Monday, 31 August 2015

3D Printer Upgrade

Over the weekend, right in the middle of a major project, my printer started acting up (as usual). One of the issues I experienced, for the first time ever, was that my drive pulleys for my uprights were slipping.

I opted for replacing them with off the shelf aluminium pulleys with 5mm belts. The next problem I had was how to tension the belts.

After a quick search online, I found some interesting and amazing belt tensioning techniques involving some 3d printed parts. These are all good and well except that they were all a bit of over-engineering.

With a non-working printer, I had some springs from the cables I were using before, some galvanised wire and a couple of tools. From the wire I quickly bent (using long nose pliers) some loops to connect the belt to the spring as shown in the diagram below.

I then looped the belt through them. Ensuring that the teeth mesh nicely, I added a small piece of plastic on both sides (to ensure the belt is not squashed sideways) and cable tied them together. Hooking the spring now supplies dynamic self-tensioning and it all works perfectly.

In most cases, simpler is better.

One potential downside to this approach could be the fact that the belt makes such a tight turn over the loops which could be a failure point when the belt starts to perish. I'll keep you posted if that happens.

Monday, 22 June 2015

Lab Power Supply: OpAmps, Analogue Control and Digital Monitoring

I've progressed to the point where I think the second stage of the Lab Power supply is probably ready for an initial board to be made.
In this video I go through the OpAmp design, the digital monitoring, Linear control and the design of the shunt resistors in the second of three main boards in the system.

Might be time to have at least the Raw Power board manufactured so that I can progress to a stage where I can start testing the design of the second stage.

Wednesday, 27 May 2015

0-30V 0-3A Variable Bench/Lab PSU

I have started work on a Bench/Lab power supply design.

The following are Required features:
  • 0-30V variable output voltage
  • 0-3A Current Limited
  • Current Limit notification (by LED)
  • Output Enable button with notification LED
  • Display set and actual output voltage and current.
  • Static 5V output
  • Static 3.3V output
  • Display current flow of 5V and 3.3V circuits.
  • USB Charge port
  • USB PC connection port
  • PC controlled via USB
  • Internal Temperature sensor and PWM fan for quite operation.
Optional features
  • LAN Connection to connect multiple PSU's together for Parallel or Serial use or Synchronised outputs
  • Mode switch & LED for extended user interface controls
Design Requirements
  • PSU Should be fully modular to allow for expansion or alternative uses or replacement of required modules with alternatives as required.
  • PSU should be as efficient as possible
  • PSU should be as cost effective as possible
  • PSU should be as small as possible
  • PSU should be as quiet as possible

Gineer - Variable Bench PSU #1  


Gineer - Variable Bench PSU #2 Raw Power

Thursday, 16 April 2015

CremaBots for sale on Tindie

I have 3 more CremaBot's and have made them all available for sale on Tindie:

I sell on Tindie

I also uploaded a full write-up of CremaBot with the Schematic, cad designs, firmware and source code.

Let me know what you guys think and get one for yourself.

Wednesday, 7 January 2015

Microsoft - Intel Galileo - Upgrade to Gen 2?

In this video I answer a Youtube comment on a previous video "Microsoft - Intel Galileo" from John Ryder and discuss the differences between the Intel Galileo Gen 1 and Gen 2 development boards and talk about some example projects.
Let me know what projects you guys decide on to help you learn.