The mission of Pax Instruments is to make opensource lab instruments, the essence of which is the creation of tools to enable your creativity. As we have seen with electronics design and 3D printing over the past few years, amazing things happen when people gain access to new tools that are useful, usable, and affordable.

Over the past few months we have refined what Pax Instruments means to us and developed several major goals. The one we would like to share today is that we will be creating a series of lab instrument development tools, so you can design and customize lab instruments to your specific needs.

The first step is to make available the custom components of the T400. This includes the injection molded enclosure, compression molded silicone keypad, LCD, and thermocouple connector. Keep an eye on our store and expect to see parts available some time in May. Our products will remain affordable and non-proprietary. All source files can be found on our Github repository.

With this goal we have made several decisions that affect our production schedule. In short, shipment of the T400 is projected for May 2015. While we would love to ship today we have to make the T400 the best we can. We appreciate all the support you have given us and look forward to giving you our best.

Now for a progress report…

The LCD we are using is a modified off-the-shelf part from our manufacturer. The LCD normally comes with a twelve pin 0.5 mm pitch connector, but the surface mount connector is very difficult to solder to the PCB. We decided to customize the cable with a 1.0 mm pitch connector. The PCB connector is a dream to solder and will easily incorporate in your custom PCB.


Final payment for the PCB purchase order was executed yesterday and the LCDs arrived today.


Thermocouple connector
The T400 is compatable with standard mini-thermocouple connectors. There are compatable PCB connectors on the market, but they are too big for our design. To meet our needs we have developed a custom thermocouple connector.

We are reviewing the design this evening and will be ready to start production on Monday. With a lead time of two weeks, we should have connectors by April 6th. There is a small risk that the design will not work and we would have a few days of redesign and another two weeks for production.


The enclosure requires several small changes to increase strength. We are also removing the embossed Pax Instruments logo and moving it to the label on the front, so the enclosure is more suitable to custom devices. These changes should be finished in the next two days. The top panel that interfaces with the thermocouple connectors are dependent on the custom thermocouple connector and cannot be approved until we approve the connector. This means we cannot start mold production until April 6th. We would then have our first samples at the beginning of May.



In the electronics we updated the soft power circuit to solve a small electrical problem. The PCBs landed today and we’ll have it tested and confirmed by Friday. We’ll have to make at least one more board revision for accomodate the custom thermocouple connector. In the mean time we can confirm the electrical design and begin ordering parts. The inal PCB design will be approved when we have our first enclosure samples in the beginning of May.

We could approve the PCB design based on the SLA print of the enclosure, but that’s just asking for trouble. Murphy’s Law dictates that doing so would result in a mold problem that will mismatch the PCB and enclosure. Instead, we are going to approve the PCB design based on actual injection molded samples. Once approved, we should have assembled PCBs in two weeks.




The firmware is looking good. We had a great leap forward in saving memory space with the SD card library, which will allow the T400 to support FAT32 rather than just FAT16.

At this point there is no concern with the firmware. The firmware will be finished in plenty of time for through testing. The goal is for users to never have to upgrade their devices to fix bugs.