Friday, 19 February 2016

Pocketqube Chassis Prototyping

Lately I've been considering Pocketqube chassis development and got to the point of prototyping a few ideas and working out a few engineering operation sequences. The first challenge began with trying to find 6061T6 stock that is 50mm rather than 2 inches (come on world it's 2016....!!)

I sneaked a bit of time on a horizontal bandsaw to cut some oversize blanks then used my small manual mill with the biggest endmill I own (16mm four flute with 63mm cutting area) to bring the blank to 50mm length. It would be preferable to face mill the piece to size but its easier to use the side walls of the stock piece as a datum.

Then over to my CNC router to play with some skeletonising ideas which was an interesting set of procedures as up until this I have tended to have only done jobs requiring the job to be cut out of sheet material. This means usually I only have to worry about zeroing the Z axis and pay little concern for accurate placement of the stock material. Using the Tee slot edges and a piece of angle stock and a small parallel it is easy to place the work piece accurately in line with the X and Y axis and touch on using feeler gauges (still haven't finalised my conductive probe!) and using a G92 command to set the corresponding axis position (minus half the diameter of the slot drill in the case of the X and Y axis).

What I would really like to do next is model some of the chassis ideas/designs I have in OpenScad and then try and perform a Finite Element Analysis (FEA) to determine which design should be most resilient to the resonance profile of a rocket launch... but despite reading a fair bit in the last few days it may be some time before I get my head round FEA techniques!!

Next challenge appears to be finding 6061/2 in 5 or 6 mm hexagonal bar stock ... but not 1/4"!