Buying built vs. soldering (MS3)

[GunMetalGrey]

So I have been debating this for a while, buying a kit that you need to solder up yourself saves you $175 over buying it pre-built.
I have done a fair amount of soldering in my days, and plenty of spare time to do it, but nothing quite as complex as ms3. My only concern is overheating components and it would suck quite a lot to not know why your system didn't work when you turned the key.
I guess I am asking if it is worth the $175 to do it yourself?

[nando]

there's very little soldering required for an MS3, assuming you use the MS3x (and you should). about half the circuits on the V3.0 board you can just leave off. the rest is pre-built SMD components (MS3 CPU card and MS3x).

the directions are easy to follow and it's all through hole. if you like to learn a little and have some soldering ability, why not? there's nothing really expensive that you can overheat, the CPU itself just plugs in.

[GunMetalGrey]

Cool, thanks for the input!
You really know your stuff when it comes to megasquirt!

Sent from the future. Or my phone, who knows.

[Wiglaf]

I think it's pretty easy to solder up. Also not being afraid to solder on it is a bonus when it comes time to mod it. :)

[nando]

Welcome!

I did all my Megasquirt soldering with a $15 Radioshack iron, lol. I mean, a good soldering station is going to be obviously nicer, but it's not absolutely required. I have something slightly better now, but it's nothing special - $30 kit from Amazon, it's not even a station - just an iron with various tips and a holder. The main difference is it has an on/off switch, temperature control, and does 40w instead of only 30w. I did SMD, through hole, harnesses, even medical equipment repairs - with that crappy Radioshack iron. The only reason I even upgraded is because you couldn't get tips for it anymore, or if you did find them, they cost like $40.

Practice is more important than equipment. I learned with an old "soldering gun" which had a HUGE tip and barely got hot at all. That said, having better equipment will probably make it easier for sure!

I'd just get a single rosin core solder in a fairly small size (0.5mm sounds good to me), I don't think it makes a whole lot of difference exactly what it is. 60/40 is pretty common and I think that's what I have. I mean, I literally used just whatever I could get - again, Radioshack. They don't even exist now, but I still have the same spool I bought 10 years ago, and I still use it.

It's basically just lead/tin and flux, not rocket science. The only worry with branding is maybe some of the cheaper ones are using toxic fillers or something. My one consideration now would be maybe finding something that doesn't have lead in it, because it's poisonous and you'll end up breathing in some of the vapors. it hasn't killed me (yet) but I've probably inhaled way more than is healthy. Honestly I don't even know if that exists, but I'll be looking into it once I finish off this old Radioshack spool (which I'm certain contains lead because I got it before RoHS was even a thing).

No-clean flux is nice but isn't strictly necessary either. you just need some rubbing alcohol and a toothbrush to clean it otherwise. However, I use it because it's convenient and you can get it in a big tube for almost nothing. You'll want extra flux in addition to whatever solder you're using anyway, It makes everything way easier. The main thing about flux is if it isn't no-clean, it can be acidic, so it ends up corroding your electronics. But even when I use no-clean flux, I still clean it off anyway because it's easy to do and I don't like sticky electronics. Use 99% isopropyl alcohol, the 1% water content isn't going to hurt anything and it'll evaporate super fast.

[JehTehsus]

So from my experience (which admittedly is almost exclusively SMT work, so maybe a bit trickier than through-hole) I would actually recommend against a lot of the lead free solder out there, for a one off personal use board. It generally does not work as well/easily when hand soldering. Obviously ensure you are working in a properly ventilated area, have a fume extractor, etc... Lots of flux is also highly recommended. You definitely still can get lead containing solder here in Canada, but I am not sure about the rest of the world. If you can't get it, get a ton of extra flux and use it.

Some good information here too https://workmanship.nasa.gov/lib/ins...uirements.html
You obviously aren't building a saturn V (although that would be quite the E30 engine swap) but many of the techniques still apply. If you follow the majority of those guidelines you may find your solder job outlasts everything else on the car lol.

[varg]

I always solder them myself, through hole components are easy. A cheap variable temperature soldering iron and a roll of the good stuff (leaded thin fluxcore solder) and you'll have a good time. Maybe buy a cheap kit of some sort to learn on. Don't forget a fume extractor of some sort though you don't want to be breathing the fumes from that leaded fluxcore solder, I just use a PC fan in a 3D printed stand.

[McGyver]

I'm never not going to reference my MS2 build thread, mostly because I wrote it as a reference:

https://www.r3vlimited.com/board/forum/e30-technical-forums/engine-drivetrain/alternative-tuning-w-a-r-megasquirt-etc/9917593-megasquirt2-v3-0-w-ms2-extra-3-4-2-build-and-wiring

Depending on how you value your time, $175 may be a good deal to skip assembly if soldering isn't fun for you. However, building it yourself helps you to understand how it works and will make troubleshooting and future modifications way easier. I'm not sure about MS3, but the MS2 build directions have built in tests to verify your work along the way. I highly recommend the JimStim to test your work and settings prior to using MS to control your car.

This was my first attempt at real soldering. (Look at the quality of the JimStim vs the MS2 board) I highly recommend the solder I used. It was almost too easy. Also the soldering iron I got was around $75 and was super handy for temp settings and heat shrinking.

[kyleconstantine]

I soldered my first ms2. I have a lot of experience building clones of vintage guitar amps. I found the components so small compared to the stuff I was used to that I hated it. However it fired right up on the stim when I was done so it wasnt so bad.

Once was enough though. My 2nd ms was. Whodwho and the third was a pre built ms2.