Buying soldering iron

[Sadlercomfort]

Hi Guys,

I'm looking to buy a new soldering iron, nothing to expensive around £40 or £50

Does anyone know what material the tips should be made of? When I last Brought a cheap soldering iron the tips were poor quality.

I found this one on ebay which looks quite good:
http://m.ebay.co.uk/itm/291619062154

 

[(*steve*)]

The brand of iron matters less than the fact that you can use brand name tips.

This lets you source known good tips. It can make a significant difference!

 

[KJ6EAD]

The station you linked is a clone of a Weller WLC100 so Weller ST series tips will probably fit. This selection of tips is limited. There are several screwdriver and double bevel tips but only one single bevel.

 

[Sadlercomfort]

The brand of iron matters less than the fact that you can use brand name tips.

This was hopefully the idea!

The station you linked is a clone of a Weller WLC100 so Weller ST series tips will probably fit.

I've checked the St series tip dimensions against the ones provided with the clone. They seem really close +/- 1mm from what I can see.

Weller tips are definitely the way to go, I'm going to be using this a lot.

 

[hevans1944]

There may be a difference in the temperature sensing element that could make the Weller tips incompatible with the import version. But at that price, you can buy and try without being out too much cash. As for the tips, make sure you keep them well-tinned, wiping on a damp sponge between use, and periodically adding solder to the tip and wiping it off. All tips will eventually dissolve in the solder over time, but as noted some are better than others. If you are planning to do any SMD work, you need a smaller iron. I saw a new one recently that has a three-ring plug on the end that mates with a barrel jack for easy interchangeability with different tips. I don't remember where I saw this (might have been in Elektor magazine) but I am definitely interested in it. More later if I find it again...

Hop

 

[Sadlercomfort]

I've brought some good quality tinner aswell, which I will keep on top of the unit. I've brought it now an will see if they are compatible.

I already have a hot air station which works great for smd components. . Not to mention the heat shrink =)

 

[Sadlercomfort]

Does anyone know where to buy the Weller St series tips? I only saw one on farnell, buts it not worth the money.. its from USA so I'd have to pay extra for shipping.

There's a few on ebay, but I'm not sure if they are originals or not. Some ebay listings dont show a proper picture of the items.

Anyway to telll if they are original weller tips?

Thanks,
Ash

 

[Sadlercomfort]

There may be a difference in the temperature sensing element that could make the Weller tips incompatible with the import version. But at that price, you can buy and try without being out too much cash.

How does the sensing element work? Put simply..

 

[(*steve*)]

There are a couple of ways, however it boils down to either a temperature sensing element or a temperature sensitive switch.

A sensing element (perhaps a thermocouple) may be integrated with the heating element and this is the technique used for irons where the temperature is variable.

If a temperature sensitive switch is used, the temperature is either fixed or can only be changed by swapping out the switch. In a few cases you can have an adjustable thermostat but the last time I saw one of these was a long time ago.

A temperature sensitive switch is usually slower and leads to more temperature fluctuation. The exception is the Weller irons which take advantage of the curie point of part of the too to switch the power to the element. Because the temperature sensing element is part of the tip you need to change tips to change temperature, but because the temperature us measured right at the tip and because the hysteresis is low, the temoerature control is very good.

 

[hevans1944]

There are two common methods: a thermocouple or a magnetic switch that operates at the Curie temperature. The latter was patented, but I am sure the patent has expired by now. A thermocouple produces a micro-volt signal at soldering temperatures so some signal conditioning is required. There may also be temperature-sensitive resistors or thermistors that respond in the range of soldering temperatures, so less signal conditioning is needed.

My Weller irons use the magnetic switch method. A permanent magnet in the body leading to the heating element in the tip closes a switch in the replaceable tip. The switch becomes "non-magnetic" at the Curie temperature, releasing the magnet and opening the switch. When the tip cools down a below the Curie temperature the magnetic attraction is restored, the switch closes, and the tip is heated again. The cycle repeats as long as the iron is on. Weller sells tips for three different temperatures, but I use the 750 F tips most of the time. IIRC, Weller also sells a variable temperature controlled soldering station. I assume (I don't really know) that this uses either thermocouple or thermistor sensors to measure and control tip temperature.

 

[Sadlercomfort]

Thanks guys! Great to know..

I came across a nice Weller iron once which was pretty neat. It used tips with three different temperatures. WTCP51 I think.

I'm going to buy some tips for the WLC100 clone i brought..