Pete's Cincinatti Arrow 500 Retrofit...

For MPG usage, normal hostmot2 encoder inputs are not ideal.

This is because the encoder inputs support 4X quadrature mode and up/down mode,
not the 1x quadrature mode that is best for MPGs (that gives one count per detent).
up/down mode will sort of work like 1X quadrature mode but will miss-count occasionally
if used with a quadrature inout

You might want to try the 7I77 quadrature input option on the 7I77 input pins,
these default to 1X quadrature mode. It may _still_ take some fussing to get the MPG
exactly right even with 1X quadrature mode because ideally the counter should count
right at the middle between detents, which may require swapping A/B or setting the
counter mode in the 7I77 I/O processor.

Pete,
Okay man honestly that is the way I wanted to do it initially, I finally went with one of the six axes of movement encoder inputs because it had the 5v input I needed to power the encoder. If I use the regular inputs how do you recommend I get the 5v power for the MPG. The encoder is of course up front of the machine with the computer and the mesa 7i77 is out back in the electronics cabinet. I will definitely try that because it will free up another axis of movement for future use. Peace

Pete

PetefromTn wrote:

Pete,
Okay man honestly that is the way I wanted to do it initially, I finally went with one of the six axes of movement encoder inputs because it had the 5v input I needed to power the encoder. If I use the regular inputs how do you recommend I get the 5v power for the MPG. The encoder is of course up front of the machine with the computer and the mesa 7i77 is out back in the electronics cabinet. I will definitely try that because it will free up another axis of movement for future use. Peace

Pete

Hey Pete,

You can continue to use the existing 5v. Should be a problem, we'll just need to move the A/B wires to the correct pins on the 7i77 board and reconfigure the hal and ini file. Shouldn't be a big deal. I'm working on your gladevcp panel right now.. I'll go ahead and add in a load meter. You want a Bar Graph or a Analog gauge ?

Thanks, Billy

Did not know you could use the 5v anyway. Honestly I would like a more permanent solution to the problem. The system may actually work the way it is once we get the PID tuning completed. It had been suggested that I just use the 5v from the computer and run the encoder wires back to the 7i77 using the I/O inputs instead of the axis inputs. Peace

Pete

If the MPG is a long way away it might be better to use
something like a 7I73 so the TTL level MPG wires dont
go so far. This would also simplify wiring for control panel
buttons and LEDs

Pete,
Funny you mention that board Billy and I were discussing that yesterday when he came over to help me. Looks like a sweet setup that would certainly add a lot more functionality to my system. Would it plug into the 5i25 or the 7i77 . Apparently it can be located a considerable distance from the computer and work fine according to your website. Can I hook it up with differential encoder settings for the MPG? Adding additional buttons and other goodies down the road would also be easier. Gonna have to look at it more closely I think. Peace


Pete

Okay guys ANOTHER update.
This morning I managed to get the Coolant pump VFD wired correctly and configured on an output pin from my Mesa card. Apparently there was a jumper that you had to change for the input to be configured the way I wanted as well as you had to input the common on a different pin. Once I did that we had control and I gotta thank the guys at Driveswarehouse for walking me thru setting up the drive and configuring it to output the desired frequency as well as adjust the accel and decell rates. It works real nice right now altho there is no coolant in the system so I only ran it for a couple seconds while testing.

Today was a banner day in the evolution of the machine build. I managed to get the Z axis motor installed and coupled to the ballscrew so I could raise the millhead and that allowed me to do several things. I was able to get the Z axis brake tested and it seems to work properly and I adjusted the timing of the release inside the drive so that the head did not fall once you hit servo off. It also allowed me to test and tentatively configure my Z axis homing routing. It is going to home to an index so I was able to test that several times. It is all going in the right directions in both axis travel and homing routine but the home position is not correct so I will have to play with that here when I get a minute. Now that the millhead is under power and I can move the table around I can double check the ballscrew pitch for the table and use that to calculate the encoder setup. It will also allow me to finally be able to plug in and test my spindle motor VFD and start getting that thing configured. I am going to play with it after dinner again tonight and see if I can get it to run the spindle and start checking my initial open loop setup. I am still working on the Spindle encoder setup here and have yet to order my spindle encoder. Just removed the resolver yesterday for testing out where and how I will be installing the new encoder.

I am just trying to take things one careful step at a time. My Pal Billy is supposed to be coming over this Saturday and hopefully we will be able to get a lot of stuff configured then. I cannot wait to start to be able to use the basic machine and maybe make a part or two. I have some ideas for some cool switch panels for the control pendant. Still lots to do here a lot of PID tuning ahead here and I will probably just unplug the Z motor and install the X and Y motors to the table and get them to work properly with the tuning and then hookup the Z motor and use the same settings for a baseline to get me in the ballpark. So far so good here fellas. Cannot wait to see it run a program. Peace

Pete

Update!!
Today was a great day in the progress of the Cincinnati Arrow 500 Retrofit. My Pal Billy came over again and he helped me get a bunch of stuff configured. We hooked up the X axis motor and started tuning that and got the home sequence sorted out. Had to swap the x for the Y home switches and got that done. Found a PID setting that seems quiet and smooth and responsive. This thing can really scream now dunno what the Max actually is but it could easily traverse at over 650 IPM. Kinda crazy in only 20 inches LOL.... He was also able to get lot of the stuff sorted out with my MPG. We got it hooked into the 7i77 inputs instead of the dedicated encoder for an actual axis which is really nice. It seems to work much better now and does not miss any tics when you move it like it did before. We also changed a setting that my Intel Atom board seemed to like. Before upon startup of LinuxCNC we were getting some kinda real-time error but once we changed that setting it stopped doing that. Everything seems to be working really beautiful now. The Z motor setup is also much better and quieter but I think there is still some more smoothness to be had in the settings. There is still some dithering sounds. We had a lot of fun playing with stuff trying to refine the system.

Tomorrow or Monday depending on my time available I will be finally making the Y axis power connection so that it will fit inside the column and then I can finally hookup the Y axis to power. Hopefully most of what we learned on the X axis will translate to the Y with some subtle PID changes. I will also finally get the spindle drive hooked up and start getting that to do what I want. Once that is done I should be able to start running some sample code to check out the machine and see where I need to make adjustment. We did run the LinuxCNC engraving and it worked real nice. Cannot wait to see this bad boy run some parts .... won't be too much longer that seems clear. A HUGE shout out to Billy and also Pete and Art for all of the help here guys. It really is looking great. Peace

Pete