HTMs
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| - | + | ==Summary== | |
| + | HTM provides an estimate as to major sources of error in our lathe. Based on our model, the major sources of error are work piece deflection (i.e. the cantilever from work piece to bearings) and head stock cantilevering. Overall error at worst case scenarios will be 100-120 microns. | ||
| - | == | + | This model is useful to gain an understanding of what the main sources of error are, but as we were already provided with a collet, setting shaft diameter, and the head stock end piece, we could only try to reduce the length of the shaft-work piece cantilever to minimise errors. Other errors were an order of magnitude or less smaller. |
| + | |||
| + | |||
| + | == Work Completed == | ||
Ani, Martin and Marcus. | Ani, Martin and Marcus. | ||
| - | + | * Initial work from meeting Wed 21st Mar, 5pm. | |
| + | |||
| + | Ani and Martin, Tues 3rd April. | ||
| + | * HTM.m file updated so that it outputs an elastic error for given forces and a thermal error for a given temperature difference. | ||
| + | |||
| + | Martin, Will and Marcus, Thurs 12th April | ||
| + | * Dimensions corrected. | ||
| + | * Compliance errors on the order of hundred microns. | ||
| + | |||
| + | Martin, 11th May | ||
| + | * Tool dimensions corrected (this was responsible for loads of our error!!) | ||
| + | |||
| + | |||
| + | == HTM Files == | ||
| + | HTM file is set up so that it is assuming a 2" diameter work piece, 240N tangentially and 100N axially. Carriage is placed in middle of rail to give max rail deflection. | ||
[http://web.mit.edu/mmcbrien/Public/2-72/HTMs/conventions.jpg Definition of coordinate systems, nodes, etc.] | [http://web.mit.edu/mmcbrien/Public/2-72/HTMs/conventions.jpg Definition of coordinate systems, nodes, etc.] | ||
| - | [http://web.mit.edu/mmcbrien/Public/2-72/HTMs/HTM.m HTM.m Script File] Contains member parameters, and HTM matrices. | + | [http://web.mit.edu/mmcbrien/Public/2-72/HTMs/HTM.m HTM.m Script File] Contains member parameters, and HTM matrices. Updated to include dimensions. |
[http://web.mit.edu/mmcbrien/Public/2-72/HTMs/moi_rect.m Script to calculate I and A for rectanglular beam] | [http://web.mit.edu/mmcbrien/Public/2-72/HTMs/moi_rect.m Script to calculate I and A for rectanglular beam] | ||
[http://web.mit.edu/mmcbrien/Public/2-72/HTMs/moi_cyl.m Script to calculate I and A for cylindrical beam] | [http://web.mit.edu/mmcbrien/Public/2-72/HTMs/moi_cyl.m Script to calculate I and A for cylindrical beam] | ||
Current revision as of 23:33, 11 May 2007
Summary
HTM provides an estimate as to major sources of error in our lathe. Based on our model, the major sources of error are work piece deflection (i.e. the cantilever from work piece to bearings) and head stock cantilevering. Overall error at worst case scenarios will be 100-120 microns.
This model is useful to gain an understanding of what the main sources of error are, but as we were already provided with a collet, setting shaft diameter, and the head stock end piece, we could only try to reduce the length of the shaft-work piece cantilever to minimise errors. Other errors were an order of magnitude or less smaller.
Work Completed
Ani, Martin and Marcus.
- Initial work from meeting Wed 21st Mar, 5pm.
Ani and Martin, Tues 3rd April.
- HTM.m file updated so that it outputs an elastic error for given forces and a thermal error for a given temperature difference.
Martin, Will and Marcus, Thurs 12th April
- Dimensions corrected.
- Compliance errors on the order of hundred microns.
Martin, 11th May
- Tool dimensions corrected (this was responsible for loads of our error!!)
HTM Files
HTM file is set up so that it is assuming a 2" diameter work piece, 240N tangentially and 100N axially. Carriage is placed in middle of rail to give max rail deflection.
Definition of coordinate systems, nodes, etc.
HTM.m Script File Contains member parameters, and HTM matrices. Updated to include dimensions.
