Torch not diving but getting super low

[Buffetkiller]

So ive been having an issue with my "THC" i believe. I start a file and it touches down then pierces, then it goes down to cutting height but in the first 2" of cut will get waaaayy to close to the material. Often times it ends up colliding with the plate.

Now it i turn my THC off it wont do this so i have been cutting without it. I have read up on THC and how it works, so i have played with the timing and voltage and no matter what it will do the same as explained....

Ofcoarse this is a shop sabre sidekick 10 and it is running with WINCNC. I have attached a pic(hope it works) of my settings. Any input would be appreciated!
(Bare with me im not good at composing a easy to read paragraph)

99FB1B76-2FCF-4E09-B63E-9962270E4699.jpeg

[weldguy]

Sounds like your THC is doing what is supposed to do to me but your target arc voltage is too low. In a nutshell your height is related to your voltage, if you want your torch to be higher when cutting you will want to increase your arc voltage. I see in the image your target voltage is set to 137v, try increasing it to 147v and you should see your torch is riding higher off the plate. Just do some 12"long straight line cuts to get used to this and get it dialed in. Remember whenever you change amperage, material thickness, cut speed, etc you will have to make adjustments to your target arc voltage to maintain the proper cut height. Auto torch height control still requires some input and THEN it will automatically maintain the proper height.

[Buffetkiller]

Thankyou. I have read about the correlation between target volts and height and this i think was bumped up from cut charts. But up ten more?! Ill have to give that a try!

[weldguy]

Yes, 10 more volts is not a big deal. Dont get hung up on voltage numbers, ultimately it doesnt matter what the volt number is so long as your at the correct cutting height. The volt number you see in the cut charts is merely a number to get you started and close but almost always have to deviate.

[djreiswig]

No sure on cutter brand you are using, but the cut charts for Hypertherms are derived from a lot of testing at the factory. I have good results with the cut charts. Different brands may be different.
But as weldguy says, the number isn't critical, the arc gap is what you're after. Set the volts to what it takes to get the correct gap for each material on your table at whatever speed gives you the best results. Then make your own chart.

[Buffetkiller]

No sure on cutter brand you are using, but the cut charts for Hypertherms are derived from a lot of testing at the factory. I have good results with the cut charts. Different brands may be different.
But as weldguy says, the number isn't critical, the arc gap is what you're after. Set the volts to what it takes to get the correct gap for each material on your table at whatever speed gives you the best results. Then make your own chart.

Ok i guess by reading your two posts i realized i have left out a vital piece of info... with the target volts where they are IT WILL come back up and cut very nicley. Its just in that first two inches that it will take a dive. But it will always come back up and level out.

I was at first thinking this was the THC active delay so i tried matching that up with the pierce delay and this didnt work.

I am using hypertherm powermax 85

Sorry for the lack of info. Basically just in that first 1"-2" im having issues. It will get low enough to catch the pierce slag. This is especially irritating with small holes like 3/8-1/2"

[impsux]

Your THC active delay looks really low, try at least 3-5 seconds.

[weldguy]

OK in that case it is likely that your system is piercing and once the "pierce delay" time has elapsed the torch begins to move and drops down to your "cutting height" which is set to .070" and cuts at that height until your "THC active delay" time elapses at which point the THC becomes active and the torch begins rising to meet your THC "target volts.

Not sure what plasma cutter your using but if its Hypertherm your cut height typically should be .060" Find the target voltage that achieves that and stick with it for this project.

Next I would get your "cutting height" accurate. Currently its set for .070 so if you are able to pause the machine before the THC becomes active (or just turn THC off) you can use feeler gauges to measure the "cutting height" and see if it is at .070 like you have it set for. If not I suspect your "touch distance" which is set to 5.00" is incorrect and if you play with that value it will affect the actual cutting height and you will be able to get it to the .070" cutting height you have it set for.

[Buffetkiller]

OK in that case it is likely that your system is piercing and once the "pierce delay" time has elapsed the torch begins to move and drops down to your "cutting height" which is set to .070" and cuts at that height until your "THC active delay" time elapses at which point the THC becomes active and the torch begins rising to meet your THC "target volts.

Not sure what plasma cutter your using but if its Hypertherm your cut height typically should be .060" Find the target voltage that achieves that and stick with it for this project.

Next I would get your "cutting height" accurate. Currently its set for .070 so if you are able to pause the machine before the THC becomes active (or just turn THC off) you can use feeler gauges to measure the "cutting height" and see if it is at .070 like you have it set for. If not I suspect your "touch distance" which is set to 5.00" is incorrect and if you play with that value it will affect the actual cutting height and you will be able to get it to the .070" cutting height you have it set for.

The .07 was to try to keep the torch up. Thats the only way i found how to make it not do this.

Where does "touch distance" come into play in all of this? That was preset and ive never touched due to not knowing.

IMPSUX- I will adjust that back into spec. That day i was just playing with it to see what would be different.

Thanks for all input guys! This combined with some other stuff on this site is going to help a bunch. Cant wait to do some test cuts tommorow!

[impsux]

WinManual 3.0r3
Touch Distance: Specifies the minimum distance (in units of measure) that the torch must move from the last material touch location
before another material touch is executed.

[weldguy]

I was unsure what the Touch Distance was but impsux appears to have the info on that which is great, I would have never guessed that. With that being known it sounds adjusting the cutting height value like you have done is the only way to go. Just like the THC voltage, who cares what the number is as long as the physical distance is correct.

[Buffetkiller]

Sorry its been a while and im just now getting back. Thanks for explaining touch distance.

So i am still kindof having the same issue. I turned my thc on with a .06 cut height. Pierces, goes to cut height(but way too low) drags the torch... then my part is bad.

So i cranked the target volts up +10 from the suggested value. Torch still drags in the first 1.5 seconds of cutting then goes way too far up and blows back because now its cutting too high.

I posted a pic with current settings. THC was on for the first couple parts but this problem happened once so i turned it off.

I will say IF the torch doesnt drag and screw up, the part will come off the table with very little dross and kerf angle. It cuts great parts, my problem is just in that first inch of cutting. And like i think i mentioned i have played with the THC active delay and not much changed...

[Buffetkiller]

Sorry but my picture wont upload....

[weldguy]

OK, it sounds like it may be as simple as changing your "Cutting Height" to a larger value. Yes, .060" is the proper cutting height but you enter that and it drags so you need to fudge it and find the number that gets you to a .060" cutting height.

You can likely do this with the plasma and THC off. Just draw a simple straight line and run that pausing midway to measure the torch to work distance with feeler gauges. Change your cutting height value and run it again and find the value that a achieves a .060" cut height.

Once you have that sorted out do the same thing but actually cut the line. If a ll goes well turn the THC on and cut more straight lines and adjust your THC target volts and find the value that gets you a .060" cut height when THC Is active.

Your picture must be no larger than 1MB or it wont load. Shrink your picture size.

[Buffetkiller]

So the cut height can be ".075" as long as the THC is dropping it to .06?

[Rhody]

Turn your TCH to "Auto" and start at the Hypertherm settings in the book that came with the machine. If this continues contact Shop Sabres tech support and they will work with you till it is resolved. Also get on Facebook, join the Shop Sabre Plasma Group that Shop Sabre monitors and replies to for help with their machine. Join the Sabre Nation University on the Shop Sabre main website under Sabre Nation that will help with questions also.

[adbuch]

Turn your TCH to "Auto" and start at the Hypertherm settings in the book that came with the machine. If this continues contact Shop Sabres tech support and they will work with you till it is resolved. Also get on Facebook, join the Shop Sabre Plasma Group that Shop Sabre monitors and replies to for help with their machine. Join the Sabre Nation University on the Shop Sabre main website under Sabre Nation that will help with questions also.

Those are all good suggestions. Which model Shop Sabre table do you have?
David

[Buffetkiller]

Sidekick 10