PLEASE. quality bad

[b.ackerman@live.ca]

hi i have a precision cutting systems table with a auto hieght control hypertherm 1250.
first problem.... the torch will not touch the plate to peirce like 1/2 inch away then go down to finish the cut or..... it will go back up and not cut at all.
Second problem..... the x axis will not cut a straight line the y axis is perfect. i put a square up to the y axis cut it follows the square... the x axis cut if i put a square along the edge of the cut it is wavy and just not straight what so ever.
i had a previous problem of not being able to cut square and followed all the advice and it seemed to help. but now these problems i just cant figure it out i spent to too much cutting and waisting metal.
hope you guys could help me out, i appreciate it
thanks
Brennen

[Gamelord]

First problem - it looks like you have an issue with your THC. If this is not setup properly, you will always have issues with cutting. What I would do is first turn the THC off and see if you can get it to pierce manually and if it will cut ok, if so then you know it is an issue with the THC. These things are super sensitive to the exact settings - both on the THC and in your software (if it has influence over the THC).

Second issue. It sounds like you have slippage in your X-Axis drive system. Two things will cause crooked cutting. 1) your gantry is loose and has some slop in it. This will cause a wiggle cut whenever your torch changed direction. The edge will have a very wavy cut and then it will seem to smooth out (depending on just how bad your gantry wiggles). 2) You have a bad motor, dirty motor/dust infestation or loose drive gear/belt/chain depending on what your system uses. Even if you look at everything and it looks ok, double check every set screw/bolt/gear/bearing for slippage. Most of these types of issues are caused by the shaft slipping inside the gear.

A little more info on the table you are using may help shed some light on some other possible things to check.

Hope this helps.

**another thing that just came to mind is slat movement. If you have a larger table with single straight slats running across the table, sometimes when your gantry changes direction the slats will have movement in them. I call this the "Slat Wave" where your entire table with the plate moves back and forth. If your slats are mounted solid where they can not move at all then this is a non-issue.

[b.ackerman@live.ca]

here is a picture

[elvenhome21]

can it cut an arc smoothly in both x and y axis planes?

[Largemouthlou]

Like said, go back to the beginning, ck all mechanics, you need to square the X with the Y and be sure that the table is sound.
Once you have the x and y square mark the side rails so you can always bring it back to these lines to ck..
You need to be sure the y and Slave have the same correct steps and settings in the motor tuning.

Need to be sure the Z is moving the correct amount as well. If you tell it to go up 1" dose it goe exactly 1" ?

All this will help with the THC.

As a 2 yr old newb in this I'm still learning a lot, so take your time and read and start at square one..

There are ways to check the x and y for square using a measuring tape, if you measure from the same point 3 foot down the X make a mark and 4' down the Y make a mark, then measure between the to points and it should be 5'..

Or get a drywall T Square and it will get you close..

Keep asking questions and read as much as ya can..

[jimcolt]

There is some sort of mechanical issue that is causing the axis to wander.....the plasma cannot make a wavy line like that unless it is being moved that way!

I would put a pen in the torchholder and do some tracings on paper to see where the problem lies.....likely there is a lot of backlash or binding in your machine....or seriously is out of square.


Jim Colt

here is a picture

[b.ackerman@live.ca]

i have tryed a pen it looked straight, and have checked motor tuning and squareness it all seems good

[jimcolt]

Could the material or tabl slats be moving? I've never seen a plasma arc that can move by itself....as much as your picture is showing.

Jim

i have tryed a pen it looked straight, and have checked motor tuning and squareness it all seems good

[b.ackerman@live.ca]

i tryed clamping the piece of metal down to the table it almost made it worse, i know my slats are not in the greatest shape, but i just cant believe these terrible cuts im getting, maybe try putting extra metal on the table?

[b.ackerman@live.ca]

i tryed your idea of paper and pen here is a pic...... my main problem is that the torch does not go down to the metal

[jimcolt]

Sorry...I went back and reread your original post...if the torch height is varying that will explain the wavy cuts. The pierce height and cut height must be accurately maintained or the cut kerf width will vary rather dramatically. The torch should be at .06" (1/16") off the plate for steady state cutting. You need to troubleshoot your height control system.


Jim Colt

i tryed clamping the piece of metal down to the table it almost made it worse, i know my slats are not in the greatest shape, but i just cant believe these terrible cuts im getting, maybe try putting extra metal on the table?

[b.ackerman@live.ca]

bought it.... its a hypertherm phc

[b.ackerman@live.ca]

Havent called them yet, im going to try on friday hopefully they can help.

[jimcolt]

Now that I know you have a Hypertherm Sensor PHC....I'll be happy to help you troubleshoot it! And, it is not an expensive THC.....expensive THC's sell for $10k to $15k and are used on high duty cycle industrial machines....the Sensor PHC is a complete standalone THC (plug and play with high quality industrial torch lifter, ohmic contact technology, the ability to operate with high frequency start plasma, etc.) for about $5k.

If you can give me some details about how the Sensor is wired up to your cnc control (what cnc? what software), and describe in detail what it is doing/not doing.

The way the Sensor PHC works:

-Part program moves retracted torch into the program start position....cnc sends a start signal to Sensor
-Sensor moves toward plate, contacts plate and senses the surface (uses ohmic contact or torque sensing depending on the choice of the machine operator)
-Torch retracts to pierce height (set by machine operator)
-Sensor sends start signal to plasma, plasma fires. Pierce delay timer (set by machine operator) starts counting.
-Once pierce delay timer times out (pierce complete) sensor moves down to a physical cut height (set by machine operator), x and y motion should then start.
- Once the cut has started and machine is up to speed...the cnc sends a AVC (arc voltage control) on signal to the Sensor....the sensor monitors arc voltage (from the plasma) and compares it to a preset voltage (set by machine operator)...and adjust the torch to work distance by raising or lowering the z axis drive.
-During corner slowdown...the cnc control sends a corner signal to the Sensor...which freezes height to prevent diving.
-At the end of cut the Sensor retracts the torch.

There are a lot of thins that can cause issues with a full featured standalone height control....if it does not have all of the functions interfaced correctly....if the cnc is not set up to interface functions, if he operator has not set parametrs correctly, etc. I need to know the cnc it is interfaced to.....and all details and I can help out.


Jim Colt Hypertherm

Havent called them yet, im going to try on friday hopefully they can help.

[b.ackerman@live.ca]

i run mach 3 with lazy cam, use a corel draw and or via cad programs, bought it from precision cutting systems.
so i am not eaxctly sure how its hooked up and controlled but ill post some pics... the torch pics, are the problems...
the regular start hieght, the torch is at the stop switch then i hit cycle start on mach 3 to start a cut. the torch then moves down about one inch, retracts up a bit ( like to the pierce hieght) all without contacting the metal and then begins to fire the torch and run the cut from there....sometimes the torch goes all the way down to the plate and others it goes up to the stop switch and stops cutting. (but where it usually goes down to the metal to make contact with the plate and the red light on the phc comes on it is not doing that anymore) hope that helps you.
thanks for your time
Brennen

[b.ackerman@live.ca]

not sure how to post 2 pictures at once sry

[b.ackerman@live.ca]

another one the control box?

[jimcolt]

You posted in an earlier post that the THC (torch height control) was a Hypertherm PHC.....the height control used in your pictures is not a Hypertherm.....If you expect help to make your system work better you will have to supply us with information about the equipment that you have.

Jim Colt

bought it.... its a hypertherm phc

[b.ackerman@live.ca]

sry .... here is a pic of the hypertherm phc...(well that is what is says on the box) so the torch holder is a ?
sorry im new to this. Im starting to go crossed eyed with all the reading im doing, trying to find info on this.

[b.ackerman@live.ca]

ok so i have been reading the phc manual over and over and i may have found something...it says for no IHS motion
Check that the stall force is not set too low ? increase stall
force setup adjustment.
but it doesnt really say how to do this? could this be my problem? it has to be something simple because it was working fine last week then now it doesnt work and still doesnt.

[jimcolt]

Your machine builder must be using the Sensor control box with their own torch lifter assembly. That is why I could not recognize the Hypertherm height control....now that you have the picture of the PHC control box...it is a Hypertherm.

I agree that the problem is likely the stall force sensor circuit is either sensing a bind in downward motion of the z axis lifter.....so it thinks it may have sensed the plate surface and fires the torch at that point. I suggest checking the motion of the z axis slide assembly before anything else to determine if it may be sticking or binding. Once you have determined the slide is moving freely....then you should follow the procedure in the operators manual to calibrate the stall force system.

9 times out of 10....when the torch starts firing above the plate it means there is something binding in the z axis....check that first before recalibrating.....otherwise you will simply be covering up the reall problem by increasing the z axis motor force.....which will cause the torch to use way too much force when sensing the surface of the plate.

If you are 100% sure the z axis is free and not binding...here is the procedure for calibrating...I copied this from the operators manual for a Sensor PHC:

Remove the cover on the bottom of the front panel of the sensor PHC ....you will find the following board with 3 calibration pots as well as a series of DIP switches:

Set the dip switch (number 16) to "on" as it instructs in the arc voltage calibration procedure ...this is from your manual. Do not adjust the arc voltage pot....however when you adjust the bottom pot (stall force) the digital display will indicate that setting on a scale of 1 to 10 .

Now...follow this procedure (from the manual as well) to calibrate the stall force:

ok so i have been reading the phc manual over and over and i may have found something...it says for no IHS motion
Check that the stall force is not set too low ? increase stall
force setup adjustment.
but it doesnt really say how to do this? could this be my problem? it has to be something simple because it was working fine last week then now it doesnt work and still doesnt.

[b.ackerman@live.ca]

ok well it seems easy enough to try, the z axis is free so ill try calibrating it this week, ill let you know
thanks
Brennen

[jimcolt]

My concern....the calibration cannot change by itself, so if it was working before and not working now....something has changed in the amount of force (current) that the z axis motor needs to produce to overcome friction. To much force will cause torch height control to think it has sensed the plate. It could be dirt on the ways or rails in the z axis slide, tight bearings on the z axis motor, torch leads or harnessing that is catching while the torch is driving down.

I would remove the motor from the z axis slide and manually slide it up and down to determine if there was something creating resistance.

Jim Colt

ok well it seems easy enough to try, the z axis is free so ill try calibrating it this week, ill let you know
thanks
Brennen

[b.ackerman@live.ca]

found my problem, thanks for all the help, the motor is shot...