Difference between revisions of "Hardware: Frame Assembly"
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[[File:Chesick3.jpg|thumb|600px|Assembly]] | [[File:Chesick3.jpg|thumb|600px|Assembly]] | ||
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#The leveling feet form the over limit protection and are not for leveling. If they are used to level, the over limit protection will break. | #The leveling feet form the over limit protection and are not for leveling. If they are used to level, the over limit protection will break. | ||
#The feet stick out from the rail and can damage the load cells if dropped or if improperly packed for shipping. | #The feet stick out from the rail and can damage the load cells if dropped or if improperly packed for shipping. | ||
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Revision as of 05:32, 3 December 2014
Contents
Material List
A detailed Parts List with part numbers, suppliers and prices is available in pdf. Strut is available from different manufacturers with different brand names: Unistrut, Superstrut, etc. It is available in galvanized steel, aluminum, and fiberglass. Closure strips are available in steel, aluminum or plastic.
If the scale will be shipped via UPS or USPS, even though the aluminum is more expensive, it will be cheaper when shipping expenses are considered.
Tools
Rail Fabrication
Transfer Layout
Cut, Drill, Deburr
Assembly
Electrical Assembly
Block Diagram
Enclosures
Several enclosures can be used.
Goals:
- Complete system parts cost under $100.
- Scale parts cost under $50 and are readily available.
- Low thermal drift and creep.
- Low power consumption.
- Overload protection.
- Automatically resumes operation after power failure.
- Can be built by 15 year old student (9th grader) using hand tools.
- No soldering.
- No lethal voltages.
Design Features
- No frame: no welding, no bending.
- Load cells are mounted in metal strut readily available from electrical or industrial suppliers in aluminum. galvanized or painted steel.
- Only straight cuts and drilled holes.
- All electrical connections are made with crimp plugs or terminal blocks.
Design Flaws
- The M6 Cap Screws stick up and require a spacer or mortising the bottom board (Use counter sunk flat head screws?).
- The leveling feet form the over limit protection and are not for leveling. If they are used to level, the over limit protection will break.
- The feet stick out from the rail and can damage the load cells if dropped or if improperly packed for shipping.
