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Mav68erick
12-30-2012, 09:04 AM
Ya really frustrated, Im to the point I dont ever wanna cut anything thinner then 11 gauge on this table. Basic shapes are ok anything with detail close lines or alot of pierces forget it. Seems like I can cut 1/4" without a working thc perfect.

So I try to cut some stainless today, about .055 thick cut it before without THC never warps, always slow the Speed down by half and cut the amps by half because another issue I notice is I cant see how anyone cuts over 200 IPM!!!!!!!! The books show 350 for 16gauage stainles, really how? When I first got the table set up I followed book specs and lowered the cut to 300 and it would not cut an inside corner at all, no radius it would cut the corner and leave a huge radius im talking like .500" on a corner that was at roughly 90* It didnt seem like it wanted to travel to the node then change direction, so whatever cut feed and amps in half problem solved cuts look nice little dross no big deal.

Well heres the big problem and I think all these people blabbling about HC forget about this on thin stuff, I read about people cutting 20 22 and even 24 g material.? and I ASK HOW!? These tables have touch and go to zero, every time I watch my torch touch to zero it self and its inbetween slats ( even worse when pieces around it are cut out ) you watch it push the material below what the table set height would be, so boom now its say .060 below table raises up pierces and the torch is touching, boom consider that nozzle toast the THC isnt fast enough to save that im afraid.

Not to mention Ive read the 3-4 latest posts about people having THC issues and today I turned it on and was playing with it, I think I seen it move once! basically the torch was dragging the entire time then I finally seen it move .030 as I seen the volts vary 30-40 the preset value of 130. The preset profiles in mach for hyertherm arent anywheres close for a Powermax65 model the volt values are way high so I changed it accordily to the manual.

So in all reality what good is the THC for other then keeping correct Torch height on a long continuous cut? once the sheets warped your screwed for the next pierce or touch off ( which I have set to every 10" ) or to comensate for an unlevel water table to gantry or slag on slats causing height difference in the material over an xAmount of distance.

I just seen in apocolypses thread a jumper wire? I think I seen that in an old thread to but I dont recall anywhere in my pdfs of reading it telling me to do it to my table.

Im just bummed out I guess tired of everytime I go to do something I have to deal with issues and working 6 days a week I dont get much free time, Finally got an actual Machine torch because the hand torch hanging I thought was giving me angular cut issues and never even tried to square it up, was working pretty good when I first mounted it, which I think was a little ghetto took the top clamp off and it seemed to fit against it fine so Its just zip tied and clamped at the bottom til I can machine a new mount.

I just want to get this straigtened out so even if I cut thick stuff I can use it thus knowing the Torch height is as close to the called out cut height as possible so I can rule that out of cut quality issues, Heck the difference in my Z offset from my hand torch to Machine torch was almost .020 because it torqued the gantry down with the handle and cable hanging so far out from it. So I know that was causing touch of zeroing issues, although whenever I stopped it and through a shim under the shield it seemed to always be close to the .060 mark.


I dont want this post to seem like a bitch fest Im just venting out some frustration

Mav68erick
12-30-2012, 09:17 AM
And all the settings match +60.0 -30 Ive adjusted fthe delay anywheres from .1 to 1 span gap volts on the profile was set at 9/4 ive changed it from 1/4 to 4/4 really dont know why they didnt make it so you just put X volts in the box like. 1 volt or .1 .25 .5 .75 etc... I can only guess that 5/4 volts is 1.25 volt and 9/4 is 2.25. Corner lock out makes sense because ya voltage changes ALOT when it slows down. So I guess 2/4 to 4/4 is good .5 - 1 volt shouldnt make or break me as what Im working with atm, unless someone knows what 1 volt = in actual height.


Oh yeah another thing Id though id bring up cut height settings are .020!!!!! for 16gauge and thinner..... thats another thing It seems pretty optimistic, ive been called out for being negative people done realize, im just being realistic and that seems like a stretch, now if I was cutting 1/8 or thicking that I cant see why you cant hold .020 at a slow feed rate but not running at 300imp on a sheet thats 1 warped 2 boucning fro the air pressure by it self it just seems like a long shot.

jeepsr4ever
12-30-2012, 12:33 PM
Never assume cut height is for initial height before your THC takes over. Listed cut height is what THC should set it to but not where you want to set you cut height at. ...confused? So lets say you want to cut with a height of .060 because the book says so. Well you want to start at about .125" cut height and after your THC delay is done then THC controls the cut height and has nothing to do with the initial number you setup in sheetcam...THC trumps that number. The other thing to consider is the distance from your electrode consumable to your actual material...if your outer sheild is making the arc too long you will get funky cuts you will never escape that. When your over 200ipm you need to change your accel and deccel numbers to at least 45. The books will say 350-400ipm @ a certain amperage for certain materials. This is the ideal situation however geometry and accel and deccel rates are very important. To obtain CRISP geometry at 400ipm you would need a accel and deccel of at least 60. It is not ideal with stepper motors and only 1% of all CNC plasma machines will do that. Some mfgs use very small motors and Hypertherm has listed a cut speed and amperage chart for cutting under 150ipm on almost all material.

Your 1.5yrs into your kit and you should have called in or posted up that you were having any kind of issue with your THC. THC delay should be at least .7 seconds for almost any material. Is your THC blinking when your cutting? Is your rate set to at least 18 and not over 25? Span gap should be in the 3-6 range. Cutting thin materials is an art and the bouncing of the material will cause issues.

Let me know if I missed anything

Mav68erick
12-31-2012, 02:55 AM
Never read anything about accel decel rates when running higher feedrates and Ive read alot, Honestly I havent cut prolly as much near as others have, dont think I cut but maybe 5 things over the summer, it was more of a table to prototype stuff and not make production runs of signs etc although I wanna be able to run a full sheet and have the stuff done which Ive done over holiday break.

Yes my thx Lights blink, All the initial tests during the build tests lights worked etc, displayed on Mach 3 correctly ( had to buy the box that the ground cable runs through because ) my pm65 didnt have the card in it to display volts that works now. all in all when the torch has settled out of a corner on a straight line the voltage is real close to the book numbers ( hell when the torch was dragging it was reading the right numbers ) I just dont see the Z number change I seen it change maybed twice yesterday over the course of 20mins and the material was touching the torch.

I wanna apologoize if my previous post was sounded bitchy I just had all of it built up in my head and thats the way I type, I type it out as I hear it I needed to vent my frustration.
I will mess with it some more but time is of the essence.

Thx


Edit: still the biggest issue that I never see anyone talk about is the touching over and pushing material below the slats and zeroing itself below the table, I mean if you set your pierce ad like .2 or something you could prolly cheat it and the THC would adjust but I think in order to not let te material sag it would need clamped on 2 opposite sides so it cant pull.

jeepsr4ever
12-31-2012, 03:14 AM
That is the #1 challenge with thin material and is also why we always tell people to NEVER USE THE BOOK SETTINGS FOR CUT HEIGHT when setting up your tool in sheetcam. Always add an amount for possible deflection. Once your one with the machine you can edit your sheetcam post for your ref distance and use a very small increase in cut height in your tool table for thin material. The deal is that if the material deflects (and it will) you need to come back far enough to pierce and to 'Start' cutting. Once you start THC will take over and you will be moving. Go to your cut profile button and see if your AUTO THC is turned on.



No problem on the post it is always frusterating your first couple of times that a hiccup happens and you arent sure what to do. The capital letters I post up are so other readers are sure to think about the statement a little more.

jeepsr4ever
12-31-2012, 03:16 AM
The thing about the book settings you get from Hypertherm or any other plasma power source mfg is that they do not list all events before settling into the cut. There are advantages like wiggle pierce that will allow you to pierce far beyond the suggested pierce capabilities reccomended by the mfg and safer than strait piercing making your consumables last longer on thick materials.

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