Budget Strapped
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Release status: unknown
| Description | A low cost RepStrap
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Overview
This printer is intended to be a very low cost 3D printer that is still capable of printing useful items. The cost of filament is very significant for a printer in this price bracket. To reduce this cost, BudgetStrapped will print with HDPE filament, which can be created relativly easily from household plastic waste.
Design Goals
- under ~$100 total cost.
- ability to print will filament made from recycled household plastics. Specifically HDPE (#2 plastic).
Structure And Motion
- Printhead will move on X and Y axes, printbed will move on Z axis
- Frame will be made (primarally) out of 2"x4" lumber
- X and Y axes will use drawer slides (like WolfStrap)
- Positioning on the drawer slides will be done using 65lb test multistrand fishing line.
- Z axis will move on four 10-24 threadded rods
- Multiple 28BYJ-48 stepper motors will be used on each axis instead of NEMA 14 or 17 stepper motors
Electronics
- An Arduino Nano will be the core of the electronics.
- A shift register will be used to increase the number of digital I/O pins
- 1 darlington array driver chip per motor (These come with the motors)
- A bottom-of-the-line PC power supply will be used to provide power.
Specifications
---ESTIMATED---
| Metric | US imperial | |
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| Manufacturer | RepRap (or anyone who wants...) | |
| Model | Mendel | |
| Technology | FFF (Fused Filament Fabrication)/Thermoplastic extrusion | |
| Price of all materials | €400 | $520 |
| Annual Service Cost | Occasional oiling = €5. It can print its own replacement printed parts at material cost. | Occasional oiling = $8. It can print its own replacement printed parts at material cost. |
| Size | 500 mm (W) x 400 mm (D) x 360 mm (H) | 20” (W) x 16” (D) x 14” (H) |
| Weight | 7.0 kg | 15.5 pounds |
| Build Envelope | 200 mm (W) x 200 mm (D) x 140 mm (H) | 8” (W) x 8” (D) x 5.5” (H) |
| Materials | PLA, HDPE, ABS & more. Uses ø 3 mm filament. | PLA, HDPE, ABS & more. Uses ø 1/8” filament. |
| Material Cost | PLA: €22/kg, HDPE: €11/kg, ABS: €17/kg | PLA: $14/lb, HDPE: $7/lb, ABS: $10/lb |
| Speed | 15.0 cm3 per hour solid (test done for PLA, similar for others). Maximum X and Y axis speed of 725mm/s. | 0.92 inch3 per hour solid (test done for PLA, similar for others) |
| Accuracy | Diameter of nozzle 0.5 mm, 2 mm min. feature size, 0.1 mm positioning accuracy, layer thickness 0.3 mm | Diameter of nozzle 0.020”, 0.080” min. feature size, 0.004" positioning accuracy, layer thickness 0.012” |
| Finish | Fair | |
| Volume of printed parts to replicate | 1110 cm3 | 67.7 inches3 |
Progress
Status as of March 5th 2014:
- Most of design is drawn out on paper (some has been modled in SketchUp as well).
- A motor testing sketch for an Ardruino Nano has been written and used to verify the ability of the 28BYJ-48 stepper motors to reliably rotate a 10-24 threadded rod through a T-Nut. The sketch makes use of a shift register chip. The rod can be turned at ~15 rpm. This results in an ability to move that axis at 0.625"/min [1.32mm/s] which seems painfully slow for anything other than the Z-Axis. As a result it was decided to switch to the tantillus-like spooled fishing line to increase the movement speed
- A wooden frame has been built to test the ability
