besr,
    Dan
  • joshaughjoshaugh Boston
    "Once the STLs are posted (hopefully soon) I'll post some photos of the disassembled system that will make assembly easier. Stay tuned!"

    Hey djfletch42, did you ever post these somewhere? Is there any chance you could along with instructions on how you assembled everything?

    Thanks
  • AlejandroAlejandro Ireland

    Hi Dan, thanks for this contribution.
    We need to modify some parts of your design to adjust for some parts that cannot be sourced exactly as you have it anymore. Is there a possibility to have the CAD files that we could make modifications on?
    Thanks again

  • wjcroftwjcroft Mount Shasta, CA

    Alejandro, this is Dan's page at Cornell, with contact info:

    https://www.vet.cornell.edu/research/faculty/daniel-fletcher-phd-dvm-dacvecc

  • AlejandroAlejandro Ireland

    Thanks William, Much appreciated! I'll reach out to him directly.

  • AlejandroAlejandro Ireland

    @wjcroft said:
    Alejandro, this is Dan's page at Cornell, with contact info:

    https://www.vet.cornell.edu/research/faculty/daniel-fletcher-phd-dvm-dacvecc

    I wasn't able to get in touch with Dan, but just FYI we were able to finish the builds with slight tweaks, all possible from Dan's original post in Thingiverse and with compatible parts sourced locally. So this is definitely still a great and usable contribution.

  • wjcroftwjcroft Mount Shasta, CA

    Thanks for that update. Dan did not answer at his email address listed on that Cornell page?

  • AlejandroAlejandro Ireland

    No, I never got a reply from him at that email address. But university filters have gotten ridiculous lately so it could be that may e-mail never reached him.

Sign In or Register to comment.

© Vanilla Keystone Theme 2025