Cold Saw/V1 Design Rationale: Difference between revisions

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=Conceptual Parameters=
=Basic Concept=


*Baseplate
http://opensourceecology.org/wiki/Cold_Saw/V1_Design_Rationale/Basic_Concept


*2 Fixed Blocks (mounted to baseplate by XXX, 2 shaft holes, 1 threaded rod hole)
=Industry Standards=


*1 Moving Nut Block (rides on 2 shafts, driven by a threaded rod that moves a nut welded to the block)
http://opensourceecology.org/wiki/Cold_Saw/Industry_Standards_Analysis


*2 Shafts (radially held on the Fixed Blocks, axially held by 2 shaft couplings on the outsides of the Fixed Blocks)
=Systems Engineering Breakdown Diagram=


*1 Threaded Rod (radially held on the Fixed Blocks, axially held by 2 shaft couplings on the outsides of the Fixed Blocks, drives a nut welded to the Moving Block)
http://opensourceecology.org/wiki/Cold_Saw/V1_Systems_Engineering_Breakdown_Diagram
 
*1 Clamp Handle (welded to the Threaded Rod)
 
*
 
=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 radial forces
 
=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.
 
=Clamp Threaded Rod and Shafts Positioning=
 
*The initial design branch split is whether the mount holes for the Shafts and Threaded Rod are propagated along a common centerline or not.
 
*Common centerline positioning provides the highest possible power transfer that can be attained through the 2 shaft 1 threaded rod system- because disjointed positioning can cause friction and bend-related force vectors not along the clamping axis of motion.
 
However, because the workpiece must be clamped above the centerline clamp system, bending can still occur.
 
*So the real design issue is which mounting style minimizes the moving block bending forces. For the disjointed mounting style, because the shafts must not take up the clamping volume, they must always practically be below the workpiece like the Threaded Rod. The Threaded Rod has to be low anyway to allow space for the blade to bottom out on; the blade must descend at the Threaded Rod for maximum clamp rigidity during operation.
 
The optimal design equalizes the drive force of the Threaded Rod and the reaction force of the workpiece such that no bending forces occur and the shafts act like a carefully balanced seesaw. Hence the shafts should be somewhere between the Threaded Rod and the workpiece.
 
However, another major design objective is to minimize the radial forces on the Threaded Rod. Threaded Rod radial force minimization requires the shafts to be close as possible to the Threaded Rod.
 
=Specific Parameters=

Latest revision as of 18:42, 20 June 2012