harmonic-analyzer v37

This release brings the drive train's machining drawings: the eight-sheet MHA-A03 assembly package plus the part drawings for the cone set, crank, cylinder bank and alignment-pinion rig, all written to the drawing-simplicity policy.

The other subsystems change little. The base picks up seats that follow the drive train, a few purchased screws get new catalogue numbers, and some sheets have small layout touch-ups. In the summing subsystem, the knife-mount sheet now states its tap-drill breakthrough as a plain fact.

Drive train

Assembly

• #836: the drive train's one-sheet stub becomes the eight-sheet MHA-A03 package. It has assembled views, a two-column BOM, three exploded and ballooned views (cylinder bank, cone set and crank, pinion rig), two sheets of assembly sequence and a sheet of functional checks.
• The A03 BOM lists the fastener part numbers you actually order. CHECK 4 now swings the cone set out to the MHA-095 stop.

Cone set

• #811: new drawings for the cone gear shaft and the crank-drive gear. The gears can be bonded with Loctite 638/648 instead of solder or silver braze.
• #834: 20 configuration sheets for the MHA-013 cone gear family (T006 to T120), plus the MHA-096 cone tip bushing. Each gear gets a larger blank and a thicker tooth so it reaches deeper into its 120T drum. The tip diameter and tooth thickness are printed per gear.
• #838: the MHA-092 cone tip block is held down by a hidden screw from below, with an MHA-146 nylon-insert nut on its flange, and a shim pack sets its height. The tip adjuster is now a #10-32 cup-point set screw tapped through the block.
• #839: the cone gear shaft (MHA-014) gets 2.9 mm shorter at the tip, which gives the tip adjuster more thread. The soldered gear seats get a looser band.
• #857: three new parts with sheets: MHA-140 cone tip block hold-down screw, MHA-141 cone tip shim pack and MHA-142 cone pivot post mount screw.
• #833: the MHA-016 cone pivot post sheet. The crank bore is located from the cone bore and both are bored in one setup. The mounting holes are drilled from the top.
• #919: the pivot post's cone boss ends are faced in the boring setup, and the north end face gets a finish mark.
• #830: the MHA-091 cone swing platform sheet. The disengage swing grows to 4.25°, so the stop hole in the base moves about 2.3 mm.
• The cone pivot post's axis height is printed with a ±0.25 band that the shim pack takes up.
• #916: the MHA-014 cone gear shaft gets an integral thrust collar that bears on MHA-016's north cone-boss face, so the cone set can't move along its axis. The 64T crank-drive gear is now bonded against the collar's other face (A03 step 1), which fixes its position along the shaft, and MHA-016's cone bore gets a 0.1 max rim break.

Crank

• #813: drawings for the crank pinion (MHA-025), its pin (MHA-134) and the other crank retention hardware.
• #831: the crank hub cluster. MHA-137 through hub, MHA-138 seam pin, a new MHA-139 crank handle pivot screw, and updated crank arm and crankshaft sheets.
• #906: the crossed 16T:64T crank gears are recut with one cutter so the mesh has enough backlash. The crankshaft's 16T seat steps to Ø9.0. MHA-016's crank bore gets one angularity control against the cone bore and the foot seat. The crank pinion's boss now starts at the tooth face.
• #960: the crank train sits at its fit-up position, carried by the new MHA-149 eccentric bushing (part model only). MHA-016's crank bore opens to Ø14.6 H7 to take it, and the crankshaft journal no longer has a land.
• #1046: the 64T crank-drive gear's rim clipped the corner of MHA-016's crank boss, and at the worst case of the printed bands it could also touch the Ø44 collar below the boss. MHA-016's crank-boss spot face now sits 2.5 mm further south and is milled as a D that also clears the collar; a new sheet 2 on MHA-016 shows it at 2:1. MHA-149 shortens to 77.5 and sits flush with the new face, and A03 step 4 sets the 16T 2.75 off the spot face with a feeler stack. At the worst case of the printed bands the gear clears MHA-016 by at least 0.3 mm, and the SolidWorks model agrees with the clearance calculation.

Cylinder bank

• #810: sheets for the arbor pedestal (MHA-004, wider foot, one hold-down hole) and the cylinder-gear arbor (MHA-028), plus the new MHA-143 pedestal hold-down screw.
• #937: the cylinder bank now goes together as a solid stack. Each MHA-027 is one station pitch thick, and a turned MHA-121 thrust washer sits at each end. The front strap is set with a 0.45 feeler. The arbor is cut to fit, domed at both ends and held by two MHA-147 cup-point set screws through the pedestal crowns. MHA-121 gets its own drawing, and MHA-147 a purchased-part sheet.

Alignment pinion rig

• #832: the alignment pinion goes to 32 teeth (MHA-002). It is a slip fit on its arbor, bonded with Loctite 638. This slice also covers the pinion cam and cylinder gear sheets.
• #837: the pinion cluster is laid out again to match the photos. The drum parks further out, and there is a new pivot block, a new lift cam and a 9 mm strap. The base seats are transferred from the parts at assembly, not dimensioned.
• #843: the pinion spring foot gets a wider pad, so the hole is no longer right at the edge. Its print is redone to the policy.
• #844: MHA-135, a new 1/16 cross pin through the pinion lever and lift rod, drilled together at assembly. The block screws are now 1-1/4 long to get more thread. The arbor head grows to 10.5.
• #814: the control drawings are finished, and the crank handle gets its retention.
• #854: the torque shaft and lift rod are shorter. The two pivot blocks locate the strap-and-drum cluster, and the front block is set with a 0.25 feeler.
• #855: the rig's parts and the base's block seats are placed from one shared layout, so the two can't drift apart.
• #858: each strap is pinned to the torque shaft with a 1/16 × 1/2 slotted spring pin, and the lever rod is now a straight Ø6.
• #860: MHA-144, a new collar pinned on the pinion arbor so the arbor can't walk out.
• #859: the MHA-114 return spring moves outboard, east of the strap, as the photos show. It is now 17-7 PH stainless strip, Condition C, 0.381 mm (0.015 in) thick and 6.35 mm (1/4 in) wide, and its base seat moves to match.
• The rig's final revision: the MHA-145 strap pins are modelled as parts, the torque shaft is 187.0, the lift rod is 198.3, and MHA-135 is shown installed. MHA-A03's parts list names it "PINION LEVER CROSS PIN"; its own drawing gives the 16.0 cut length and the stock.
• #1082: MHA-A03 step 14 now says to bond both MHA-116 follower pins, one into each MHA-056 strap's follower seat.
• #1045 (#1061): MHA-A03's assembly steps 11 to 23 now describe the revised pinion rig. The rig's seats on the base are transferred at fit-up using the base drawing's own transfer callouts, not pre-drilled.

Channel

• #936: the rocker bank is retained and its brackets screw into a deeper support rail (channel).

Drawings across parts

• #955: three leaders on MHA-092 (cone tip block) and MHA-077 (top frame) now come in from their features' short sides.
• A sheet that has an accepted shortfall (a thin web, a short thread) now states it as a plain fact with its value, for example "ENGAGEMENT 5.92-6.35 (0.93-1.0D)". The reasoning lives in the policy's named-exceptions table.
• #963: every title block prints the part or assembly's short name in its PART cell.
• #1062: a callout moved clear of its neighbours now lands a fifth of a millimetre past the 2 mm clear gap, so reading its position back can't put it a hair inside the gap. MHA-062's match-drill callout failed that check on a clean build.
• #1083 (#1075): MHA-004 (arbor pedestal) had its crown drawn at R22 and printed the apex set-screw tap as "↧ 0.00". It now draws and prints the R11 crown the part has, and the tap callout reads "TAP TO BORE 4-40 UNC-2B THRU" inside the border. A drawing no longer re-reads a model diameter as a radius. Taps placed on curved faces now keep their thread class and termination.
• #1078: on MHA-014 (cone gear shaft), the collar's stock callout now sits clear above the part. The pivot-journal Ra 1.6 leader no longer crosses it. The T006 station now reads "142.168 20X EQ SP" on one line.
• #1063: MHA-035 (harmonic base) no longer rewrites its transfer and cross-tap callout prefixes itself. The shared callout helper already puts each thread on its own row, and the sheet's second pass broke the drawing on a clean build.

Build and checks

• #950: parts and assemblies no longer save with construction geometry showing, so stray sketches, planes and points are gone from the renders. On the base part, the save-time check went from about 11 s to under 1 s. #1031 does the same for the reference planes the paper drive's chain and belt features generate.
• #956: when a part refuses to rebuild, the build names the features behind it.
• #1089: the MHA-016 cone pivot post now saves its plan and bore-spacing reference sketches hidden, so its preview render and native part no longer show stray centreline rays. The drawing prints exactly as before. No part saves a reference sketch shown any more.
• #901, #902, #941, #946: a layout audit on every sheet, in report mode. It fails no drawing yet: border and title-block findings start failing the build once a full-fleet count reads zero (#1052). #941 also boxes datum tags and control frames from their own display data. #927 logs how many centre marks each automatic insertion adds.
• #1058: the drive-train and channel assemblies now pick the faces and axes they mate by name instead of by a point on screen. The cone shaft's collar seats on a named plane on the MHA-016 post's north boss, and the pivot and fulcrum shafts carry a named axis. Before this, how the SolidWorks window happened to be sized and zoomed could decide which face got picked, and one build seated the collar on the wrong face and failed.
• #1043: before saving, every part with more than one configuration (the cone gear's T006 to T120, and the removable transgear) switches to each out-of-date configuration and rebuilds it. A reopen check then confirms every saved configuration loads cleanly, the way an assembly loads it. Before this, the cone gear's T006 to T114 were saved broken and the drive-train assembly couldn't place them. Saving the cone gear now takes about a minute longer.
• Interference limits between two parts are now checked against the pair's total overlap, not one body at a time (issue #853).
• A new offline check rejects inverted or zero-width tolerance bands.

Known issues

• The connecting-rod pin's axial retention on the rocker isn't defined yet, and a rod head sits nominally 0.23 mm from the next rocker; at tolerance extremes the heads can reach the neighbouring rocker. #948

• The crank bore on the MHA-016 cone pivot post carries the MHA-149 eccentric bushing, which sets the crank gear backlash at fit-up. MHA-016 says so ("DRAWING PENDING"). This package includes the bushing's part model but not its drawing, and the MHA-A03 assembly drawing has no MHA-149 note or BOM row yet. #952

• If you open the drive-train or full-machine assembly (or their STEP files), the crankshaft sits at its fit-up position inside the opened MHA-016 bore, but the MHA-149 bushing that carries it there isn't placed. The bushing's placement, BOM row and drawing come with #952.

• The drive-train model doesn't yet place the MHA-092 tip block's hold-down (the MHA-140 screw and MHA-146 nut). The drawings specify it; the placement lands with the cone-set fit-up rework (#957).

• 61 drawings in this package ship without an independent machinist review of the version they ship at. Those reviews follow after the release, one issue per drawing, tracked in #964.

• Limit dimensions print ISO-style "max." / "min." instead of ASME "MAX" / "MIN" (MHA-142's cut-end break, for example). The templates will be moved to true ANSI after the release. #953

• The MHA-123 rocker pivot bracket (qty 2) ships without a drawing. #954

• The crank's taper-pin keeper ring (MHA-128) and its anchor eye (MHA-130), both formed from brass wire, ship without drawings. MHA-A03 lists them and gives their assembly step. #1076

• Side-to-side play in the cone set can eat the cone-to-drum mesh window, and the fix is deferred to after the release. No assembly step sets the cone-to-drum backlash; only MHA-A03 CHECK 2 checks it (0.06 to 0.38 mm). #917, tracked in #957

• The MHA-114 pinion spring only stays within its preload and stress limits if its pad is placed within about ±0.09 mm east–west, and no stop the drawings give locates it that closely. Place the pad with care; the spring is redesigned after the release. #1037

• Neighbouring amplitude bars have only a 0.71 mm side gap, and at the worst case of the printed bands the notch clearances and the plate positions can close it, so neighbouring bars may rub. The notch widths print as minimum-fit bands for now; the stack is redesigned after the release. #1038

• About 45 part preview images still show that part's own surface-finish symbols, tolerance frames and axis lines on top of the shaded part. The drawings aren't affected. #1047

• Four leaders read awkwardly but point at the right feature. On the MHA-035 base, the STAMPED ID "2" leader crosses the plate diagonally, the top-face Ra 3.2 leader crosses the rim and fillet to land mid-face, and the RD2 keeper-transfer tap callout takes a long way round. On the pivot shaft, the lower arrow of the Ø6.350 tolerance touches its own text. #1053, #1054, #1055, #1056

• The MATERIAL cell in the title block prints the modelling material, not the stock specification, on 58 drawings. Two of these name the wrong alloy. The cone gears T006 to T024 must be C67500 manganese bronze, not brass. The MHA knife mount must be AISI O1 tool steel, hardened and tempered to 58-60 HRC, not plain carbon steel. These made parts print only a generic material:

  • Plain carbon steel: use AISI 1018 cold-finished. Amplitude bar, crank pin, cylinder end disc, fulcrum keeper, fulcrum shaft, pinion lift rod, pivot shaft and platen guide.
  • Brass: use C36000 free-machining brass. Cone gears T030 to T120, cone tip bushing, cylinder gear, pen marker, pen rod, pen V-block and rack pinion.

  Order purchased parts by the supplier part number each drawing prints, not by its MATERIAL cell. #1080

• Three magnifier drawings still carry the "DO NOT RELEASE" hold they had in v36: the magnifying wheel (hub material, grooves and wheel retention), the lever wire (formed hook, hub wrap and cut length) and the magnifying bracket (mounting holes). Don't make those three parts from this package yet. #374, #549

• On nine drawings a note, tolerance frame or dimension prints over the sheet border or into the title block, as it did in v36. Each issue shows where. #1065–#1073

• On the platen guide drawing, the flatness leader crosses datum A's extension line near the corner, as it did in v36. #1084

Decisions that shape this release

• The drawings are written for a novice machinist. Where a wall or margin came out thin, the geometry was changed and the tolerances were left loose. Webs aim for 2 mm, with a 1.5 mm floor at the worst case of the printed bands.
• Only the project owner can accept a shortfall against the rules, one part at a time, and each accepted one is listed in the policy. This release has five: MHA-142 post-mount screws at 0.90D minimum thread engagement (cut to fit, never proud of the plate); the T006 cone gear's 0.62 mm web; contact ratio under 1.1 on T006 to T042, kept for fidelity to the book; the MHA-025 crank pinion boss wall at 1.56 mm; and the MHA-139 crank handle screw at about 1.33D worst case.
• The cone-set fit-up rework (dowelled post and tip block, a match-reamed pivot and a step that sets backlash) moves to the next release (#957).
• MHA-149 and MHA-123 ship without drawings; theirs follow after the release.
• The drawing templates move to true ANSI after the release.

Also in this release

Changes already on main since v36 ship too. The ones a builder will notice: every part configuration is rebuilt before its final save (#928), the title block's PART cell is wide enough for long names (#790), section cutting lines are placed exactly (#791), and the worst-case wall and thread rules are written into the policy (#842).

Bundle

Scripted SolidWorks reproduction of Michelson's 20-channel harmonic analyzer.

The repository is source-of-truth (doit regenerates every part). This release attaches a single CAD bundle harmonic-analyzer-v37.zip so the model can be opened without rebuilding -- with or without SolidWorks:

• solidworks/ -- native Pack-and-Go (128 referenced documents, flattened): open harmonic-analyzer.SLDASM as-is
• step/ -- AP214 STEP for 125 parts; stl/ fine binary STL (mm) for all 125 parts plus 24 per-configuration STLs (cone gears / transgears)
• gltf/ -- glTF binary (.glb) for all 8 assemblies (metre units, per-component named nodes, appearance materials): drop harmonic-analyzer.glb into any glTF viewer
• boxes/harmonic-analyzer.json -- assembly scene graph (mm): per-component transform, mesh key and colour, so the comparison gallery renders from this bundle with cad/comparisons/tools/render_offline.py (no SolidWorks)
• png/ -- isometric preview renders (133 images)
• comparisons/ -- this model overlaid on Michelson's ch30 photos (18 pairs, mean RMS score 69.8; open comparisons/index.html)
• diff/ -- changed-parts diff renders vs v36 (see below)
• Size: 1112.5 MB

Changed parts vs v36

49 part(s) changed geometry (red = changed, confirmed by Hausdorff distance; tessellation/byte noise excluded): alignment-pinion, amplitude-bar, arbor-pedestal, arbor-set-screw, cone-gear, cone-gear-shaft, cone-pivot-post, cone-swing-platform, cone-tip-adjuster, cone-tip-block, cone-tip-bushing, cone-tip-pinch-screw, cone-tip-shim, crank-arm, crank-drive-gear, crank-handle-pivot-screw, crank-hub, crank-hub-pin, crank-pinion, crank-pinion-pin, crankshaft, cylinder-end-disc, cylinder-gear, cylinder-gear-shaft, harmonic-base, knife-hanger-stud, lag-screw, pedestal-hold-down-screw, pinion-arbor, pinion-arbor-collar, pinion-bracket, pinion-cam, pinion-cam-pin, pinion-handle, pinion-lever, pinion-lever-pin--installed, pinion-lift-rod, pinion-pivot-block, pinion-pivot-shaft, pinion-spring, pinion-strap-pin, pivot-bracket, pivot-shaft, post-mount-screw, rocker-arm, rocker-arm-support, rocker-thrust-washer, slotted-screw, top-frame

more views

Generated by cad/comparisons/tools/render_diff.py; renders also ship in the bundle under diff/.

Provenance

• Source commit: 1268c23d4 (v36-1525-g1268c23d4), working tree clean
• Built with SOLIDWORKS 3DEXPERIENCE R2026x, revision 34.3.0
• PROVENANCE.json + SHA256SUMS.txt ship inside the bundle (1239 files hashed; verify with sha256sum -c SHA256SUMS.txt)

Logs: harmonic-analyzer-v37-logs.zip -- the per-task build logs (parts, assemblies, verify/check gates) plus the full release log -- is attached as a separate asset.