Need to build Mach3 Controller - HELP

[CNYDWW]

So i've been waiting for six months to get the rest of the money from my investor to get my prt running properly. With no date in site for the remainder of the funds and without a properly functioning cnc spring looks bleak to say the least. I'm looking into the cost of building a mach3 based controller and need some help. I can get an ebay special with a five axis board and five g540 drives within my current financial reach as a starter. What else do i need besides a power supply,case and relays. Usually when i build a computer i work from a checklist. If anyone can give me a hand setting up such a list it would be appreciated. I'd still like to run five drivers for a four axis setup. Basic wiring would also be a big help. I'm currently researching the "proper" way to set everything up.

Thank You
Regards
Randy

[Brady Watson]

Where is your ShopBot controller?

-B

[gc3]

take a look over on cnczone.....

[danhamm]

What model shopbot and what steppers do you have.? and whats up with what it came with..?

[CNYDWW]

Where is your ShopBot controller?

-B

When I bought my PRT the original controller was just a shell with the two power supplies in it. No board, no drivers and no relays. I bought the 5x10 machine for $2300 with 5hp 3phase spindle that i couldn't use and sold for $1000.

I currently have four 3.6/1 standard motors and one 7.2/1 motor i plan on using for an indexer. The machine came with all 7.2/1 motors but i did a horse trade for two of the original motors that still worked for the 3.6/1's.

The reason I ask here is simply because i trust the advice given. I'd like to see what others have done for their controller that are non shopbot. Right now the "signal generator" i'm using is only four axis, one being slave only on the x. I also can only get about 40IPM rapid transverse with it. I did find however that since it's made by flashcut inc. I may be able to get one of their DB breakoutboards and simply wire up some Geckos in a separate box with a new power supply and relay for the router.

[gc3]

do a search on g540....mach, controller upgrades.....




The G540 is limited to 50VDC, so those motors would have to be wired half-coil (black/yellow wires, red/white wires) to stay under 50VDC. Wiring the motors full-coil would require a 70VDC power supply (or something close). In other words, the torque loss from running the motors wired full-coil at 50VDC would be greater than the torque loss running the motors wired half-coil at 35VDC. To me, that is pretty good performance from a motor running on a 35VDC power supply.

Remember, that is with a 7.2:1 gear ratio and a 2,000 pulse per shaft rotation pulse requirement. Using a 3.6:1 motor (i.e. PK296A2A-SG3.6) would give you 2X the speed and the same resolution as the PRS-Alpha (7.2:1 gear ratio, but only 1,000 pulses per shaft rotation). However, the gearbox on the PK296A2A-SGxx series motor is not as robust as the gearbox on the Alpha motor, so I would be hesitant to run those PK296A2A-SGxx motors continually at high speed under heavy loads.

In any case, the limiting factor is probably the torque of the motors, not the pulse rate of the G20x board.

There are two other concerns that I have with the G540 stepper controller. The first concern is an obscure notation in the instructions. Mariss wrote: "Choose a motor that has a rated winding inductance of 2.5mH to 3mH if maximum power output (>100W mechanical) is a requirement."

Oriental Motor does not sell a geared PK296 motor that falls within the 2.5mH to 3mH range. The PK296A2A-SGxx motor is rated 1.5mH half-coil and 6mH full-coil. The PK296A1A-SGxx motor is rated 7.7mH half-coil and 30.8mH full-coil. I've posted a note on the Geckodrive forum about the 2.5mH - 3mH statement, but, so far, there has been no response.

The second concern is the use of DB25 connectors to connect the motors to the G540. At one time, I built a process control computer to replace the original electronics in the Kodak S-series photo printers. A competitor used DB-25, DB-37 and DB-50 connectors. I used much heaver duty connectors. I was often called in to trouble-shoot the competitor's electronics. Often the cause of the problem was an intermittent connection on one of the DB-xx contacts. Many DB-xx female contacts use a split (two-piece) slanted 'finger' assembly. That means that 100% of the current passing though that DB-xx contact may very easily be passing through a single contact point that is smaller than the head of a pin. That's not very much area to carry the current required by a stepper motor. If a good quality DB-25 connector is used, and if the contacts on both sides of the connector firmly mate with the contacts on the G540, then things should work properly. However, to me, that is a problem just waiting to happen. Sometime down the road, after the contact point has arced several times and carbon has built up between the two conductors, that contact point may easily become intermittent.

Even with those two concerns, if I had an extra $350 or so laying around, I would order a G540 to play with. It looks like an interesting product that could easily be connected to the G201 that Shopbot was kind enough to let me test. On the surface, it looks like the G20x from Shopbot, the G540 from Geckodrive and the PK296A2A-SGxx motors from Oriental Motor would be a good match if the motors were wired half-coil and used with a 35VDC power supply.

[garyb]

PMDX 126 breakout with 107 spindle controller the 134 gecko board and since you have the 3.6.1 motors I would go with the gecko 203's
You could add a smoother stepper as well but I'm not really a fan
Gary

[richards]

Randy,

You'll need four PK296A2A-SG3.6 or PK296A2A-SG7.2 motors wired half-coil. You'll need ONE Geckodrive G540. You'll need a 25VAC, 300VA toroid transformer, a 25A bridge rectifier (they're the same price and size as the 10A) and at least 20,000 uF capacitors (two or three caps connected parallel), various switches (disconnect, on/off, start, etc.), a contactor, and a box to put everything into.

Note that you should use the PK296A2A-SGxx, not the PK296A1A-SGxx model. The A2A model has 1.5mH inductance when wired half-coil which makes them an ideal match for a 35VDC power supply (a 25VAC transformer gives you 35VDC after the bridge rectifier and capacitors have done their job). The A1A model has 7.7mH inductance when wired half-coil, which means that you would need an 80VDC power supply. That means that you would need to use one Geckodrive G201x or G203v stepper drivers per motor and a 50VAC transformer (which would give you 70VDC).

If you use a 25-tooth pinion gear (1.25-inch pitch diameter), a motor with a 3.6:1 gearbox will move 0.000545 inches per step and the 7.2 motor/gearbox will move 0.00027 inches per step.

I've built test-bench controllers using both the G540 controller and the G203v stepper drivers (with a PMDX-122 break-out-board). With the PK296A2A-SGxx motors, either stepper driver seems to work equally well. If the G540 has all the features you need, it is much less expensive than using four G201x or G203v stepper drivers and a break-out-board.

[CNYDWW]

Thanks everyone for your suggestions. Although most of the information is over my head. I am getting help from another source that is familiar with the process. Currently i'm looking into some options with FlashCut. It's the company that produces the controller i have on the bot at the moment. The one thing i do like about Flashcut's controllers is the software. My old machine could be running in the background while i'm working on other files without issues with background processes, networking and the like. The controller itself does also run on usb. it's the connection from the controller box to the driver box that would be DB25. Once i verify the wiring i'm most likely going to purchase the parts i need from Pmdx. If i get two of their tandem motherboards five Gecko G203v's and a couple cables all i'll need is a box and power supply. I do understand the drawbacks to using the DB25 connection on the back of the controller that i do have but for the sake of my budget getting this machine up and running with acceptable performance. It may be the way to go. In the future i should still be able to use the drivers, power supply and motherboards once i can afford the rest from Shopbot. I probably wouldn't bother with the 5th driver for the fourth axis however the millwork company that i subcontract for is more interested in that then the typical work they throw my way.

Best Regards and Thanks
Randy

[HelicopterJohn]

Hi Randy,

I am just finishing up a complete electronic conversion on my Shopbot PRT 48 X 96 CNC Router. Basically, replaced everything except for the Stepper Motors.

I am in the process of putting together a video of the electronics and software that I currently use.

I used the PMDX-126 Breakout Board, 2 each PMDX 133 Motherboards, 4 each Gekco 203V drives, PMDX 107 Isolated Speed Controller coupled with the Super PID Speed Controller. I have the capability to run the software via parallel ports or USB via the Smooth Stepper. I have installed solid state relays for turning both my dust collector on/off as well as my Gast Vacuum pump. I am using an Antek 70 Volt power supply with fused circuitry. I am using the Mach3 2010 Screen Set that I have modified slightly for my use. It even has a semi-automatic tool changer macro that works like a dream. I also installed proximity switches on all the axis and have plans to possibly install a 4th axis in the future.

I just put together a general list (may have missed a couple of items) with associated prices in case anyone is interested. It is in Microsoft Word format. I have attached it for your review.

If you would like any further information just send me a PM with your e-mail and phone number and I will give you a call.

John

[Brady Watson]

For that kind of money, you can get a brand new control box from ShopBot that is plug & play with warranty & free telephone tech support FOREVER. It will have all the performance of the Mach system and be a heck of a lot easier to use. PLUS there is no assembly. You can sip pink lemonade and eat bon-bons while someone else does all the work. All you have to do is plug it in. I'm not really seeing the 'value' with a DIY control box. Help me to understand.

-B

[gc3]

For that kind of money, you can get a brand new control box from ShopBot that is plug & play with warranty & free telephone tech support FOREVER. It will have all the performance of the Mach system and be a heck of a lot easier to use. PLUS there is no assembly. You can sip pink lemonade and eat bon-bons while someone else does all the work. All you have to do is plug it in. I'm not really seeing the 'value' with a DIY control box. Help me to understand.

-B

and the support is priceless!

[adrianm]

The one thing i do like about Flashcut's controllers is the software. My old machine could be running in the background while i'm working on other files without issues with background processes, networking and the like.

Confused by this statement. I thought Flashcut was Windows based as well?

[CNYDWW]

If i had the money, I would just simply order a plug and play controller from SB but unfortunately, even if i had the rest of the planned funds it'd still be parts from SB. $1300 difference for the internals for the controller compared to just the internals. Yes, i'll have to get my own box etc. But $1300 is $1300. If i had the money i'd have a brand new prs alpha sitting in the shop for that matter. Having the turnkey controller would also increase the PRT's value but again, money money money. With over $50k in medical debt, no real options for work due to liability issues(i have to hide my medical problems to just clear snow in the winter on call part time), and no credit. I have to get things done however i can. Coming from nothing and building up to what i have now, a shop, some tools and a non functioning machine has taken a lot of hard work specially with my issues. I've spent money i couldn't afford to get my original machine which didn't hold up to all of the companies promises. With out a properly working cnc my shop can't function. When my old machine went down, it took me two weeks to build four simple office cabinets by hand. I don't normally talk about this but i guess i'm in that kind of mood. Don't get me wrong, i'm not looking for pity. Pity angers me in general. I'm not dead yet but understand, if i can make something work for less then $1k it's gonna get done however i have to do it. In the long run, i don't care about exactly how much money i make, i just need to work, produce and pay bills. I need to be busy or i go insane. I could sit around on welfare but i'm the type that'd rather put a bullet in my f...ing head whether i really deserve welfare or not.

[danhamm]

Motors.? pk296a1a or pk296a2a

Keling power supply = 160.00
PDMX 122 = 81.00
Drivers md882 4 = 240.00
Mach3 or flashcut = 150.00
low voltage
Contactors x 3 = 60.00 plus shipping...

[Brady Watson]

I was referring to the ZIP posted that totals $1835 in parts. This puts you well in the range of a 4G control box or even a developers board + geckos and power supply.

An even cheaper option would be to score a used PRT control box & just plug everything into that. You can probably get a whole control box for $300-500 tops. It isn't going to be a 4G box, but it at least will get you going with minimal drama - and let you get down to the business of cutting, not tinkering. Plus, you still retain telephone support - which really should not be underestimated. If you see yourself browsing through pages & pages of support posts, desperately looking for an answer to your technical problem, then Mach might be right up your alley. Mach works fine as a controller, but it can be very overwhelming when you are new to it.

I totally get the saving a few bucks thing...but don't be fooled by false value. When you are in the middle of a big job & your tool has a hiccup, who ya gonna call? That situation can be stressful - something to think about. Murphy is always lurking...Have a contingency plan if your machine goes down.

-B

[CNYDWW]

I was referring to the ZIP posted that totals $1835 in parts. This puts you well in the range of a 4G control box or even a developers board + geckos and power supply.

An even cheaper option would be to score a used PRT control box & just plug everything into that. You can probably get a whole control box for $300-500 tops. It isn't going to be a 4G box, but it at least will get you going with minimal drama - and let you get down to the business of cutting, not tinkering. Plus, you still retain telephone support - which really should not be underestimated. If you see yourself browsing through pages & pages of support posts, desperately looking for an answer to your technical problem, then Mach might be right up your alley. Mach works fine as a controller, but it can be very overwhelming when you are new to it.

I totally get the saving a few bucks thing...but don't be fooled by false value. When you are in the middle of a big job & your tool has a hiccup, who ya gonna call? That situation can be stressful - something to think about. Murphy is always lurking...Have a contingency plan if your machine goes down.

-B

It was an attack, sorry Brady. Just frustration

[CNYDWW]

Motors.? pk296a1a or pk296a2a

Keling power supply = 160.00
PDMX 122 = 81.00
Drivers md882 4 = 240.00
Mach3 or flashcut = 150.00
low voltage
Contactors x 3 = 60.00 plus shipping...

Here's a pic of the motors. Funny thing is the company that sells the flashcut software wants $429 for an upgrade to the current full version that's rebadged in their name. I know they've "black listed" me already and they wont see any more money from me. Besides the point.

[CNYDWW]

I was referring to the ZIP posted that totals $1835 in parts. This puts you well in the range of a 4G control box or even a developers board + geckos and power supply.

An even cheaper option would be to score a used PRT control box & just plug everything into that. You can probably get a whole control box for $300-500 tops. It isn't going to be a 4G box, but it at least will get you going with minimal drama - and let you get down to the business of cutting, not tinkering. Plus, you still retain telephone support - which really should not be underestimated. If you see yourself browsing through pages & pages of support posts, desperately looking for an answer to your technical problem, then Mach might be right up your alley. Mach works fine as a controller, but it can be very overwhelming when you are new to it.

I totally get the saving a few bucks thing...but don't be fooled by false value. When you are in the middle of a big job & your tool has a hiccup, who ya gonna call? That situation can be stressful - something to think about. Murphy is always lurking...Have a contingency plan if your machine goes down.

-B

I understand the issues with cobbling together something that functions properly. Also i hadn't thought of an older PRT controller. Once cash is in hand i'll see what's out there

[HelicopterJohn]

Hi Brady,

I am a retired guy and use my Shopbot more for hobby use that production like most of you guys.

I purchased my USED Shopbot PRT about 9 months ago from a guy that had modified it for use with Mach3. The original Shopbot control box that came with the machine had the Gekco 202's modified so that the step and direction pins were bypassed in the Shopbot control board. Those pins went directly to an aftermarket breakout board that took care of all the inputs like E Stop and proximity switches etc. while running Mach3 control software. Nothing in the Shopbot controller was modified in any way. The Shopbot controller that I still have was upgraded to a V4.17 control board (P/N 001740).

I have never used the Shopbot software so I can't tell you how it compares to the Mach3 Software that I am currently running. Maybe if I had elected to purchase new Gekco drives and install them in the original Shopbot controller and use Shopbot Software and the excellent technical support I too would better appreciate the fondness you and others have for the Shopbot operating software.

You said:
"I was referring to the ZIP posted that totals $1835 in parts. This puts you well in the range of a 4G control box or even a developers board + geckos and power supply.

I didn't run a total on the amount of money spent but it includes upgrades that would not be included if I had elected to just use the Shopbot and associated software.

My used machine didn't come with any proximity and homing switches. Also, I upgraded my Porter Cable 7518 router with the Super PID Speed Controller that allows me to control the speed of the router from 5000 to full speed either from the screen set or via GCode while maintaining excellent torque even at the lower speed range. The price also included 4 each new Gekco 203V drives and a new 70 volt power supply. It also included updates for both dual parallel port options and also for USB Smooth Stepper operation. Furthermore, I think I included the price for a Dust collector and associated solid state relays for operating both my dust collector and vacuum pump. Control of these items can be easily accessed from either the Mach3 Screen Set that I am currently using or via GCode in the software. I spoke to Chris in the Shopbot Technical support the other day and I would agree that they have excellent people in place to provide good support to their customers.

The reason I decided to upgrade all the electronics was that I liked the Mach3 software and didn't like the idea of running a modified Shopbot Control unit. My goal was to sell the Shopbot Control unit with the G4 upgrade once I completed my electronic component installation and Mach3 software installation.

I am not a Mach3 salesperson, just using what came with my USED Shopbot when I purchased it. I was fortunate that one of the guys here on the Shopbot forum was nice enough to help me along the way building my controller. I realize MOST people would prefer to just purchase pre-packaged i.e. Plug-In-Play software and hardware along with Excellent Technical Support provided by Shopbot and I respect their decision to move in that direction. I have learned a lot in the last 9 months or so and would not trade it for anything.

I have signed up the 2012 Shopbot Camp in Florida and hope to learn more about the Shopbot and it's associated software. It will be my first time seeing a Shopbot run on their software. Who knows, I may decide to use the Shopbot G4 Control box I have instead of selling it.

Sorry to be so long winded but thought you might be interested in my particular situtation and why I elected to do my Electronics Retrofit. With the knowledge I have gained during this retrofit processI would be able to retrofit other manual machine tools in my shop to CNC.

John

[Brady Watson]

This is a very 'touchy' subject - this Mach controller business. Fact be known, I own 3 Mach licenses, LazyCAM and a few other 'pay to play' plug-ins. I was messing with Mach before it was Mach (Master5) and it is a good piece of software. At the end of the day, it is YOUR machine, and you are 110% free to do with it as you please.

Personally, I will never run Mach on my ShopBot. SB3 is reliable, robust and has a clean, straightforward interface perfect for both new & seasoned users alike. I can run it on my laptop, just as reliably as a desktop. I have successfully run parts over 170 hours without stopping. I cannot say the same about Mach & I do my homework and build my own PCs to spec...but that's my experience with it. I still run it on a mill & 2 lathes. I tolerate it. The mill is getting converted to run SB3 with an Alpha control.

There was a brief time in history where Mach made sense because it wasn't easy to interface Geckos to a v3.x control board. With the advent of the 4G board, any advantage Mach had over SB3 for speed & resolution as the result of going from 1/4 stepping drivers to microstepping drivers, has past. Granted, there are probably a few features Mach has that would allow easy integration of some hardware (such as a PID controller for a router), but there are not many, and of those few, they probably are not 'professional duty' hardware choices. Again - a matter of preference and you afford what you can.

Let me make clear again, I really don't care what YOU run for a controller in your shop. My perspective is to 'pay it forward' and 'hook yourself up' and not shortchange yourself on the support end of things. If something goes down, I don't want to be the last guy on the support chain (and really didn't want YOU to be that guy either!) - which was my point in mentioning it in the 1st place. Also, IF you had to ever sell your ShopBot, it would be much easier and more valuable if it had OEM components all the way around. It's a little like selling a Camaro with a Ford 302 in it. Just sayin...So - just to be clear, my comments were from a place of empathy & understanding, rather than a proverbial stone breaking.

I hope you get it running soon, the way you like it, with whatever hardware you can afford.

-B

[bruce_taylor]

I think Brady's point of view is always well thought out and candid, I really appreciate the effort he puts out to help other botter's through the maze that is cnc. I find the support that shopbot offers is PRICELESS-PRICELESS. When your in the middle of cutting a job and your machine has a problem and you can call and get someone as knowledgeable as Frank,Ryan or now Gary Campbell, that support has saved me more than once . When it stops working right and you don't know why, a simple phone call helped solve simple issues, I was able to continue my path to make whatever it was. You may put a post out looking for the parts you need, you never know botters are continually upgrading and letting old parts go at a reasonable price so you could get lucky. I certainly wish you well with your project.

[gc3]

I think Brady's point of view is always well thought out and candid, I really appreciate the effort he puts out to help other botter's through the maze that is cnc. I find the support that shopbot offers is PRICELESS-PRICELESS. When your in the middle of cutting a job and your machine has a problem and you can call and get someone as knowledgeable as Frank,Ryan or now Gary Campbell, that support has saved me more than once . When it stops working right and you don't know why, a simple phone call helped solve simple issues, I was able to continue my path to make whatever it was. You may put a post out looking for the parts you need, you never know botters are continually upgrading and letting old parts go at a reasonable price so you could get lucky. I certainly wish you well with your project.


yup well said!

[richards]

Listen to Brady. Buy a used Shopbot controller that works. Don't worry about the 4G for now (unless you find one at a really good price - because you'll need to modify the 4G if you want "alpha" torque and speeds).

After you've learned to run your machine and after you know its limitations, THEN think about changing a few things to let it make heavier cuts at higher speeds.

If you decide to upgrade to the 4G model:

- Change the motors. The motors you have only have four wires exiting the case. That means that you have to wire them in the bipolar series connection. Bipolar series has great low-speed torque, but that configuration was not designed to produce speed. Buy some Oriental Motor PK296-F4.5A motors, wire them bipolar parallel and build a 3:1, 3.6:1 or 4:1 belt-drive gear box. Look through the archives and you'll see enough photos to see how a belt-drive gear box is put together. The PK296-F4.5A wired bipolar parallel with a 3.6:1 belt-drive will give you 99 in*lbs of torque, which is 20% MORE than the 7.2:1 alpha gear box is rated to handle. Resolution per step will be exactly the same because the Gecko G203v produces 2,000 per revolution and the Alpha drive produces 1,000 steps per revolution.

- Add a good 35VDC power supply to drive the motors. (A toroidal transformer runs much cooler than a standard transformer.)

- Add heat sinks to the G203v stepper drivers to keep them from overheating. The PK296-F4.5A motors pull a lot more current than the motors that you have. Heat sinking the stepper drivers keeps the heat within tolerance.

- Add opto-isolation to any digital I/O. Most digital lines toggle at 2.2VDC. In a CNC shop, with long runs of wire going to the router/spindle and to the motors, with dust extractors and vacuum hold-downs, you're going to produce a lot of electrical noise. That electrical noise has an amplitude much higher than 2.2VDC. Do yourself a favor and learn about the 4N2x series of optical isolators. They cost less than $1 each and they work wonders when it comes to reducing/eliminating electrical noise.

- Learn how to use ALL the Shopbot commands. You'll be surprised at what you will be able to do when you know what the Shopbot CAN do. Just like Brady, I had a licensed copy of Mach 3 on the test bench but I never used it on my PRT-Alpha Shopbot.

[myxpykalix]

There are far WISER guys on here technically then ME and there are some who use Mach3 to control their bot. For me the interface is confusing and I just don't like the way it is set up, but thats just me.

The problem that i see you running into, is when you have technical or software issues you have eliminated a vast pool of knowledge here and can only pull from the mach3 botters for most of your issues, and you have to ask yourself, what am I saving, or what is the major point in running mach3 as opposed to the regular shopbot software?

I think you also eliminate technical support from shopbot as i doubt they support mach3.

[richards]

Sometimes we get into the wrong state of mind when we think about a tool. The Shopbot is just a tool. Like any tool, it has characteristics that make it different from other tools. Most of those characteristics (at least to me), make it easier to use for someone who is new to the CNC world. But, like any tool, it has its limitations.

When you fight against a limitation, then it's time to decide whether another tool or modification will allow you to do the things that you need to do.

Some of us are very comfortable tearing into the electronics on a CNC machine. Some of us have the proper instruments to check signals and to verify proper operation. To us, it's "no big deal" to try different components or to custom build part or all of the controller; but as others have said, once the machine has been modified, YOU are automatically the technical expert.

One of the traps that most of us fall into is to make a wish list of things that we would like to have without knowing IF those things are necessary or what real advantage those new "bells and whistles" really provide.

A basic Shopbot, no matter which model, is an extraordinary machine. It can replace most of the machines in a typical shop and it allows a knowledgable operator to do things that he couldn't do with other tools customarily found in a typical shop.

During the years that I owned a PRT-Alpha, I resisted the urge to make major modifications, mechanical or electrical. I added 3:1 belt-drive gearboxs and then replaced them with the 7.2:1 Alpha that was offered as an update. I custom built a proximity switch interface and replaced the original proximity switches. After a while, I added a 3hp spindle and several variations of vacuum hold down systems. I replaced the original MPU on the controller board when it failed with a newer model. Other than that, the machine remained "factory fresh". It served me well during the years that I owned it, and, the last I heard, it is still serving its new owner well.

I knew my machine's limitations and more importantly, I knew MY limitations. I didn't try to make the machine do things it couldn't do and I didn't expect it to do things that I couldn't do. Other than being frustrated with excessive chatter that the geared motors almost eliminated, the machine worked better than expected. The learning curve was steep, even though I had been building and using computers since 1976. Once I learned to do my part, the Shopbot performed very well.