This is a project I started sometime ago after setting up on eBay selling resistors/kits.
I found that the process of sorting resistors into kits was painfully slow and considering how well they were selling, I could not supply quick enough to meet the demand.
So I thought I would come about and try and design a machine to aid this process.
Machine design went through a few conceptual phases and various specifics were changed.
The initial bipolar stepper motor design was initially going to use LM675 amplifiers to control motor steps but found that they were unreliable and board design was a nuisance so was replaced for an L298 board bought for a few ££ on eBay.
The H-Bridge design for the motor is of my own design and board layout using BD139/BD140 and a BC337 to allow for directional movement. The board works incredibly well and generates next to no amount of heat.
The Picaxe is a 14M2 and the control board is also of my own design. All of the chips I/O pins have been broken out into pluggable sockets both sides of the chip. Along side the pins is 5V power and a GND so that external components to the board can be plugged directly into it.
The board is powered off my bench PSU with a 30V supply. An LM317 and SMD components drop this voltage to 20V to power the stepper motor and print head motor. Another SMD LM340 5V regulator provides 5V supply a download socket and filter capacitors are also mounted on the board. Massive hunk of aluminium provides a heat sink.
An IR LED and IR sensors are used to determine the position of the print head in order to change direction and stall the print head. No other sensors are used though I do regret the selection of the IR sensors as they are sensitive to sunlight. (should have used IR leds in reverse)
http://www.youtube.com/watch?v=7cKMnIQioSg
Video here shows the initial version and cutting
http://www.youtube.com/watch?v=EnZyv3VeO8Y
Video here is a bit more narrated and shows how much better it now works.
Thanks!
I found that the process of sorting resistors into kits was painfully slow and considering how well they were selling, I could not supply quick enough to meet the demand.
So I thought I would come about and try and design a machine to aid this process.
Machine design went through a few conceptual phases and various specifics were changed.
The initial bipolar stepper motor design was initially going to use LM675 amplifiers to control motor steps but found that they were unreliable and board design was a nuisance so was replaced for an L298 board bought for a few ££ on eBay.
The H-Bridge design for the motor is of my own design and board layout using BD139/BD140 and a BC337 to allow for directional movement. The board works incredibly well and generates next to no amount of heat.
The Picaxe is a 14M2 and the control board is also of my own design. All of the chips I/O pins have been broken out into pluggable sockets both sides of the chip. Along side the pins is 5V power and a GND so that external components to the board can be plugged directly into it.
The board is powered off my bench PSU with a 30V supply. An LM317 and SMD components drop this voltage to 20V to power the stepper motor and print head motor. Another SMD LM340 5V regulator provides 5V supply a download socket and filter capacitors are also mounted on the board. Massive hunk of aluminium provides a heat sink.
An IR LED and IR sensors are used to determine the position of the print head in order to change direction and stall the print head. No other sensors are used though I do regret the selection of the IR sensors as they are sensitive to sunlight. (should have used IR leds in reverse)
http://www.youtube.com/watch?v=7cKMnIQioSg
Video here shows the initial version and cutting
http://www.youtube.com/watch?v=EnZyv3VeO8Y
Video here is a bit more narrated and shows how much better it now works.
Thanks!
