Anyone with Mesa 5I20 and 7I33 stories?

[karl1]

Well I just pulled the trigger and bought the Mesa 5I20 PCI card and the analog servo control module 7I33(T) for a quick project, 3 axis router. I plan on using the servo control tied to Advanced Motion Control's BD25a20 for the amplifier portion and servo motors with encoder feedback on all 3 axis. My question is, has anyone had any experience with this controller under the Linux/EMC, other than the ones posted under the EMC WIKI? I hope to have the Mesa cards in my hands by next weekend, as the other portions of the project sit idle while I wait - the MESA purchase is the only out of pocket purchase I had to make.

Thanks!

Karl

[unterhaus]

are you going to do something like the 7i37? There is board design on Anders Wallin's web site.

I am trying to get my mill set up with a Mesa right now. There is a lot of work to do, almost none of it involving the Mesa board. I am working on the estop and limit circuits, which are fairly important when you have hundreds of pounds of metal sliding around at high speeds. I'm afraid to test my wiring until then. I stumbled upon some 50 pin ribbon cable to screw terminal boards, which makes things easier with the mesa. I did have some problems with packaging the breakout boards. They are inside the computer now.



I have a couple of the BD23a20's, but I decided to use different drives. Not that it makes much difference. In my case, the encoder wiring goes through the drives. I do have the drives wired to the mesa. I got a spreadsheet from someone on the emc irc channel and modified that.

I'm posting it in open office format

[karl1]

are you going to do something like the 7i37?

I'll be using the few I/O points on the 5I20 for E-Stop(maybe), Home and limit inputs. The output will be for the control of a router spindle - I brewed up a circuit for digital Voltage control to be connected to this output.

There is board design on Anders Wallin's web site.

I'll Google for this site - Thanks for the lead!

I have a couple of the BD23a20's, but I decided to use different drives. Not that it makes much difference. In my case, the encoder wiring goes through the drives. I do have the drives wired to the mesa. I got a spreadsheet from someone on the emc irc channel and modified that.

My freebie BD25a20's don't have encoder inputs, just the commutation control via hall sensor inputs (BLDC) and +-10V swing for motor speed control - made the 7I33T an easy choice.

Swinging a heavy metal vertical has been a dream of mine to own - but ebay and the local swap sheet are out of my price range. Funny, I have all the electronics to build several large machines, but no machines to put them on! yet!

Karl

[buckie555]

I've used the Mesa 5i20, 7i33 and 7i37 boards on a recent Cincinatti VMC retrofit. Absolutely no problems to date so far. I've only got about 1000 machining hours on it so far, but all is looking good. The hardest part of the retrofit I've encountered is the logic for the automatic tool change but that's virtually cracked now. The large amount of IO on the 5i20 made it a sinch. FYI I've used the 4th axis on the 5i20 to control my spindle and am using the encoder feedback to allow accurate speed control when rigid tapping. I plan to add a 4th axis to the machine shortly and will buy a second 5i20 to handle that. I did initially try to use a PWM signal via a HAL component and a simple low pass filter to provide my spindle speed analog output but I didn't have great success - mainly to do with a lack of speed resolution - I need quite fine control for my particular app. But to cut a long story short; the difference in performance between EMC2 and the mesa cards controlling the VMC versus the original siemens acramatic control is like night and day. I was VERY glad I took the plunge. I've also been using Mach 3 on production machines over the last couple of years. From our experience with EMC over the past 6 months on a couple of mills we're now planning to change all our Mach machines over to EMC, but that's a different story.

Go with EMC and Mesa - you won't look back.

[unterhaus]

http://www.anderswallin.net/2006/08/...ocard/#more-77
here is the card design

[Dan Falck]

buckie555,

Can you give us some details of how you interfaced to your servo drives? I recall reading on IRC #emc that you are using Fanuc drives. A lot of people would be interested in your experience with this.

Thanks,
Dan Falck

[JR1050]

[QUOTE=buckie555;373874]I've used the Mesa 5i20, 7i33 and 7i37 boards on a recent Cincinatti VMC retrofit.


Would you mind elaborateing on your set up.Ive been looking at EMC for a Brown & Sharpe retro.What hardware did you use for your Cincinatti?Did you use a template that comes with the EMC or did you start from scratch?I started with Delta Tau,but this seems much cheaper and in the end faster.Can classic ladder be programmed in text?Im used to macro and got used to the text plc in Delta tau and would prefer not to learn regular symbolic ladder.Thanks.

[buckie555]

Dan,

Certainly - I used all of the original drives and motors on the VMC. The axis drives are a triple-stack fanuc unit (all 3 axis drivers on a single pcb set), the spindle drive is a fanuc unit which drives a rather large 15hp fanuc servo motor. All motors are brushless ac servos. Interfacing to the drives was really quite easy since I had the original wiring diagram for the mill and most of the connections were obvious. Each of the axis drives take a +/-10v analog signal for velocity control and a simple digital line for enable. I used a mesa 5i20 board with 1 x 7i33 (4 axis servo card) and 2 x 7i37 (opto-isolated IO cards). The axis velocity signals come straight from the 7i33 and the motor encoder feedback (8000cpr) goes back into the 7i33. The enables are triggered from 3 io lines on one of the 7i37 cards. The spindle drive is similar except it takes a 0-10v signal for the velocity and 1 of 2 contacts must be closed to request either fwd or rev motion. I used the 4th channel on the 7i33 for this and fed the spindle encoder feedback back into the 7i33 to provide speed feedback for rigid tapping, etc. Most of the rest of the IO is used to control the automatic tool changer which was by far the longest part of the retrofit. Infact it's still in progress but should be complete within the next week or so. The rest of the mill has been finished for some time now and I've been using it in anger for a while. I'm very very pleased with the retrofit and in the process have learnt a lot about EMC, HAL and ladder logic.

I ripped out the original siemens acramatic control from the rear (control) cabinet and it now houses the mesa cards (on din rails), an old p3-500 and lots of fresh air.

Next time I have the camera in the shop I'll take some photos. Once the automatic tool change is working I plan on posting some video.

I should add that I retained all of the original relay driven safety circuits and am very glad I did so. When this thing moves it's scary and with 1kW ac servo motors on the x and y axis it's not going to stop in a hurry.

[buckie555]

JR1050,

I used the stock m5i20 hal config files as a starting point, which basically got me to 3 axis closed loop control pretty quickly and then adding simple hal pin links to hook up enables, the spindle controls, flood, drawbar, etc. For the tool change logic I've used a combination of hal components and classic ladder. It avoided the need for any external logic/plc, etc. Once I upgraded from EMC version 2.1.7 to 2.2.1 I found classic ladder a pleasure to work with, before then I found it unusable due to a number of bugs but they appear to all have been addressed in the most recent version. As far as configuring the ladder by text, I'm not sure. You can certainly edit the raw clp text files if you're feeling brave - I found the gui perfectly usable. Oh and I made use of pyvcp to build a gui panel for testing the toolchange, etc. Also the sample hal file from the mazak mill conversion was a great reference.

My ATC would be fully functional by now were it not for a little "mishap" that we had during the final stages of testing which set us back a few weeks. The previous owner of the machine had "serviced" the z axis ballscrew and then put the ballnut back in upside down, with only half the balls and without properly tightening the locknut. Of course we were unaware of this. The result was that the loose locknut finally gave way and the whole z-axis assembly, spindle, spindle motor and ballscrew fell to the floor - well into the y axis guide covers which thankfully absorbed most of the impact and prevented damage to the spindle and table. At the time I was cursing but it turned out to be a blessing in disguise as the ballscrew was in desparate need of replacement so a brand new precision ground screw was used in it's place. I was very lucky, minutes earlier I had been leaning over the table clamping down a part. If the crash had happened then I certainly wouldn't be here to tell the tale. In my opinion it's actually a poor design having the whole weight of the z-axis held by the angular contact bearing locknut and the z-axis motor brake. I guess it was cheaper than adding a counterbalance to the machine though. After this episode I'm very much considering retrofitting a counterbalance even though we've replaced the parts that failed.

If you have any questions fire away. Once the ATC is finally finished I plan on detailing the whole retrofit along with photos and videos on the EMC wiki. I can't praise EMC and the support of the developers highly enough. Whilst I was configuring the ladder logic and hal components for the tool change I would go onto the irc chat channel and get answers to any questions I had instantly. The guys over there are very helpful. I'm due to start my next retrofit later this week and am going the same route again (EMC and MESA cards).

Cheers,

Neil

[JR1050]

Neil,

Thanks for sharing your info.I can appreciate the non counter balanced head episode,as Brown & Sharpe didnt beleive in it either.I had an axis board die on the B&S we still run(with the GE 1050-its not that bad) and the head fell about 6 inches before the control caught it and slammed e-stop.It occurred to me to take a page from Haas and put a gas filled or hydraulic counter balance on the thing for piece of mind.What was the original control on your mill?Thanks again.

JR

[buckie555]

JR,

The original control was a siemens acramatic 850 (not the sx version). The machine was built in 92 and I'd say the control was a late 80's design. The original control was running when I bought the machine but was just too antiquated for our needs.

Cheers,

Neil

[hooeey]

Hello,

I had installed emc2 and connected mesa 5i20 with 7i33.
However, the analog voltage output I had measured gave me different polarity from the value I had set. For example, I had set the dac 00 to be 8V but I had measured -8V instead and vice versa.

Does anyone have encountered the same problem as me?
Thanks.

Daniel