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Tuesday, 24 January 2017


Frame



From a log I cut some planks... then thin strips...


on the bandsaw...

Thickness the strips...



Then route a groove on one side...


then join with mitres at the ends... and glue...






Frame.





Replacement Canopy Fitting

Replacement Canopy Fitting

Due to a failure of a fitting in a canopy, I am attempting to make a replacement out of nylon. The original is an injection moulding made of an indeterminate plastic. It has cracked due to impact and isn't easily glued.

The large block of nylon was chopped into a block of roughly the correct size:


I used the bandsaw to shape the block roughly to the shape required.






The block is at the limit of what can be machined on the mill




Watch V6 (With Pogos)

The latest iteration of the watch uses a smaller OLED display I found on ebay. Due to the problems and size of the USB socket I used on previous watches I have gone with pogo pins on this version. This means a jig is required, this is done with stacked PCBs in this case. A cutout allows the PCB to fit into the jig when the pogos re used. The pogos have the programming interface, which includes power for charging the battery.

The PCB fits well in the jig:


I used gcode to cut the rectangle in the top and second PCBs in the stack.


The second PCB has a slightly smaller cutout so the PCB doesn't just fall through the top PCB.

The pogo pins are at just the right height to press on pads on the bottom side of the watch PCB.



The PCB when populated is quite small:





This is the first PCB, which had a few mistakes. I've fixed these in a later PCB. The new PIC (16F1829) has a way to measure the battery voltage with no external voltage divider, so a couple of resistors can be removed form the layout. This PIC also has a larger amount of RAM and flash, and may also be able to measure temperature with no external components.




Aluminium Melting


The latest piece of equipment has been fired up and the result is here:






These used to be food trays. There's a lot of dross with this process, maybe due to a large amount of oxide on the trays due to their high surface area. I'll try other sources of aluminium and see if I get better results.

Wednesday, 4 January 2017

Die Holder


I have no way to hold dies on the lather. I have just bought a collet chuck for the lather tailstock so it seemed sensible to try to make a die holder for the collet chuck. The collets I have only go to 20mm and the dies are 25mm, so they can't just go in to a collet.

One end was turned to 19.5mm so it will fit into a collet. The other end is bored out to hold the die.


The final die holder has four tapped holes around the edge to hold and align the die.






I have some smaller screws coming...