Bridgeport Retrofit motion control?

Hi guy's,

I've been on this project for a while now and its getting to the point where I'm sick of it sitting in the corner gathering dust, when I could be making loads of swarf with it and possibly earning a few quid at the same time.

I bought a Bridgeport MDI series 1 about 2 years ago, the iron was really good and apart from a dodgy servo, mechanically and electrically it was great, bargain price too! I bought with the intention of retrofitting to modern controls so I'd end up with a machine I could easily fire up and either run a quick conversational type program or load a complex cam outputted G code file. Since then I've had a few hurdles to overcome, but I've ended up with a machine that has CNC Drive Dugong type servo drives, original DC servomotors with new encoders and a custom built power supply. I've tested all of this up with a cheapo parallel port breakout board and mach3 just to try out the movements. All servo's tuned and working great individually, however, run a bit of a simple circle program and there is some weird stuff going on... It seems that when say the x axis is doing a movement then another axis starts to move, all axis pause momentarily then the desired movement is carried out. To watch it cutting fresh air, its hardly noticeable, but if i were to try and cut some material then I'd end up with a lot of problems. Also, I've tried out the MPG function (if you can call it that) in mach3 and its less than useless, I really wouldn't trust it to work with in a production environment.

So, my dilemma is this: do I opt for something like an ethernet smooth stepper and put up with mach3 until mach4 is properly developed and all features available? Or do I go with something like an Eding cnc package? I've heard good things about Eding, but the boards that I consider affordable don't offer as many inputs and outputs as I'd like. Mach3 is a pile of crap, I know this because I use it every day on my plasma cutter. I've just about got used to its "moments", but wouldn't build a machine on this platform, especially based around the parallel port!

I've spent probably 6 months debating which system to go for, Ideally I don't want to spend too much over £200, but I'd also like to have a machine I can use without thinking about it for another 6 months!

Any words of wisdom?

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Mach3 is a pile of crap, I know this because I use it every day on my plasma cutter.

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I don't think it's quite fair to blame Mach3 especially when using a plasma and a PP. But have you seen this http://www.pmdx.com/PMDX-410 you could also try Linuxcnc with a mesa card. ..Clive

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I don't think it's quite fair to blame Mach3 especially when using a plasma and a PP.

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Yes a little unfair, I was having a rant. I have tried mach3 a few times on different machines and have just fallen out of love for it, I'm looking for something a bit better. Don't get me wrong, I've made thousands of parts with mach and thats really brilliant, but I think I want something a bit more bullet proof for my mill.

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have you seen this http://www.pmdx.com/PMDX-410

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I have seen the pmdx mach4 stuff, but I'm not sure if I've got enough confidence in mach4 yet, I need someone to convince me that its ready and stable enough. Obviously, its on on the hobby version release of the software, I'm hoping to use my mill in a small scale commercial environment where down time would be costly.

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you could also try Linuxcnc with a mesa card

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I do really like the idea of the linux route, the mesa cards are also really cheap for what you get :) Each time I convince myself to go for Linux I get put off by fact that I might have to spend ages messing around getting the thing up and running... I've messed with computers quite a bit and am confident I could get a system up and running, but how much learning have I got to do to get to that stage?

Hmm decisions decisions......

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Originally Posted by drumsticksplinter

I do really like the idea of the linux route, the mesa cards are also really cheap for what you get :) [...] I've messed with computers quite a bit and am confident I could get a system up and running, but how much learning have I got to do to get to that stage?

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Then go for it, you'll be fine.

The question to ask is if you would like to have CAM capability on the same PC running your motion control. If so then stick with Mach3 and a motion controller. Mach3 becomes a joy to use when you are confident that you machine is not losing steps and communication.

This is mine before I had converted the quill too:

https://www.youtube.com/watch?v=M_VA...ature=youtu.be

If Mach is not working for you then it's not Mach's fault because it's Proven by 10,000's of users rangeing from plotters to very large powerful mills and lathes that it work perfectly well when correctly setup and left unattended for hours on end..!! . . . . Like Hoods Spidery beast.:onthego:

https://www.youtube.com/watch?v=MUkyRjqGGow

I am a lover of linuxcnc. Using either the printer port or other external interface cards - Rock solid. Any bugs that are found are fixed pretty darn fast. Pair Linuxcnc with mesa hardware (very inexpensive) and you have an industrial grade control.

Current released version change log
http://wiki.linuxcnc.org/cgi-bin/wiki.pl?Released_2.6.X

Next release version change log (you can test it now if you want) 2 exciting additions - support for mesa Ethernet connected interface boards and the new trajectory planner. (unknown at the time that it was funded by tormach and given back to the community) - Tormach used linuxcnc for their new control.
http://wiki.linuxcnc.org/cgi-bin/wiki.pl?Released_2.7.X

I have used mesa hardware in my systems and have found it to 'just work'. The owner is also very active in the linuxcnc community.

Linux isn't as scary as others would like you to believe. You do not have to be a 'programmer' to use linuxcnc. Between linucnc's HAL layer and its integrated ladder logic - pretty much anything is possible without writing a line of code. (although you can if you want to.. There is a C like language that allows you to write realtime components for your system - not to mention you have access to the source code) most people only scratch the surface.

sam

Welcome to the forum Sam I use Linux on my mill and lathe and Mach3 on the router The one problem I can see with Linux when using slaved axis (joints) with a router is the homing Linuxcnc as of this time has never got this sorted yet.
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So we can throw all the Linux questions your way:hysterical::beer: ..Clive

Yes - I can field questions or at least point you in the right direction.

Ugh - Slaved axis.. I have not had a machine that has used slaved axis. I know there are atleast 5 different ways to set it up. Strictly hal, gantry kins, other ways I can't think of.. It is doable but the setup hasn't really been standardized. Plus I know there is some development work that hopes to standardize the setup. (not to mention the joint/axis work also.)

Looks like you asked here :)
http://www.linuxcnc.org/index.php/en...ate-slave-axis

Like was mentioned there are a couple of gantry configs in linuxcnc to check out.
some other examples..
http://wiki.linuxcnc.org/cgi-bin/wik...yPlasmaMachine
https://www.google.com/search?q=slav...utf-8&oe=utf-8
http://linuxcnc.org/index.php/englis...gantry-machine

random google search
https://www.google.com/search?q=slav...oming+linuxcnc

Like I say - many people do it - it just seems like eveyone does it their own way.. I hope there is a better standard in the future..

sam

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Originally Posted by Clive S

Welcome to the forum Sam I use Linux on my mill and lathe and Mach3 on the router The one problem I can see with Linux when using slaved axis (joints) with a router is the homing Linuxcnc as of this time has never got this sorted yet.
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So we can throw all the Linux questions your way:hysterical::beer: ..Clive

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Originally Posted by JAZZCNC

If Mach is not working for you then it's not Mach's fault because it's Proven by 10,000's of users rangeing from plotters to very large powerful mills and lathes that it work perfectly well when correctly setup and left unattended for hours on end..!! . . . . Like Hoods Spidery beast.:onthego:

https://www.youtube.com/watch?v=MUkyRjqGGow

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I know that mach 3 has a large following and many people use it successfully all day everyday including myself. However, in my experience you can get mach to work quite well very quickly, but I don't have a great deal of faith in it in an industrial environment, probably because it was never intended for that purpose, hence the promise of a mach 4 industrial version. I like the look of mach 4, but don't believe its quite ready yet.

Don't get me wrong, there are some amazing machines using mach such as Hood's and many others and I'm almost tempted to get hold of a smooth stepper and jump right in, but in the back of my mind I know I'll be disappointed. Has anyone got any experience of an MPG that works well in mach 3? when I've tested it it was horrendous to use and wouldn't trust it at all!

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Originally Posted by drumsticksplinter

I know that mach 3 has a large following and many people use it successfully all day everyday including myself. However, in my experience you can get mach to work quite well very quickly, but I don't have a great deal of faith in it in an industrial environment, probably because it was never intended for that purpose, hence the promise of a mach 4 industrial version. I like the look of mach 4, but don't believe its quite ready yet.

Don't get me wrong, there are some amazing machines using mach such as Hood's and many others and I'm almost tempted to get hold of a smooth stepper and jump right in, but in the back of my mind I know I'll be disappointed. Has anyone got any experience of an MPG that works well in mach 3? when I've tested it it was horrendous to use and wouldn't trust it at all!

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Mach 3 works best with a motion controller like a Kflop. If I understand it correctly a motion controller actually does the majority of the work and mach3 almost acts like a fancy interface?

Hi Sam,

Thanks for the info, I've toyed with the idea of linux in the past, but only got as far as loading the demo operating system off a disk. Other than that I have no idea about it. I've seen other people using the mesa cards and they certainly are cheap for what you get. What combination of card and daughterboard would you recommend?

Say if I were to set up linux for the first time without any previous experience and little to no programming experience, how quickly could I have stuff moving around? I'd like to build a custom control panel with MPG FRO and spindle speed over ride etc, are these easy to implement in linux cnc?

You've got me thinking now.... I'm also finishing off a router at the same time, so if I could crack linux on my mill then I'd use it for that also :beer:

Thanks,

Adam.

what is your hardware now? analog servos? Step/dir? Mesa has a 5i25 or 6i25 (pci or pci-e) that right out of the box acts like 2 printer ports on steroids. (so you could use your existing bobs if you are using printer ports) On steriod - I mean it does hardware (high speed) step/gen, pwm gen, encoder counting, and i/o. ie - well into the mhz..

if you need more i/o than 2 printer ports - you can get daughter boards like the 7i76 that is a stepper interface. (gives you 5 axis step/dir output, analog spindle output, 48 i/o, spindle encoder input - and still expandable)

you can buy it as a kit..
http://store.mesanet.com/index.php?r...product_id=215

linuxcnc has a configuration utillity for mesa hardware - I have never used it but it is constantly being improved.
http://linuxcnc.org/docs/2.6/html/config/pncconf.html
main docs
http://linuxcnc.org/docs/2.6/html/

do some reading....

sam

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Originally Posted by drumsticksplinter

Hi Sam,

Thanks for the info, I've toyed with the idea of linux in the past, but only got as far as loading the demo operating system off a disk. Other than that I have no idea about it. I've seen other people using the mesa cards and they certainly are cheap for what you get. What combination of card and daughterboard would you recommend?

Say if I were to set up linux for the first time without any previous experience and little to no programming experience, how quickly could I have stuff moving around? I'd like to build a custom control panel with MPG FRO and spindle speed over ride etc, are these easy to implement in linux cnc?

You've got me thinking now.... I'm also finishing off a router at the same time, so if I could crack linux on my mill then I'd use it for that also :beer:

Thanks,

Adam.

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drumsticksplinter ] You can also buy them here in Europe http://eusurplus.com/index.php?route...tegory&path=63.

Sam I would like to ask you some questions re threading with G76 could I do it with email to you. ...Clive

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Originally Posted by drumsticksplinter

However, in my experience you can get mach to work quite well very quickly, but I don't have a great deal of faith in it in an industrial environment, probably because it was never intended for that purpose, hence the promise of a mach 4 industrial version. I like the look of mach 4, but don't believe its quite ready yet.

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Correct But Why anyone would expect a £130 Control software using windows parallel port to be industrial strength is beyond me if I'm honest.!! . . . . Your simply being unrealistic in your expectations.!

Now while Mach was never intended for industrial control that was using the Parallel port.!! Windows and parallel port we all know are rubbish for anything but simple hobby use but Mach works like a Charm with a Quality Motion control Card Like Cslabs or Kflop, Galil etc

Without getting into the Linux vs Mach rubbish both softwares do a great job for very little to No money in Linux case and when correctly matched with Hardware can give some of the very very expensive industrial controls a very good run for there money but unfortunatly all to often People are too quick to fire and blame the software. Often it really is case of " Poor workman blaming is tools". .!!

At the link Clive provided they have the C23 dual LPT BOB for only 72eur, surplus. Big, cheap and reliable, did i say big :-) .

Thanks for pointing to that shop, i have been searching for something like that some time.

That bob is huge!

I (being biased) still think for being under 200 euros the 5i25+7i76 gives you a lot more flexibility. The daughter board gives you..

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The 7I76 is daughtercard/breakout board for use with MESA's 25 pin I/O FPGA cards like the 5I25. The 7I76 is designed for interfacing up to 5 Axis of step & dir step motor or servo motor drives and also provides a spindle encoder interface, isolated analog spindle speed control and 48 isolated I/O points for general purpose field I/O use. All step and direction outputs are buffered 5V signals that can drive 24 mA. All outputs support differential mode to reduce susceptibility to noise. An isolated analog spindle voltage with direction and enable outputs is provided for spindle control as is a single spindle encoder channel with TTL or differential inputs. 48 points of isolated field I/O are provided for general control use including limit switch and control panel inputs, coolant enable and tool changer control outputs. Isolated I/O includes 32 sinking inputs and 16 sourcing outputs. Inputs can sense 5V to 32V signals and the outputs can switch 5V through 28V signals. Maximum output load is 300 mA. Outputs are short circuit protected. In addition to the being able to read digital on/off status of each input, four input pin voltages are readable with 8 bit resolution, and two MPG encoder inputs are provided as an option on four field inputs. Field I/O is powered by an isolated 10-32V field power source. One RS-422 interface is provided for I/O expansion via a serial I/O daughtercard. All field wiring is terminated in pluggable 3.5 mm screw terminal blocks.

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Plus it is expandable be it the 2nd port on the 5i25 or the smart serial port on the 7i76. (not to mention if you want to go full closed loop servo the 7i77 daughter board is for you)

Did I mention that I love mesa hardware? It is well built and 'just works' tm

Other similar solutions are going to be more money like ESS+C23.. (plus - who wants to rigid tap? :) )

most have seen this - linuxcnc + mesa (my conversion of old K&T HMC) 4 axis + 96 i/o (full closed loop) Still running great.

https://www.youtube.com/watch?v=39q6kvrSBSk

sam

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Originally Posted by JAZZCNC

Correct But Why anyone would expect a £130 Control software using windows parallel port to be industrial strength is beyond me if I'm honest.!! . . . . Your simply being unrealistic in your expectations.!

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I think you misunderstand, I'm not expecting the parallel port and mach3 configuration to be industrial strength because it obviously isn't. Conveniently though using a breakout board and parallel port provides a very quick and cheap means of testing the bare bones of a machine build and thats all I'd use it for.

I'm just looking for a good stable solution to a motion control system on my machine. The thing that has really put me off mach3 is the MPG feature, which is what i really want to work well, I've tested it with a pokeys board, which claimed to offer the feature, but the results were terrible. I've read about other people having serious issues with the MPG feature in mach3 too. No matter how much I ask about the functionality of mach3 with and MPG, nobody seems to be forthcoming with information, why is that? Because it doesn't work? Artsoft have said as much, thats why part of their selling point for mach 4 is "Higher quality manual pulse generator (MPG) = very smooth jogging and positioning without lag time.".

I was wondering if the MPG feature worked well with the ESS or CSlabs?

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Originally Posted by drumsticksplinter

...Because it doesn't work? Artsoft have said as much, thats why part of their selling point for mach 4 is "Higher quality manual pulse generator (MPG) = very smooth jogging and positioning without lag time.".

I was wondering if the MPG feature worked well with the ESS or CSlabs?

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Agreed to some extent. Linking the MPG directly to the LPT or other motion control many not yield totally reliable results. but then you can always go with the Vistacnc stuff like:

https://www.youtube.com/watch?v=x9GJIXa_aR8


I will be evaluating this for my own purposes.

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Originally Posted by komatias

but then you can always go with the Vistacnc stuff

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I've admired the vistacnc pendants for a while now but haven't got round to ordering one to try. I'd be interested to see how they perform, though I wouldn't be surprised if it was something like the pokeys inside with a fancy plugin written around it....

Thanks Clive, I was looking for other sellers of the mesa boards.

I am very happy with jog performance in linuxcnc. On the k&t I use it all the time for setting parts/tools. (I use a 1/2 dowel pin and jog wheel for setting zero - rolling it between the part and tool)

http://linuxcnc.org/docs/html/examples/mpg.html

There are a bunch of ways to hook a physical jog encoder up. The above example is similar to how I have implemented it on my machines. That example is also a real time jog implementation.

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I am very happy with jog performance in linuxcnc. On the k&t I use it all the time for setting parts/tools. (I use a 1/2 dowel pin and jog wheel for setting zero - rolling it between the part and tool)

http://linuxcnc.org/docs/html/examples/mpg.html

There are a bunch of ways to hook a physical jog encoder up. The above example is similar to how I have implemented it on my machines. That example is also a real time jog implementation.

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Thanks for all your input regarding Linuxcnc, I have decided to take the plunge and have ordered the mesa 5i25 and 7i76 kit, which should arrive to me next week sometime. I was really impressed with your machine setup, some complex stuff going on there for the toolchanger to work so well ;) Thanks also for the info on the MPG setup, the code doesn't mean a whole lot to me at the minute, but I'm sure I'll get my head around it!

I'm going to ditch out the windows install on my bridgeport pc and load up linux asap. I've been afraid of trying linuxcnc for a while and I'm sure I'm not the only 1 who'd consider it to be a move over to the darkside, but hey! it might turn out to be the best thing I've done :thumsup:

Its all still very daunting and I'm sure there is a learning curve, but from what I'm reading this seems the right decision for my machine at this time. I know there is always a linux vs mach3 battle going on as with the Windows vs Apple. I use a Mac 90% of the time btw :friendly_wink:

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Originally Posted by drumsticksplinter

I was wondering if the MPG feature worked well with the ESS or CSlabs?

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Can't speak for any other MPG on Mach but these but Cslabs MPG Module works perfectly.!

Pokeys is a toy in comparison to real motion control but to be fair I've setup a MPG with Pokeys and didn't have any issues. Thou in fairness I didn't push it or look for any issues and it was just a small lathe.

Thanks for sharing your experiences with the MPG feature and the motion controllers. I really liked the look of the cslabs stuff and the add on modules seems like a nice feature. I was a bit reluctant to pay the price for the IP-S at this stage though and the IP-M won't do exactly what I require.