THC problems

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Railmen
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THC problems

Post by Railmen »

I have a CandCNC ethercut IV system running Mach3 with sheetcam, on a 5x10 with hypertherm 85, with 50' machine torch

does anyone find that this THC has many problems???

it seams that every time I change from one size of material to another its a crap shoot whether the THC is going to work right or not????

I've been cutting a ton of 12ga steel and had it dialed in pretty good then I noticed yesterday that the torch now wants to pierce then head right to the plate and as soon as it starts to move it heads right back to cut height???????? so today I had to cut some 1/2 steel worked ok for that, tonight went back to cut a 12ga torch knocks its self right off the mag mount WTF???? tried cutting 3 different times, failed all 3 times.........

my old system that I got rid of to built this "better" machine had a simple THC300 for height control, two knobs and 98% of the time you never had to touch the second knob, it was so simple didn't matter what you were cutting with in 1 sec you could set the tip height and never had to mess with it again....................... fucking simple.

sorry for the small rant, if I didn't have so much money tied up in this table I would be out in the shop smashing the shit out of it.

I hope that this is a small fixable problem, cause if this is going to happen all the time, I'm not going to be very happy.....

I will be calling CandCNC tomorrow or the next day after my blood pressure comes some where back to normal....

Is anybody else with this system seem to have the same stuff happening???

Railmen
sphurley
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Re: THC problems

Post by sphurley »

Tell us a little bit more. Do you have the RS485 and Hy-T option for the PM85? In SheetCam are you selecting the right tools?
If the torch is diving it is trying to lower the cutting voltage (height) based on arc voltage feedback. If your delay on turning on DTHC is to low, then the pierce current/voltage will be height for a moment and the torch will dive to try and lower it if the DTHC is coming on to early. With the new 1.9 firmware for the DTHC you can set in Hub Administration app for the DTHC the up and down speeds different from each other to help with torch dive.
I cut two sheets of 3/8" on Thursday, 10ga on Friday and 16ga on Saturday. I did change consumables to fine cut for the 10 and 16ga, but all were cut at book settings on my PM65. The 10ga was 300+ pierces and it never missed a beat.
Steve
Platform CNC Plasma table
CandCNC Ethercut IV DTHC
Hypertherm 85/CPC/RS485
Miller 350P
Miller Dynasty 280DX
Railmen
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Re: THC problems

Post by Railmen »

Just the CPC port, I loaded the same tap file that I cut yesterday, so no changes just tried to recut a same part.

Firmware 1.9

1 second delay on DTHC

I had a problem with the torch taking off before firing, talked to Luc he sent me a fix for 50' torch that did not seem to change anything........ The only thing that I found to fix the problem was to change the pierce time to 1 second, anything less and the torch seems to leave before final pierce, now this is not so much of a problem on the thin stuff as the hypertherm has so much jam that it pierces fine on the fly.

Sheetcam settings are mostly set to hypertherm book and tool sets from CandCNC.

Railmen
BTA Plasma
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Re: THC problems

Post by BTA Plasma »

Proper grounding of the cutting table is a very serious, very real requirement. After hundreds of installs with Hypertherm plasma cutters I can tell you when you get above 85amps the grounding or lack of will have really strange effects on THC. So will the proximity of the plasma power source to the pc, control box, floor..ect.
Railmen
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Re: THC problems

Post by Railmen »

BTA Plasma wrote:Proper grounding of the cutting table is a very serious, very real requirement. After hundreds of installs with Hypertherm plasma cutters I can tell you when you get above 85amps the grounding or lack of will have really strange effects on THC. So will the proximity of the plasma power source to the pc, control box, floor..ect.
The plasma cutter sits up on a shelf about 8' in the air, control box is mounted on the opposite end of the table almost 16' away, the computer in on the other end of the table, 14+ feet from control box, and 10' from plasma cutter.

Plasma cutter is grounded to the underside of the table with second cable for a direct ground to hook to the sheet being cut.

And most of the problems are at low amps 45 and less

Railmen
BTA Plasma
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Re: THC problems

Post by BTA Plasma »

Why is your plasma cutter mounted off the floor? I have seen that be a big problem on installs. Not saying that is your problem BUT I have seen it be an issue. When you THC activates to early and your ramping up to cut speed or still in the pierce spot what can you expect it to do but jam the torch into the steel. This is a function of THC delay. Increase it by a second or two in your tool in sheetcam or even in the Gcode if you know how to edit. Also try restarting the control box and hub. The other thing that can play a factor is security essentials, firewall and windows defender. Any of those especially defender or security essentials can delay or inhibit signals from THC. Before you blow your top and flop around like a fish out of water you need to know that setting up a PC to run ethercut or even the machine to cut consistently is not a simple task. It is super easy to just throw someone your credit card for a kit but you know... You should also check any and all cables going to and from the PWM box. Water, moisture can occasionally cause a false tip volts reading. Some folks run a machine in an unheated garage and expect 100% performance at 20 below zero. The laws of thermal dynamics are a mother
Railmen
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Re: THC problems

Post by Railmen »

If the plasma is mounted on the floor or the roof what does that matter????????

I mounted it up for space reasons and the fact that moisture does not like to run up hill, I have two dryers inline before the plasma.

Now the funny thing is that I went out to the shop and cut the same file today with no problem?????????? WTF??

The computer is running Windows 7 and it came from CandCNC so I'm guessing that they would have made sure that all anti-virus and defender stuff is well turned off, screen saver off.

System turned off every night after use.

Railmen
Railmen
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Re: THC problems

Post by Railmen »

On ya sorry heated shop at 60* all winter long
sphurley
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Re: THC problems

Post by sphurley »

I also think the DTHC might need to go up. I can't remember if the DTHC timer starts on torch fire or Arc OK. But if you have 50' of cable and having to push pierce time out that far then Yes I would increase the DTHC delay time.
During pierce the arc voltage is high (as is torch height) if the DTHC turns on to soon (and you have too fast of speed on the DTHC Down settings) it will drive the torch down to lower the voltage.
Difference between one minute and another? You are likely taking milliseconds between working and not.
Steve
Platform CNC Plasma table
CandCNC Ethercut IV DTHC
Hypertherm 85/CPC/RS485
Miller 350P
Miller Dynasty 280DX
BTA Plasma
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Re: THC problems

Post by BTA Plasma »

All anyone can do here is take a stab at the issue. If it was in front of me here I could tell you in 5mns. But I think you should unplug every wire and connector and plug them back in. If the environmental changes didn't do it, the air pressure wasn't the issue, the power going to the control box is correct then you most likely have a bad connection somewhere. Also the hub should have 4 lights on it, 2 red, 2 green.
tcaudle
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Re: THC problems

Post by tcaudle »

Basic trouble shooting starts with turning the DTHC OFF and watching the feedback (torch volts). If the values are off then so will be the action. You listed 45A...are you using Fine CUt consumables> They need a specific shield and they are MUCH more touchy for settings

The Support Forum will have hundreds of users with the exact same system and with a factory response.

I designed the original THC300 and the DTHCIV is like the difference between a go cart and a Indy racer. LOTS more speed . Lots more settings and the ability to make cuts the THC300 coul dnot even start to. You CAN tune the DTHCIV down tot he point where it responds so slow you can mimic the old THC300 of one of the other parallel port input THC's

There are some logical tests you can do to narrow it down and lower your blond pressure

The dreaded manual (DTHCIV Setup and Config REV 3.1 off the website starting at page 22 covers the important aspects of the DTHC Settings . On page 100 is a test procedure to determine where the problem /

One final thing. The Workclamp from a plasma is NOT ground. Its positive oltage in reerence tot he electrode in the torch. So i you clip it to a structure that is not (separately) grounded it turns it into an antenna instead of killing any noise . You can separate the systems as far as you want but if the noise is being pumped out from the table is how far your controls are from that.
keldanmedia
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Re: THC problems

Post by keldanmedia »

Railmen did you resolve the issue and if so, what was the solution?

Allow me to expand on a couple previous comments...

- DRY AIR > Adequate air pressure was mentioned above - air is key but it must be "dry" air - bone dry. The OP described achieving good cuts then later same day, cut quality went to shit which sounded familiar. Turned out my issue was inadequate inline air drying; the moisture would randomly creep up during the day based on usage and seemingly without notice my cuts would go to shit.

- EARTH GROUND > From Jim Colt at Hypertherm... RFI and EMI grounding and shielding is the grounding system that limits the amount of electrical “noise” emitted by the plasma and motor drive systems. It also limits the amount of “noise” that is received by the CNC and other control and measurement circuits. PDF file courtesy of Hypertherm https://www.hypertherm.com/Xnet/library ... =HYP103900

- HF NOISE/SHIELDING > installing an earth ground greatly reduced HF noise issues (which caused missed steps, torch misfires, etc) combined with properly shielded motor/control cables in addition to a liberal use of clip-on ferrite magnets on peripherals such as mouse, joystick controller and keyboard cables all worked together to prevent HF from interfering with controller functions. **PROXIMITY SWITCHES** HF has a field day with many proximity or limit switches. For the purpose of troubleshooting, disconnect wires to proximity switches and disable in software (if applicable)

- ASSUMPTIONS > while it is perfectly logical to assume the PC provided by CandCNC was configured properly (and I'm confident it was) the reality is one bad website visit or over-enthusiastic Windows Update (like selecting ad hoc all the Recommended updates, for example) may install apps that tap necessary resources when you really only want critical driver updates like video. Run at least once a month; Windows Disk Cleanup and Disk Defragmenter software tools under ALL PROGRAMS > ACCESSORIES > SYSTEM TOOLS -- Ensure your hard drive has plenty of free space 50 Gb or more -- Go to CONTROL PANEL > PERFORMANCE INFORMATION & TOOLS > ADJUST VISUAL EFFECTS > Select Adjust For Best Performance -- Remove CD/DVD from PC to prevent system from re-reading/indexing disc information.

lots of bone dry air, properly configured earth ground and HF shielding along with an optimized PC is mandatory before attempting to setup a high performing THC.
motoguy
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Re: THC problems

Post by motoguy »

Thanks for the info. After initially being told it isnct necessary, I'll be installing a ground rod for my table this weekend. It may NOT be necessary...but for the little time/expense involved, it seems worth it...particularly if it saves me from a couple hours of cursing, trying to find the source of an "issue"! I hadn't considered the ferrites, but I'll order/install some of those, too!
Bulltear 6x12 w/ Proton Z axis & watertable
CommandCNC/Linux w/ Ohmic & HyT options
Hypertherm Powermax 85 w/ machine torch
Solidworks, Coreldraw X7, Inkscape, Sheetcam
keldanmedia
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Re: THC problems

Post by keldanmedia »

the earth ground is particularly important for the DTHCIV. I imagine there is a bunch of extra length with that 50 foot plasma cable - keep that away from motor/controller cables. Keep high voltage (AC 110/220) isolated from data, motor and controller cables - don't run power and data in parallel helps further mitigate HF. Reach out to Jim Colt at Hypertherm.
tcaudle
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Re: THC problems

Post by tcaudle »

If the "fix" Luke sent you for the 50 ft cables did nothing then t was not installed right. It has a custom M3.m1s macro that FORCES the motion to hold until the ARC OK on the MACH screen turns on. The longer hose causes the trigger (normally when the torch is turned on) to release too soon.

There should have been a document with the file you were sent that explains how it MUST be installed. If you put the macro in the wrong MACH profile it does nothing
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