Cold Saw/V1 Design Rationale

Conceptual Parameters

• Baseplate

• 2 Fixed Blocks (mounted to baseplate by XXX, 2 shaft holes, 1 threaded rod hole)

• 1 Moving Nut Block (rides on 2 shafts, driven by a threaded rod that moves a nut welded to the block)

• 2 Shafts (radially held on the Fixed Blocks, axially held by 2 shaft couplings on the outsides of the Fixed Blocks)

• Threaded Rod (radially held on the Fixed Blocks, axially held by 2 thrust washers and 2 shaft couplings on the outsides of the Fixed Blocks, drives a nut welded to the Moving Block)

• Clamp Handle (welded to the Threaded Rod)

• Operation Handle (welded to the Motor Plate)

• Motor Plate (rotates on the Operation Shaft, mounts the hydraulic motor)

• Operation Shaft (mounted on the Operation Blocks)

• 2 Operation Blocks (mounted on the Baseplate, mounts the Operation Shaft)

• 1 Shaft Coupling (mounted on the hydraulic motor shaft and setscrewed into its keyway; spindle inserted and welded on from opposite side; precision flattened on working face then welded to Fixed Driveplate)

• Fixed Driveplate (welded to

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

Threaded Rod and Shafts Radial and Axial Hold

• The shafts can be radially supported by inserting through a block at each end; axially supported by shaft collars at each end on the outside of the blocks.

• The threaded rod does not require much radial support as the shafts handles the brunt of it. Axial load is handled by thrust washers or bearings to be mounted between the blocks and shaft collars on the ends of the threaded rod.

Shaft Collars and Thrust Washers Selected

Operation Shaft Precision Axial Hold

• The Operation Shaft uses shaft collars to precisely hold the Motor Plate and Support Plate.

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.

Drive Support Frame

• 2 Operation Blocks radially support the ends of the Operation Shaft.

• The Operation Shaft is axially held by shaft collars on its outside ends.

• The Operation Shaft has thrust washers on its inside ends.

• The Motor Plate and Support Plate are mounted on the Operation Shaft between the thrust washers.

Specific Parameters

• 1.25" Spindle Diameter

• 10" Blade Diameter