Today I built ...

on-topic Acorn-related news and discussions not covered by the other forums
User avatar
richardtoohey
Posts: 3354
Joined: Thu Dec 29, 2011 5:13 am
Location: Tauranga, New Zealand

Today I built ...

Postby richardtoohey » Tue Apr 25, 2017 2:30 am

Not going to get any prizes for my soldering errr "skills" (butchery might be more apt!) but it works. :D

I ended up having to put the switch on the bottom - every time I soldered it on the "right" side it just didn't work. #-o :!: :?:

Got it a couple of years ago - wanted to try a bit of soldering/electronics before I went anywhere near an old machine, and I have a few projects from *. that I still want/need to build :oops: (and again, wanted to practise on something less important.)

But I've made a start! :D

IMG_6509.jpg
And the "soldering" ... I was trying to "tin" the iron each time but still ended up with a lot of mucky stuff.

IMG_6510.jpg

When you plug the battery in the capacitor charges and then powers the LED for the amount of time set by the pot, controlled by the IC timer. The switch allows you to start the process again without needing to disconnect/reconnect the 9V battery/cell.

User avatar
danielj
Posts: 5133
Joined: Thu Oct 02, 2008 4:51 pm
Location: Manchester

Re: Today I built ...

Postby danielj » Tue Apr 25, 2017 6:30 am

=D> good work! You have to wipe the tip of the iron clean before tining it on a damp sponge or one of those things that looks like a brass scourer. If you're being reasonably quick you don't have to tin between each joint - eg, I might do one side of the ic, clean the tip, tin it and then the other side. It really depends on how gunked it's getting though.

Go you!

d.

User avatar
1024MAK
Posts: 6676
Joined: Mon Apr 18, 2011 4:46 pm
Location: Looking forward to summer in Somerset, UK...

Re: Today I built ...

Postby 1024MAK » Tue Apr 25, 2017 8:58 am

Well done Richard =D>

Leaving the button aside for the moment, your soldering looks fine :D

As Daniel says, cleaning and then tinning is good. How often depends on many factors.

The push click button switches may look like they can go in any way you please, but then you only have a 50% chance of getting it right :(

Most have two legs connected to each contact.

Internally they are like:
I I when the button is not pressed (at each end of each line is a leg). When the button is pressed, internally they are like:
H where the horizontal bit of the H is the moving contact.

So to work it out, use a multimeter on continuity or a resistance range. If you get continuity between two legs without pressing the button, that’s the two legs of one of the contacts.

Mark
For a "Complete BBC Games Archive" visit www.bbcmicro.co.uk NOW!
BeebWiki‬ - for answers to many questions...

User avatar
flaxcottage
Posts: 2734
Joined: Thu Dec 13, 2012 8:46 pm
Location: Derbyshire

Re: Today I built ...

Postby flaxcottage » Tue Apr 25, 2017 9:39 am

Well done. :D

An LED flasher today. Tomorrow an SD card interface on the User Port. :wink:
- John

Currently running Level 4 Econet with BBC B, BBC B+ 128K, Master 128K, 4Mb A3000, 4Mb A3020, 4Mb A4000, 4Mb A5000 dual FDD; UK101; HP41CX setup; Psion 3a, 3mx and 5mx; Z88; TI-58c, TI-59 and printer

cmorley
Posts: 215
Joined: Sat Jul 30, 2016 7:11 pm
Location: Oxford

Re: Today I built ...

Postby cmorley » Tue Apr 25, 2017 9:49 am

Soldering just takes practice and know a few simple tricks...

Never use lead free solder unless you are awesome! Get some good quality (not from eBay) 60/40 or 63/37 solder. Buy a brand from rapid, farnell, RS, mouser, digikey etc.

Get 0.7mm or thinner solder. Do not bother with 1mm or fatter - it is so much easier to control the solder volume with thin solder.

Get Rosin core solder with a high % flux. Get RMA or RA for home soldering (rosin mildly activated/rosin activated). Flux is the key to soldering. RA is a more agressive flux and will work better with corroded/older components (i.e. not brand new from the humidity controlled room and just baked!)

Get some extra flux. Pen. Bottle with brush. Paste. Many options. Again get a brand and RMA or RA for home work. Ignore water based fluxes. Flux cleans the joints and lowers the surface tension making the solder flow much better.

Use the flux!

Don't dwell long with the iron. If the solder joint doesn't work within a few seconds then remove the iron... allow it to cool... come back to it later.

Get some decent solder wick (e.g. Chemtronics Chemwick) and don't get stuff that is too wide - or your soldering iron won't cope. Try 2mm. And/Or a spring loaded hand desolder pump. Don't be afraid to remove the solder and try again on a bad joint. This time with extra flux.

Use the flux!

I'd put all of this ahead of buying a fancy soldering station.

If you'd like a demo of how not to do it then feel free to buy any of my boards :D

P.S. Use the flux!

User avatar
1024MAK
Posts: 6676
Joined: Mon Apr 18, 2011 4:46 pm
Location: Looking forward to summer in Somerset, UK...

Re: Today I built ...

Postby 1024MAK » Tue Apr 25, 2017 11:13 am

cmorley wrote:Soldering just takes
...flux...
Use the flux!...
P.S. Use the flux!

To be fair, if you are using brand new clean components on a new (and clean, and that means no sticky finger marks) PCB, you should not need any extra flux. The flux in the solder is normally enough. One source of grease is humans and their skin. So wash your hands before you start.

If the board is not clean, use IPA and wipe it clean with a clean rag.

Anything that you want to solder should be clean. If in doubt, clean it first!

When working on PCBs that are not brand new, then clean the area first. If only to break through the dirt and any existing old dried up flux residue. If the existing solder is really dull, scrape the surface with a flat bladed screwdriver. Then apply some flux. Now a tinned iron should be able to get the joint to heat up, some new solder will help the heat transfer.

And keep practicing :wink:

Mark

PS I may have mentioned "clean" just a few times :lol:
For a "Complete BBC Games Archive" visit www.bbcmicro.co.uk NOW!
BeebWiki‬ - for answers to many questions...

User avatar
tricky
Posts: 1816
Joined: Tue Jun 21, 2011 8:25 am
Contact:

Re: Today I built ...

Postby tricky » Tue Apr 25, 2017 11:37 am

Do you have any tips for cleaning the iron's tip?
I have a small pile of tips that won't clean and tin with my old RS tip cleaner and tinner.

cmorley
Posts: 215
Joined: Sat Jul 30, 2016 7:11 pm
Location: Oxford

Re: Today I built ...

Postby cmorley » Tue Apr 25, 2017 11:41 am

I use the brass wool type. If they are really badly corroded then you can use emery paper to remove the corrosion and get back to metal, then tin - but this wears the tip out sooner of course!

User avatar
1024MAK
Posts: 6676
Joined: Mon Apr 18, 2011 4:46 pm
Location: Looking forward to summer in Somerset, UK...

Re: Today I built ...

Postby 1024MAK » Tue Apr 25, 2017 11:49 am

tricky wrote:Do you have any tips for cleaning the iron's tip?
I have a small pile of tips that won't clean and tin with my old RS tip cleaner and tinner.

Are the tips copper or iron coated (long-life iron plated)?

Iron coated tips are grey. Copper is err, copper coloured...

With copper tips, if they are badly corroded or pitted, use a file or emery cloth.

With an iron coated tip, if a damp (NOT wet) sponge or "brass wool" don't work, use a ink eraser or PCB cleaning block. If you use something that is too abrasive, you will wear through the coating.

With new (or cleaned) iron coated tips, you have to tin the tip as soon as the tip gets hot enough for the solder to melt. You should also do this with a new or cleaned copper tip.

This pops up with a search. I have not had time to read it all. They may be some useful advice here...

Mark
For a "Complete BBC Games Archive" visit www.bbcmicro.co.uk NOW!
BeebWiki‬ - for answers to many questions...

User avatar
richardtoohey
Posts: 3354
Joined: Thu Dec 29, 2011 5:13 am
Location: Tauranga, New Zealand

Re: Today I built ...

Postby richardtoohey » Tue Apr 25, 2017 11:48 pm

Thanks, guys.

I did try the switch multiple different ways and the notes talked about polarity (but the illustrated switch was quite different to the pushbutton one supplied); will have to have another go and try with the multi-meter. I got it working on the right side but as soon I as soldered it (in exactly the same position, not even removed & plugged back in) it stopped working. Tried twice ... will definitely be me and something simple!

I was most worried about the soldering/killing the IC but in the end the two hardest parts were the switch & resistors. Even with my magnifying glass the resistors were too difficult for me to "read", but before I asked on here I remembered to use my multi-meter and got that sorted.

The next kit I've got in the set is Speak like a Dalek and the final one is Knight Rider lights. Watch this space! :D

User avatar
1024MAK
Posts: 6676
Joined: Mon Apr 18, 2011 4:46 pm
Location: Looking forward to summer in Somerset, UK...

Re: Today I built ...

Postby 1024MAK » Wed Apr 26, 2017 7:06 am

Resistor calculators: digikey.co.uk or hobby-hour.com. There are also apps for iPhones, iPads, etc...

When trying to read resistor colour codes, natural daylight is best. Note that some CFL and LED lamps have a poor colour index, and so some resistor band colours look the wrong colour :(

The first step is to work out how many bands. Then work out which band is the tolerance band. This is easy on 5% resistors, as it is gold. It's less easy on 1% and 2% resistors. Then often you have to work out the value from both directions. Then compare the value to a list of standard values (Wikipedia's entry). The E12 and E24 values are the most common.

But unless you are used to reading the code (and are 100% sure), it's best to check using a meter :mrgreen:

Mark
For a "Complete BBC Games Archive" visit www.bbcmicro.co.uk NOW!
BeebWiki‬ - for answers to many questions...

cmorley
Posts: 215
Joined: Sat Jul 30, 2016 7:11 pm
Location: Oxford

Re: Today I built ...

Postby cmorley » Wed Apr 26, 2017 7:23 am

richardtoohey wrote:Thanks, guys.
Even with my magnifying glass the resistors were too difficult for me to "read", but before I asked on here I remembered to use my multi-meter and got that sorted.


Spare a thought for those who are colour blind! In the 90s I built the Maplin Nicam decoder kit when it first came out... my mother read, sorted and labelled 100s of resistors for me!

User avatar
BigEd
Posts: 1392
Joined: Sun Jan 24, 2010 10:24 am
Location: West
Contact:

Re: Today I built ...

Postby BigEd » Thu Apr 27, 2017 11:40 am

Soldering tip I read recently: Don't try to use the soldering iron like a paint brush. It's not for delivering solder to the joint, it's for heating the two things to be joined. Then you feed solder on to the hot things. (The tinning of the iron is just to improve the heat transfer to the things. Likewise tinning the things.)

User avatar
1024MAK
Posts: 6676
Joined: Mon Apr 18, 2011 4:46 pm
Location: Looking forward to summer in Somerset, UK...

Re: Today I built ...

Postby 1024MAK » Thu Apr 27, 2017 3:24 pm

BigEd wrote:Soldering tip I read recently: Don't try to use the soldering iron like a paint brush. It's not for delivering solder to the joint, it's for heating the two things to be joined. Then you feed solder on to the hot things. (The tinning of the iron is just to improve the heat transfer to the things. Likewise tinning the things.)

That's the first rule of soldering :lol:

Mark
For a "Complete BBC Games Archive" visit www.bbcmicro.co.uk NOW!
BeebWiki‬ - for answers to many questions...

User avatar
BigEd
Posts: 1392
Joined: Sun Jan 24, 2010 10:24 am
Location: West
Contact:

Re: Today I built ...

Postby BigEd » Thu Apr 27, 2017 3:30 pm

Nobody told me about this when I soldered my Compukit... but on the second pass it all worked!

User avatar
dgrubb
Posts: 133
Joined: Thu Jun 02, 2016 8:36 pm

Re: Today I built ...

Postby dgrubb » Thu Apr 27, 2017 3:54 pm

cmorley wrote:Use the flux!


Can't stress this enough. It looks live you've had a few problems getting the solder to flow and adhere cleanly which a touch of flux would help address.

richardtoohey wrote:Not going to get any prizes for my soldering errr "skills" (butchery might be more apt!) but it works. :D


With a little practise you'll be surprised how adept you'll become. :)

User avatar
roland
Posts: 2778
Joined: Thu Aug 29, 2013 8:29 pm
Location: Born (NL)
Contact:

Re: Today I built ...

Postby roland » Thu Apr 27, 2017 8:20 pm

cmorley wrote:Use the flux!


I have never used any additional flux for soldering through-hole components....
256K + 6502 Inside
MAN WOMAN :shock:

User avatar
1024MAK
Posts: 6676
Joined: Mon Apr 18, 2011 4:46 pm
Location: Looking forward to summer in Somerset, UK...

Re: Today I built ...

Postby 1024MAK » Fri Apr 28, 2017 12:04 am

For a "Complete BBC Games Archive" visit www.bbcmicro.co.uk NOW!
BeebWiki‬ - for answers to many questions...

cmorley
Posts: 215
Joined: Sat Jul 30, 2016 7:11 pm
Location: Oxford

Re: Today I built ...

Postby cmorley » Tue Aug 22, 2017 5:15 pm

Today I built...

Photo1051.jpg


Now it is time to put the soldering iron down and step back from the antistatic mat! I think I'll clean and test them tomorrow!

User avatar
flaxcottage
Posts: 2734
Joined: Thu Dec 13, 2012 8:46 pm
Location: Derbyshire

Re: Today I built ...

Postby flaxcottage » Tue Aug 22, 2017 8:20 pm

Veree nice. =D>
- John

Currently running Level 4 Econet with BBC B, BBC B+ 128K, Master 128K, 4Mb A3000, 4Mb A3020, 4Mb A4000, 4Mb A5000 dual FDD; UK101; HP41CX setup; Psion 3a, 3mx and 5mx; Z88; TI-58c, TI-59 and printer


Return to “general”

Who is online

Users browsing this forum: No registered users and 2 guests