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:
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.
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
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
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.