add belt peel guard to prevent deflection on long prints as they leave the belt end

app.js

@@ -167,6 +167,8 @@ function initModule(mod, file, dir) {
             time: time,
             guid: guid,
             mkdirs: util.mkdir,
+            isfile: util.isfile,
+            confdir: util.confdir,
             datadir: util.datadir,
             lastmod: lastmod,
             obj2string: obj2string,

src/kiri/conf.js

@@ -341,6 +341,7 @@
                     outputLayerRetract: false,
                     outputOriginCenter: true,
                     outputLoopLayers: "",
+                    outputPeelGuard: 0,
                     outputInvertX: false,
                     outputInvertY: false,
                     detectThinWalls: false,

src/kiri/init.js

@@ -1788,7 +1788,8 @@
             arcTolerance:        UC.newInput(LANG.ad_arct_s, {title:LANG.ad_arct_l, bound:UC.bound(0,1.0), convert:UC.toFloat, modes:FDM, show:() => { return isDanger() && isNotBelt() }}),
             antiBacklash:        UC.newInput(LANG.ad_abkl_s, {title:LANG.ad_abkl_l, bound:UC.bound(0,3), convert:UC.toInt, modes:FDM}),
             fdmSep:              UC.newBlank({class:"pop-sep", modes:FDM}),
-            gcodePauseLayers:    UC.newInput(LANG.ag_paws_s, {title:LANG.ag_paws_l, modes:FDM, comma:true}),
+            outputPeelGuard:     UC.newInput(LANG.ag_peel_s, {title:LANG.ag_peel_l, convert:UC.toInt, modes:FDM, comma:true, show:isBelt}),
+            gcodePauseLayers:    UC.newInput(LANG.ag_paws_s, {title:LANG.ag_paws_l, modes:FDM, comma:true, show:isNotBelt}),
             outputLoopLayers:    UC.newInput(LANG.ag_loop_s, {title:LANG.ag_loop_l, modes:FDM, comma:true, show:isBelt}),
             outputLayerRetract:  UC.newBoolean(LANG.ad_lret_s, onBooleanClick, {title:LANG.ad_lret_l, modes:FDM}),
 

src/mode/fdm/export.js

@@ -47,6 +47,9 @@
             lout = null,
             last = null,
             zpos = 0,
+            bmax = 0,
+            blast = 0,
+            blastz = 0,
             process = settings.process,
             loops = process.outputLoopLayers,
             zhop = process.zHopDistance || 0, // range
@@ -55,6 +58,7 @@
             retSpeed = process.outputRetractSpeed * 60, // range
             retDwell = process.outputRetractDwell || 0, // range
             timeDwell = retDwell / 1000,
+            peelGuard = process.outputPeelGuard || 0,
             arcDist = isBelt || !isDanger ? 0 : (process.arcTolerance || 0),
             originCenter = process.outputOriginCenter,
             offset = originCenter ? null : {
@@ -272,7 +276,7 @@
             let epos = isBelt ? { x: pos.x, y: pos.y, z: pos.z } : pos;
             if (isBelt) {
                 epos.x = originCenter ? -pos.x : device.bedWidth - pos.x;
-                epos.z = pos.z * icos;
+                epos.z = blastz = pos.z * icos;
                 epos.y = -pos.y + epos.z * bcos;
                 lout = epos;
             }
@@ -335,6 +339,7 @@
                     (process.firstSliceHeight || process.sliceHeight) : path.height);
 
             zpos = path.z || zpos;
+            bmax = Math.max(bmax, pos.z * icos);
             subst.z = subst.Z = zpos.round(3);
             subst.e = subst.E = outputLength;
             subst.layer = layer;
@@ -342,6 +347,12 @@
 
             if (isBelt) {
                 pos.z = zpos;
+                if (peelGuard && bmax > peelGuard && blast < peelGuard) {
+                    peelGuard += 50;
+                    append(`G0 Z${(blast + 55).round(decimals)} F200 ; peel guard`);
+                    append(`G0 Z${blastz.round(decimals)} F200 ; unpeel`);
+                }
+                blast = bmax;
             }
 
             if (pauseCmd && pause.indexOf(layer) >= 0) {

web/kiri/lang/en.js

@@ -585,6 +585,8 @@ kiri.lang['en-us'] = {
     ag_menu:        "gcode",
     ag_nozl_s:      "nozzle",
     ag_nozl_l:      "select output nozzle or head",
+    ag_peel_s:      "peel guard",
+    ag_peel_l:      ["starting at this belt z positoin","periodically roll the print off and","back on to the belt to unstick it","and prevent rolling deflection"],
     ag_paws_s:      "pause layers",
     ag_paws_l:      ["comma-separated list of layers","to inject pause commands before"],
     ag_loop_s:      "loop layers",