Disclaimer: the experiences described here are my personal opinion. I bought the product privately and paid for it myself.
So far I have used “traditional” soldering stations consisting of a base for power supply and temperature control and a handle with heating and replaceable soldering tips, like the Hakko FX-888D.
The crucial thing is the way the soldering tips are heated: the heating element is part of the handle and the soldering tips are only made of metal and are heated by the heating element. As a result, it takes a relatively long time for the soldering tip to reach the temperature of 350 °C required for lead-free solder after switching on. With the Hakko FX-888D this takes about 30-40 seconds. Since the temperature is also not measured directly in the soldering tip itself, the control can react to changes only with a delay.
Due to the long heating-up time, devices of this type also lack an automatic “sleep mode” to reduce heating power if the soldering iron is not used for a few minutes. This can lead to residues on the soldering tip oxidizing heavily and the soldering tip then having to be laboriously cleaned so that it accepts solder again.
Soldering tips with direct heating
As an alternative, a variant was developed many years ago: soldering tips with an integrated heating element and temperature sensor. The handle is then only used to hold the soldering tip and make the electrical connection. As a result, the working temperature is reached 10-15 seconds after switching on and can be regulated very quickly if the soldering tip cools down due to heat loss during a soldering process. This also makes it easy to automatically reduce the heating output during breaks – if the handle is placed in a holder provided for this purpose, the soldering station recognizes this and lowers the temperature to such an extent that the soldering tip can be brought up to working temperature in a few seconds, but there are residues still not oxidize on the surface.
Soldering stations that work according to this principle are e.g. Hakko FX-951 or JBC CD-2BQF. However, these devices are designed for professional use and are therefore relatively expensive with prices starting at about 300 EUR. In addition, Hakko have retained the same cumbersome operating concept of the FX-888D with a simple 7-segment display and few buttons, but you also have to insert a special “control card” to be able to make changes to the settings at all. The JBC model is easier to use, but significantly more expensive and in many cases oversized for the hobbyist.
Pinecil V2
The Pinecil V2 from PINE64 is a compact soldering iron with all the electronics integrated in the handle. The name “Pinecil” is the combination of “Pencil” (pen) and “PINE64”. There is also an extensive wiki page on this.
The construction is based on the structure of the Miniware TS100 and looks very similar to this device at first glance. Soldering tips for the TS100 can also be used with the Pinecil V2. However, there are also fundamental differences if you look at the technical data:
- Firmware: “IronOS”, available at Github
- Microcontroller: Risc-V BL706, 192 kB Flash, 132 kB RAM
- Display: OLED 96×16 pixels
- Powered by USB-C PD 3.0 with 12-20 volts (or 28 volts with EPR PD 3.1) and 3 A or DC5525 connector with 12-24 volts and 3 A.
- Heat output depending on the soldering tips used and power supply from 50 to 126 watts. Temperature range 100-400 °C (the firmware also allows up to 450 °C – however the tips are only specified for a maximum of 400 °C).
- There are shorter soldering tips for the Pinecil V2 with a lower resistance of 6.2 instead of 8 Ω, which increases the power to 88 watts at 24 volts or 64 watts at 20 volts via USB-C PD.
- Motion sensor for automatic sleep mode after an adjustable waiting time when the soldering iron is put down and not used.
- Hall sensor that reacts to magnets and allows the construction of stands where the soldering iron automatically goes into sleep mode as soon as it is put into the stand.
I bought my copy together with a suitable power supply unit, a USB-C connection cable with a silicone sleeve, a tray and a set of additional soldering tips (“gross” and in the short version with 6.2 Ω – ST-I, ST-C4, ST-D24, ST-K). A soldering tip is already included, but only in the conical shape “B2”. However I prefer the “D24” chisel shape or “C4”, which work much better in practice due to the better heat transfer.
Practical experience
The setting options are very extensive:
- Display on request with detailed information on temperature, voltage and power consumption.
- Adjustable time and temperature for sleep mode and sensitivity for motion detection.
- Adjustable time for automatic shutdown.
- Optional limitation of the maximum voltage and power consumption for operation with rechargeable batteries or USB-C QuickCharge.
- Adjustable, regular short power consumption (e.g. 0.5 watts every 4 seconds) for operation on a USB power bank so that it does not switch off due to insufficient power consumption.
- Debug mode for displaying firmware version, hardware properties and device identification to verify authenticity on https://pinecil.pine64.org.
Handling is very comfortable due to the low weight of only 28 grams (including soldering tip) and the rubberized grip area. The distance from the middle of the handle area to the end of the soldering tip is only 7.5 cm, which makes soldering work on small-scale constructions or SMD components much easier. For the cable connection, I can also highly recommend the USB-C cable with silicone sleeve – it is very flexible and heat-resistant, so accidental contact with the hot soldering tip will not cause damage.
As expected, the soldering tip heats up very quickly. Almost 350° C is reached after just over 10 seconds, after about 15 seconds the point is reached where the heating only keeps the temperature at low power, as you can see in the following video:
If the soldering tip has cooled down to 150 °C in sleep mode, it is heated up again within a few seconds to 350 °C and is ready for use.
The temperature can be changed easily using the two buttons. You can also change the step size in the settings from 1 degree to a higher value (in my case I changed this to 10 degrees since I never need to adjust the temperature just by 1 degree). Holding the “+” button pressed activates the “boost” mode which heats up the tip to 420 °C (the temperature can be changed in the settings as well).
In general I have never felt that the soldering iron is insufficient. For me, the Pinecil V2 is a real alternative to classic soldering stations. In conjunction with a suitable power bank or a battery pack, mobile use is also no problem. It’s just a pity that currently (as of February 2023) you can’t get Pinecil’s short soldering tips individually, but only in packages of four. TS100 soldering tips are also available individually, but these are longer and have a slightly lower heat output.
