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View Full Version : ShopBot Controller - Next Generation - What would you do?



rcnewcomb
06-16-2010, 07:28 PM
I'd like people's opinions about what the next generation of Shopbot controller should be like.

Should they use a dedicated card like WinCNC so that the CPU isn't tied up running the machine, i.e. all the pulses are handled by the card?

Should the control box INCLUDE it's own dedicated PC internally? The shop computer would essentially be used to send files to the controller and perhaps handle some keyboard commands, but the internal PC actually runs the machine.

Should Shopbot switch over to a controller that can run Mach3?

What are some ways to eliminate the pesky COMM errors that plague some people?

Any other thoughts?

John David
06-16-2010, 07:43 PM
I like the idea of a stand alone cnc. Download the program to the drivers and let it go. All my Motion stuff is like this and I love it. This would make it so you do not have to have a second computer for design and the design computer would send the program to the cards. You could even disconnect the design computer from the Shopbot.

I dont have a new system (PRS) with the new software I am using Part works, solid works and Artcam (sometimes) for design and Thats OK. I do plan on getting Vectric Aspire when I start using the machine more. Shopbot is an excellant system for the price the way it is.

We are using a 2001 PRT and a 2004 PRT ALPHA I purchased both new and Love what can be done.

ironsides
06-16-2010, 08:30 PM
I would like to see a totally dedicated, rack mounted PC for SB Control.

Also I would like to have the cutting file sound a loud tone when it is done with a job.

George D Kelly

Gary Campbell
06-16-2010, 09:41 PM
Randall.....
Dedicated card woud be OK, Internal dedicated CPU would be better.

Mach?... dont care. If I go to a Gcode system it will be included with a different color machine. Maybe yellow. Not the machine, I want a yellow crane to lift it off the truck and a big yellow forklift to set it in place.:D

Comm... I have posted a bunch. Some even worked.

George...
Take a .wav file you like that is loud and copy it to your C:\SbParts folder.
Add this to your post right before the end:
PLAY C:\SbParts\{filename}
PAUSE {number of seconds you want file to play}
END (should be there)

bleeth
06-16-2010, 10:10 PM
My next SB controller should show up every morning at 7 rain or shine, take a 10 minute break at 9, 30 min at 12, make sure that when he does so he just started a new file running, and keep working all the way till 3:30!

Gary Campbell
06-16-2010, 10:20 PM
I'll be there at 7 on the 7th of July. Can I get paid by the sheet? Can I bring my own software and CNC? Can I make coffee?:D

gc3
06-16-2010, 10:31 PM
well i am a newbie at this game

but

my idea of a control system would be to be able to load and run files from anywhere on the planet even planets...

i think dod/nasa has a system similar...maybe ted can link in to that

gene

jdervin
06-16-2010, 10:33 PM
I kind of lean towards the dedicated card over the stand alone PC, though mostly because I fear the cost and/or the difficulties of maintaining a PC that will quickly become outdated (parts/peripherals/ports etc. that won't keep up with PC trends -- I've had lots of bad experiences with this in dedicated computer lighting control boards, including one that is only about 10 years old and wants me to run files from 3.5" floppy; imagine having to do something like that for your "Bot of the Future" 10 years from now, such as your WinCNC card being too big for the card slots on a replacement board).

I must say, though, that I also like the idea of having a design computer that could feed cutting files to a dedicated controller...

I also would like to drop the USB to serial bridge (assuming that hasn't already happened since my Bot was purchased -- 2007).

Lastly, wouldn't it be great if there could be greater two-way communication between the steppers and the control software? (E.g. A command to move X number of steps is followed by X number of steps being counted in the motor and returned as successful or not so that the X/Y/Z position would never go out of sync, or at bootup, a query would return the X/Y positions rather than having to re-zero.) Again, I fear costs and smell a certain amount of science fiction where we all visualize a world full of flying cars...

dana_swift
06-16-2010, 10:35 PM
The controller question is a good one. In another thread the consequences of leaving the control box on was discussed. Why not add a pilot light indicator? Shouldn't cost much and then we wouldn't be as likely to go off and forget the power is still on. Currently I count on noticing the LED's on the prox switches, not very effective.

The current controller card does generate all the motion pulses, the PC just feeds the list of move commands to the controller. So not much more can be gained there I suspect.

I like the idea of an ethernet interface. Then we would have 100megabit or 1 gigabit transfer rates. Comm delays would go away entirely. Connections can be limited to the local subnet to prevent interference from hackers. Encryption might be a practical option also.

I am still advocating UDP interfaces to user provided peripherals. I have posted elsewhere about the idea.

And its worth mentioning that the way it is works so well.. perhaps "if it ain't broke don't fix it" applies.

D

gc3
06-16-2010, 10:39 PM
I kind of lean towards the dedicated card over the stand alone PC, though mostly because I fear the cost and/or the difficulties of maintaining a PC that will quickly become outdated (parts/peripherals/ports etc. that won't keep up with PC trends -- I've had lots of bad experiences with this in dedicated computer lighting control boards, including one that is only about 10 years old and wants me to run files from 3.5" floppy; imagine having to do something like that for your "Bot of the Future" 10 years from now, such as your WinCNC card being too big for the card slots on a replacement board).

I must say, though, that I also like the idea of having a design computer that could feed cutting files to a dedicated controller...

I also would like to drop the USB to serial bridge (assuming that hasn't already happened since my Bot was purchased -- 2007).

Lastly, wouldn't it be great if there could be greater two-way communication between the steppers and the control software? (E.g. A command to move X number of steps is followed by X number of steps being counted in the motor and returned as successful or not so that the X/Y/Z position would never go out of sync, or at bootup, a query would return the X/Y positions rather than having to re-zero.) Again, I fear costs and smell a certain amount of science fiction where we all visualize a world full of flying cars...


all systems will be outdated in a geometric progression, the tec industry is just too fast or...ingenious

copy shopbot

and this is from a owner of a vintage machine.....which still cranks out the product

Gene

bleeth
06-17-2010, 06:10 AM
I'll be there at 7 on the 7th of July. Can I get paid by the sheet? Can I bring my own software and CNC? Can I make coffee?:D


Works for me!!

ed_lang
06-17-2010, 07:48 AM
I like the Ethernet link between the control computer and the SB controller suggestion Dana makes.

The idea of having a dedicated CPU inside of the control box with a USB connector(s) on the box is one I have voiced several times. I would like to give ShopBot (the company, not the tool) total control over the system so everything is just like they designed and configured it. Then there are no issues with the parts that the customer supplies.

I hope everyone knows that they are asking for the price to go up again!

richards
06-17-2010, 09:59 AM
Let's take the mystery out of the operation of a CNC router. Each move is made up of straight line segments. Each motor moves its axis in a straight line. A circle is cut by sending at least two motors a whole bunch of coordinated straight line moves. The various sensors are really nothing more than Go/No Go switches. If a limit switch is active, then there is a No Go flag. If a limit switch is not active, then there is a Go flag.

My idea would be to have a "master" PC computer disassemble each instruction into its component straight line moves. Each axis would have a dedicated computer, perhaps a low cost Z-world module or even a PIC controller with lots of memory. The master computer would fill the queues of the dedicated computers and a master 'clock' computer would 'tick' when each line in the queue was to be executed. Three Z-world modules could cost about $100 to $200 total. The interface between the computers would be ethernet. The Z-World Rabbit Core modules have plenty of I/O to monitor actual movement vs commanded movement.

There is no reason to have a Windows PC perform low-level functions. That's where the COMM errors come from. A PC can only handle so many interrupts per second, so why not off-load all real-time code onto dedicated computers that were designed to run real-time programs?

I designed master/slave Z80 computers in the early 1980s that could perform those simple tasks (albeit without ethernet). I wrote multitasking software that time-sliced all functions expected of the slave computers. That was thirty-years ago. With Z-World rabbit modules, a system could be developed at minimal expense and in minimal time.

dana_swift
06-17-2010, 04:21 PM
I like the idea of direct support for 3D Bezier curvers, or 3D-NURBS. Not a series of straight lines beyond the individual pulses for the steppers.

Curves should be definable in 3D, or a possibility of compound motion, where X&Y are driven in a true circle, while Z plunges linearly. Then "drilling" would become an elegant machine operation instead of millions of micro move commands.

Ramps should be replaced with acceleration terms in G's, in the mathematical sense. The velocity and position with respect to time should be entirely predictable. Then pre-computing the time to make a cut should become quite accurate instead of a wild guess as it is now. I can imagine a minimum velocity where ramping would not be required, and then acceleration would be used to accomplish the transition to the steady velocity of the current move command.

The control language should support modern flow control, such as "for", "while", and "do" loops.

I have written about this elsewhere, but still believe it is the direction for the future.

Perhaps a future control board should be based on a high-bandwidth DSP chip instead of a uController based on the 8051.

If anything I am amazed at what Ted Et. Al. have been able to extract from the controller they are using. What could they accomplish if it had some real horsepower?

How about support for a water jet cutting head? Plasma? or Laser? A composite machine.. hmmm ;)

The mind boggles.. its a question of what upgrades would justify buying an new bot just for the improvements. I think this is a good start at the list I would want to see.

Its not about the costs, when the benefits are substantial enough.

D

ironsides
11-19-2010, 07:35 PM
George...
Take a .wav file you like that is loud and copy it to your C:\SbParts folder.
Add this to your post right before the end:
PLAY C:\SbParts\{filename}
PAUSE {number of seconds you want file to play}
END (should be there)

Gary,
Thanks for the tip about adding a .wav file at the end of my cut files, it works great.

George

dlcw
11-19-2010, 10:01 PM
It would be nice to eliminate the comm errors. This would, I assume, necessitate putting a "PC" inside the controller. Use a USB key or a network cable to download the files to the controller and let her rip.

The PC inside the controller should be comprised of one of the mini mother boards available. This way as technology changes, the board can be upgraded as the technology gets better. The controller could have the necessary plugs to accept keyboards (wireless preferred), mouse and monitor.

The ability to remove much of the two-way communications issues would be a major step up. I would even pay to upgrade my controller to a new one with these features.

Gary Campbell
11-19-2010, 11:39 PM
George...
Glad it worked for you.

Don...
I am with you. Micro ATX board inside the control box. Get a list of the basic required XP services, kill the rest. I would suggest Linux as an OS, but then my Link wouldnt work! :)

Now that the "masses" have the easy button, how about a "machinists version"? No previewers, in fact no preview mode, no editors, toys, toolbars, or setup, virtually no commands except run and exit. All work can be done on the design (other) computer and tranferred via thumb drive. A version of SB4 (sic) that has the axis position boxes, an integral spindle display (as the 5th or 6th axis box)

You know, an industrial type display for cutting only, no frills, not geared for the hobbyist or occasional user. Instead of a 3D colored toolpath, I prefer to know my offsets, tool numbers and axis 4-5 move and jog speeds. Throw in a few goodies for the indexer. And the big one..... max penetration into the spoilboard. I bet I am not the only one that would like that setting.

SB3 is superior to most of the gcode control software in features, programmability and ease of use. Not so for dependability, reliability or reputation. If OpenSBP ever hopes to become "an industry standard" it has to appear to be more "professional" than hobbyist and more bulletproof than buggy. And a higher comm rate that allows high speed and high resolution might be on the list.

Oh yea, and some of those things that those scary smart guys like Dana and Mike want too! :)

curtiss
11-20-2010, 05:13 PM
It would seem the bot could run off a fairly small cpu/screen that would import toolpaths off a usb drive. This could either be a touch screen or a mouse interface for those who have grubby fingers most of the time.
A cell phone screen would be a bit small, but a 7 x 5 might be about right.

The mouse might be a closed system wireless that would work from say 75 feet away.

A clean bluetooth system would broadcast the screen to another computer for those who want to be out of the room...which can have its downfalls.

A small gooseneck camera on the cpu would show the bot movements and an E stop could be hit from the other room...

michael_schwartz
11-27-2010, 07:59 AM
If the actual controller were integrated into the shopbot hardware all you would really need for an interface would be a very basic PC such as a netbook. Keeping the user interface separate from the controller would also add a layer of redundancy. The more complicated GUI, would be separated completely from the simple and hopefully reliable controller.

In theory as well a single PC could then be used as an interface for multible shopbot's.

I could see the controller itself having a very basic interface accessed perhaps with a keypad with a small LCD. The keypad would have the ability to load files that are stored on the controller, view basic information, and start/stop the machine. However a $175.00 net-book might in fact be cheaper when its all said and done than developing such a device.

frank134
11-27-2010, 09:38 AM
All I want is to not see the words (LOSS COMM PORT). Did I pay $25,000.00 TO LEARN THE WORDS LOSS COMM PORT?

Is this really that hard to do?

That my only complaint.

ken_rychlik
11-27-2010, 10:23 AM
Adding another computer to the mix will just make them harder to troubleshoot. You would have to figure out which computer was messing up if you had two of them.

Also with the ecab link, where would that fit into the mix ??

I agree with Frank. It just needs a more reliable link.

I think so many people running different brand parts on their machines is also causing each machine to run (or not run) differently.

If it needs a certain cable, or hub, or whatever. It should come with the machine and be available as an upgrade for older ones. A grounding kit should also be an oem item.

One more thing that sould be changed is when you pause a file, it should have two boxes that say (destroy part) or (quit) Resume does not work.

frank134
11-27-2010, 08:18 PM
Why can't they try a different kind of link like serial ata or ether net. I no It not a ground problem.

ironsides
11-29-2010, 11:39 AM
All I want is to not see the words (LOSS COMM PORT). Did I pay $25,000.00 TO LEARN THE WORDS LOSS COMM PORT?

Is this really that hard to do?

That my only complaint.

Amen to that!

George Kelly

jerry_stanek
11-29-2010, 03:53 PM
I don't know what I did right but I only had one loss comm link and that was do to the controller board going out. The only other times is when my Shopbot is shut down and the SB software is still running.

joecmay
12-03-2010, 08:11 AM
we have 15 shopbot based machines 3 are setup as routers, something that has worked for us, we moved the computer into the controller cabinet, keeping the usb line as short as possible we then ran a longer usb and video line to our control station. the usb to the control station gives us keyboard, mouse and touch screen control. the video line to the touch screen is 25' long the usb line has a powered hub at the control station end feeding a 20' usb line to the computer. our routers have 12 18 or 24 position tool changers the 24 has 2 12 position tool changes using a&b axis drives. grounding and getting the computer as near to the controller is the secret to eliminate com errors for us.

joe may

frank134
12-05-2010, 11:44 AM
My computer is almost sitting in the control box. I used the cords shopbot send me. Even bought gold leaf usb short cords. I still get com lost. Thankfully I only got one in the middle of a program. Mine all most always seem to be at the beginning when I try to start the program. Then I have to shut down everything and restart. Some time I have to reload the firmware just to get the connection back. Usually after that it will stay till I am done. When I talk to the people at shopbot they say they cannot reproduce the same problem in their shop. So it hard for them to fix. I can understand that intermittent problem is hard to fix. Oh and they are trying to work on it. Oh so what to say I will have to live with it till one of us find a solution. I HOPE IT SOON.

khaos
12-05-2010, 02:21 PM
... I like the idea of an ethernet interface. Then we would have 100megabit or 1 gigabit transfer rates. Comm delays would go away entirely. ...

This is my opinion as well. I think the USB was a great step in the right direction but CAT5e or CAT6e when the specification is finalized. Minimum cable requirements to eliminate crosstalk and the ability to use an existing interface to validate comms and resend if confirmation is not received. Electronic shielding of the signal is a cool plus as well.

jmnsho

curtiss
12-05-2010, 03:05 PM
An amp meter (or some type of load indicator lights) on the router would show how hard the router is working with any given toolpath.

Some sort of "chipload readout" might be a possibility for a given bit and speed.

bleeth
12-06-2010, 10:11 AM
I must agree wholeheartedly with better communication design.
At this point USB is just not robust enough in the long run and needing to add miscellaneous parts between the computer and the control board (ie: USB Hub and High USB to serial convertor) to get the equipment to run effectively borders on absurd. It just leads to more problems in troubleshooting issues. Put me down on the side of straight Cat 5 or 6 port to port connectivity.

widgetworks_unlimited
12-06-2010, 11:14 AM
I did the same thing that Joe May describes - the computer is 6" away from the control box, with 25' powered USB extension/hub to handle keyboard, mouse, WiFi antenna, software dongle, and 25' video cable for monitor.

I hope I don't jinx myself here, but I have never had a Lost Comm Port error.


I'd like to see the control software show my actual/live feed rate in real time. I used to have that with Mach3 and have found that it really helps when you're trying to dial in parameters in a cut file.

I'd like to have some more complex looping statements added to the SB programming language.

I'd like Vectric to complete/release their SDK for creating widgets for PartWorks.

I'd wish there were an ATC that most SBer's could afford.

ken_rychlik
12-06-2010, 11:28 AM
Russ, Here is an option that I am watching. http://store.blurrycustoms.com/SearchResults.asp?Cat=46

I agree 15 grand for a tool changer on a machine that cost the same ammount is kind of out there.

frank134
12-06-2010, 12:36 PM
WOW!!!!! See that what I am talking about. I think 15000. for a tool changer is way to much also. Then I have to replace the 4 hp spindle I all really have. So if I going to spend 40,000 on a 5x10 with tool changer I may as well start looking at a big iron machine. So I am going to keep and eye on that too. that more in my price range.

Back to com port. I think they should go to cat5e or cat 6. Again today I took me 1 -1/2 to get started. I really getting tired of having to shut down and restart or reload firmware.

Gary Campbell
12-06-2010, 08:44 PM
Russ...
reread Joes post. They move the control computer INTO the control box. I am so happy that it actually works. After the rotary carousel and Indexer... my next project.

Russ and Kenneth...
ATC is like divorce... Very expensive.... cause its worth it. Or like a Lamborghini.... they only seem expensive till you drive one :D

myxpykalix
12-07-2010, 07:49 AM
I know nothing about the workings of the cpu's and steppers, and the comunications between computer and controller so my thoughts are just from a theretical perspective.

If you eliminate the external computer as the driver of the files then in an emergency, or when you want to stop the file when using the E-stop you lose all your settings ( at least i do).
So if you don't have control of the internal computer because your external computer is now not controlling it, it would seem you would need to take an extra step to regain control by pulling up the program that may be running in the background as a monitor, ect while you are designing.

In an emergency i can see how that wouldn't be good. But i can also see how maybe they could modify the Estop to have a pause button (similar to hitting the spacebar) to give you time to regain control from the internal computer to be able to do whatever you needed to do to rectify your issue.

Because i don't use my machine 8 hours a day everyday like some of you i have never experienced some of these communication errors you talk about and in theory it sounds like a better idea communication wise to keep it "in house".
That would at least eliminate you tripping over the usb cable and losing communication that way...not that I have EVER done that!:rolleyes:

meatbal80
12-07-2010, 08:23 AM
I seem to find that most of my controller problems stem from the computer i have, mainly its OS. I have found windows to be the root problem with most of my pc related headachs, associated with the shop bot and not.

Could shop bot maybe look at making a pc that they could sell. Something that is more suitted for the dusty and not computer friendly enviroment of most shops. With all the different PCs controlling shop bots out there how many issues could be resolved by having eliminated that variable(s)

adrianm
12-07-2010, 12:45 PM
I think if the PC is used to control the Shopbot and nothing else, plus all the guidelines are followed regarding screen savers, updates etc etc then it all works pretty faultlessly. The only issues I've ever had have been of my own making.

Human nature being what it is though guidelines and instructions are rarely followed so, as others have said, an embedded computer board with a minimal operating system and nothing but the Shopbot software on it would probably save a lot of support time.

geometree
12-07-2010, 09:08 PM
I run my shopbot with an old Dell Latitude 610? laptop, using a stripped down version of windows xp called xp-lite. Before I got my shopbot I used it to control another machine with mach 3 and set it up according to this optimization document. I've never had a problem with comm errors. I know there are lots of people out there that don't have any problems and some that do. Shopbot should at least be able to put together a computer and software package that is optimized,tested and configured out of the box.

michael_schwartz
12-08-2010, 07:09 PM
Some thoughts.

I was having some problems and I believe they were caused by the dime a dozen keyboard and mouse I was using that came with the refurb PC I run the bot from.

Long story short the issues included com errors, and occasionally the keyboard would drop com while in use, sometimes while I was moving the bot with the keypad requiring the use of the E-Stop.

I picked up a new name brand keyboard and mouse for about 40 bucks and the the problems went away. Lost coms have been a rare thing for me since, and have only occurred while the bot is idle. I think those may be a problem with my PC.