On Monday, November 12, 2012, Mike Lutz wrote:
> The master source of Zenbot info is the wiki:
> http://wiki.lvl1.org/Zenbot_1216_CNC
> (url looks nicer because of wiki voodoo ccprek did)

> *In short* -- three steps forward, Zenbot is marginally functional, but
> future progress is likely to slow and application specific

> spindle belts found and installed, system moved to the basement, first cut
> in wax, motor controller repared

> Virtually all progress in this update (and most from last) is thanks to
> the *continued heroics from Chris Pettus.* He is the unsung hero of this
> project and will be the reason the machine gets to whatever level of
> operation that it gets to.

> Detail for this week:

> *Progress made*:

>    - Chris P found some < $4 faucet o-rings that are the right size to
>    link the spindle motor to the spindle arm
>       - They are installed on the zenbot, have about 30 min of time on
>       them, haven't shown any issue with wear or slippage.
>    - Spindle power supply interface case built with integrated fuses
>       - currently fussing the spindle at 10 amps, though the power supply
>       really should be able to drive 30 amps safely, we are using the low fuse to
>       better learn what the spindle will really need -- In other words, if anyone
>       tries to cut something really hard (or jams the cutter) the spindle fuse
>       will likely blow.
>       - I expect we will increase the fuse as we better understand the
>       spindle (unless we find it never blows)
>    - Last meeting, with the help of many other Lvl1'er, the Zenbot was
>    moved down stairs next to the big CNC.
>    - Running the spindle at full speed (likely too fast for the wax)
>    Chris P and Mike L did a cut of the first few letters of "LinuxCNC" in
>    machining wax. See the wiki page for full desc or jump here for picture:
>    http://wiki.lvl1.org/File:Zenbot_Clockwise_cut_(first_cut).jpg
>    - The spindle motor speed controller has been repaired and tested with
>    a separate motor, not yet integrated back into the zenbot.

> Next actions:

>    - Get the speed controller installed between the spindle and its
>    supply (also, perhaps trying to connect the PWM interface to LinuxCNC) -
>    Chris P
>    - Measuring spindle speed (at full and different settings of the speed
>    controller - Chris P and Mike L
>    - Writing up the software complexities of working with the CNC (Need
>    CAD & CAM before can use LinuxCNC) - Mike L
>    - Learning various CAD and CAM packages so-as to create g-code that we
>    can mill with the Zenbot - Mike L, Chris P, and anyone else who is thinking
>    they want to use this system

> Future/dream/stuff-it-would-be-nice-if-other-people-would-jump-in-and-tackl e:

>    - More bits for the Zenbot
>       - We now know that the collet in the zenbot takes 1/8" bits (...
>       and given the collet is high-spec it will likely ONLY take 1/8" bits - it
>       *might* be able to take 3mm bits, but I wouldn't be surprised if
>       they slip given the collet design
>       - The bits for the spindle are both expendable (very breakable and
>       will dull if cutting hard stuf) and kinda pricy (new < 1mm blades seem to
>       be around $35 new).
>       - As talked about in the last update, multiple parties have said
>       "get used blade off ebay", and while I'm starting to understand what they
>       are talking about, I'm still not ready to plunge into the used blade world,
>       nor has anyone committed to this work.
>       - So I can keep working, I'm going to personally order a few new
>       blades for my personal use and use the experience to better learn about the
>       used market.  For anyone else thinking about using the zenbot in the near
>       term, I guess what I'm saying is "for the time being, the zenbot is a
>       'bring your own bits' device".  (I'll add a bit ordering guide to the wiki
>       as I better understand the process)
>    - X, Y, Z limit switches
>       - Chris P has some switches which may be quite good for this, we
>       are not sure when or if we will get to this though (neither of us are
>       mechanicals, so making readjustable and robust mounting brackets for
>       switches is a bit baffling to us)
>    - X, Y homing and measuring the cutter in the Z
>       - X & Y homing might be doable with the limit switches depending on
>       what the controller can do.  Measuring Z will likely require something new.
>       Chris P has this in mind when he is working with the X,Y,Z controller but
>       no new work has been done on it since last update
>    - Integrated vacuum system
>       - Gerrit said at last meeting that he might have a vacuum that
>       could be used for this.  I have a 15A ac power relay (
>       http://adafruit.com/products/268) that might also be able to be
>       used, but no planning other then ideas of parts have been done.
>    - Sacrificial milling surface overlays and/or jigs
>       - Chris P, Gerrit and I have all agreed that it would be *very* good
>       idea to build some type of sacrificial overlay over the Zenbot milling
>       surface given how easy it is to drive the blade right through the mills
>       surface (the -z limit won't help for this, the spindle is such that the
>       cutting blade would always go through the mills surface before the limit
>       hit)
>       - With that said, no one has picked up the ball on this, and I
>       doubt Chris P or I would any time soon.  Help would be welcome, especially
>       if you know what your doing with the big CNC and/or know how useful jigs
>       would be built for specific tasks, like circuit board milling
>    - All-in-one enclosure
>       - Gerrit has been dreaming of an all-in-one enclosure for the
>       zenbot, with its controls, and the computer system that LinuxCNC runs on
>       packed underneath the zenbot.  (something like
>       http://buildyourcnc.com/redSproutCNCComputerSystem.aspx under the
>       zenbot) Chris P has continued to refine/repack the control electronics and
>       this may be relatively straightforward in the furture but no one has taken
>       the ball for this task.

> The CNC is nearly at the point where different tracks of work will need to
> be done for different projects (molds vs. circuit boards).

> I'm interested in 3d mold making and to get the ball rolling for that
> sub-project on the zenbot, I've started a new wiki page about that use:
> http://wiki.lvl1.org/Copying_Guerrilla_guide_to_cnc-mold-casting
> (I've also ordered a board of Renshape 460 - millable plastic for mold
> making - that I would be up for selling parts off of for anyone else
> wanting to try 3d part mold making)

> I know that a number of other people in the group are interested in
> cutting circuit boards, thats not really my cup-of-tea (at least not until
> I have my brain wrapped around the mold making stuff) so I'm hoping some of
> the other interested parties will jump in, start researching the
> software/router-bit/jigs that are required to do that work, and building
> documentation to teach others.

> -Mike