ShopDroid [custom sized]

[zool]

It all began in Border’s Book, I was looking for book on robots and ran across Geoff Williams’ book CNC Robotics: Build Your Own Workshop Bot. Robots suddenly took a distant second.

The first 3-axis router took about 2-years from idea to cutting the first part. [See attached photograph.] Along the way I’ve learned MACH3, two CAD programs, and two g-code conversion programs, and accumulated an encyclopedia of errors. I still have all 10 fingers and all 10 toes. My mind: Gone long ago.

With increasing experience, and the resulting higher expectations, it soon became obvious that a 3-axis machine with a cutting area of 19-inches by 16-inches by 2.5-inches was not going to meet the needs of furniture making, even though currently that is limited to a variety of boxes: jewelry; storage; boxes for antique weapons; and urns. My designs avoid as many right angles and straight lines as possible; the number and complexity of the jigs necessary is ridiculous.

After six-months researching [CNCzone played a HUGE part] and then searching for a new CNC machine ended when I found ShopDroids [http://www.needfulthings.net/host/nosleep/index.html]. After some emails back and forth, I ordered a custom-made Droid with a cutting area of 4-feet by 7-feet; it will have 4 axes [X,Y,Z, plus a rotary axis]. The seller is a CNCzone regular: tulsaturbo. The emails I have received, and the parts I subsequently received, reflect positively on his intelligence, experience, courtesy, and attention to detail; a cool guy!

In analyzing the errors made with the first machine, the major source of the errors was lack of planning, which lead to the extended period of time it took to build the machine. This time I designed, analyzed, and planned [CAD drawings, written notes, and spreadsheets], and then analyzed the design, the analysis, and the resulting plans.

The one operational source of the extended build time for the first machine was that parts were not there when needed. This time everything is in one small pile, literally, as can be seen in the attached photograph. All the ShopDroid rails and trucks; all the electronics; the steppers motors; the 8020 aluminum for the base [and the 424 nut and bolts sets to assemble it .. counted ‘em BEFORE the order went in!]; the router [PC 690] and the Super PID to control it; all the other bolts; and all the tools. The computer MACH3 will be on is setup, running and ready; and the monitor, keyboard and mouse are ready as well.

Metalworking is a big unknown to me [still], so this time I lined up a machinist BEFORE I started. He works for a friend on mine who is a specialty manufacturer of high-performance automobiles. The attached photograph shows the capacity available to me.

I expect to be done in early March.

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[CarveOne]

Looks like you are going to be having fun real soon. Having more working room on the table opens up a lot of possibilities for projects.

CarveOne

[Jesse B]

Congratulations on not losing any appendages in the process

Should be a fun build, good luck!

[zool]

Thank you for the encouragement.

A note on tapping threads in extruded aluminum.

I had to tap 24 holes in the legs [6 legsx4 holes each] of the base to attach the mounting plates for the leveling feet. The threading was put where there is a channel in the aluminum extrusion. There are four ribs in that channel. A typical tap has four flutes. Not an ideal situation. Hard on the hands and mediocre threads were the result as the tap did not stay straight in the hole as it was not held securely.

The head machinist at my friend's shop introduced me spiral taps. They are like a drill with the cutting portion of a tap around the flutes on the drill bit. See the attached photograph.

They cut much easier and leave a much better thread. The holes were counter sunk before the threading was started. Even though the spiral tap did do a excellent job once started it was hard to start. The typical tap is still needed to start the threading process as the first portion of the typical tap is tapered up the shaft about 1/4- to 1/2-inch, while the initial portion of the spiral tap is tapered maybe 1/8-inch. With that small taper it will not begin cutting easily.

A spiral tap is most often used to tap blind holes as this type of tap ejects the chips much like a drill bit. A typical tap does not eject the chips and they end up packed into the bottom of the hole.

Also used a tapping guide to keep the tap straight during the first portion. See photograph.

Here is a site that is a virtual encyclopedia of information about tapping: Tapping Threads & Associated Reference Tables

[zool]

Here is a build of a PlasmaBot that the builder bought parts from TulsaTurbo, the same guy I bought my parts for myRouterBot [ShopDroid].

http://www.cnczone.com/forums/plasma...4x4_table.html

[zool]

Tonight I tinned the wires on the stepper motors and then installed spade connectors on them. OK ... please no lectures about overkill.

Also installed steppers on the trucks. The connections between the motors and the wiring is junction blocks. Old fashioned yea, but I am a visual kinda guy.

It was not bad doing this as I was doing the laundry at the same time!! I am happy and so is my wife. What a deal!!!

For crimping the solderless spades I used a set of Hollingsworth crimpers. These are the cream of the crop of crimpers. Instead of opposing blades that seem to ruin every other connector [at least for me] there is a die that crimps the spade EXACTLY the same each time. As well there is an alignment jig so the solderless connector is set in the crimper EXACTLY the same each time. Hollingsworth site is here: Welcome

Also Daniels Manufacturing Company makes high quality crimpers and solderless connectors as well. I have a pair of their crimpers for pins. Their site is: Daniels Manufacturing Corporation

I got these both on eBay.

[winegar]

I'm really jealous right now.... I have my table all built and about in my last phase of getting my Plasma table built... but your work area is so dang clean.... Honestly to cold here to keep my shop clean right now... hell, even my office where i'm doing a lot of my wiring and little stuff is a mess!.... Looking good though!...

[zool]

Winegar:

Be assured the neatness is a fleeting condition.

It always amazes me that it takes hours to cleanup after minutes of work.

[winegar]

How are things coming along????

[zool]

Just getting over a design competition. Sit in a chair designing for 10-days, then hobble around and do back exercises for a week.

During that time on needed breaks was putting nut and bolt sets together in joining plates and gussets. Loose fit them on legs and rails. Holes on one foot mounting plate were machined off center so had to take that to the machinist to enlarge the holes so it fit square of the bottom of the leg.

Wiring up steppers and controller to test electronics before getting it all on the Droid. Electronics is not one of my strong areas, so missing a few parts as these details just go whizzing by me.

Going down to the electronics store tomorrow. After that, finish it all up while I do the laundry. I'm happy, my wife is happy.

[zool]

Steppers, control board, power supply, computer, and all the ancillary wires, fuses and what-not, are all connected and sitting ready for tomorrow morning.

Test all power supplies for output, even checked input voltage [108volts AC].

Software [MACH3, D2nc] all installed and configured.

[zool]

Leveling and anti-vibration feet are the foundation essential for a CNC router. Commercially available leveling and anti-vibration feet are generally made for a much heavier machine than a DIY machine, hence are quite substantial and well-made, and therefore they are quite expensive for the hobbyist.

Hockey pucks are often mention and used for machine tool feet. A hockey puck is heavy, is very very dense “rubber”, and is 3-inches in diameter and 1-inch in thickness. Most of the examples on CNCzone have a bolt though them with a washer and nut on the opposite site which is good for a fixed anti-vibration foot, but leaves something to be desired for leveling.

Ideally, a carriage bolt should have been used, as these are metric and I could not find a carriage bolt in metric, rather than machining the bolt so it had a oval head a spiral pocket was milled in the hockey puck 0.85-inches in diameter [which is just a bit larger that the edge-to-edge distance of the bolt head [0.83-inches] and 0.3-inches deep [which is just a bit less than the thickness of the bolt head]. [Three-flute down-spiral 0.25 router bit; 40-IPM feed; 20-IPM plunge.]

Inserted into the center of the milled pocket in the hockey puck is an oval headed screw with an integrated washer. Course threads are much easier to use than fine threads.

The bolts have a shoulder so they can be turned with a pair of vide-grips [No messy threads; I like neat!!], and the nut serves as a jam nut against the foot mounting base on the 3030 extruded aluminum.

The hockey pucks were $1.50 each, the metric bolts $2.60 each [yea YIKES!] and the metric nuts were $1.10 each. The screws were in the box of miscellaneous “stuff”.

Even with the price of the metric bolts and nuts, the cost of each foot was only $5.20 or $31.20 for all six. It took about an hour total to mill the pockets [setup and milling].

If the threads in the foot mounting base on the 3030 extruded aluminum had been SAE instead of metric the cost would have been less. And though someone will no doubt indicate that the holes in the foot mounting base on the 3030 extruded aluminum could have been retapped to SAE, I estimated it would take less time [hence lower cost] to stick with the metric rather than retap the holes.

On the bottom of each foot will be cemented a piece of sand paper cut from a used sanding belt.

All in all, this seems a real bargain.

[zool]

Setting up the ports and pins on MACH3 is giving me fits. I do not recall setting up MACH3 for my first CNC being this difficult.

MACH3 DROs move, the steppers do not. Yes, the addresses for the boards shown on MACH3 match the addresses in the device manager in WINXP; yes BIOS is set properly; yes I read the manual; yes I have read more forum entries on this topic that one should in a lifetime.

The parallel port on the motherboard puts out 4.97-volts; the parallel port on the add-on board puts out 0.7-volts. Which no one has mentioned before.

In reading though numerous forum threads on the MACH3 forums, and here, it appears that invariably the topic of each forum is a work-around for some quirk in MACH3. An astonishing number of participants in the forums come up with a answers to their own question, in a manner that defies reason and logic.

Having used a computer since the DOS days, and having used a lot of software starting with version 1, I have to ponder why MACH3 still has so many quirks.

And yes MACH3 is quite flexible and quite powerful, and there are a wide variety of add-ons, that does not negate that most of the forum topics dealing with MACH3 appear to focus on work-arounds for MACH3 quirks, as well as the quirks of the add-ons, and those introduced to MACH3, or vis-a-versa. This does certainly make one wonder about the efficacy of MACH3 as written.

Maybe if it did not try to be all things to all people.

[zool]

After a frustrating time with MACH, and a horrid experience with vicious sadistic flaming on the Yahoo MACH form, I have switched to EMC2.

Initially EMC2 did look more complicated, however, after printing out all the documentation [best have a fast laser printer!!] and doing a first read through, the logic of LINUX and EMC2 is easy to grasp. Must be the residual from writing all those DOS routines for my first computer, and from BASIC and FORTRAN coding in college.

Hope to have the 8020 base completed and Droid rails installed today.

[CarveOne]

After a frustrating time with MACH, and a horrid experience with vicious sadistic flaming on the Yahoo MACH form, I have switched to EMC2.

Initially EMC2 did look more complicated, however, after printing out all the documentation [best have a fast laser printer!!] and doing a first read through, the logic of LINUX and EMC2 is easy to grasp. Must be the residual from writing all those DOS routines for my first computer, and from BASIC and FORTRAN coding in college.

Hope to have the 8020 base completed and Droid rails installed today.

The biggest issue for me with EMC2 was learning to zero a job where I wanted it consistently. I never felt like I had it figured out in spite of all the reading I did. Other than that it worked fine. I did finally find the dual motor on the X axis info and got it working successfully. It isn't very obvious how to do it.

In Mach3 Loader I copied a previous setup and created another setup based on it, and it didn't work correctly. Major racking with the cloned setup. Now I always start a new setup each and every time I need to make a new one.

CarveOne

[zool]

C1:

As the Shop Droid uses a slaved A-axis for the Y-axis, and I am using a Rockcliff board [XYZA], where did you find how to slave an axis?

All the manuals together for EMC2 are about 4-inches thick..lots of reading this week end appears!

[CarveOne]

C1:

As the Shop Droid uses a slaved A-axis for the Y-axis, and I am using a Rockcliff board [XYZA], where did you find how to slave an axis?

All the manuals together for EMC2 are about 4-inches thick..lots of reading this week end appears!

I found it on web searches. Even then it was not very detailed. Use the Configuration Wizard to start a new XYZ router machine configuration. On the screen where you are configuring the step and direction pins you need to set two pairs for Y, one pair for X, and one pair for Z. One of the Y pairs needs to have the direction pin inverted so the motors both run the same direction.

I have screen shots of all of the configuration screens if you want me to post them. Or just that one screen.

CarveOne

[CarveOne]

Here are the two important screen shots for the EMC2 dual drive setup on one axis. This was in Ubuntu 8.04/EMC2, so there may be changes in later versions of Ubuntu/EMC2.

On the Basic Machine Information screen you can see that Axis Configuration is XYZ. Set the Driver Type to whatever you are using in the pull-down list. In my case it was Gecko, for the G203V drives I was using at the time I set up this configuration.

The Parallel Port Setup screen is where you will see the two entries for the X axis in my case. On my machines the long horizontal axis is X motor #1 and X motor #2, Y is the gantry motor. Note that pin 3 and 5 are both inverted. That is because I had reversed one phase of the motor wiring at the G203V drive for motor X axis motor #2, and I don't do that now. It made sense at the time, and it works fine, but I don't bother with it anymore. They are both inverted in this configuration so both motors go the correct direction at the same time. Just toggle the Invert check box until you get a combination that goes the correct direction using normal motor wiring.

After setting up the other screens, you can use the Test This Axis feature in StepConfig to check the motor directions. Use a slow jog speed for this initially so you don't seriously bend anything if the dual motor axis isn't configured correctly. There will be racking during this test until you get the right combination.

Note that when you start the XYZ configuration you will see all of the Step and Dir pins for four axes. Once you configure it for a 3 axis machine and save it you can't edit it and see the fourth axis Step and Dir pins again. They get "lost".

As in Mach3, the X, Y, and Z axes can be defined on any pair of Step and Dir pins. I used this to prevent the wiring from my breakout board to the motor drivers from crossing over each other in order to minimize cross talk.

CarveOne

[zool]

C1:

Thank you.

New User's and Setup manuals were published in January 2011, so maybe details on XYZA slaved-axis setup are in there. I ran though the new manuals at 1:00 this morning just after getting into bed. All I recall with any certainty is that they sure helped me go to sleep fast.

Burned a CD and ran EMC2 from that so got an idea of what it all looks like without installing it. For some reason though it trashed my user parameters for Windows XP, as well as made all my Firefox bookmarks vanish. Ah, had too many book marks I didn't look at; the important ones I remember. But making monitor 1 into monitor 2, and visa-versa did not make me happy at all; still trying to get them switch around.

I have a PIII computer with a graphics card and lots of memory I will convert for the EMC2 machine.

Again, thank you for the direction and sharing your experiences.

[CarveOne]

I haven't seen what the later versions of EMC2 look like so I don't know if there are any improvements on how StepConfig Wizard works in regards to slaving drives. I never got the XYZA configuration to do slaving.

I also haven't looked to see if there are any auto-zero utilities for it. It needs one.

One of these days I'll download the newest version and replace it on my EMC2 only machine. I have a dual boot WinXP/Ubuntu/EMC2 but I won't bother upgrading EMC2 on that one.

I use Firefox on Windows and Linux and don't recall having any bookmarks lost or stolen. You may find that they were transferred to the new Firefox installation instead of copying them. I wish they would just copy them and leave the older installation as it is.

CarveOne