From 8c3984a3042ce157eb79dc88d9dd1019496d6a78 Mon Sep 17 00:00:00 2001
From: Jethary <jethary@opentrons.com>
Date: Tue, 7 Jan 2025 14:30:50 -0500
Subject: [PATCH 1/2] fix(step-generation): only aspirate disposal volume to
 first chunk

closes RQA-3807
---
 step-generation/src/commandCreators/compound/distribute.ts | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/step-generation/src/commandCreators/compound/distribute.ts b/step-generation/src/commandCreators/compound/distribute.ts
index 9c4c2cc865e..b9fa24d78eb 100644
--- a/step-generation/src/commandCreators/compound/distribute.ts
+++ b/step-generation/src/commandCreators/compound/distribute.ts
@@ -490,7 +490,10 @@ export const distribute: CommandCreator<DistributeArgs> = (
         ...mixBeforeAspirateCommands,
         curryCommandCreator(aspirate, {
           pipette,
-          volume: args.volume * destWellChunk.length + disposalVolume,
+          volume:
+            args.volume * destWellChunk.length +
+            //  only add disposal volume if its the 1st chunk
+            (chunkIndex === 0 ? disposalVolume : 0),
           labware: args.sourceLabware,
           well: args.sourceWell,
           flowRate: aspirateFlowRateUlSec,

From 94c772337900c01e5860f23d4e3e433d622d60c1 Mon Sep 17 00:00:00 2001
From: Jethary <jethary@opentrons.com>
Date: Tue, 7 Jan 2025 14:51:31 -0500
Subject: [PATCH 2/2] correct logic to take blowout into account

---
 .../src/commandCreators/compound/distribute.ts           | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/step-generation/src/commandCreators/compound/distribute.ts b/step-generation/src/commandCreators/compound/distribute.ts
index b9fa24d78eb..ceba8f3e89b 100644
--- a/step-generation/src/commandCreators/compound/distribute.ts
+++ b/step-generation/src/commandCreators/compound/distribute.ts
@@ -483,7 +483,7 @@ export const distribute: CommandCreator<DistributeArgs> = (
             }),
           ]
         : []
-
+      const aspirateDisposalVolumeOnce = chunkIndex === 0 ? disposalVolume : 0
       return [
         ...tipCommands,
         ...configureForVolumeCommand,
@@ -492,8 +492,11 @@ export const distribute: CommandCreator<DistributeArgs> = (
           pipette,
           volume:
             args.volume * destWellChunk.length +
-            //  only add disposal volume if its the 1st chunk
-            (chunkIndex === 0 ? disposalVolume : 0),
+            //  only add disposal volume if its the 1st chunk and changing tip once
+            //  and not blowing out after dispenses
+            (args.changeTip === 'once' && blowoutLocation == null
+              ? aspirateDisposalVolumeOnce
+              : disposalVolume),
           labware: args.sourceLabware,
           well: args.sourceWell,
           flowRate: aspirateFlowRateUlSec,