Sunday, 18 October 2020
Sunday, 4 October 2020
Wednesday, 30 September 2020
After designing the MTV robot I've been slowly tinkering with numerous add ons. I wanted to add some high power LED lights and so I bought some 1 watt white LED's in an SMD package. They offered a lot of light and I'd read that the 1 watt LED didn't need heatsinks to keep the running temperature within the datasheet operational temperature range.
Testing them on the bench they get hot enough to be uncomfortable on the fingers so I decided that a PCB breakout that enabled them to be easily mounted but also acted as a slight heatsink was desirable. I quickly whipped up a design using the fabulous inkscape plugin SVG2Shenzhen and finished the design off in KiCAD . The PCB has a large pad that interfaces with the LED "slug" and in the PCB pad there are some via's connecting that pad to the large copper flood on the back of the PCB. This flood is under the mask so heat doesn't dissipate massively but I wanted it to just slightly reduce the temperature of the LED. When soldering on the LED I've added a small spot of thermal grease between the LED slug and the PCB pad. Finally I made sure that the M3 mount hole (3.2mm diameter for clearance) wasn't copper plated so that hopefully the heat in the LED and PCB wouldn't wick into mounting bolts etc.
I got some of the PCB made by the fantastic OSHpark and mounted up some LED. Driving them at 1 watt is made simpler by using one of the cheap constant current capable DC-DC buck driver boards that are readily available now. They certainly are bright!
I wanted to test how well everything was working and a friend kindly lent me his very nice FLIR camera. You can see a couple of things below comparing images from both mounted and unmounted LED's, firstly the PCB does indeed reduce the overall temperature a little as compared to the unmounted LED. Rather splendidly you can also see that the PCB mount hole doesn't couple and transfer the heat which is nice to know when bolting them into 3d printed parts.
Monday, 14 September 2020
Tuesday, 8 September 2020
Sunday, 23 August 2020
Thursday, 20 August 2020
The fabulous TS100 soldering iron (I posted a review of it here) comes well packed in a cardboard box which would be fine as a case apart from the foam inside is cut to hold the body and the tip/element separately. I've been meaning to make or print or CNC a slick case for it that would hold the iron as a complete unit, but it's one of those jobs I never seem to get around to.
Randomly this week my father in law gave me an old tool (a small spirit level) that was in this sort of glasses case with a nice rusty patina! I also today had to take the ts100 out with me to a space I am borrowing for the boat building project (more on that soon!) and so I quickly mashed up the old foam shapes from the original packaging into the metal case! I'm filing this in the "I'll replace this with something better made at some point" pile... I bet its still in this case in 5 years :)