Right after I finished milling out the parts for the next Kikori gantry up at MakeIt Labs, it got shut down. This meant that instead of getting to work on the kickstarter rewards I had to dismantle my entire operation up there, move everything down to my new space at the Artisan’s Asylum (living up to their name, as always), and build a new gantry first.
If you’ve been following my photostream on Flickr, you’ve watched as I assembled a new Kikori gantry. While I did find a few minor things that needed tweaking, for the most part it came together beautifully. This was especially encouraging since the Kikori up at MakeIt was having all sorts of mysterious issues that prevented it from maintaining positional accuracy (given that the new machine has none of these issues, I’m told that it could’ve been caused by a “dirty” power supply in the MakeIt building, which would’ve caused the machine to miss steps). This showed that even under a worse-case scenario, the Kikori is still capable of self-replication.
In rebuilding the Kikori I also tried out a couple different methods of driving the X axis. The problem I was having with the original setup of using a single NEMA 23 motor to drive sprockets on both sides of the gantry was that I’d get significant twisting along the drive shafts; enough that the gantry would ‘chatter’ as is moved in that direction. My first solution was to upgrade to a NEMA 34 motor which uses a 1/2″ drive shaft instead of the 23′s 1/4″. While this did eliminate the chatter, it also revealed that without the twisting rod acting like a spring, the motor wasn’t powerful enough. Finally, I decided to try using two seperate NEMA 23 motors to directly drive the sprockets on either side. This proved to be by far the best solution: it gave me the best strength, the smoothest motion, and also eliminated the need for drive shafts, bearings, and couplers.
The Kikori is now performing beautifully, maintaining accuracy to within 1/32 of an inch even at feed rates of 100 IPM! This means that production of the Kickstarter rewards has finally begun. I’ll be milling out the sets of gantry parts first, then working my way down the list of rewards. I hope to get them all out within a month, but we’ll see how things work out.
This also means that I’m about to start selling Kikori kits as well! After all the changes and additions, it looks like I’ll just be able to keep it under the $5,000 goal, but I’m going to try to do a special introductory sale to get things moving. I’ll send out an announcement soon!