Projects with an inexpensive hot air rework station

[Bill Shen]

I purchased a 858D hot air rework station from eBay, it arrived early this week.
 https://www.ebay.com/itm/858D-700W-Electric-LED-Hot-Air-Heat-Gun-Soldering-Station-Desoldering-Tool/223996148019

I purchased it with three projects in mind, but I'm sure I'll have more projects later:
1.  Remove and reuse Altera EPM7064STC100
2.  Remove and recycle 2Mx8 DRAM from SIMM72 memory stick for the ZRC project
3.  Solder MC68EZ328 (DragonBall) BGA to a carrier board.

The first project:  I purchased about 60 of these recycled Altera EPM7064STC100 boards several years ago--no reasons, other than they are too cheap to pass up.  ;-) 

Now I have the right tool to remove it.  It does it very quickly and cleanly.  Chips look good, no bent pins, a few shorts but that's easy to clean up.

Now I need to breadboard one and see if it works and then design a prototype board to use these parts.  (to be continued...)
 

[Phillip Stevens]

Bill Shen wrote:

I purchased a 858D hot air rework station from eBay, it arrived early this week.
 https://www.ebay.com/itm/858D-700W-Electric-LED-Hot-Air-Heat-Gun-Soldering-Station-Desoldering-Tool/223996148019

I purchased it with three projects in mind, but I'm sure I'll have more projects later:
1.  Remove and reuse Altera EPM7064STC100
2.  Remove and recycle 2Mx8 DRAM from SIMM72 memory stick for the ZRC project
3.  Solder MC68EZ328 (DragonBall) BGA to a carrier board.

I bought a 853D hot air rework station some time ago, too. (Actually I bought two, because the first one was stolen from my garage).

The solder iron is a bit weaker (lower wattage) than my Weller, but is still very useful.

It is great option, if you don't have a temperature controlled iron already.

[Bill Shen]

I have a Metcal soldering station for probably 20 years now. It is the standard equipment in assembly floor, not cheap, but reliable and well supported.
Bill

[Jim McGinnis]

Hi.

Does anyone recommend a good training video(s) for using hot air systems like the 858D?

I have never used one but have wanted to be able to prep a fine pitch part correctly, prep the board with solder paste or ???, and just flow the part on.

But I really have no formal training and need hints on how to make good use of the tool without destroying parts (and possibly boards!)

Any recommendations?

Thanks in advance for your most valuable time and contributions...

Jim

[Rob Gowin]

Please be aware that there have been 858D units shipped with incorrect power wiring, potentially exposing users to mains voltages:

https://www.eevblog.com/forum/chat/deadly-wiring-fault-atten-858d-hot-air-rework-station (from 2011).

http://www.williamosman.com/2015/12/dangerous-wiring-fault-858d-hot-air.html (from 2015).

I don't know of the companies involved have improved their QA since then, but anyone using these should open the unit and inspect the power wiring before plugging it in for the first time.

-- Rob

[Colin MacArthur]

I think you are going to LOVE the Hot Air rework unit...

I have 2 on my bench, if not for the Arthritis, I would still be using them...

  
I do still use the Soldering Iron half, as they work better than my OLD one-LOL

CM

[Bill Shen]

I only use 858D for de-soldering right now.  Soldering may be more difficult since I need to dispense solder paste and figure out a visual indication when all pins are properly soldered.  For BGA, when all balls are soldered, the part will sink down due to surface tension pulling it down.  I don't know what the visual cue for leaded SMT are.
  Bill

[Bill Shen]

Continuation of Project 1...

I breadboard one of the EPM7064STC100, dead-bug style, on a single-sided copper board.  The ground pins are bent down to the copper foil, the VCC are bent up to be connected as a ring.  The 4 JTAG signals go to the Altera programming header.  There is a reset button, 8MHz clock and a LED output. 

Just want to be able to program the CPLD and blink the LED with a 23-stage ripple counter. 

It all works, so I'm going to design a RC2014-compatible prototype board based on EPM7064STC100

Before doing that, I set aside a little area on the protoboard to play with WS2812B RGB LED...

  Bill

[Bill Shen]

Added two WS2812B RGB LED to the breadboard.  Designed a state machine in the CPLD to drive WS2812B.  The LEDs are so bright that I can only tolerate up to 25% brightness.  One LED is white color with its intensity driven from 0-25%, the other LED is driven with different color.  Made a YouTube video, but the color is washed out and I have to place a piece of paper over the white LED because it is so darn bright.

https://www.youtube.com/watch?v=PJfW6p1Xw_s

I'm satisfied that EPM7064STC100 has survived the de-soldering process and is working properly.  Next I'll design a RC2014-compatible prototype board using the CPLD.
  Bill

[Jim McGinnis]

Rob,

Thanks for your very important post about potential wiring problems with the 858D unit.

As soon as mine arrives, I am going to do a tear down and see if later production runs have the same risks.

Again, thanks for saving me a bit of smoke and potential pain...

Cheers

Jim

[Mike Strange]

I have very recently acquired an 858D too and am very pleased with it. I will be checking the wiring before I next use it to; thanks for the heads-up.

Mike

[Bill Shen]

The manual router of my old IVEX Winboard does have curved corner capability, so I thought I hand route the EPM7064STC100 prototype board and use curved corners for that "retro" look.
  Bill

[Bill Shen]

Schematic and gerber photoplot of rev4 of ProtoRC based on EPM7064STC100 can be found here:
https://www.retrobrewcomputers.org/doku.php?id=builderpages:plasmo:protorc4
At the bottom of the page is CPLD template with I/O pins assigned as well as an example design that drives the on-board WS2812B RGB LED.
  Bill

[Colin MacArthur]

Another GREAT looking board!!!

CM

[Jim McGinnis]

Hi Rob.

My unit arrived yesterday.

I must offer that this unit is also not safe. No connectivity to the power plug ground pin. It is wired, just no connectivity in the cable whatsoever.

Certainly not "ESD Safe". LOL.

I replaced the power cord (wasn't hard to tear down and replace) and made some measurements. It appears that the power cord was the only defect, so far.

Also, this unit when heating pulses on and off and draws a lot of current instantaneously. I have not measured the peaks. With the wiring inside the unit (wire sizes) it appears marginal.

// SKIP THIS IF YOU DON'T CARE FOR RANTS  ;-)

It is really aggravating the degree to which the Chinese Communists apply quality inspection and certification labels when it is obvious that their measure of quality often only means "ok to sell and make money."

They have no liability path back to them for issues we experience. None whatsoever. They have no incentive to make the product meet reasonable tests of quality and safety. They dodge liability even on EBAY and Amazon. The unit is probably sold by dozens of vendors - the packaging and unit have no markings differentiating the source of manufacture. So, the same factory can supply numerous vendors and if a vendor has bad reviews, they stop supplying the vendor and start supporting a brand new one.

And they have now set up local (domestic) suppliers that are just a front for their CHINA factories. As if this makes a difference other than ship time - which wasn't great from their NJ source. It was slow.

How many vendors have no reviews? Wonder why a product that has been available for a long time has a vendor with no reviews?  I don't. It just makes me suspicious of product quality.

// END OF RANTING

Cheers!

Be safe!

Jim

[Alan Cox]

That's not usually how it works. A lot of the stuff that is pedalled abroad by the unscrupulous wouldn't actually pass muster and be sold in the originating country. Quite a lot of the people involved are not fronts to some sinister plot either - they are people who've figured out a way to make money and as with any country not all are iffy. China btw has pretty decent quality control and safety regulations. It (like the USA) has some serious enforcement problems.

The real problem is that they can dodge liability law, because amazon/ebay are allowed to act as fronts for all of this stuff but deny they are the importer or seller in any way (in fact in many places you'll find you committed the offence of importing dangerous uncertified goods if you try and report it!). No liability law leads to totally quality failure. That's why all computer software sucks, because the software industry is unique (except for religion) in somehow managing to dodge all liability law.

If you deal with reputable Chinese businesses who sell goods through proper channels then it's no different to dealing with anywhere else, if not better than some. If you buy something on the cheap from a person you've never heard of, at a residential address you've never heard of and with no sight of the goods or reputable recommendation it doesn't matter where it comes from you'll get what you paid for!

Alan

[Jim McGinnis]

I just watched a video from a guy claiming the 858D is unable to go beyond 220 degrees C. This is unfortunate misinformation. Possible the unit he received?

I just calibrated the 858D at max temperature (450 c) and the unit was easily able to reach the temperature set point. Calibration at that high temp is a bit touchy since the CAL pot gets sensitive at that setting. But it can be set close enough (+-10 C).

Then collected temps (C) per setting (dwell time about 2-3 minutes after temp appeared stable):

Setting        Actual

450 (cal)       450 +/- 10 

400              378

350              340

300              297

250              253

200              212

150              172

100              125

Temperatures were measured with a proper thermocouple to a Fluke 287 meter with recent calibration - not that it is needed for this type of gross experiment.

This is good performance for the cost.

YMMV depending on the unit you receive.

As I indicated at the start, some youtube videos contradict these results.

Cheers

Be safe...

[Bill Shen]

Didn't submit the board to JLCPCB until last week.  This is what it looks like assembled.
  Bill

On Thursday, June 25, 2020 at 2:59:03 AM UTC-6, Bill Shen wrote:

[Sergey Kiselev]

And here is another option if you want to play with CPLDs or practice your SMD soldering skills:

My MAX7 Proto board - small form factor, breadboard compatible, includes an optional 3.3V LDO, so that (still in production) MAX7000AE CPLDs can be used.

https://github.com/skiselev/max7_proto

I have a couple of OSH Park made PCBs left. I can put them in a letter envelope and send them (for free in the US), if any of you are interested.

Cheers,

Sergey

[7alken]

hi, hotair will be in action for sure on this samsung beast K5L6331CAA-D270 (NOR Flash + ""UtRAM"" async at 3V0) and Dragonball 68ez328 in BGA144, together with MHP30 from bottom ...
cant wait when the beast lands here (first try expired for some reason, but they are still somewhere...) - I just want to glue them together as tiny 2-chip m68k system ... will see;
Petr

[7alken]

btw that NOR flash + UtRAM (quite slow?) weirdo discussed here, together with something about tight timings etc
https://chatgpt.com/share/68c7bab1-6530-8000-bf5d-bde92832a35f