brownout.com

I finally decided that the way to go was to make a coupler that accepts a QD bushing and bolts to the back of the flywheel.

I drew the part up a couple of times in Rhino until I got it the way I wanted and then decided to draw it up in the emachineshop.com software to see how much it would cost to have them fabricate it.

The price is quite reasonable considering the amount of time it would take me to make it myself.  It’s around $250 for two of the couplers (2 of them was only about $20 more than one so I got two just in case).  Unfortunately, I messed up on one of the dimensions.  I didn’t realize that for the taper on the back of the part they wanted the dimension of the smaller end, not the larger end.  I gave the software the dimension of the larger end and ended up with a hole that was too large.  I fixed the design and ordered another two.  So, I have two expensive paperweights.

The second version seems to be correct. I was kind of guessing on the size of the tapered hole and made it a little small so it doesn’t seat quite as deeply as I would like but it should be fine. I attached it to the motor shaft and spun up the motor and it seems to have very little runout (from what I could tell visually and by running my finger on a smooth portion while it was spinning).

Overall the quality of the part is impressive. The surface finish of the part is beautiful (much better than I could have done). My one complaint is that it took a full month to get the parts (each time). They must be pretty busy at emachineshop…

Now I just have to make the adapter plate. Our CNC machine is about to be online again so I need to get the part drawn up so I can cut it out.  I have measured the transmission (using a Microscribe arm for most of it and a dial indicator and DRO for the dowels and input shaft).  I need about 2.5″ of thickness in the adapter so I will probably use a stack of two 1.25″ plates (I actually found a 2.5″ thick plate on EBay and was tempted but I can’t bring myself to waste that much aluminum).

Tags: adapter, cnc, emachineshop

This entry was posted on Wednesday, June 4th, 2008 at 7:32 pm and is filed under EV. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.