DIY basic hot air station - Page 1
Forum section: electronics / projects

author: SuperGiachi
author_rank: Contributor
timestamp: December 14, 2018, 09:05:03 pm
content: Hi, I want to build a very simple DIY hot air station to solder/desolder difficult SMDs such as QFNs, large QFPs, etc. I will use an ATX PSU to power the whole thing. I was thinking about winding a heating coil around an insulator(mica, duratec and comparable stuff) and controlling how much power goes through it by a simple PWM signal outputted by an Arduino. Temperature control would easily be done by a thermocouple. Air would be provided by a small fan mounted inside the handle(i don't need this thing to be small, I don't need to use it every day.)Are there any mosfet capable of 30-40A that can be directly driven by the arduino or do I have to use a smaller mosfet to drive a bigger output mosfet? I would use a low switching frequency because i don't need this thing to be extremely accurate.And no, I'm not buying a cheap chinese station, want to DIY it.Do you think it would be a good idea to try to build it?(again, it is not something that's going to be used often)Thanks in advance!

author: wasyoungonce
author_rank: Frequent Contributor
timestamp: December 14, 2018, 10:31:09 pm
content: IMHO by the time you defogger and build it and fix issues you could buy at least qty 2 good hot air stations Hakko or such like. There are other quality mfgrs as well

author: SuperGiachi
author_rank: Contributor
timestamp: December 14, 2018, 10:42:32 pm
content: Is there anything of a decent quality under 300-400 euros? I can't afford a 700+ fr-810b right now.

author: sleemanj
author_rank: Super Contributor
timestamp: December 14, 2018, 11:02:26 pm
content: There is nothing wrong with the various Chinese hot air stations, such as the 858 / 858D for $30 - $40 from Aliexpress.As usual just open it up when it arrives and double check the wiring looks OK, and that the exposed metal on the handpiece is grounded.Building a hot air station seems like an exercise in futility, and buying an expensive one... well, I reallly don't know what sort of additional features would make me buy an expensive one over a cheapy.

author: tsman
author_rank: Frequent Contributor
timestamp: December 14, 2018, 11:14:01 pm
content: If you're determined about making your own then consider just buying a handle assembly which includes the heater and fan. You can then construct your own controller for it. Not sure how worthwhile it is to do this except as a learning experience though but it'll be a lot easier than DIYing the entire thing from scratch.

author: Nusa
author_rank: Super Contributor
timestamp: December 15, 2018, 12:50:28 am
content: Quote from: SuperGiachi on December 14, 2018, 10:42:32 pmFind Quick 861DW from some place convenient to your location. It should do the trick.

author: james_s
author_rank: Super Contributor
timestamp: December 15, 2018, 01:00:24 am
content: I don't like cheap Chinese soldering irons, but the cheap hot air stations seem to work just about as well as the expensive ones. I like to build things but I wouldn't bother building one of those.

author: DaJMasta
author_rank: Super Contributor
timestamp: December 15, 2018, 01:13:32 am
content: Quote from: james_s on December 15, 2018, 01:00:24 amYeah, I've got a Hakko FX-951 and it sits on my WER (WEP?) 858D. It's not as nice, a more expensive station will be more accurate with the temp, will be more powerful (heat and airflow) and can be quieter.... but unless you're working with very small pin pitch or high pin count large chips, the cheap 858s do a pretty good job. The quick seems like a step up, and is around the ballpark of an expensive air rework station from a big manufacturer... and the 858 is perfectly serviceable for most tasks, especially if you have a preheater (for big boards and chips) and are careful with your temperatures.I've gone down to 0.5mm or so pitch TQFPs and things, and have done work on 6+ layer boards, large packages with heat tabs, DIP IC removal from just the top of the board, QFNs, etc. with my 858D and the only time I've made a board layer bubble was in desoldering parts from a board I was salvaging. It may not be the ideal hot air station, but it is a hell of a value.