[solidONE]

I've soldered stuff before. I learned from playing with RC cars when I was younger, but don't have much if any experience doing intricate soldering of IC boards and resistors and all that electronical doodads. I've rewired my speed controller with thicker wire, and thats about it. more recently I learned to weld and braze


My point: I'm looking into a unassembled Megasquirt kit to see if it is worth it to try to assemble one myself to cut down cost.

What's it going to take for me to turn a bunch of little bags of electronical parts like this:

Using a soldering iron to make something like this:

Tips, how-to's, links? What kind of tools do I need? Different soldering tips or tools to help solder small, intricate stuff like this?

 

[NeverEndingNinja]

 

[Iakayak81]

make sure you use a low wattage pencil iron, the adjustable types are nice. Jewelers goggles are a must IMHO. and very fine solder helps a lot. you may want to pick up some sort of cheap kit to practice on first as well.

 

[vwgti303]

I would say patience first off. And as was said before an adjustable soldering iron and fine tip. I have all these things at work and would be more than happy to put it together for ya. Understand too, that so long as you don't melt anything, soldering is pretty forgiving, just make sure you have it right before you fire it up!

 

[NeverEndingNinja]

So, how much would you save soldering it yourself?

 

[gearman]

I'm no expert, but I've done some pc board repair (pinballs) and I wouldn't touch that project. I assume the small sub-board is already assembled. I always installed sockets for ic's as they are prone to damage from overheating. Some boards are better than others for soldering. Thin traces can actually lift from the board if overheated so be careful with components that have heavy leads (like those large diodes). In addition to practicing on a cheaper project, I would also suggest getting a desoldering tool and practice using it on a scrap board. Good luck.

Edit: Almost forgot...look here for tips and tricks.

 

[DieTrying310]

make sure you use a low wattage pencil iron, the adjustable types are nice. Jewelers goggles are a must IMHO. and very fine solder helps a lot. you may want to pick up some sort of cheap kit to practice on first as well.

+1

I've got a buddy that builds all his own megasquirt kits for the volvo's he races. Seeing as this same buddy also blew out his eardrum by making an acetylene torch explode in his hand, it's safe to say this isn't rocket science. I've put a few circuit boards together and as long as you're patient it's not that bad.

 

[solidONE]

So, how much would you save soldering it yourself?

'Bout a buck fifty. For the set up that I want, MSII, costs little more than $400 for the assembled unit. The unassembled kit cost almost $250.

It is a lot of soldering for someone who has never done this kind of work before. I'm sure the $150 difference is well worth it. The up side of piecing it together is that if I need or want to to repairs, upgrades or modification of the hardware I will have learned to do it from having assembled the unit myself in the first place.

The $150 difference still doesn't cover the difference in cost when I got to buy solder, flux and a decent soldering iron. How much do those adjustable soldering irons cost anyway?

 

[pne]

soldering is easy. I could do that board with my harbor freight 30w soldering station which cost $10.

As for tips, you can get by with a pointy tip and a chisel tip. Other tools, a tin of rosin or flux, wet sponge to clean your tip with, obviously some solder with flux core, needle nose pliers, and wire clippers/side cutters. A well lit work space and a small fan.

tips- heat the surface and not the solder for thicker pieces. Keep the surfaces as clean as possible with flux or wet paper towel. Clean surfaces with a tiny bit of solder transfer heat the fastest. Only use enough solder to do the job.

So for something simple like a resistor, you'd thread the two ends through the board, position the resistor, flip the board over, wipe tip on wet sponge, put your point tip so it contacts the wire and the board, and dab the solder wire on this contact point. Pause for half a second to let the solder flow, remove and wipe iron, clip excess wire with side cutters.

For something larger like the transistor, apply flux to the leads and melt it with the iron. Heat up the leads and apply a small mount of solder to them. Do the same to the contact points on the board. (this is called tinning) then postition the transistor and use the iron to melt the tinned contacts together. Add extra solder if necessary.

Solder is similar to brazing, but you don't have to heat the metal up as much, because there's chances of damaging the component that the lead is attached to. Just warm the metal up with the clean iron for a few seconds, then apply solder to the iron tip, and you should see the solder wick across the surface.

 

[gearman]

Something to consider: the extra $150 probably includes testing of the assembled product as well as a warranty. A single faulty or incorrectly installed component will likely render the unit useless. Unless there is extensive detailed documentation on testing/troubleshooting the self assembled unit and you have a fair degree of ss electronic knowledge, correcting the problem could be daunting.

 

[solidONE]

Cool. Process sounds real similar to brazing/welding. I think I can handle that. I just got to get down all the procedures for prep and finishing. Like the pretreatment with solder before mating the parts or "tinning" I've done with larger wires and parts, but this stuff seems really delicate. I would want to make sure I got the right tools and techniques down before I start melting a couple hundred dollars worth of electronics together.

I should have asked about the soldering irons earlier, cause I just got back from harbor freight a little earlier for a radiator fin straightener. I don't mind going back there, though. The sales manager there is a pretty hot chick.

 

[solidONE]

Something to consider: the extra $150 probably includes testing of the assembled product as well as a warranty. A single faulty or incorrectly installed component will likely render the unit useless. Unless there is extensive detailed documentation on testing/troubleshooting the self assembled unit and you have a fair degree of ss electronic knowledge, correcting the problem could be daunting.

Yes, very good point and definitely taken into consideration. The vendors that sell the assembled units will back their work one way or another.

They're pros, and I've never done anything like this. Though, I think I can get a handle on it. The soldering part. All the other stuff I have no idea. I'm pretty retarded when it comes to these little risistors and electrical thingamabobs.

 

[gearman]

Don't get me wrong, I'm not questioning your ability to master the assembly part of the project. The board you would assemble allows the smaller board (the "brains")programming input, an output interface to perform it's functions, as well as power regulation. Lots of fairly basic circuits that, if properly explained, could remove a much of the mystery surrounding those "thingamabobs". Myself, I wouldn't consider attempting it without first checking out the assembly/operation documentation for testing and troubleshooting procedures. Even then, it wouldn't hurt to have a knowledgable friend on standby.

 

[BossMan]

I think you should seriously consider doing this yourself.

The way I see it, if you screw something up then that's $250 down the drain. Some of those components cannot take heat for very long, so you could be doing everything correctly, but if you leave the iron on it too long then the little guy is toast. I also cannot even imagine how you would troubleshoot that if something did go wrong.

Just my thoughts. Soldering itself, well in theory, isn't that hard, but much like bleeding brakes, or changing tires (for me at least) it never seems to go as planned.

You're also going to want to have at least one more hand, so I would factor in some kind of clamp or something to hold the board into your costs.

There are plenty of videos on the internet as well.

I personally think you should start small and work your way up.

 

[solidONE]

I personally think you should start small and work your way up.

Problem is, I don't have anything that I need to solder right now. Even if I did have something to solder, it would probably only include some red or black wire and connectors. Nothing involving resistors, IC boards or anything like that.

I wouldn't mind learning how to solder this stuff by putting together one of those adjustable air flow sensor trickers. Not sure what they are called, but it alters the signal from the air flow sensors tricking the stock ecu to run leaner or richer than the factory settings. Any idea where I can find something like that in a unassembled form?

 

[BossMan]

Problem is, I don't have anything that I need to solder right now. Even if I did have something to solder, it would probably only include some red or black wire and connectors. Nothing involving resistors, IC boards or anything like that.

I wouldn't mind learning how to solder this stuff by putting together one of those adjustable air flow sensor trickers. Not sure what they are called, but it alters the signal from the air flow sensors tricking the stock ecu to run leaner or richer than the factory settings. Any idea where I can find something like that in a unassembled form?

I'm pretty sure those are just a resistor to trick the computer into richening (is that a word?) the mixture. Check the manual to see what the cold air resistance is.

One thing you could do is wire up a garage door opener. That's what I'm working on. It's fairly simple, but it is wiring on a circuit board.

http://cbrforum.com/forum/showthread.php?t=62473

 

[solidONE]

I'm pretty sure those are just a resistor to trick the computer into richening (is that a word?) the mixture. Check the manual to see what the cold air resistance is.

One thing you could do is wire up a garage door opener. That's what I'm working on. It's fairly simple, but it is wiring on a circuit board.

http://cbrforum.com/forum/showthread.php?t=62473

Not that I know for sure all the differences, but the resistor trick does not allow for adjustment. It alters the signal to a set level and stays there. No adjustment, no fluctuation. They might even trigger error codes on newer cars.

Garage door opener is a good idea. I could use one mounted on my bike.

 

[Iakayak81]

i think you can find plans for a do it yourself yosh-type box online, may be a cheap(er) practice project

 

[pne]

to keep the transistors from overheating, put a piece of soggy toilet paper over the chip leaving the pins exposed. If you tin them heat should not be problem. If you want a really cheap practice project, build something like a little headphone amp, or an led circuit. Breadboard is available at radioshack for cheap.

 

[gearman]

I've never had much trouble with transistors as the leads are usually fairly long. I regularly installed sockets for ic's because they were a b1tch to remove if something went wrong and the boards were only gonna take the heat a few times before the traces gave it up. This pic is the backbox of a '95 Gottlieb Stargate pinball I once owned. Williams and Ballys of the same era were somewhat more complex. Lots of transistors, hi watt resistors and caps to go bad. I do miss working on them though.