Greenie problems configuring 6i25 with 7i77, using Granite Devices VSD-E drives

I took another stab at the GE drive last night. Frankly, the conformal coating makes it really tough to probe, identify, etc. Plus, the drive is pretty old so I'm punting on it. I bought a 5HP unit through Amazon because that way I know it is coming from Huanyang. I opted for the newer GT series which is a vector flux type. Why? Dunno. At 3:3 is about $20 more, but because I went to a 5HP, that was about $60 more. I opted for the more expensive one because I'd rather not have to power up a phase converter if I don't have to and with a 2.5HP spindle motor, I've always been told to oversize the VFD by about 100% if you want to run the VFD on single phase.

Eventually I hope to get rigid tapping working, which is why I went with the 5HP vector unit. My (albeit unsubstantiated) thought it that I'll have better speed control with it... I have to make an encoder mount for the spindle motor, though, which is a bit of a challenge. And, I'm not sure if I'm better off with ModBus (or look alike) control or the 0-10VDC input. My guess is the ModBus is probably better,
but I'm also not sure that I have a serial available (literally just thought about that). I'm delving into an area that I hadn't expected to have to worry about. But, $200 later, I obviously have no choice but to address spindle control.

Alan

I was wondering about the USB delay, etc. as being a motivation to stick with the 7i77 and analog control. I'm glad you brought that up. . Thank you.

There is only a 1:1 belt drive in there between the motor and the spindle sheeve. However, there is a large disc brake. I plan on installing the encoder under that. I'm not too sure what CPR to use right now though. Any suggestions there? This is a relatively low speed (1980s) machine, so the max RPM is only something like 3500 or 4000.

Yeah, I could certainly make an encoder that way. I'm curious about your comment though. I'm assuming that you are going down the path of a phase quadrature and an index pulse (hence 3 photo electrics), right? That is a lot of holes to drill although a CNC could obviously do it (I could run my machine without a brake). But, I also have a fair amount of space under my brake. My original thought was to make a coupling and put a commercial encoder below the plate that way. This is likely easier than making my own encoder from the disc... but I like the idea.

My biggest concern about using a commercial encoder is that I'm not sure I have very many low resolution ones. I mean a 1000 line encoder will result in 4000 counts. At 4000 RPM, that is 266,666 counts per second which is, well, rather quick! . I'm not sure what is 'typical' for spindle encoders. My guess is something closer to 100 lines

Frankly, the spindle encoder is a longer term project that I'm not worrying about right now. I ran the cable for it and figured I'd get my machine up and running before I do anything else. I don't have a tool changer on my machine and rigid tapping isn't something I regard as a mandatory feature and it is the only thing I can think of, off the top of my head, that will require the direct encoder feedback. So, my first order of business is to get this beast running as a plain old 3 axis CNC.

After I finish that, I need to make my control console. I'm already scratching my head as to what I need there. Clearly start and eStop buttons, possibly a brake enable... But what else? Stuff that isn't used as often can be accessed through mouse input on the screen. I need to start collecting pictures and asking questions about what other people have made and what they did well/poorly.

Once the control console is done, I am thinking about working on a 4th and 5th axis. I've incorporated spaces in my control for amplifiers to that end. And after that, I'll start to think about the spindle encoder.... Or maybe I'll swap those two around. Whatever the case, I don't regard either of these to be pressing issues. I'm more interested in just getting the machine working reliably and then creating a nice control panel.

I'm presently using Axis because I think that is what people said was the most common. I wanted to minimize confusion with people while asking for help during commissioning of the control. However, I think I'll likely go to Touchy at some point and then, eventually, I want to code some highly customized displays that emulate the Deckel Mode construction found on Deckel Dialog 3 machines.

With Touchy, can you also use a mouse and have dropdown menus (meaning... I know you don't *typically* need one, but does that mean you can't have one?)? I haven't played with it at all so far. In addition, are there any limitations (such as no touch probes or tool zool probes).

I bought a VistaCNC P4SE pendant that was delivered yesterday. That will likely be a major player in setup/jogging. I have to say that I am pleasantly impressed with its construction. I was worried that it would be kind of crappy but it actually feels quite the contrary.