Sindrian Arts

I figured it out!

As is often the case, after stepping away from the problem for a bit I came up with a simple solution:

First, secure one side of the gantry to the table (or have a friend hold it).  Next, apply power to the machine, but engage an e-stop.  Now take a long square (I used a drywall T-square) and place the short side flush against the side of the gantry that is secured so the long side is pointing across the table to the unsecured side.  Make sure that one edge of the long side is lined up with some landmark that appears on both sides of the gantry (I used the vertical edge shown in the above pic).  Finally, go over to the unsecured side of the gantry, manually deflect it until the same landmark is lined up with the appropriate edge of the square, and then release the e-stop switch to apply power, thus locking it in.

Granted, this is not a super-precise method, but given that you’ll probably get your deflection down to less than an eighth of an inch over the entire width of your table, it should be close enough for most work.

Ok, back to making Kickstarter rewards!

My apologies for the long silence; the last month has been a bit of a rollercoaster.

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!

It’s making things!

About damn time too.  Turns out that the problem all along was that the computer was missing steps (not moving as far as it thought it did), so after I swapped it out for an old p4, it’s running like a dream.

I’ve been told by people on here and elsewhere that the fact that it’s a dual-core machine that can’t do core isolation might have been the culprit (since newer dual-core machines don’t have this issue).  Whatever the case, it’s fixed now!

The picture is of a new router plate I made for the bottom of the Z gantry.  This new plate serves 4 functions: diverting the air blowing out of the router (so it doesn’t blow dust everywhere), allowing access to the collet (see here and here), creating an attachment point for a vacuum hose, and providing a surface onto which a future removable brush shroud can be mounted (this is why the vac hose is where it is, even though it’s largely ineffective without the shroud).

I’m now in the final stages of testing and refinement before I make the next set of gantry parts.  Once that happens I can move into the Asylum, build the next version, and FINALLY GET DOWN TO BUSINESS.

The new couplers are doing great!

Mostly.  I think.

Since I’m done traveling for the next few months, I finally got to spend some time working on the Kikori last week. I wanted to mill out one of my tablet stands, but to make sure everything was staying nice and accurate, I did a test first.  I decided to drill a hole at a known location, do an air-cut of the hole pattern, and then have the machine return to the hole location to see if it had gotten off at all.

It had.  Only about 1/16th of an inch in X, sometimes in Y (I tested it multiple times), but it had.

The two most likely culprits are set screws working themselves loose and couplers slipping.  I applied loctite to the set screws before I left, so today they should be set.  I’ll make registration marks on the couplers to check on slippage there.  Wish me luck!

Remember the coupler issues I was having?  Fixed ‘em!

While I was in Oakland I did a fair bit of research on what my options were, and finally decided on these “light duty” couplers from McMaster-Carr (Part no. 6115K18).  As you can see, not only are they aluminum (instead of plastic (nylon?) like the last ones), they are HUGE.  You can see the size difference here.  I actually had to dremel out the x-axis motor mount to get it to fit, but thankfully it didn’t need much.

After slapping those puppies in and tightening up some things (I really need to remember to put loctite on those set screws), I milled out a couple new test pieces.

Beautiful.  Not only did they have wonderfully smooth edges, free of steps and ripples, but they also fit together snugly!  This means that they are likely within 0.01″ of their intended dimensions.  I’ll have a better sense of it’s accuracy once I mill a harder material like masonite.

Of course, now that my machine is finally working well I’ve got to go to Chicago for my nephew’s bris, but once I get back on Monday, I’LL FINALLY GET TO MAKE STUFF!!!

I’m very excited.

Ok, so we’re really getting close now.

3 days left and just $1300 left to raise.  Hopefully, this new reward will help us get over this final hump.

Allow me to present the cleverly-named vial box!

I designed this box after noticing that several friends of mine who are fans of Black Phoenix Alchemy Lab (commonly known as BPAL) had piles of these small vials called ‘imps’ with no good way to store them.  Some people use bullet boxes, but this requires wrapping the label around the imp, and makes it impossible to tell at a glance what you’ve got.

I knew I could do better.

After playing around in my CAD program I came up with this clever system that would hold each imp in such a way as to make all the labels easily read and each imp accessible.  It also closes securely, keeping the imps safe from harmful sunlight.

The box is 10″ x 9.75″ x 3″, holds fifty imps, and I’ll do a custom bit of inlay work on the lid! It’s available now for a pledge of just $60!  Hurry, the project ends Sunday!

The launcher is now available as a reward on Kickstarter!

This puppy is a cross between a slingshot and a crossbow, and can launch almost anything that’s about the size of a tennis ball.

Other features include:

• A stop that keeps the ammo in place until it is launched.
• Safety bolt that can be set to engage upon cocking.
• Adjustable length frame to allow for adjustment of launcher power.
• Interchangeable parts that allow for the attachment of a butt stock.
• A sturdy cup made out of recycled bicycle tire.

I’m quite proud of the internal mechanism of this thing.  Getting the stop and the safety to work correctly took quite a bit of tweaking, but I think I’ve got a design that will work beautifully.

As you can see in this side view, when the cup is pulled back the U bolt engages with the rotating catch.  When the trigger rotates to engage the catch it also pulls the stop up to hold the ammunition in the cup.

When the trigger is pulled the catch is allowed to rotate forward releasing the cup.  At the same time the stop rotates down and out of the way.

In the first side view you can also see the safety bolt resting in the channel in front of the cup.  In this position the stop cannot fully retract, preventing the trigger from being completely pulled.  Only once the safety bolt is moved to the position shown in the second side view can the launcher be fired.

I really wanted to wait until I could show how it works with a video, but at this point I’m running out of time before the end of the project.

With the $5,000 in matching funds that should hit my Kickstarter project today, we only need to raise another $2,500 over the next 11 days!  Head on over and check it out!

What do you think of the launcher?  How’s the size?  Are there other features you’d like it to have?  Let me know in the comments!

The Kikori is now at MakeIt Labs!

Granted, right now it’s little more than a pile of MDF and various bits of gantry, but it shouldn’t take long to put back together.

My biggest concern right now is the torsion box.  Unfortunately, very few of the ribs survived the move intact; most of them are in two if not three pieces.  Thankfully, I have all the pieces and it’s clear which pieces go together. This means that while I can reassemble the torsion box, but I’m not sure how strong it will be.

My current plan is to put it back together as-is and immediately use it to make a new set of ribs out of 3/4″ MDF instead of 1/2″.  This means I would have to use the reverse side of the skins since these new ribs would no longer fit into the slots the original ribs fit into, but given that the slots were too tight to begin with, this might actually be a good thing.  Another option is to make them out of 1/2″ MDF again, and simply make them taller this time, increasing their strength that way.  I could sand out the slots to make them looser.

Of course, if the reassembled torsion box seems fairly strong even with the broken ribs I might just use it as-is. After all, having a perfectly flat milling plane is only super-important if you’re doing 3D carving; it doesn’t matter as much for simple profiles.  Besides, I’m itching to start prototyping the launcher!

The 2′x4′ Kikori is out!

The MDO parts are available now for just $400, but hurry; I’m only offering five at that reward level.  After that, they’ll go up to $500.

The reason they aren’t cheaper is because  only nine pieces actually change between the 4′ version and the 2′ version.  However, this also means that the 2′x4′ Kikori gantry has the ability to upgrade itself by making only nine new pieces!

I’m also offering the mechanical and full kits at reduced reward levels: for the first three backers the mechanical kit is only $2000, and the full kit just $2500!

In other news, since the Artisan’s Asylum is going to be moving to a new location, it’ll be closed during the month of August.  This means that even if I got the Kikori set up there for July, I’d have to turn right back around and tear it down again, and then have no place to work for an entire month.  As you can imagine, I was not happy about this prospect, so I got to work finding some place to work.

I remembered that Joseph Schlesinger, one of the guys who helped me build the the blackFoot at the Asylum, had just moved MakeIt Labs (a “Makerspace/Hackerspace/Open-Access Workshop”) into a new space up in Nashua, so I shot him an email asking if I could set up the Kikori there.  Sure enough, a few emails later and he’d talked his board into letting me set up shop there for a couple months!  This means I’ll be able to get rewards out for the Kickstarter project much sooner.

I’ve also been hard at work finishing up another reward: the launcher!

While it’s designed to launch tennis balls, it’ll launch pretty much anything under 4″ in diameter: water balloons, snow balls, confetti…  It’s designed to be adjustable, so you can alter its strength without swapping out the elastic.

I can imagine all sorts of uses for this, from playing fetch with your dog to ambushing your friends with blasts of glitter.  However, I know I’ve just barely scratched the surface.  What would you use something like this for?