Treadle Reducer
Found on the Tools Menu
What It Does
Treadle Reducer decreases the number of treadles your draft requires by finding places where pressing two treadles at the same time (a "double-press") can replace a single dedicated treadle. The cloth structure stays exactly the same — you're just using fewer treadles to achieve it.
This is especially useful when a draft calls for more treadles than your loom physically has. For example, a pattern that requires 12 treadles might be reduced to 8 by using double-press combinations for some picks.
Opening Treadle Reducer
Ribbon: Tools tab > Treadle Reducer button
The Treadle Reducer Dialog
Settings (Left Panel)
Current Treadles Shows how many treadles your draft currently uses. This is your starting point.
Target Treadles The maximum number of treadles you want to end up with. Set this to match your loom — if you have 8 treadles, set the target to 8. TempoWeave will try to find a solution that fits within this limit.
Time Limit How long to let the search run (0.5 to 60 minutes, default 2 minutes). Simple reductions finish quickly, but complex patterns with many treadles may need more time. If the search times out, you can try again with a longer limit or a higher treadle target.
Prefer Single Treadles When checked (default), the search favors solutions that use single treadle presses where possible, only resorting to double-presses when needed. This produces a more comfortable treadling sequence — fewer picks require pressing two treadles at once.
Use Frequency Weighting When checked (default), the search gives priority to shaft combinations that appear most often in your treadling. This tends to assign single treadles to the most common picks and double-presses to the rare ones.
Preview (Right Panel)
Shows your original tie-up on the left and the reduced tie-up on the right, side by side. Each cell shows which shafts are connected to which treadle. This updates after the search completes so you can compare before applying.
Show Mapping
After a successful reduction, this button opens a detail view showing exactly how each original shaft combination maps to the new treadles — which picks use a single treadle and which use a double-press.
How to Use It
Go to Tools tab > Treadle Reducer
Set your Target Treadles to the number your loom has
Adjust the time limit if needed (2 minutes is usually enough)
Click Run Reduction
Wait for the search to complete — a progress indicator shows it's working
Review the result message and the preview
Click Apply if you're happy with the result
Understanding the Results
After the search runs, you'll see one of these outcomes:
Success — The reduction worked. The message shows how many treadles you went from and to (e.g., "12 → 8 treadles"). The preview shows the new tie-up. Click Apply to use it.
No Reduction Possible — Your draft already uses the minimum number of treadles for its shaft combinations. Every treadle is unique and no double-press combinations can replace any of them.
Timed Out — The search ran out of time before finding a complete solution. You can:
Increase the time limit and try again
Raise the target treadle count (a less aggressive reduction is easier to find)
Accept a partial result if one was found
Impossible — The pattern cannot be achieved with your target number of treadles, even with double-presses. You'll need to increase the target.
Step-by-Step Example: Fitting a Draft to Your Loom
You have a Summer & Winter draft that uses 14 treadles, but your loom only has 10:
Open Treadle Reducer from the Tools tab
You see "Current Treadles: 14"
Set Target Treadles to 10
Leave the other settings at their defaults
Click Run Reduction
The result shows "Success: 14 → 9 treadles" — even fewer than your target
Check the preview to see the new tie-up
Click Apply
Your draft now uses 9 treadles. Some picks will require pressing two treadles at once, but the cloth is identical.
What Changes in Your Draft
When you apply a reduction:
Tie-up — The columns are reorganized. You'll have fewer treadle columns, and each column represents a "building block" that can be used alone or combined with another.
Treadling — Switches to multi-treadle mode. Most picks still use a single treadle, but some picks will show two treadles activated (a double-press). The treadling display reflects this.
The cloth — Unchanged. Every pick raises exactly the same shafts as before.
Limitations
Tie-up mode only — Treadle Reducer is not available in liftplan mode. Convert to tie-up first (Tools tab > To Tie-up).
Requires at least 2 treadles — A draft with a single treadle can't be reduced further.
Double-press maximum — The reducer uses combinations of at most two treadles per pick. It won't ask you to press three or more simultaneously.
Tips
Undo works — Ctrl+Z (Cmd+Z) reverts the entire reduction in one step.
Start with the default settings — The defaults (prefer singles, use frequency weighting) produce the most comfortable treadling for most patterns. Only change them if the default search doesn't find a solution.
Try a generous target first — If you're not sure how far the pattern can be reduced, start with a target slightly below your current count. You can always run it again with a lower target.
Check the mapping — Use the Show Mapping button to see exactly which picks will need double-presses. If there are too many, try a slightly higher target.
Pairs well with Treadle Expander — If you later want to undo a reduction and go back to single-treadle picks, use Treadle Expander to convert double-presses back into dedicated treadles.
Quick Reference
Target Treadles
Min of current count or 12
1–128
Time Limit
2 minutes
0.5–60 minutes
Prefer Single Treadles
On
On / Off
Use Frequency Weighting
On
On / Off
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