More IR6500 tweaks - silencing fan - fixing flipped polarity of thermocouple socket - adjusting temperature offset - run bottom heater independently

Silence the fan

The fan is annoyingly loud. It is a line voltage fan, so you cannot just put some PC fan in there. The remedy is simple. I used four rubber mounts I had left over from my last PC build. I dumped the grill. It is unnecessary.

What a relief!

Non-standard K-Type socket polarity

This device is full of surprises. I damaged the original thermocouple recently and plugged in another K-Type I had lying around. Surprise! The temperature figures were going down instead of up when I heated it.

Why was that? For what reason ever, they managed to flip the polarity of the K-Type socket. It is non-standard! The original sensor also had the polarity wrong. Dafug?

It is easy to fix though. Just open the bottom cover, unscrew the wires and put them back on in reverse.

To make positioning of the sensor possible without fiddling with tape, I bough an adjustable holder HERE. The integrated magnet is too weak. I glued a powerful neodym on top of it. This thing sticks!

Very nice, sensitive, yet a little fragile sensors are THESE. They need a readjustment of the controller, which I will address next.

My sensor setup looks like this:

Adjusting temperature offset

The new sensors were off by a few degrees and I investigated possibilities to fix this. Thankfully there is a decent manual available for the controller. The manual that came with the IR6500 is utter useless.

It works like this:

• Measure the temperature in boiling water to get the difference to a reference  My new sensor was 6°C off in reference to 100°C.
• Press PAR/SET and hold until the controller switches to configuration mode. You will see some text instead of the usual temperature reading.
• Press PAR/SET until OFSt appears.
• Use the arrow keys to offset the difference.
• Press PAR/SET until the normal display returns.

Run bottom heater independently

It always annoyed me that it wasn't possible to use the preheater alone, without running a program. I like to have the bottom heater at its max temperature and the board pre-heated before I even start the reflow process.

It is easy. All you need is three wires and a toggle switch.

The bottom controller's terminals 4 and 5 output the control voltage for the heater power relay. Terminal 5 goes straight to the relay. Terminal 4 is looped through the main controller's terminal 7, which gets connected to terminal 6 when a program starts. Terminal 6 goes to the heater relay.

• Remove the wire between main controller terminal 6 and the bottom heater switch.
• Wire the toggle switch to choose between terminal 4 of the bottom controller and terminal 6 on the main controller. The common wire goes to the heater relay.

In ON position the bottom heater controller works independent from the main controller. With the temp set to 300 I get around 110°C on the upside of the boards.