Aluminum build v2

[zdayton]

I ordered a few nxp kmz60. They are surface mount so I need to get some breakout boards for testing. They are system on a chip so it should be fairly straightforward, they have onboard amplification, temperature comp, and filtering. I also bought a shiny new oscilloscope that gets in tonight

[jeruw]

Nice. Those look to be a lot like what I had seen. I probably should try some circuit board building. There are people doing it with the laser cutter at our shop. Technically you can do it with the shapeoko as well. If I could have either sourced or felt I'd could manufacture a board cheaply I would have gone that route. I'm not entirely sure my sensor is going to work, we'll find out soon. I'll probably just cut some longer shafts and try rigging it up on my current throttle for testing. I'll need to order some sleeve bearings to get things functional on the new parts.

[jeruw]

Getting back into my build. I've got the capacitors needed to get the sensor boards going. Hoping to work on those tonight.

I also decided to switch up the bearings for my pivot arm shafts. Instead of using bronze bushings I'll use F686ZZ bearings (6mm ID x 13mm OD x 5mm W with a flange). I'll need to get checked out on the lathe and turn my shafts down from 3/8" to 6mm. This step down in diameter will also provide shaft retention between the two bearings.

I'm considering swapping out the Traxxas rod ends and threaded studs and instead ordering these metal 3mm rod ends with a male thread - http://www.ebay.com/itm/20pcs-3mm-Male- ... 19d504aa29

It'd give a little more high-end look than the plastic and cost wise they're the same or cheaper than the traxxas joints when you factor in the studs. The one part I haven't sorted with this idea yet is whether I'd also need to source some conical washers/spacers for bolting these up. The balls on the Traxxas joints have the spacers built in. Without the spacers i'm not sure I'd have enough range of movement.

If I went with the metal rod ends, I'd use longer standoff spacers. Either threaded brass standoffs or carbon tube (epoxying the rod ends in the tube).

I'm updating my cad models and will post more screen shots when I have some of these changes accounted for.

[jeruw]

It's been awhile, but I'll be picking this back up shortly. I have some more design work to do and then I'll be ready to cut parts.

Speaking of cutting parts. Here's what I've been working on recently.

Just finished up getting the cable chains installed last night and running the wires. I've got some calibrating and tuning to do, but it's nearly ready to cut parts. This should be a little stiffer and more accurate than the Shapeoko I used for my first build. The frame is 1530 heavy extrusion from 8020. The gantry is 50mmx150mm Maytec extrusion. 0.5" 6061 for the uprights. THK steel rails for motion and some chinese ballscrews for the drive. I bought most of the parts surplus on Ebay and at a few local places here in Minneapolis. It's a lot bigger and heavier than I first imagined. Looking forward to putting it to use!

[Zispinhoff]

Wow! Any new pics of the Aluminum build?

[jeruw]

Almost!

I've been working on the designs a bit as I've had time and sorting out some details. I've been using the CNC and testing it's limits a bit. Getting a feel for how it cuts different materials. Last night I ran a test part for the top half of the walnut handle, I have some tweaking to do to get it to feel right. I haven't cut new versions of the aluminum parts for the throttle yet only because I've been sorting out how I want to do the axles for the pivot arms. I don't have a 4th axis or lathe at home. I tried to figure out a way to work around that for this build but ultimately I think it'll be better with a proper stepped shaft. I'm working with the machinist at the local maker space to work on the lathe there. We'll hopefully knock out a set of shafts next time I can connect with him.

With those out of the way I can probably get all the mechanicals assembled in a day. Then I'll need to tackle getting the Hall sensor boards soldered and wiring done.