They are nowhere to be found in the TE store.
Thats what i was thinking This afternoon as well. Where are the sensors And the orange tray
Ya know, I’ve brought up the sensors and the TE sneakers in the Ohpeewon forum and I don’t think many people bought into it here. To me, it seems it would be fun to experiment with, especially if you own the oplab.
I emailed them about the sensors, and they said that they’re all “on back order with no definite time as to when they’ll be back in stock” or something cryptic along those lines. I know they were not the best sellers, but now that Oplab is functioning better, I think they could sell a few more. I’m looking to buy myself 
You can make the sensors. The accelerometer is a part you can get for Arduino projects. The pressure sensor is just a piezoelectric transducer (Radio Shack buzzer innards). The drum is similar.
Check out the Adafruit website. Do a little soldering to mini leads. Voila!
I sent an email to TE and just got the reply that the sensors are discontiued and will not be available again. 
The tray was never available either. I asked once
So… is there anywhere that ideas and tutorials on how to build different sensors and things for the Oplab are published and discussed?
I’ve just bought the Oplab and would like to have something easy to start with and get into it.
get a sensor put it to input and ground.
Some sensors are for sale in the London popular store. They had the trainers at least;