Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: DMBGO on April 14, 2015, 09:20:11 PM
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KVR 3500 mill and Servos
Hi it's been a while since my last question, but here goes.
I have a Kingrich KVR3500 mill that I purchased new from Standaco about 4 years ago. I bought it with ball screws etc, setup for the Prototrak CNC system.
About 4 years ago I had discussions with Hood on this forum about the type of Mill to buy, and the control system.
Hood recommended a bed mill, but at the last minute I went ahead and ordered the KVR3500.
I took delivery and the very next day I had a car accident, suffering multiple injuries including a head injury that led to memory loss.
What I know now is limited to re-reading old posts, and looking at correspondence with the suppliers of various things, such as servo motors and drives etc.
Over the last few years I got the mill working using a GSK980mda CNC controller, GSK servos and drives etc. I had ordered all of these before the accident, but now that the CNC controller has developed a fault, I have decided to convert it to a software based CNC package, rather than deal with GSK's almost nonexistant support.
I have some experience using Mach3 and have a lathe that works well using an ESS and stepper motors.
I have also posted on the Linux-CNC forum asking for advice, but I think in hindsight that I'd be better off sticking with what I know best, which is Mach3.
The servo drivers on the mill are GSK DA98Bs and they accept Plus + - and Sign + - inputs. Plus is also variously called by GSK Puls and Pulse, so I think that Pulse is what they mean. Sign is probably direction?
Anyway I have a lot of trouble deciphering their chinglish manual.
I think what I need to do is convert the single ended step and direction signals from Mach, to the aforesaid plus and sign, as well as provide other signals, but I have been unsuccessful so far.
I have created a spreadsheet with my initial connections but needless to say it doesn't work. I have attached a copy of this spreadsheet to this pos.
I have also contacted GSK support, and what follows is their illuminating reply (not).
"The DA98B driver must be need the pulse and direction siganls And the driver don't have the a step and direction mode. The DA98A is using the pulse and direction.
So it is not match with the mach3 controller."
I have the manuals for the servo driver and the old cnc controller which I can attach if needed.
Lastly I would like to say thanks in advance for any help you can give me here, the mill has been a white elephant as I'm just not as capable as I was before the accident, and for the last few years I have spent far more time trying to get it to work than I ever have using it.
Cheers
Dave
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Whoops forgot to attach the spreadsheet. Here it is....
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I guess I just need to know if what I am trying is possible, or whether I should look at another solution?
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If you could attach the manual that would be good, it may be they only accept CW/CCW signal, that however would be unusual.
Are you just trying with the parallel port or do you have an external controller?
The i/o signals from/to the drives will almost certainly be 24v, so if you use the parallel port then you will need to convert to/from 5v.
If using an external controller such as the CSMIO/IP-S or M then they accept 24v.
Hood
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Hi Hood, thanks for the reply.
I am using an ESS. so the I/O will be 5v. Here is the manual for the servo controller.
I believe there is a way to use a second spindle on the GSK MD980B CNC controller, so I will investigate that as well in the interim.
I would really like to make this work with MACH, you will see what I mean when you read the manual :)
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Ok your drive can accept Step/Direction, it calls it Pulse Direction but it is the same thing.
It can be connected single ended but the preferred option is differential.
Step/Dir is 5v.
The Drives I/O is 12v to 24v so if using the ESS you will need to convert the drives outputs to 5v to input to the ESS and convert the ESS outputs to 24v for the servo drive.
The CSMIO range of controllers (CSMIO/IP-M and IP-S) can accept 24v I/O and have differential step/dir signals it may be a better option for you rather than the ESS.
Your drive can also be set up as analogue command (+/- 10v) but to use that you would need an external controller capable of using analogue command. If you want to go down that route then there are a few that are capable, the one I use is the CSMIO/IP-A. The benefit of using the IP-A is that the controller keeps track of the encoders and updates Mach3 with that position info, so Mach always knows where it is, even after an E-Stop or even with servo drives disabled (logic side of drive still powered) That means even manually moving an axis Mach will know where it is.
Hood
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Hi Hood thanks for looking at the manual. I was thinking of using something like this to boot the output from the ESS from 5v to 24v
http://www.linear.com/solutions/4798
and a 7805 voltage regulator to switch the output from the Servo controller down to 5v for the ESS.
My question now is: Do you think this solution will switch fast enough, so that I don't have problems down the track with signal delays?
Thanks again
Dave
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Oh and you did suggest the CSMIO range of controllers which seem like a good "out of the box" solution. I however already have 3 x Ess, 2 of which are not currently in use, so being a bit of a cheapskate I am keen to use what I already have. If you think my solution will lead to issues, I am happy to just go ahead and buy The CSMIO.
Differential output sounds good too, but I do have some differential converters already, so I was going to use a few of those as well.
Dave
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I am not an expert on electronics so can't really say whether that circuit will work or not.
The ESS works well enough but it is just a bit of a pain to integrate as you need to convert voltages, use line drivers, get spindle control board if needing analogue spindle control, get breakout boards, if you want analogue inputs for feed override and spindle overrides then you have to do something there. The CSMIO/IP-S does all of that so it saves a lot of time/effort and probably works out as cheap.
As you already have the ESS then you may be as well just using it.
Hood
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Oh meant to say, my preference out of the CSMIO's would actually be a CSMIO/IP-A as it has the added benefit of updating Mach as to position.
Hood
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Thanks Hood. I have paced an order for the CSMIO/IP-A as per your recommendation. Although I have a small amount of electronics know how, I think this would be easier. Quite expensive though - about $1000.00 au
Don't tell the wife :).
Thanks again for your help, I'll let you know how it goes when it arrives.
Dave
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Oh no, now I will get blamed if you don't like it :D I am sure you will however :)
$1,000 seems expensive but when you then look at what you don't have to buy when using another controller, then it gets less so. For example no need for multiple breakout boards, no need for line drivers, no need for spindle controller, no need for means of getting analogue inputs, no need for converting from 5v to 24v and vice versa etc etc.
I realise it is a lot of cash but if I had known you were contemplating going down that route I would also have said to consider getting the MPG module as well, it allows you to get really nice MPG control more akin to Industrial machines style and you can fit it in your panel and connect physical switches for other controls, also you can use the analogue inputs on it for FRO and Spindle Overrides. The main controller also has analogue inputs so you could still use them, just you will have to run cables to it from your front panel.
Also an Enc module is a nice thing to have if you want rigid tapping, even with a VFD spindle it is still possible, all that is needed is the Enc module and an encoder fitted to the spindle 1:1.
Maybe I should learn to keep my mouth shut, luckily though Oz is a fair bit away for me not to feel the ire of your good lady so I am probably safe and hopefully you are too :D
Hood
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Every thing is here now, I decided to spend the extra and get an MPG module and controller and a 24v power supply as well.
After all I spent a lot of money buying the mill in the first p[lace, so I might as well do it properly.
As soon as I finish my CNC router, which is nearly there, I will start the process.
I think I will aim to do it once and properly, so any recommendations as to how to lay out the control panel, and what to allow for would be most welcome.
Even suggestions as to what type of enclosure to to make would be good. I was thinking that since the mill already has an arm with various switches etc on it that this would be a good place to attach the entire shooting match.
I currently have the GSK 980mda on there.
I can post a photo of the mill as it is if you'd like.
Cheers
Dave
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Not sure if you bought the hand held pendant as well, personally I do not like them but that is just me :)
What I would do regarding the control panel is what I did with the Chiron. I had the MPG module along with an extra I/O module, 24v PSU, the computer and the computer power supply all contained in the control panel. That meant the only cables that went to the main panel were power, network and the Canbus from MPG/ExtraI/O top the IP-A which is housed in the main panel.
Couple of pics below
As for an enclosure, I would say one of the best I have seen for a knee mill is the one my friend made, see here.
http://www.machsupport.com/forum/index.php/topic,29886.0.html
Hood
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Thanks for that Hood, You have given me a lot to ponder.
I will shortly attach some photos of my mill, as it is now and after the conversion.
Cheers
Dave