[Elecraft] K2

[Josh Fiden]

Sorry, that simply is not true. You don't understand how these Metcal, 
newer Hakko (and other) irons work. Our production facility produces 
thousands of through-hole boards per month. After testing the newer 
soldering stations we immediately started replacing conventional Weller 
WTCPT and Hakko 936 irons because both time per joint is faster and 
temperature is more consistent as you move to the next joint.

These newer designs intentionally use tips with low thermal mass, have a 
fast control loop (rather than slow on/off cycling), and sense 
temperature at the tip. Adjusting the iron temperature is normally not 
required because the iron instantaneously provides more heat to maintain 
the set temperature. If the rate is too slow, you would first look at 
tip geometry to more efficiently transfer heat.

This document describes the functional difference between conventional 
vs new irons.
http://www.eis-inc.com/Files/pdf/supplier_showcase_page_downloads/oki/Tech_Note_High_Throughput_With_SmarHeat.pdf

73,
Josh W6XU

On 6/2/2016 10:25 AM, Don Wilhelm wrote:
> That "rule" still applies - if less than 2 seconds, reduce the iron 
> temperature, if longer than 3 seconds, increase it.
> A lot will depend on the size and heat mass of the soldering tip more 
> so than the recovery time of the iron.  A quick recovery is fine, but 
> is not the whole story.
>
> 73,
> Don W3FPR
>
> On 6/2/2016 12:43 PM, Josh Fiden wrote:
>> I would respectfully disagree with this advice. It is dependent on 
>> the type of iron you're using. The Hakko FX-951 behaves quite 
>> different from the traditional temperature controlled stations. It 
>> has very fast thermal recovery, so typical through hole pads will 
>> flow in much less than 3 seconds, but not because the iron is too hot.