From 231b75eca939ceb042fecddf2517bb18d306a1a6 Mon Sep 17 00:00:00 2001 From: Anders Einar Hilden Date: Sat, 17 Jun 2023 19:49:36 +0200 Subject: [PATCH] Add more info on printed parts to README.md (#123) Co-authored-by: Scott Bezek --- README.md | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/README.md b/README.md index 5873ac6..30c6073 100644 --- a/README.md +++ b/README.md @@ -61,8 +61,6 @@ View the latest auto-generated (untested) [Base PCB Interactive BOM](https://sma A few miscellaneous notes in the meantime: - - This can _probably_ be FDM 3D printed with a well-tuned printer, but the parts shown in videos/photos were MJF printed in nylon for tight tolerances and better surface finish - - If you wanted a simpler build, you could omit the LCD and just merge the knob + glass from the model into a single STL to get a closed-top knob - There's limited space inside the LCD mount for wiring, and 8 wires need to fit through the hole in the center. I used 30 AWG wire-wrapping wire. Enamel-coated wire would probably work too. - Strain gauges are BF350-3AA, and glued in place with CA glue (I'll include video of this process in the future, but essentially I used kapton tape to pick up the strain gauge and hold it in place during curing). This has to be done after reflow soldering, and would be hard to remove/fix in case of a mistake, so MAKE SURE TO PRACTICE GLUING strain gauges to other items before attempting on the PCB! - The TMC6300 is _tiny_ and has a bottom pad, so I would seriously consider getting a stencil along with the PCB order. Even with the stencil I needed to manually clean up some bridging afterward; I _highly_ recommend Chip Quik NC191 gel flux, available on [Amazon](https://amzn.to/3MGDSr5) (or use this [non-affiliate link](https://www.amazon.com/Smooth-Flow-No-Clean-syringe-plunger/dp/B08KJPG3NZ) instead) or from your electronics distributor of choice. Flux is also very helpful when soldering the LCD ribbon cable to to screen PCB. @@ -137,6 +135,22 @@ Latest auto-generated (untested and likely broken!) artifacts⚠️: ⚠️ For tested/stable/recommended artifacts, use a [release](https://github.com/scottbez1/smartknob/releases) instead. +#### Printed parts +You will need six printed parts. The current stable designs can be found as STL assets in the [v185 mechanical release](https://github.com/scottbez1/smartknob/releases/tag/releases%2Fmechanical%2Fv185-dummy-tag) or you can export the latest untested designs from the CAD model by opening it in Fusion 360: https://a360.co/3BzkU0n + +The parts can _probably_ be FDM 3D printed with a well-tuned printer, but the parts shown in videos/photos were MJF printed in nylon for tight tolerances and better surface finish. + +If you wanted a simpler build, you could omit the LCD and just merge the knob + glass from the model into a single STL to get a closed-top knob. + +Export and print the following 6 parts: +* `Enclosure` +* `Knob` (RotorAssembly->KnobAssembly->Knob) +* `ScreenPlatform` +* `RotorSpacer` (RotorAssembly->RotorSpacer) +* `MountBase` +* `BackPlate` + +⚠️ If you opt to go for MJF Nylon printing from JLCPCB, their system may complain about `< 0.8mm wall thickness detected` on the `MountBase`, `ScreenPlatform` and `RotorSpacer` parts. This appears to be a false positive, possibly on some of the print tapers. You should be able to ignore this, as all print orders at JLCPCB are subject to a final manual review, and they will contact you by email if there are any job-stopping issues or risks with your prints. ## NanoFOC (3rd party) If you're looking to tinker with FOC/haptic feedback, but don't want to build a full SmartKnob View yourself, I can