March 11, 2014 in 8 Channel PDU by Joshua Oster-Morris
I went to my wife’s lab this morning to cast the latest Motobrain in the new mold. I did this because a friend of mine suggested I concern myself with voids in the epoxy creating temperature instabilities and ultimately reliability issues. I have no evidence this will happen, but the fact that it may happen and the fact that vacuum is not that difficult to access in the lab convinced me to go that route.
My wife’s lab literally has vacuum on tap so it was not too tough to make it work. It was only modestly effective though. I was able to pull air bubbles out of the goo but my container was not great so prolonged exposure to the vacuum was hard to achieve. I’ll do better next time I’m sure. The casting otherwise went ok I think. The mold would be more effective with four posts rather than two so there is no tendency to twist out of position. I am basically pleased though.
Currently the Motobrain is in an incubator with some flasks full of stinky yellow fluid staying warm so the epoxy will set faster. I have jury duty tomorrow I just remembered so I may not get to look at it until Thursday. I’m excited though. This is the first time I’m not worried about the process of removing the Motobrain from the mold. It should be a piece of cake.
March 10, 2014 in 8 Channel PDU by Joshua Oster-Morris
The new molds are here and they look great. I need to head over to the hardware store for a few bits and bobs and then I can do the deed. The process is a bit involved but I should have a Motobrain coming out of the mold Wednesday morning. I may take these to my wife’s laboratory (she is a fancy science type) where she has an incubator which will speed up the process a bit.
This has been an exciting journey. With the Motobrain I designed from schematic to CAD drawing, had turned into a printed circuit boards, then built with a pick and place machine I designed and built for this sole purpose, soldering them in an oven whose electronics I designed and built and installed (into a Sears toaster over), sitting in a mold I imagined, drew in 3D, and had built, running code on two microcontrollers I programmed talking to software I wrote on my iPod I am quite astonished at the scope of this project and it is extremely satisfying to see it all come together.
March 7, 2014 in 8 Channel PDU by Joshua Oster-Morris
I’ve got the new insulating top cover that will keep the terminals from shorting to anything on accident. I think this is a simple and elegant solution.
The new molds shipped today and with any luck will arrive tomorrow. I will then have everything I need to begin building more samples for the patient throngs who are waiting on them. My mold maker was a week late on these parts and they are seriously screwing up my time line. It is time to find a new vendor.
I also have put out to bid the manufacture of Motobrains. I should have some useful information about how much it will cost to make these guys in bulk very soon.
March 5, 2014 in 8 Channel PDU by Joshua Oster-Morris
The covers are in hand and look pretty nice. I am pleased with them. One is cheaper than the other but both look fine to me so we will go with the less expensive one (I cannot tell you which one is the cheaper of the two, I don’t know).
March 1, 2014 in 8 Channel PDU by Joshua Oster-Morris
I designed and ordered a new mold this weekend and asked a friend of Motobrain, OSHStencils.com, to laser cut a cap that will be placed onto the wet resin to make a “finished” look. This cap also includes some holes for stand offs and I intend to provide a clear piece of acrylic that will be screwed into those to isolate the terminals from the outside world. I have also begun conversations with some contract manufacturers who will ultimately be doing the manufacturing of Motobrain. Next week I intend to build up a few more units and get them out the door and into testers hands. If I like what I hear from the manufacturer, I may be done building these things myself and begin outsourcing this particular task.