The user manual shows how to enable write protect to lock the wash count, allowing for a continuous feed system where you don't need to refill/rewind cassettes, but does not go into much further detail on how to set this up. I've picked up the torch and will show in this guide how I have set up my continuous feed, and hopefully everyone can learn from my experience and have an easier time.
- Around 2m of 8mm inner diameter x 10mm outer diameter silicon tubing.
- Approximate cost £6 (~£3/m).
- Ideally the non-rigid clear silicon form as it's easiest to work with.
- For non-destructive attempts, best try smaller, like <5mm OD.
- I used this due to availability and have 3m left over.
- 2x Straight 10mm to 4mm barb fitting hose reducers.
- Approximate cost £8 for brass reducers
- If not using 10mm OD tubing above, make sure you match the reducers to your tubing, e.g. 5mm to 4mm. So long as one side is 4mm, to match Bob's internal tubing
- Brass is good for the long run, although you could probably 3D print these if you are so inclined.
- I used these
- 2x Mason Jars with dispenser taps.
- Approximate cost £10 for simple cheap ones.
- A tap diameter of 8-10mm is ideal, as I did not need any additional sealant for making the pipes leak proof.
- I used these
- Junior Hacksaw
- Scissors
- Needle nose pliers
- Small file
This is fairly easy, there is one larger tab on the top of the black tray (right hand side) which keeps it from swinging out too much. Simply open the door slightly, and gently bend out the bottom of the door frame while pulling on the tray, it should 'snap' out to a near horizonal angle.
Then you can unhinge the draw, by shifting it to the right (the two pegs which hold the tray on slot in to the left). There should be a clear plastic guard at the bottom and you should see the two small tubes going from the tray to the pumps, as well as the cassette chip reader. The tubes are 'locked' into the tray via the custom connectors (which extract the detergent from the cassettes). Simply rotate the underside of the connectors to unlock and pull them out. This can be a bit tricky, so possibly use a set of needle nose pliers. The chip reader is held on at the back by a tiny metal clip. I recommend taking this off last as the thin silicon tubes are far more easily broken by stretching, than the more hardy wires.
With the tray removed, you should be able to see the two pumps which draw controlled amounts of detergent and rinse aid into Bob from the cassette. The Green (left) draws detergent, the Blue (right) draws the rinse aid, from opposite sides of the cassettes via 3mm ID x 4mm OD silicon tubing.
Carefully remove the tray connectors from the tubes. They are only held on by pressure fit, and can be replaced by reducers, and connected to the larger continuous feed tubes.
The connectors look like this:
Once the reducers have been fitted, it should look something like:
It's best to keep as much slack as possible in the small tubes, which is why I have inverted my setup, so the detergent is pulled from the left tray hole, and rinse aid from the right.
Now we have a solid feed from long 10mm tubes, we want to feed them through the tray to the external tanks. These tubes nicely pull through the original connector holes like this:
However 10mm tubes get easily pinched by the front cover of the tray (which can be easily unclipped) and by the bottom of the door as it swings open. To prevent this, I cut a small section from the top of the tray and the plastic cover using the junior hacksaw, and filed them smooth with the small file:
Once the tray is put back on, and the tubes are kept roughly horizonal, these cuts give the tubes just the clearance they need when opening the door:
If you do not wish to make these permanent modifications, it could be possible to use smaller diameter feed tubes and keep the front tray cover off. So long as the tubes are the same or wider diameter than the 4mm internal tubes, the pumps should not have too much strain trying to pull from them.
We want to feed Bob detergent and rinse aid from large, external tanks. I used two plastic mason jars, intended to dispense party drinks. These had annoyingly square taps, but these were easily cut off by a junior hacksaw.
The Bob cassettes primarily feed by gravity, as the small pumps are mainly used to measure precise amounts of detergent for the washes, so you need to set up the tanks in a higher position than Bob. You could even put the tanks directly on top of the unit, however this could get awkward if you are manually filling with water, and potentially dangerous if the rising steam after a wash damages the pipes.
I ran the feed tubes through the taps like so:
Now we have pretty much everything in place, connect the tubes to the tanks, ensuring a good water-tight seal. I recommend having the feed tube sit in the tank and rest at the bottom, so the magical physics of siphoning can allow it to be emptied lower than the level of the tap on the side. Insert the write-protected board removed from the cassette into the tray, and fill the tanks with water and perform a test run. The highly-concentrated detergent is nasty stuff to clean up in case of a leak.
I have noticed Bob does have an on-board counter which decreases after a wash cycle. My cassette is frozen at 16 washes, but after using it once, the display will decrease to 15. This is not written to the EEPROM, as turning Bob off and on again or re-reading the chip will display 16 again, so don't panic when it appears to be going down.
If all goes well and your setup is leak proof, fill your tanks up with the recommended detergent/rise aid and enjoy care-free continuous feeding!
My completed setup:
