DIY Quality Control

[Krallum]

Any tips on making pedals more durable. Also where can i get those sticky pad things that some builders put under circuit boards

[ianmgull]

There is a NASA build guide somewhere on the net that shows a lot of their build quality requirements for their electronics (hopefully someone has a link). Every time I start getting an ego about me I'll read that and realize my pedals are not YET ready to be shot into space.

Some people use regular double sided tape to affix boards (it is thicker than normal tape) or you can use sticky standoffs such as:

http://www.smallbearelec.com/Detail.bok?no=76

[deadastronaut]

Any tips on making pedals more durable. Also where can i get those sticky pad things that some builders put under circuit boards

in what way more durable?..

if you use an aluminium box and pots/ metal jacks /  a 3pdt ,its pretty much bomb proof already!...

what are you planning on doing to it?

[anchovie]

Also where can i get those sticky pad things that some builders put under circuit boards

I usually get them from stationery shops. Or if you live in the UK, you can get a pack containing loads of pads and a reel of double-sided adhesive foam tape from Poundland.

[deadastronaut]

Also where can i get those sticky pad things that some builders put under circuit boards

I usually get them from stationery shops. Or if you live in the UK, you can get a pack containing loads of pads and a reel of double-sided adhesive foam tape from Poundland.

good old poundland. ..yeah me too....and  nick the superbright leds from moody halloween/toys etc.. ha ha...
maplins wants 1.90 for 1 superbright...taking the proverbial eh?...when i can buy 6 led lighters for a pound!!!!!....
great for primer too..and black spray...ha ha......and odd tools....arghhhhhh..been going there too long ha ha....

[Processaurus]

Great question.  As a DIYer unencumbered by the economics of mass production you can make your electronics more reliable than companies that need to watch what they're spending time and money on, like NASA or the military can.  The general philosophy is find the thing that's most likely to fail (either from typical use, or ingenious idiotic misuse) and fix it, and repeat until you're satisfied.  Does anyone have a link to how to do mil-spec wiring?

Some of the things I can think of that will make an unusually high quality pedal that can survive the violence and neglect of a life of live music:

• Use switchcraft open frame 1/4" jacks
• Use all panel mount controls, that are wired, not PC mounted directly to the board.  That's in the mil spec, and an easy improvement a DIYer can make, over commercial pedal makers.  I like a deep socket set to tighten the nuts rather than a crescent wrench, to get them nice and tight.  Lockwashers help.
• Drilling holes for the locator tabs on pots, rotary switches, and the funny tabbed washer that comes with toggle switches will stop them from spinning if they get loose, and stop rotational torque.  The new hole is unfortunately a beer hole, a sticker or something can seal it up.
• A thermal wire stripper makes wires less likely to break at the solder joints, from nicking the wire with the regular hand wire strippers.
• Hot gluing or silicon wire connections at the board can save the wire connections from breaking there from handling.  This makes it more reliable, yet harder to service.  Boss obsessively does it with some funny kind of yellow glue.
• Hot glue big components like large electrolytics to the board, their mass can disturb their solder joints if dropped, the glue is like a seat belt.  Only glue half of the cylinder, they breath/vent a little bit over time.  Boss does this as well.
• Heat shrinking connections that could short out if the wire frayed, especially coax.
• Use a panel mounted DC jack.
• If you can afford them, and want to go above and beyond, sealed, stainless steel CTS pots are much stronger than the aluminum alpha pots, though they are pretty big.  Pedals from the 60's that are still kicking often use these.  For smaller those blue Bourns pots are very nice, steel shaft I believe.  The universally used alpha pots' aluminum shafts are usually good enough, but can't survive something extreme, like getting jumped on a lot or ran over or dropped from a great height.  If I was trying to destroy a DIY'd pedal by smacking it on the ground, about all I could do is snap the aluminum shaft pots.  RG calls it a "flattop"!  Alternately, a roll bar can help protect controls.  
• Knobs made of metal, or plastic with a metal insert for the set screw are tougher, and less likely to get loose and lost.
• Mounting the board on aluminum standoffs is the most bulletproof way of securing the board in the box, I think, there was an interesting discussion of that point here a while ago.
• Short shafted miniature toggle switch bats are less likely to get bent.  Small Bear has some. I try to keep them away from edges, and make a knob fort for them.  Toggles might be the most accident prone mechanical part on pedals... they're almost always bent on neglected/thrashed pedals you see around, like soviet EH pedals.
• Polarity protection for the power.  I like a series schottky diode.
• Some kind of series 470 ohm or 1K resistor if an output jack is directly AC connected to an opamp output, so if it is shorted it won't kill the opamp.

Other people will probably have some good tips, but these are some of bits I've discovered through personal experience fixing busted stuff, reading here, and looking at reliable commercial pedals.

[ckyvick]

^Here's a mil spec guideline for soldering
http://www.everyspec.com/MIL-SPECS/MIL+SPECS+%28MIL-S%29/MIL_S_45743E_3367/

[DougH]

Some people use regular double sided tape to affix boards

Yuck.

Use aluminum standoffs and countersink flat screws from the top to mount them. Use your imagination for ways to hide the screws with graphics.

[Krallum]

Any tips on making pedals more durable. Also where can i get those sticky pad things that some builders put under circuit boards

in what way more durable?..

if you use an aluminium box and pots/ metal jacks /  a 3pdt ,its pretty much bomb proof already!...

what are you planning on doing to it?

I'm 20 and i've built like 3 pedals total, but in the next 10 years i'd like to be in production building my own designs. I wouldn't feel comfortable shipping the ones i've made to the mailbox, let alone someone who paid money or space. lol



^^thanks you touched on many of the things that i was worried about, mainly wires breaking at solder joints. .

[jefe]

Some people use regular double sided tape to affix boards

Yuck.

Use aluminum standoffs and countersink flat screws from the top to mount them. Use your imagination for ways to hide the screws with graphics.

Personally, I can't get away from using aluminum standoffs. I've been holding them in place with J.B. Weld, which is obviously not as good as a screw. One time I did use screws, but I didn't even try to hide them, just some panhead screws right on top of the box. I doesn't look all that bad to my eyes, kinda has an industrial look. And that board isn't going anywhere!

[Krallum]

ALSO a battery question, if i'm not going to put it one of those battery drawers any good ideas for fitting in batteries? I have been just using those aluminum standoff posts that you get at radio shack to lock it in a corner but i'm sure theres way more space efficient ways to do that.

[DougH]

Some people use regular double sided tape to affix boards

Yuck.

Use aluminum standoffs and countersink flat screws from the top to mount them. Use your imagination for ways to hide the screws with graphics.

Personally, I can't get away from using aluminum standoffs. I've been holding them in place with J.B. Weld, which is obviously not as good as a screw. One time I did use screws, but I didn't even try to hide them, just some panhead screws right on top of the box. I doesn't look all that bad to my eyes, kinda has an industrial look. And that board isn't going anywhere!

I used to use JB Weld until over time the standoffs all came loose. Nothing wrong with screw heads, and if you can integrate that into your look, even better!

[jefe]

I used to use JB Weld until over time the standoffs all came loose. Nothing wrong with screw heads, and if you can integrate that into your look, even better!

Yeah, I'm keeping a close eye on the JB Weld. One trick I use to prepare the surface of the box is to score the heck out of it. I use a very dull utility knife to scratch a deep cross-hatch pattern in the aluminum. And I mean DEEP. I press down on the knife with all my might. It leaves very rough, ragged gouges, which gives the JB Weld quite a bit to grab on to. So far, they're holding.... but like I said, I'm keeping an eye on them.

[Hides-His-Eyes]

I don't get the hate for board mounted pots; my only real reason for not doing so is an inability to drill accurately enough!

[MikeH]

I'd say the number one thing is to perfect your soldering technique!  Just because those joints are holding up fine when you first solder it up, doesn't mean that the stress of changing temperatures, moving around (not to mention being stomped on), etc will cause them to fail eventually.

[amptramp]

Be careful what you wish for:

http://src.alionscience.com/pdf/MIL-HDBK-454.pdf

A little light reading.  A lot of items are not applicable to all cases, but it is a bit of light reading.  All 194 pages.

[chromesphere]

Great advice processaurus. I was going to start a thread specifically asking, how to stop those pot wires from breaking!  Very annoying.

Only thing i could suggest would be to spray the copper side of your PCB with some of that PCB lacquer spray to prevent the tracks from corrioding.  Seems to help protect then.

CS

[Krallum]

Be careful what you wish for:

http://src.alionscience.com/pdf/MIL-HDBK-454.pdf

A little light reading.  A lot of items are not applicable to all cases, but it is a bit of light reading.  All 194 pages.

i want Do it yourself, not nuke them yourself

[jkokura]

Be careful what you wish for:

http://src.alionscience.com/pdf/MIL-HDBK-454.pdf

A little light reading.  A lot of items are not applicable to all cases, but it is a bit of light reading.  All 194 pages.

i want Do it yourself, not nuke them yourself

If I knew how to create a signature, this would be in it. Made me Laugh out loud and surprise my in laws.

Jacob

[arma61]

If I knew how to create a signature, this would be in it. Made me Laugh out loud and surprise my in laws.

Jacob

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