An oily rear extension, mainshaft, speedo gear, and rubber mounts.

Progress has been slow lately on the direct drive conversion for my EV.  I’ve been a bit busy with life lately.  There’s been a lot of planning and discussing with local experts concerning the best way to implement the direct drive system.  I’ve settled on using the rear extension off of the back of the transmission.  Using it will require some work arounds, but it means I don’t have to worry about the speedometer, the rear mounts, or having to change and rebalance the driveshaft.

Measure twice, cut once.

Meanwhile, I had a number of parts and metal bits on their way.  They’ve mostly all arrived, so now I just need to find the time to start fabricating.  I started with the metal plate that couples the motor to the rear extension.  I used some calipers to measure out the radius of the motor, and where the mounting holes should be.  In the center I’ll have to drill a hole big enough for the 2″ OD shaft coupler to go through.

Ready to plunge out a hole.

The hole saw is adequate for the job.  Aluminum is soft enough to cut easily.  It’s a loud job, and the plate got pretty hot to the touch afterward.  But, it works.  I predrilled a starter hole for the hole saw to follow.  With everything clamped down, it’s a pretty straight forward task.  I spend most of my time in the machine shop setting up the big cuts.  The cuts themselves don’t take much time at all.

Getting the circle out of the square.

The next step is to cut the 9 1/4″ circle out.  Bandsaws are great for this.  The key is to go slow, and let the bandsaw do its work.  With slow steady pushing, and some guidance  by my hands, the result looks professional.  It’s not hard to get it right, but it takes some patience.  That’s usually true for machine shop work though.  It’s taken me years of machining to really learn that lesson.  The best way to get a good finished product is to take your time.

My own Aluminum donut.

I still need to drill out some the holes, but it’s definitely taking shape.  After I make cuts, I always deburr.  I’ve got hands covered in tiny scars to remind me to do this.  Not only does it help avoid getting blood on your parts, it also makes the piece look finished.  It’s worth the extra few minutes to take pride in your work.