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JamesJmcGEE
09-16-2006, 04:25 PM
I want the hobby cnc board but I have never tried anything like PCB soldering, wires yes, welding yes. Is it hard to do? Any special tools? I'm not a klutz, I can do a lot of things I have just never attempted it. Is there a tutorial or something somewhere? Have any of you tried it as a first attempt?
Should I try something else first? Any help will be greatly appreciated.
Thanks
J,

fkaCarel
09-16-2006, 04:54 PM
The trick is as always in the tools. If you approach soldering from a plumbers point, such as high power soldering iron and big soldering wire, you can create shorts and damage the PCB. If you can afford it, buy a regulated solder station, they keep the tip at a constant temperature. Buy one with replacable tips and if possible nickel plated tips. Nickel plated lasts longer. Use a fine tip and thin solder wire. I use 0.7mm (0.0275") flux core wire. For removal of excess solder use desoldering wire, least risk of damage.

diarmaid
09-16-2006, 05:08 PM
Hey, this is really good. Any more soldering suggestion from anyone?

Im waiting for my HobbyCNC Kit to arrive, already bought it. I've only done a very little amount of soldering and I dont even own a soldering iron, but likewise with James regarding I should be able to do it ok I think.

James, if you haven't gone ahead and bought it before I've done mine I'll post pics and keep you udated on how it goes.

fyffe555
09-16-2006, 05:29 PM
Carel's covered it. Right tools, right solder, keep it clean, practice till the joints are shiney.

There are some good soldering tutorials on the web, do a search. Here's one of the better; http://www.epemag.wimborne.co.uk/solderfaq.htm

pminmo
09-16-2006, 05:34 PM
If you can weld, solder is a piece of cake.

If your not doing any really fine stuff, and I don't think it's required with the new HobbyCNC board. A simple 25watt soldering iron will do with a normal tip for electronics. (very fine to plumbers :-) ) A RadioShack http://www.radioshack.com/product/index.jsp?productId=2062737&cp=2032058.2032236.2032313&pg=2&parentPage=family will do fine. Or for a few bucks more: http://www.mpja.com/listitemsdirect.asp?dept=480&main=79&item1=15860+TL&item2=15845+TL&item3=15140+TL&item4=15141+TL

Invest more if your going to do more soldering and want something for 15 years or so.

get a piece of copper perfboard and some 22 gauge wire and practice before you start on the kit.

diarmaid
09-16-2006, 05:40 PM
lol. when I opened that radioshack site the first thing that loaded was their advertisement for something worth $300. When I just saw the $300 I nearly had a heart attack!!! :)

fkaCarel
09-16-2006, 05:55 PM
When I just saw the $300 I nearly had a heart attack!!!
But if that was the price for the soldering iron for your pacemaker, it would'nt be a problem, not?:D

JamesJmcGEE
09-16-2006, 07:55 PM
I have a heavy duty weller pencil 80 watts I think, I also hav a cheaper 15 watt pencil, I belive eithier will work, the 80 is like 900 degrees.the other is 750 or so. I am going to place my order and hope I can pull it off, Thanks for the links and tips!

smarbaga
09-16-2006, 09:43 PM
some older components get corrosion or get tarnished.
the cleanest pc board, solder ant tip won't fuse these.
the leads would have to be sanded with 400 grit emery.
older solder gets dirty as well and may have to be cleaned.
it is very importana to get the proper solder.
60/40 flux core. ( kester or multicore )
and 27 to 35 watt iron for component leads.

NC Cams
09-17-2006, 01:09 PM
PCB soldering is both a skill and an art that uses science as a critical part of the process. Practice does make perfect

Digikey and Mouser sell soldering irons that are suitable for PCB use. I like the Weller brand and you can get new tips for them - not the case with the Radio Slack stuff as it is mostly imported. Besides, the way Radio Slack is going anymore, you never know if the electronics stuff will be replaced with cell phones or RC models the next time you go in.

A 15-20 watt iron will do a nice job on PCB's providing that you use the proper grade and size of rosin core solder suited for electronic work. The small diameter 0.030" or so diamter stuff melts readily and you don't have to heat the board super hot to get it to flow. WIth care & practice, a 30 watt iron is a bit quicker and easier but it is NOT for beginners.

When soldered, the joint should look shiney and almost wet - not globbed or hazy or frosted.

A neat trick to desolder thru hole solders that is less stressful than the wicking tape/braid involves the use of compressed air.

Tape off the area around the joint to mask it. Then heat the joint with a hot iron on the pin side OPPOSITE the part to be removed. When the joint is still hot/wet/liquidy, hit it with a blast of compressed air from the pin side of the joint (the masking helps cleanup of solder blown from the hole).

This should blow the solder up into the part to be removed. If you do it right, the pins should be solder free, the joint should be solder free (asside from the tinned area) and you can lift the part free by gently prying it up and out of the board.

A badly oxidized solder joint won't melt easily. Sollution: add new fresh solder until it is shiney and silvery again. It will then 'blow free' with the heat/air jet trick quite readily.

martinw
09-17-2006, 08:53 PM
PCB soldering is both a skill and an art that uses science as a critical part of the process. Practice does make perfect

.
This is through-hole advice only. NOT SMT.


First of all, clean up the copper track on the PCB with a fibreglass rubber. You can buy these from electronics suppliers. You can also get fibreglass- tipped pencils for the same purpose.

Most through-hole components are pre-tinned. There is no need to prepare them.

All you have to do is to heat up the copper PCB track and the component lead at the same time. Then you apply solder. Do not put solder on the tip of the iron. Just apply solder to the pre-heated track and component lead.

Job done. NC Cams is right. Practice makes perfect.

Best wishes,

Martin

Megahertz
09-19-2006, 02:36 PM
I also try to touch the copper solder pad and the component lead at the same time. When the joint is hot, I touch my solder wire on the opposite side of the component lead and let molten solder flow into the joint. (Molten solder follows the heat). I also prefer 63/37 tin-lead ratio solder.

bill south
09-19-2006, 04:05 PM
And don't forget, check and recheck the component layout and value for correctness prior to torching the board. Soldering is much easier than desoldering and resoldering. BTW, try to use as little heat as possible to prevent damage to the heat sensitive components. If it's taking a bit longer to heat the joint, lift for a sec and try again. Good luck.
Bill
:cheers:

fkaCarel
09-19-2006, 05:10 PM
If it's taking a bit longer to heat the joint
This is what I call the hesitation. Time to check the tightening nut on the Weller. The nut runs loose in the end because of the thermal cycles, while temperature is controlled by a magic magnetic, lenght sensitive thermostat.
For SMD I spray generously with flux, it cancels out hesitation and the stickyness helps keeping parts in place. Flux sprayed after the board is ready also helps to keep it shiny till assembly is done.

JamesJmcGEE
09-19-2006, 07:36 PM
I Like this site, I'm pretty much getting the short course on soldering, I think I have learned more reading these post than I would have ruining a couple good boards with the trial and error process.
You guys are great!
Thanks

paulC
09-19-2006, 10:07 PM
The soldering iron tip is most importent.
You need a clean tip that is hot enough and tinned before you place it anywhere near your board. If you can't melt solder with a touch the iron is too cold or its dirty. You may need to clean the tip with a bit of sand paper and tin it immediately.
It should be cleaned regularly while soldering to remove impurities that will build up. The occasional quick wipe on a paper towel or damp sponge is all that is needed.
The flux cleans the board of oxidation etc as you heat it so this will build up on the tip.

martinw
09-20-2006, 07:13 PM
The soldering iron tip is most importent.
You need a clean tip that is hot enough and tinned before you place it anywhere near your board. If you can't melt solder with a touch the iron is too cold or its dirty. You may need to clean the tip with a bit of sand paper and tin it immediately.
It should be cleaned regularly while soldering to remove impurities that will build up. The occasional quick wipe on a paper towel or damp sponge is all that is needed.
The flux cleans the board of oxidation etc as you heat it so this will build up on the tip.

Dear paulC,

This is excellent advice.

My only two cents is that if you use a paper towel to clean the iron tip, you usually burn your fingers. As you suggest, a damp, NOT WET sponge does a far better job. A sponge, usually about a quarter of an inch thick, usually comes on top of most electronic soldering stations. Just keep it damp, and wipe the tip of the iron on it between joints. If the tip of your iron is covered in crud, you really do risk the possibility of a dodgy joint.

Best wishes

Martin

paulC
09-20-2006, 08:47 PM
Another thing some people may not be aware of is the flux to use.
Most cored solder will have talow as the flux. This is ideal for electronic work.
Do not use a plumbers flux when soldering components. These are normally hydrocloric acid and will cause problems. They can be used when tinning the board but it is important to wash the board after.
Fluxes all give off toxic fumes so be careful. I used to have a fan blowing across the work bench when I was soldering for hours on end just to stop inhaling the fumes directly.

pminmo
09-21-2006, 01:14 AM
Just to add 2 cents, I tin my irons with silver solder before I ever use them. I find it keeps the fine tips in better condition MUCH longer.

Megahertz
09-21-2006, 02:29 PM
Another tip is...

Don't light your cigarettes with your soldering iron.

diarmaid
09-21-2006, 02:34 PM
What is tin-ing the irons ?

paulC
09-21-2006, 06:37 PM
What is tin-ing the irons ?

Its the process of covering the tip with new clean solder. Some tips are coated and don't need a lot of maintaince. You just let them heat up give them a wipe and melt new solder over the tip. Non coated tips may need sanding or filing to get them back to clean metal then immediatly coating with solder. This clean solder transfers heat to the work in the most efficent manner. A dirty tip will result in dry joints or you holding the heat on the board for to long. This heating too long can result in the copper lifting off the board or component damage.

martinw
10-09-2006, 07:32 PM
I want the hobby cnc board but I have never tried anything like PCB soldering, wires yes, welding yes. Is it hard to do? Any special tools? I'm not a klutz, I can do a lot of things I have just never attempted it. Is there a tutorial or something somewhere? Have any of you tried it as a first attempt?
Should I try something else first? Any help will be greatly appreciated.
Thanks
J,

Dear James,

One other thing, clean the flux off all the joints on the underside of the board with some solvent when you have completed your soldering. Do not put off this job. It gets harder with time.

Best Wishes

Martin