Series 1 problems and solutions

2018-03-17 The Series 1 printer is _still_ currently inoperative. Russ Nelson and Vic Aprea spent some time poking around and found the following to be true:

1. The current pronterface does not support 230400 baud naturally. The source needs to be patched in the printerun/gui/toolbar.py and settings.py files to add it to the list. grep -r 115200. for a hint as to where to find the changes. We were unsuccessful in doing this on Windows or Mac, but Linux worked pretty easily (some python easy_installs later). 2. X, Y, and Z stages worked OK 3. Z limit switch is still FUBAR'ed 4. Encountered some thermistor weirdness / errors. But we made them go away mysteriously (possibly indicative of flimsy wiring or thermistor intermittent connections, but that's just speculation). 5. The biggest problem is that the extruder seems to be slipping. When external pressure is applied to the idler wheel (i.e. Russ pushing the filament down), it seems to feed about the right amount, but failing it seems to fall short.

The Series 1 printer is currently inoperative.

There are currently three main problems and two upgrades that need to be completed (edit date 1/19/2016):

1. The new E3D hot-end was installed in November, and is still not extruding plastic correctly. Research and process of elimination suggest that the root cause of this is probably related to firmware tuning, which means that the code on the microcontroller that runs the printer needs to be updated. This process is time consuming, and is important to get right. We hope to have the firmware upgraded before January 31, and hopefully that will solve the problem. ***UPDATE*** The printer behaved for a few prints on 1/21. We're making progress and seem to be on track for a 2/1 up-time restart.

2. The z-axis limit switch is flaky-- the post that actuates the switch proved to be too short for the new hot-end, and has been replaced with a temporary fix. Additional engineering is required to make this switch operate properly, ensuring that the printer can be leveled correctly.

3. The wiring needs to be redone. When the new hot-end was installed for testing, we didn't have the correct connectors to make quick-disconnects for the hot end, thermistor and cooling fan. The connectors need to be installed and wiring needs to be routed correctly through the cable harness back to the RAMPS 1.4 microcontroller board.

Steps for fixing the Series 1:

A) Update and test the printer firmware. We think the problem rests in the fact that the printer now uses a different thermistor, and a value in the code needs to change, and PID loop autotuning should be completed, and detailed testing shold be performed to ensure the extruder is working properly.  Click here to see the steps involved in updating the printer firmware.

B) The z-axis switch should be re-engineered. The switch and actuator don't line up correctly, and the nut assembly that holds the actuator has always been troublesome.  In addition, the actuator itself is a temporary fix, and should be replaced.  Making sure the z-axis stop switch is repeatable is very important to making sure the printer bed is level, and is a huge factor in making successful prints.

C) Connectors have been ordered and need to be installed, and the wires need to be rerouted correctly once the printer is working properly.

Additional upgrades that are planned include:

- engineering of a new, heated print bed. The heated bed will allow printing with "exotic" filaments like nylon, bronze, carbon fiber, etc. There are currently several obstacles to finishing the heated bed upgrade. Some components have already been purchased, but other items need to be procured. A complete accounting of this upgrade can be found here: Series 1 Heated Bed Upgrade.

- "headless" printer control with Raspberry Pi and Octoprint. This upgrade requires a dedicated Raspberry Pi, but would allow users to connect wirelessly to the printer to start jobs, get progress alerts, and watch print progress on web camera.

- full software toolchain renewal. The current linux machine is badly in need of a system wipe and full reload. When the machine is renewed, we will reload the latest versions of printer control software and provide how-to instructions.

- a new filament spooling arrangement. The Series 1 is configured for 1.75mm filament. The current filament dispenser system is kludgy, and needs rework. Care should be taken to protect expensive filament from dust and moisture. New "exotic" filaments need special care and should have dedicated storage solutions.