BasicScheduler_motorway_edition

BasicScheduler is the workhorse of ComfyUI's custom-sampling world - the node that turns a model plus a scheduler name into the actual sigma schedule a sampler walks down. Nine scheduler choices, a steps count, a denoise value, done. This is its Motorway-ed clone, which means the model comes out of the Motorway by key name, the sigmas go back in by key name, and the only wire on the canvas is the single MOTORWAY 🚌💨.

How it works

Read a model out of the Motorway, compute a sigma schedule, write it back. The inputs that matter:

• INPUT_model_key - key for the model (default model). The schedule shape depends on the model's architecture, which is why the model needs to be in the Motorway at all rather than just picking a name.
• scheduler - the dropdown with the nine core options: normal, karras, exponential, sgm_uniform, simple, ddim_uniform, beta, linear_quadratic, kl_optimal. This is where the actual decision lives.
• steps - default 20.
• denoise - default 1.0. Lower for img2img or multi-stage passes.
• OUTPUT_SIGMAS_key - where the sigmas land, default SIGMAS. Whatever your sampler expects to read, that's the key to set.

The wrapper pulls the model from the Motorway, calls the real core BasicScheduler, stores the sigmas under your output key, and passes the Motorway on. The node's only visible output is the Motorway itself.

Choosing the scheduler

The nine names are the same ones you've been picking in KSampler for years, so the usual rules apply, with one important modern twist. On SD1.5 and SDXL, karras is the classic safe default - it concentrates denoising where those models want it. On flow-matching models (Flux and friends), the community consensus flipped: Karras and exponential actively hurt on the straighter trajectory, and beta or simple is what you want. In the sampler-sweep threads that dominate r/comfyui, "any scheduler but karras or exponential" keeps coming up for the new architectures. So: karras for the old guard, beta for Flux, and normal when you want no cleverness at all.

The Motorway angle

One thing to watch: this node has a connection input (the model), so unlike some of its siblings the MOTORWAY 🚌💨 input here is required. Your chain still starts at MotorwayStart (or a primitive starter), and whatever key you set for OUTPUT_SIGMAS_key is what the downstream sampler must read - if you changed it from SIGMAS, update the sampler's key field to match, or you'll get the pack's trademark 'MotorwayClass' object has no attribute 'hash_' error when it tries to pull a key nobody wrote.

Install

cd ComfyUI/custom_nodes
git clone https://github.com/agilly1989/ComfyUI_agilly1989_motorway

Restart, or search "ComfyUI_agilly1989_motorway" in ComfyUI Manager. No extra dependencies, no downloads.

Fine print

The pack is an explicitly-unfinished beta - README opens "BIG BROKEN WITH ASYNC WILL FIX WHEN I GET THE TIME/MOTIVATION" - and the current hotfix release has the _motorway_edition clone generation commented out of __init__.py, so on the latest main these nodes may not register at all. If you loaded a workflow that references them and they're missing, that's the why. Open an issue if you hit it; the author has said not to DM him on Discord.