MESA 7i96 AC Servo spindle setup

Hi Guys, I have just received my AC Servo finally, 2.6kW 240V model. Was trying to google some basic tutorial how to setup servo with my MESA card and LinuxCNC, but for some reason I cant find any documentation for that exact case. I am sure I am definitely not the first person setting up a Spindle with AC servo and its driver, maybe someone knows some good links with "how to" guide or some article that would cover basics? It's my first servo setup. I looks like I can either use a parallel connector on a driver or a RS port there. With RS it is absolutely unclear to me how that connects to MESA board, as it is basically an UART as far as I understand. RX, TX.. etc. Basically looking for some instructions on how to wire data route from mesa board to servo driver, or maybe some example setups that were documented, I could go from there too.

At this point positional control isn't that important to me at all, I am basically just going to use it as a silent higher speed spindle motor upgrade, not going to do rigid tapping at all, not worth it for me, I can do that by hand faster, as most of my parts are soft metals and small. All I need is to be able to enable it, read errors and control speed from LinuxCNC.

Also after reading up on this forum, I settled for poly V belt, not sure how much better or worse that will be vs common timing belts like 3M, going to figure this out soon I guess. One of the reasons to use that is that you can turn those pulleys custom to your size rather easy on any lathe, which is a huge advantage, as you wont need to pay high price, and what's even more important to wait until it gets to you by mail. I guess you could cam and mill 3M pulleys too, but another advantage imo is that poly-V pulleys are self centering and dont need ridges to control belt position. They are supposedly more silent too, but will require much more tension which isn't great but we will see.

Really need more information and manual for the exact servo you are running. With a 7i96 your options may be a bit limited without purchasing an additional card. The 7i96 lacks a +-10v interface that most servos use and would be the easiest control method to setup. You may be able to run the servo off step/for signals of you have one of those 5 channels free on the card. This is a road less traveled but possible. More information on the servo setup is needed however.

This is basically my servo: www.ebay.com/itm/265372903980 and I am attaching the PDF too. Looks pretty generic to me actually, very popular driver and my main problem here is probably not the servo but the fact that I have never done this before and unfamiliar with interfaces. I have a simple 3 axis mill setup, so I have 2 spare STEP/DIR ports + encoder port (for whatever it is there, could be just for input?). Was hoping to find some basic guide somewhere.

Oh well, cant attach it here, 4mb is apparently too large lol. Here:  file.io/taUTiKUJ9SE1

I also saw some knowledgeable members here mentioned that simple spindle control can be done via RS422 rx/tx method. And I see those pins are present on mesa board, and that wiring sounds clean too, I would definitely go that route if there are no caveats to it.

I am using a smaller version 1.8kW of this on my lathe as the spindle drive.

Step/Dir is what I am using. I just don't recall all the changes I had to make on the servo drive, but here is how I would start:

Use Pncconfig Wizard update your config (if you have used Pncconf Wizard) or build a new test configuration with a Spindle on StepGen3 (0 - 2 for XYZ and 3 for your Spindle). Replace the Spindle section in HAL/INI with your test config.

On your Servo Amp change or verify that location / position mode is active. This will use the Step/Dir inputs. Velocity mode would be more appropriate for a spindle but will switch input to -10V / 10V - which you don't have.

Pn002 = 2 (location mode aka position mode)
Pn003 = 1 (auto enable servo after power on)

Not sure if there is a perfect guide for it but if you can get it wired with Step/Gen, we should be able to help you with a bit of trial and error.

Thanks, that's what I was thinking to try first after yesterday's research online too. And its a good start. Analog controller is better but its waiting time and $70 more from mesa, so I'd rather try step/dir method as you said. With this method, are you able to turn spindle on and off in the software? Since you mention Pn003 there, I wonder if that would affect that ability.

As a side note, has anyone seen those Teknic motion controllers? They look very appealing actually and price is competitive.

Yes, everything is working on my Lathe. We should be able to get you going.

Is your spindle 1:1 - if so you can use the built-in encoder including index. If it's different than you would need a separate index signal, but that is step 2, after the basics are working.

Awesome then! Definitely going this route! Thanks a lot man.

My servo is 2500RPM only, so I am planning to use poly-V belt drive with two pulleys in order to make spindle RPM at least 5000. Need to turn those gears from aluminum (on my mini lathe), which is on order and badly delayed. So I have to entertain myself with something else for now! With that said I am planning to aim at 1:2.5 ratio there. But as I said, positional control isn't really necessary at this time. I also like the lock feature actually, this will allow me to easier change tools hopefully, as spindle wont rotate freely at tool change. Now with my cheap AC motor there it freely rotates so I have to use two tools to release end mill, and then I need to use the third hand to make sure the mill doesn't fall into my iron table and shatter.

My servo also gets super hot even without a load. I ran it yesterday at 2500RPM for about 10 minutes and it got into 80C area. Is your servo getting same hot too?

That temp isn't horrible. I have a 1.8kw as well as a spindle on a small machine for years now and run it at full speed for hours on end. It's usually around 160 deg f.

I would personally go with a timing belt setup for the spindle. It will be a bit noiser but you want to make sure all that power is delivered to the tool. How complex is the mounting for the belt setups you would like to use? Misumi does custom bores to order for timing pulleys.

80C is more like 190F tho. And that is on a floor with no pulley and no load even... 

For bores I actually prefer to do them myself, this way I can match them perfectly with my shaft, as I have a lathe. I considered a 3M setup, but aside from noise those pulleys are hard to get and expensive and shipping time is super long. On top of that machining them with good concentricity will be a huge challenge if I buy from chinese junk market, and so far everything I have seen on amazon and ebay is a total junk, mcMaster prices are ridiculous for this type and they often sell same junk. And for spingle pulley I an gonna need to customize it myself regardless, because its angled shaft on my machine. I cant imagine how to do that on a finished 3M pulley, as they are not concentric outside. Then I saw people using Poly-V profiles and thought thats a great idea actually, less nosie, plenty of grip, while pulleys are super easy to make on a lathe. Belt is also self centering unlike most timing belts that wobble left and right always. Well, anyways, that was my logic and why I chose Poly-V setup. Ordered all material on midweststeelsupply.com website. Their prices are actually one of the best I could find, but sneaky people took my order and only next day sent me an email about additional 10-12 business days delay. Now I have to wait quite a bit to get this all setup.

As far as Misumi is concerned, they are nice as an option when you dont have tools to do it yourself, but if you have machines it is way easier to do it yourself and will save a lot of money for you, as for what I need material alone is already over a $100.

I mistook your statement to mean your lathe was on order.

For my setup I used aluminum XL timing pulleys. Pretty cheap and everyone has them. I did my first round from Misumi and have done some others with a 4 jaw chuck.

My temp is on a well broke in servo motor. When I first broke in the setup I had some temps climb up pretty high. After a run in period it all settled down.