Belts and Zstage

Here's a series showing how construction happened. Left, the basic box with electronics mounted to them. Middle, the z-stage rods were added in and the clear z-stage platform was built (placed in front of the bot). Right, shows the addition of the belts that drive the zstage screws and show the X-Y stage assembly installed.

Here is an image looking down through the unit. The little small platform has 5 brass colored ceramic magnets that hold the build platform to the stage. The platform is held on by magnets so it can be easily removed.

The serpentine belt is driven by a stepper motor. This in turn causes all 4 threaded rods to rotate. On the rods are nuts. When the nuts are holding the z-stage platform, the effect is that the z-stage platform raises or lowers.

The next photo shows the the orange build platform installed. It also shows the clear z-stage platform installed and resting on the threaded rod nuts. The extruder assembly has not been installed yet. Before installing, the z-stage platform and build platform must both be leveled. Adjusting the build platform is done by adjusting each individual threaded rod nut till the z-platform becomes level. By having both the build platform and z-stage made level, it insures that the plastruder extrusion head remains at the height it is supposed to be at no matter what location it points to on the moving build platform.

Building housing & mounting electronics.

In previous Makerbot editions, the circuit boards and components came in pieces. Then, people would use hotplates or ovens to "bake on" the components. Fortunately, in today's kit, the circuit boards now come pre-assembled and hopefully pre-tested. Should you want to impress your friends about the makings of a makerbot, here's a cheat-sheet.

1) Extruder board - controls the flow of plastic. It feeds signal to a motor that gradually feeds plastic into a heated build head (not shown). This shows the original board that drove a DC geared motor and controlled temperature of the extruder directly. As a result, this board would usually get hot. Due to this, later upgrades would only require low power signals from the board to drive heater element relays and a separate extruder driver board. At a later time, two types of extruder driver boards were tried and were mounted on top of this board (not shown).
2) Motherboard. Programs can either be fed to this board via a USB cord from a PC or programs can be loaded using an SD card (SD card slot is a rectangular metal thing located on the lower right of the board)
3) Stepper motor drivers (3 of them). These will accept digital signals from the motherboard via ribbon cable. The pulses to the stepper motor driver are amplified so they achieve precise movement of the X & Y build platform. A third board controls a stepper that controls raising & lowering for the Z dimension. In addition to getting signals from the motherboard ribbon cables, they also get signals from end-stops.
4) Relay Kit mounting location. On the top stepper board is a mounting needed for a "relay kit". This accessory allows the extruder board to remain cool since it only needs to signal a relay board rather than drive the heating elements directly. One relay controls current for heating the extruder while the other controls current for heating the build platform.

When assembling, the electronic boards seemed easier to mount if I could get to both sides at once. So, I mounted the board on a vice and attached the electronic boards as seen in the photo.

On each piece, I sanded the tabs down AHEAD of time so the project could be put together more easily. It worked. By only screwing and not gluing, future repairs will be easier to perform. There are LOTS of screws to this kit. The task of tightening them took quite a while!

Building the X-Y stage

The next steps are before and after shots. With the exception of the orange build platform holes being a little off from the wooden build platform and having to use occasional sandpaper on a tab or two, the Y-stage build went pretty well. The maker bot logo on the wood platform should be on the other side (and magnets reversed of course). However, after realizing my mistake, I just went with it anyway. I figure the logo, showing through the plastic, makes a nice effect. The plastic is held on by m3x16 screws so if I decide to try different build platform materials, it should not be difficult to swap out.

The X stage, where the Y-Stage sits on went OK as well. I did need to get out the Dremil cutting wheel to trim 5mm off of the black idler wheel bolt. The small silver stepper motor wheel was quite difficult to push get onto the stepper motor shaft. (and yes, I did take out the hex nuts before trying) I finally resorted to using a dab of graphite oil to convince it to fit on the stepper motor shaft.

After moving the idler wheel back to tighten the belt, I found the closer the movable Y-platform got to the stepper motor, the more resistance there was to free movement. Is it a design defect? Silly me, I put the "Y" platform on backwards! Fortunately, the design uses more "screws" than "glues" so this kind of thing is easy to fix. One complication I ran into was with motor mount screws. I only have 6 and I need 12. Lowes didn't have Hex M3 screws which is just as well since they would want quite a bit for each one since they are sold individually! Fortunately, the kit provides lots of extra 16mm screws so I'll cut some down to the 10mm size so I can use them for the X and Z motors should they be needed in later steps. Anyway, here's a series of photos showing the build platform as it is so far.

Oh, and if you're using end stops, the rear X-bar holder is on backwards. Just flip it. Both end-stop mounts should be on the near side as in the photo below. In fact, it's probably not a bad time to construct and install the Y end stop boards (and make some paperclip wire holders) now while the stage is easily worked on. So, if you have end stops, check out how to install them HERE.

Makerbot #2380 arrives! Take inventory, coat parts.

I've ordered the "ultimate" kit which should have all parts & tools for the Makerbot, heated build platform and automated build platform. They even provide wrenches! Inside the big box there are a series of well labeled packages. Whether the packages have all parts inside is something I'll be finding out as I build. About a week after the kit arrives, I get an email that some kits were shipped with one component that had holes drilled into it that were too small. Fortunately, my plate holes seem OK. One possible problem that's no problem. Those are the kind of problems I like!

I've decided to assemble the kit at the Syracuse Innovator's Guild. It's nice to have heat, light, electricity, tables, Internet and most important, expertise in case I run into a problem! It's in Downtown Syracuse so I find it's easily reachable by car or bus. They have a monthly membership fee of $50 which, even in spite of needing to pay for parking during weekdays, is a very good value.

As for the kit itself, quite a few parts are made from laser cut plywood. At first, I was a little skeptical of this material. However, other makerbot users seem to not mind and now I can see why. The wood parts have surprising precision to them!

Before arriving at the assembly site, I decided to pre-coat the wood parts with a clear enamel spray paint. Clear, due to wanting to see the markings on the parts. Enamel due to needing a coating method that was quick, easy and not too messy. Plus, I happened to have a can from a previous project so that made my plan especially attractive from a cost standpoint. It is winter. Due to temperature being in the 20's outside, I decided to paint inside my basement. Big mistake, although I didn't know it at the time! So, I hang the parts. Then put on a thin coat. The first respirator I had did almost no good. Fortunately, I had a second 3M paint respirator that had some fresh cartridges. Ok, I didn't count on needing to use another set of expensive cartridges but at least painting goes quickly. Then, I go upstairs and discover the paint fumes made their way into the living area! Fortunately, nobody is there. So, I quickly opened up every window in the basement and set up a temporary fan to blow air out of the space. For the next two hours, I wait, reading a book, with my respirator on, occasionally taking it off to test if the fumes are gone.

Anyway, once painted, smaller wooden parts are punched out and sanded. For the excellent punching and sanding job, I thank Mike Smith, who stopped by during the day to help.