Messages

1

General Mach Discussion / Re: Mach3 stability issues concerning G31 floating head on my plasma cutter.

« on: October 31, 2018, 10:37:19 PM »

Craig,

I have learned my lesson with the china Crap. It has given me way to much grief. Between this NVEM controller and a torch height controller I wasted a lot of money that I thought I was saving. I did not think of the 57CNC. I will investigate that tonight.  I ended up using a Proma SD THC that works well on its own but not perfect. I was looking at a small atom type computer for a small package. That should work great for Plasma. (maybe on My second Build.) My mill is a full servo unit running Centroid controls and it works well with no issues. Thank you for sharing.

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General Mach Discussion / Re: Mach3 stability issues concerning G31 floating head on my plasma cutter.

« on: October 30, 2018, 09:06:06 PM »

Craig, I see you on this forum a lot but I do not know what you run. I have read thousands of posts and get a lot of mixed information. Some people can sound so confident in their answers and are dead wrong. This is in no way an accusation. I am just simply stating some of my frustration with some of thees forums. I have learned through this build that there are many different components out there and you have to be very careful with compatibility. It would be great if someone would compile a list of cnc controls that all played together nicely. I may do this when all said and done. The mechanical side was a breeze. The THC side was a nightmare.  oh I have not given up on that china crap yet. I have it now where I can E stop it raise the Z and start the cut again. I may add a switch the floating head to automatically do this if it goes past the probe switch. It does not happen that often now.   In your opinion what is the best hobby controller? I have been looking at the uc400eth and the smooth stepper. I like the smooth stepper option because I can wire the BOB in ahead of time and test and then slide the Smooth stepper in the middle. Would you mind sharing what you run on your machine?

3

General Mach Discussion / Re: Mach3 stability issues concerning G31 floating head on my plasma cutter.

« on: October 29, 2018, 11:04:53 PM »

So, If I go to a straight Parallel port with a standard BOB I will see probing improvement? I really do not need accuracy. My THC will take care of .010". It is frustrating because I will have to destroy my nice neat wiring job to change to the BOB. That is perhaps why I have drug my feet for so long. I will rewire this thing some day and report back. Thanks for your reply.

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General Mach Discussion / Re: Mach3 stability issues concerning G31 floating head on my plasma cutter.

« on: October 28, 2018, 09:15:15 PM »

Hello Craig,

Thank you for your reply, I have been suspect of this controller. However, the controller has only so much control. No Pun intended. If Mach receives the probe signal then Mach should stop and set to zero etc etc... Or am I oversimplifying the process. I could definitely see it being the controller if the position is inconsistent. Mach is receiving the signal and keeps driving past the probe input. I have switched to Mach 3.042.40 and there is some degree of stability. One more question, I observe the G92 offsets in the diagnostic screen and there are all over the place. Where does the G92 offset number come from? My code reads G92 Z0.0 but I never see it go to zero on the diagnostics screen. If I can not figure this out I will be migrating to the smooth stepper.

5

General Mach Discussion / Mach3 stability issues concerning G31 floating head on my plasma cutter.

« on: October 27, 2018, 11:02:50 PM »

Hello everyone: I have been working on the stability of Mach 3 for awhile. I started out with windows 7 and a laptop without good results. I had problems with inconsistent Z moves. mach wanted to reset zero all over the place one time and then cut fine the next. This was very frustrating. I now have a dual core 3.2 GHZ dell with 4 GB of ram. Standard on board video running on XP Pro. I am also running a Novuson NVEM Ethernet controller. (Mach version 3.043) I ran the first part with multiple profiles (letters) and it ran the first 3 letters fine and failed to stop on the G31 command (top of plate routine) on the 4th letter. This was odd. I went to the diagnostic screen and the probe light was on. I just rewound the program and hit start and it ran with out a hitch 5 times. The 6th time I over-road the feed bumped it to 70 inches a minute and it ran past the probe switch on the 8th letter. Again I just rewound the program, restarted and it ran flawlessly several times. I then bumped the feed down again and it ran past the probe switch again. After rewinding and restarting again it was ok. I have gone in and changed the start up to open nothing upon windows startup and erased several non essential programs. What am I missing? I can include some G code but this must run deeper than the code. should I create a macro with wait states in it to keep the computer in check? Can anyone help me here I am stumped. and very frustrated not being able to run a part reliably.  Is Mach 3 simply an unreliable program!!!!! 

Dave

6

Mach3 under Vista / problem with plasma cutter touch off control.

« on: September 25, 2018, 11:47:59 PM »

Hello all I am narrowing in on my home built cnc. However I am about to cry. I can not for the life of me get the touch off/ floating head to work properly.

I have a floating head with a limit switch attached to the probe input. I am using G31 and G92 in my touch off sequence. I have shamelessly stole the programming from this site. The machine will run down and touch off of the plate and set the dro to zero some times and some times not? usually it goes to -1.0 and then it will go to the next cut, and touch off. each cut it wants to raise another inch until it is out of stroke. I also have gone from version .066 to .062 with no help. What is odd is that it will sometimes runs some of the cuts right but never all. It is not consistent, the next time it will act up in a different spot in the program.

If you have seen this before or have a suggestion please help a brother out.

Thanks!

Frustrated Dave!

7

General Mach Discussion / Re: Stepper calculations

« on: June 13, 2018, 09:35:04 PM »

{most} Stepper motors take 200 full steps/rev. if you have a pulley or gear with a pitch diameter of 1" you will get 1" of travel per 200 steps. and so on. speed is relative to your machine, size of stepper etc. etc. so there is not a newby answer for this one. Yes everything can be calculated. If you are embarking on a cnc build I would suggest copying some ones design that has a proven machine. buying the wrong parts and then buying the right parts cost a lot of money and time.

Weldsmith

8

General Mach Discussion / Re: Torch Height control Methodology.

« on: June 12, 2018, 09:35:25 AM »

Thanks Dave that is good information to hear. Even though I have a stepper motor on My Z axis I just purchased a floating head with a z lifter. hopefully this will be quick enough.

 I am curious if the new Proma SD will work faster. This unit does not talk to mach it is completely stand alone.

9

General Mach Discussion / Re: Torch Height control Methodology.

« on: June 11, 2018, 10:30:29 PM »

Thanks for the replies. Dave is right there is a function in Mach3 that turns off the THC when the feed rate falls below your preset value. My THC has a corner function input (anti dive). Mach does have an option to turn on (input 5) if the THC is on. does the anti dive function of mach3 turn this on and off during a corner or does it simply ignore signals to raise and lower the z axis in the corners. if I could get the input to my THC during during ramp downs below 90% I would be golden. now the sluggishness might be a problem. I still can use the arc OK and the stand alone THC but it makes me nervous that when the torch slows down it will dive into the plate.

The problem is that there is many different ways to implement Torch Height Control. and ,you must be careful on your choices. I bought a Proma 150 that would not work with my cheap Chinese Ethernet controller. The Proma 150 works with a standard parallel port BOB. I got the inputs for up and down to work but there is no way for mach to control the Z axis on the fly with the HVEM controller. Proma does make a controller that has the step and directions signals from the mach controller go through the the Proma. If the torch needs to go up or down the Proma will drive the stepper up or down. I had not realized this at the time of purchase. Now I have two THC controller that will not completely work with my setup. I am running on at the mouth because I believe this is a good discussion to have to help others from making the same mistakes that I have made.

If any one has more knowledge on this input 5 that Mach talks about or a way to externally control the THC auto, I would like to hear about it. and if you have any other advice on any THC, spit it out. I think a lot of people are struggling with THCs.

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General Mach Discussion / Torch Height control Methodology.

« on: June 09, 2018, 07:41:06 PM »

I am working on a home built cnc and I am working on a Chinese purchased THC with purchased 24V Z lifter/floating head.

Here is what I see in Mach3

AntiDive settings (what output would mach use to communicate this to the THC) Output 5 that is turned on in the Mill options page? Does this go on and off with antidive?

THC up  I think these Two are straight forward and I will not use these because I am using a torch lifter.
THC Down

arc ok   This is also self explanatory. the machine will not move until an arc ok signal is received.

I need some help specifically with an antidive signal. can I write code to produce this output?

This has been brought up many times (THC items) and not a lot has been said. I hope people can expand on the Mach 3 THC controls because it is poorly documented.

Thanks in advance.