Cold Saw/V1 Design Rationale

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< Cold Saw
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Basic Concept

A blade rotates. The blade and/or workpiece move toward the other. The blade cuts the workpiece.

ColdSawV1BasCpt.png

Features

  • Hydraulic Direct Drive (to provide high torque and low speed operation without complex transmission)

ColdSawV1HydDirDrv.png

  • Auto-Centering Vise (to improve cut quality)

ColdSawV1Clamp.png

Notes: The shaft collars prevent the shafts and threaded rod from moving under friction and clamping tension, respectively. The thrust washers minimize friction caused by the rotation of the threaded rod's shaft collars under clamping tension.

  • Swivel Head (to allow angled cuts)

ColdSawV1SwvHead.png

  • Adjustable and Removable Vise Jaws (to accommodate variety of workpiece shapes and dimensions)

ColdSawV1ViseJaws.png

  • Fixed Blade Guard (to protect against unintended blade contact during operation)

ColdSawV1BladeGuard.png

  • Forward and Backward Drive Stops (to prevent cutting into vise and to hold blade in mid-air while mounting the workpiece)

ColdSawV1Stops.png

Uniform Part Dimensions

  • Plate: 25.4mm x 304.8mm (Base Plate, Swivel Plate)


  • Flat Bar: 76.2mm x 50.8mm (Shaft Block, Fixed Block, Moving Block)
  • Flat Bar: 25.4mm x 127mm (Support Bar, Bridge Bar, Interface Bar)
  • Flat Bar: 3.175mm x 25.4mm (Blade Guard Support)
  • Flat Bar: 1.6mm x 152.4mm (Blade Guard)


  • Round Bar: 152.4mm DIA (Base Disc)
  • Round Bar: 127mm DIA (Blade Mount Disc, Shaft Collar with Axial Tensioning)
  • Round Bar: 50.8mm DIA (Shaft Coupling, Shaft Collar)
  • Round Bar: 31.8mm DIA (Shaft)
  • Round Bar: 8mm DIA (Pin)


  • Setscrew: M8x1.25 THREAD
  • Bolts and Nuts: M12x1.75 THREAD
  • Threaded Rod: M30x3.5 THREAD

Uniform Mounting Dimensions

  • Base Disc Mounting Rectangle Sides: 60mm x 110mm


  • Vise Mounting Rectangle Sides: 40mm x 90mm


  • Hydraulic Motor Mounting Rectangle Sides: 40mm x 100mm


  • Center-to-Center Distance Between Support Block Screws: 55mm


  • Center-to-Center Distance Between Vise Shaft and Threaded Rod: 95mm


  • Interface Mounting Rectangle Sides: 75mm x 80mm


  • Center-to-Center Distance between Blade Guard Support Screws: 100mm

Block to Baseplate Mounting

  • Permanent mounting methods include welding.
  • Modular mounting methods include:

Bolt into countersinked baseplate hole into block hole into nut.

Screw into countersinked baseplate hole into tapped block hole.

Screw into block hole into tapped baseplate hole.

  • Precision is achieved with tapped holes, and for ease of manufacturing, non-countersink methods are better.

Screw into block hole into tapped Baseplate hole Selected

Clamp Threaded Rod and Shafts Positioning

  • The workpiece must be secure during operation.

Therefore the cut must occur near the center of the clamping volume.

  • The blade must not contact the Threaded Rod at any cut angle. The Threaded Rod is at the center of the clamping volume.

Therefore a space must exist between the blade bottom-out and Threaded Rod at all cut angles.

  • We want the clamp volume to be as close to the Baseplate as possible for minimizing material usage and improving Fixed Block rigidity. Lower height of blade bottom-out permits lower working volume, hence allows the clamp volume to be designed closer to the Baseplate. Below the blade bottom-out plane must be a space, then the Threaded Rod.

Therefore the Threaded Rod must be mounted as close to the Baseplate as possible.

  • The shafts must balance the Threaded Rod's driving force and the workpiece's reaction force such that the Threaded Rod and Moving Block do not bend.

Therefore the Shafts must be mounted between the middle of the Threaded Rod and the middle of the clamp volume's height.

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