Jogging From The Keyboard

[alan]

Does anyone else experience the lead screws seizing up when jogging with the keyboard? Mine does - in both the axes. Basically, that means I can't jog using the keyboard. If I issue a jog command (JX, JY, J2), it jogs just fine.

[Joe Porter]

Alan, am not at my machine and can't check for sure, but are you talking about the yellow keypad window that opens up when you hit the "K" key? If so, is the "Fixed Move" tab activated and set to a small number? If so, just unlock this and you can move with the keypad. Hope this helps...joe

[alan]

Hi Joe! Thanks for the input. I'm happy to know about the Fixed Move (thanks to you) and what it does. But alas, that's not the problem. When I use the yellow keypad (K) and try to jog, if the jog speed is 3 ips or higher, it has problems. At 3, it will start to rattle. As I increase to around 3.5 ips, it will rattle REALLY hard and seize up. Any jog speed higher than that and it will seize up almost immediately. I just got my Desktop a couple of days ago and if everyone else's doesn't have this behavior, I'm going to be worried. I already asked tech support and they are not sure (yet). I will take a video of the problem so that tech support can see it. But it's just as I described. It's the weirdest thing because if I give it the command to jog, say JX 15 (from X=0), it will jog smoothly with no problem at all at 6 ips. But with the yellow keypad popup window, it will begin to fail jogging at about 3 ips!

[jdervin]

Definitely not my area of expertise, but a thought that occurs to me regarding the differing results might have something to do with how the commands are being sent. As I understand it, a Jog command is a single command, sent once and the machine jogs to that point. From the yellow window, pressing and holding the arrow keys is sending a command that repeats over and over until you stop holding the key. Perhaps at the higher speeds, the 'Bot and/or the computer aren't keeping up with one another?

[alan]

Thanks John. That makes sense and it could be the problem. But then it would mean that it doesn't work the way it's supposed to work. Sigh...

[alan]

John, you are a genius! I was mulling over what you said. I focused on the fact that a command will tell the machine to jog in one step. Knowing a little about computers I also know that you are correct that such is not the case with keyboard control. In that case, the software must check the state of the key being pressed - is it down or is it up... It must do this extremely rapidly without buffering so that the motor will stop immediately when the key is released. If it buffered, the motor would stop with latency. "Hey," I thought, "Even though I meet the minimum hardware requirements, what if my laptop just isn't powerful enough? Maybe it can't check the keypress state fast enough (or something similar)."

So I hooked the SB up to my gaming computer and BINGO! Smooth as silk at any jog speed from the keyboard.

Thanks John, I wouldn't have solved it without you.

[jdervin]

Glad I could help. I still think it's a bit of a mystery though. Several people here have indicated that they're running their 'Bot with a laptop. I've even used my laptop as a backup when the tower was having problems, so it seems likely that it's not simply a laptop problem.

Hopefully others with way more computer knowledge than I can offer insight.

[myxpykalix]

Don't get cocky John, you know what they say..."even a blind squirrel can find a nut once in a while"....lol
Actually that was a good answer that I wouldn't have guessed (maybe)lol

[chiloquinruss]

On my bot I have a keyboard on the pc that works fine using the K keypad and another keyboard plugged into the usb hub that I use as a remote puck. Using the usb keyboard will SOMETIMES give results like those discussed, so I think it is a timing issue as the wonderful world of Gates is not kind to things tied to timing! Glad you got it working like you want. My frustrations have always been related to NOT knowing what was causing an issue and in most cases it has come back to something I was doing! Russ