Also just a note, the packaging on the magnetic sensor is a 14 pin tssop with 0.65mm pin spacing (read really fricken small). I’ve hand soldered a couple before (years ago before I had much experience, there was a lot of cleaup with solder wick and an exacto). Its doable but tricky depending on your level of surface mount soldering experience, and its also 8 bucks, so don’t screw it up.
The processor is a little easier with a 48 pin with 0.8mm spacing, but there are also a bunch of 0402 (imperial fortunately, 1.0 mm × 0.5 mm equiv) sized passives, which are fricken tiny. I usually like staying above 0603, but hey challenges are fun (and at least its not 0402 metric).
TL:DR - wouldn’t recommend this as a first surface mount soldering kit.
Yeah, Luke and I talked about that yesterday, and I do not enjoy soldering
0402.
Fortunately, at least three people on the list have reflow ovens or hot
plates
Is it possible to get a stencil for the paste?
This tends to way better than trying to apply it by hand when you have such small parts
I picked up a stencil from OSH Stencil for the FadeCandy board that worked really well. If there is enough interest I could order one that could be shared for anyone who is interested in reflow oven work.
Mark
That would have been a good idea but it’s too late to order with the pcbs.
The PCBs are on a truck somewhere in the GVR so I should get them this afternoon. My total order cost was $US83.90 of which the PCBs were $US22.26, $CA95.57 on my credit card makes the PCBs $CA25.33.
The duty/bribe/ripoff from DHL was $CA19.57, the portion for the PCBs was $5.20.
So we’re at $CA30.50 or so for n pcbs. I’ll update this post when I get them.
Tilt Campaign
https://www.tilt.com/tilts/mechaduino-group-build-vhs
To claim a kit you must pledge for it on Tilt (simply participating in this thread doesn’t get you one).
Price breakdown
- Board: $1 USD
- Fancy components: $20.70 USD
- Passive components: $2.14 USD (we’ll order plenty of extras for VHS)
- Magnet: $0.50 USD
- ~10% margin for unforeseen expenses: $2.43 USD (to be donated to VHS if unused)
- TOTAL: $34 CAD
Reality Check: This is a difficult build
I have spent quite a bit of time double- and triple-checking the components, and roped @Jarrett and @TomKeddie in to help me. However there is a risk that a part might be wrong or missing, or that something won’t work quite right. It’s open-source hardware, not a professional kit.
Also know that this will be very difficult to solder and assemble, since some components are tiny. Are you game for a challenge?!
Signed on.
We could laser cut stencils, many people have done that before. I don’t
know how well it works.
If we’re missing some components, we can definitely find/bodge together
passives from somewhere, or make another Digikey order for the missing
stuff.
Should be fun!
Tilt is up to $918. Only 8 Units left as of Fri June 24th 10:30pm
Just took one, thinking it might be great addition to the pcb milling cnc I’m building.
Oh FINE I’m in. Hopefully someone will make a solder mask and coach me through the SMD parts. Otherwise I guess it can sit on my dresser for a few years like the last SMD group build project I bought into.
Yayyyy Alex coming to the space. I also just joined in.
There are only 5 units left! The tilt closes tonight, so tomorrow I’ll put in the DigiKey order.
I’ve also ordered some nice stainless steel solder stencils to help with the SMD soldering.
Just grabbed an eighth. I realized that 7 is a pretty dumb number.
Any idea when the group build event thingie will be? I have a summer vacation coming up.
Dammit I missed the tilt. Can someone add my name to that list
All parts have been ordered. We are making 37 boards. I got exactly the right number of high-priced components, a few spares of medium-priced components, and plenty of extras of the tiny cheap ones. One part was slightly backordered but should still ship in a week.
I will post once the parts arrive. We should be able to start making some test boards the week of July 11th.
Hi all! I just thought I’d let you know that we’ve launched a Kickstarter for assembled Mechaduinos:
Best of luck with your build!
-Joe
Glad to see you made it to Kickstarter, great work!