Impressive CNC, mold and resin casting guide (with an eye to robot mechanics) - Anyone tried this?

[Mike Lutz]

The "Guerrilla guide to CNC machining" http://http://lcamtuf.coredump.cx/gcnc/ is sitting at the top of Hacker News right now, and strikes me as a fairly amazing overview of the process of working toward custom robot mechanics via CNC molds and resin casts.

This is the first I've seen this guide (though google seems to say versions have been around as far back as 2008) and it seems amazingly complete (... though I could be fooled, I'm new to much of this).

Has anyone in LVL1-land done fine spec CNC molds? I know there is a CNC in the basement, but I was assuming that was for large course projects. I hadn't realized, until I read this guide, that small, cheap-ish CNCs were hitting such a high precision.

-Mike

[Ben Hibben]

Nicely written -- some arts of that should be posted as printouts nar our mill so people know how to use it properly (and don't overload it).

Blenster

[Raj]

Thanks for the guide.  I believe the larger CNC machine we have in the basement is accurate to within 1/64 of an inch, according to Brian.  We also have a smaller CNC in the big room, a ZenBot 1216 http://www.zenbotcnc.com/all-products/zenbot-1216-cnc-router , that is supposed to be accurate enough to mill PCBs.  I don't know the current status, but if it's up and running it should be able to make fine-spec molds.

---

From: Mike Lutz <mil...@gmail.com>
To: LVL1 - Louisville's Hackerspace <lv...@googlegroups.com>
Sent: Sunday, October 21, 2012 9:40 PM
Subject: {LVL1} Impressive CNC, mold and resin casting guide (with an eye to robot mechanics) - Anyone tried this?

[John Coder]

Asron and greg were working on zenbot check with them

[Mike Lutz]

I stopped by the space and I think I found the zenbot Raj talked about sitting disconnected on the floor on the east  side of the front room.  There is a hand written note sitting on top of if (included).  From the note I'm guessing it either has never has been brought online because of missing parts or its now in a broken state.

Anyone have any more background on the unit?  Particularly is it something that is owned by lvl1 or is it someones personal CNC?  (I searched the wiki and the list but I can't find any notes about it).  I'm curious to see what it can do, and if its lvl1's I'm tempted to work on it, but I certainly don't want to mess with it if its someone's personal system.

At minimum I'll create a wiki page for it (assuming it belongs to the space) and pull the known info together in one place.

John coder said "Asron and greg" were working on it, I'm not sure who they are and thus far they haven't replied to the thread. If I make it to the meeting tonight could someone point them out to me?

Thanks

-Mike

On Oct 22, 2012, at 3:57 PM, John Coder <cod...@yahoo.com> wrote:

Asron and greg were working on zenbot check with them

On Oct 22, 2012, at 1:01 PM, Raj <rgsh...@yahoo.com> wrote:

Thanks for the guide.  I believe the larger CNC machine we have in the basement is accurate to within 1/64 of an inch, according to Brian.  We also have a smaller CNC in the big room, a ZenBot 1216 http://www.zenbotcnc.com/all-products/zenbot-1216-cnc-router , that is supposed to be accurate enough to mill PCBs.  I don't know the current status, but if it's up and running it should be able to make fine-spec molds.

---

From: Mike Lutz <mil...@gmail.com>
To: LVL1 - Louisville's Hackerspace <lv...@googlegroups.com>
Sent: Sunday, October 21, 2012 9:40 PM
Subject: {LVL1} Impressive CNC, mold and resin casting guide (with an eye to robot mechanics) - Anyone tried this?

The "Guerrilla guide to CNC machining" http://lcamtuf.coredump.cx/gcnc/ is sitting at the top of Hacker News right now, and strikes me as a fairly amazing overview of the process of working toward custom robot mechanics via CNC molds and resin casts.

[Tim Gillespie]

A good source for bits:  http://www.precisebits.com/

[Raj]

I'd have to check the QR code on it to be certain, but if I remember correctly the ZenBot was donated to LVL1 by Dmitri.  It came with a functioning 4-axis stepper controller box that I believe was parallel.  I'm not sure if John was referring to Greg Miller, but "Asron" is definitely Aaron Verdow.  He worked on it and I recall watching him move the spindle along the X and Y-axis.  Last I saw it, the spindle was attached but not wired up.  If I'm correct that it's a donation, feel free to work on it!  When Dmitri dropped it off, he mentioned that it was accurate to better than 0.001", so it should be capable of making very fine molds or parts.  It would be really nice to have it working.

There isn't much to the manual, but it might help:  http://www.zenbotcnc.com/assets/user-manuals/1216%20.9.pdf

Good luck!

---

From: Mike Lutz <milutz@gmail.com>
To: lvl1@googlegroups.com
Sent: Tuesday, October 23, 2012 3:25 PM
Subject: Looking for background on the Zenbot CNC in the space (Was: {LVL1} Impressive CNC, mold and resin guide)

[Christopher Cprek]

There should be a tag on it with basic ownership info. IIRC, this was when Jon was making tags so they were not being generated from the wiki. Also IIRC, the unit came from chorgy, but I'm unsure if it was an outright donation or a loaner. Maybe chorgy can chime in if I have information wrong.

Gary took a swing at this and I believe those are his notes. I spoke with Gerrit last week, and he has (had?) plans to get the necessary replacement parts. Thus I believe Gerrit 'has the ball' on the Zenbot, but sounds like maybe Aaron and Greg too? 

Regardless, make a reasonable effort to contact these folks. (Note: This thread should be enough reasonable effort). If none of the people mentioned here respond, it's 'your ball'. I'd very much like to see this working.  

Chris

[John Coder]

It was probably Gary I know they had some issues with the computer. Then a friend of mine donated 4 or 5 One of which made the grade for the Zenbot.

[Greg Miller]

    It's not me working on it.

On 10/23/2012 3:52 PM, Raj wrote:

[John Coder]

Gary, Musta been a senior moment made me say that.

[D.s.]

It's an outright donation. So have at it.

I might have a config file for emc2... It took me a couple of days to work it out, so it's probably a good idea for me to dig it out and mail it over.

Btw, did someone burn the power supply that came with the machine? I think I brought one over, if not it should be somewhere around the garage. Let me know if I needs to look for it.

--

chorgy

On Oct 23, 2012, at 3:56 PM, Christopher Cprek <paxti...@gmail.com> wrote:

There should be a tag on it with basic ownership info. IIRC, this was when Jon was making tags so they were not being generated from the wiki. Also IIRC, the unit came from chorgy, but I'm unsure if it was an outright donation or a loaner. Maybe chorgy can chime in if I have information wrong.

Gary took a swing at this and I believe those are his notes. I spoke with Gerrit last week, and he has (had?) plans to get the necessary replacement parts. Thus I believe Gerrit 'has the ball' on the Zenbot, but sounds like maybe Aaron and Greg too? 

Regardless, make a reasonable effort to contact these folks. (Note: This thread should be enough reasonable effort). If none of the people mentioned here respond, it's 'your ball'. I'd very much like to see this working.  

Chris

On Tue, Oct 23, 2012 at 3:30 PM, Tim Gillespie <gillesp...@gmail.com> wrote:

A good source for bits:  http://www.precisebits.com/

On Tue, Oct 23, 2012 at 3:25 PM, Mike Lutz <mil...@gmail.com> wrote:

I stopped by the space and I think I found the zenbot Raj talked about sitting disconnected on the floor on the east  side of the front room.  There is a hand written note sitting on top of if (included).  From the note I'm guessing it either has never has been brought online because of missing parts or its now in a broken state.

Anyone have any more background on the unit?  Particularly is it something that is owned by lvl1 or is it someones personal CNC?  (I searched the wiki and the list but I can't find any notes about it).  I'm curious to see what it can do, and if its lvl1's I'm tempted to work on it, but I certainly don't want to mess with it if its someone's personal system.

At minimum I'll create a wiki page for it (assuming it belongs to the space) and pull the known info together in one place.

John coder said "Asron and greg" were working on it, I'm not sure who they are and thus far they haven't replied to the thread. If I make it to the meeting tonight could someone point them out to me?

Thanks

-Mike

<photo.jpeg>

[D.s.]

For bits I'd go to eBay and search for used carbide end mills. The pcb shops discard theirs while they still have a crap ton of usable life. And they are dirt cheap.

On Oct 23, 2012, at 3:30 PM, Tim Gillespie <gillesp...@gmail.com> wrote:

A good source for bits:  http://www.precisebits.com/

On Tue, Oct 23, 2012 at 3:25 PM, Mike Lutz <mil...@gmail.com> wrote:

I stopped by the space and I think I found the zenbot Raj talked about sitting disconnected on the floor on the east  side of the front room.  There is a hand written note sitting on top of if (included).  From the note I'm guessing it either has never has been brought online because of missing parts or its now in a broken state.

Anyone have any more background on the unit?  Particularly is it something that is owned by lvl1 or is it someones personal CNC?  (I searched the wiki and the list but I can't find any notes about it).  I'm curious to see what it can do, and if its lvl1's I'm tempted to work on it, but I certainly don't want to mess with it if its someone's personal system.

At minimum I'll create a wiki page for it (assuming it belongs to the space) and pull the known info together in one place.

John coder said "Asron and greg" were working on it, I'm not sure who they are and thus far they haven't replied to the thread. If I make it to the meeting tonight could someone point them out to me?

Thanks

-Mike

<photo.jpeg>

[Brad Luyster]

We've been unable to locate the power supply.  If you could take a second look around your garage, that would be great, but I wouldn't rule out carelessness on our end either :)

[Brian Wagner]

Several months ago I got the xy and z axis working on this machine. I configed the emc distro on the computer. It is working. What is not working is the spindle. It is missing a belt. Figure out what we need an lvl1 can get it. 

[Mike Lutz]

Following up on what I found out about the zenbot:

• Chris connected me to Gerrit, he is the writer of the note (that I sent earlier) on the zenbot  and seems to be on top of what needs to be done to get it going. (I.E. he does "have the ball")
• Current status
• Believed capable of high precision operation other then a non-operating spindle (the router part) because of multiple missing parts, and likely incompletely configured control software.
• Parts needed to get the zenbot operating:
• Power supply for the spindle motor
• either found by chorgy or an expense of $75-150
• Belts for spindle
• Gerrit had an exchange with Wolfgang Eng (maker of the spindle part) and thinks he may have enough info to order from a parts house (price currently unknown, though expected to be low)
• More bits (there is one with the zenbot now)
• Both Gerrit and chorgy agree that ebay is the way to go.  Gerrit's comment was that the reason that ebay bits are so cheap is because they are partly used and have become slightly out of dimensional spec.  With effort, the bits can be re-measure there-by enabling them to be used at full precision.
• Config for EMC2? (x,y,z stepper motor control software)
• The current assumption is that the EMC2 on the linux box doesn't have a fully configured config for the zenbot.  Gerrit has contacted the zenbot and they have said they will send him a (customer supplied) EMC2 config, though they haven't yet so he is planning on bugging them again.  
• Brian W posted that he had x,y,z working a few months back, Brian if you think the config is complete then please reply so Gerrit doesn't have to keep hassling the zenbot folks

If the zenbot gets up and running, there are number of improvement that Gerrit is already thinking about ("stops" to calibrate the arms - likely requiring a different controller, enclosure for the control systems, vacuum system, etc..)

The consensus seems to be that machine is in good shape, and should really be capable of high accuracy milling if the parts/config are done and the machine is treated gently.

I have some extra time over the next few weeks and I'm going to try and help Gerrit move things forward, I suspect that may not be enough to get the system operational, but if nothing else I'll make sure to document what happens.

All the best,

-Mike

[d.s.]

So no power supply here... and since I had some time to ponder on it
while looking around the garage, I'm now very certain that the PS came
along with the zenbot. I actually remember having it stuck as I was
pulling the zenbot out of the back of my car.

Looks like zenbot switched over to using a gekco g540 based controller
now. Don't know about the PS there.

[Brian Wagner]

I had the configuration on the zenbot working.  There was a problem with one of the axis, but I fixed it by finding a loose stepper motor wire on the controller.  The power supply was there or I would not have been able to get to that point.  I do not remember what it looked like.

b

[d.s.]

It has a connector that resembles an enlarged s-video barrel with 4 prongs.

I'm trying to get the source and part number out of zenbot. But no answer yet.

[Mike Lutz]

I think I might have confusing things in my last email. There _IS_ a power supply with the Zenbot now, but Gerrit's view (which also makes sense to me) is given load that spindle system seems to need, that the known power supply is only for the X,Y, Z system, not for the spindle motor too.

Its the power supply for the spindle motor that we are assuming is missing, and guessing that it should be 12Vish with 30A peak. (the power supply that plugs into the x,y,z controller is 19V at 6.3A which looking at the x,y,z board info seems right - and has no left over power)

I've written a lot more detail on the wiki (including links to a lot of the parts), see: http://wiki.lvl1.org/index.php?title=Zenbot_1624

-Mike

[John Coder]

This is what I found from the ZenBot forum. Why we need a 12DVC/AC power supply I don't understand given this info.

Wolfgang Engineering TB-350 Specifics: the Drive Motor (110V, 100watts cutting power ...note: theoretically 746 watts = 1 horsepower) and the Standard Mount in a “bundle”. Main features include: 3 Sealed and Greased Stainless Steel Bearings per Spindle, Stainless Steel Housing is Resistant to Scratches and Won't Tarnish, 1/8" (.125") Tri-Split Collet (OR 3mm on Request), Typical T.I.R. .0001", Max T.I.R. .0004", End Play <.0003", Max Recommended Spindle Speed: 24,000 R.P.M., Average Bearing Life: 1000 Hours @ 20,000 R.P.M. , Spindle Length Measures 5.000" and has A .750" Diameter Body., Each Spindle is Hand Crafted for "Hands-On" Quality Control, Made in the U.S.A. Estimated price $203.
  
Wolfgang Engineering TB-650: specifics: The drive motor is200w motor driving 2 belts. main features include: 3 larger sealed stainless steal bearings, dual belt drive, 1/8" or 3mm collet, typical t.i.r. .0001", max t.i.t. .0004"end play <.003", average life: 1200 hours at 25,000 rpm, max. rpm 30,000, 1.2 inch diameter by 4.5 inches long body, no tool required for tool change, hand made in the usa. looks to be great spindle combining high precision with good power and the ability to machine non-ferrous metals. price: $285 with drive motor 

Hope this helps.

On Sunday, October 21, 2012 9:40:17 PM UTC-4, Mike wrote:

[d.s.]

The spindle motor is a 12v at 20amp peak. No datasheet, I tried
looking, but that's what wolfgang told me when I emailed him about it.
I don't think you'll need the full 200wats that the motor can push
unless you are about to break something.

The drive belts are just some o-rings. 1.5 to 2 inch maybe?

--
chorgy

[John Coder]

A 12 VDC power supply shouldn't need need AC ( except for input power) as far as I know we are just talking a 240 watt computer  power supply with a potentiometer to control the spindle speed. we were asked for a DC/AC power supply which shouldn't be needed.

[John Coder]

Unless I'm totally out to lunch which might be possible.

[d.s.]

I also brought a dc motor driver with the router. That should be wired
up the the PS, and the thing can be controlled from emc2.

Though I don't think that there are enough outputs available through
the parallel port to PWM the spindle and to have a relay control line
to kill the spindle power.