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Ewww pierce points...

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Pat4rd
Posts: 68
Joined: Thu Apr 06, 2017 6:32 pm

Ewww pierce points...

Postby Pat4rd » Tue Nov 07, 2017 6:56 pm

I've read and read topics about pierce points. I cannot find any pictures on what's acceptable.. these however I feel
Are not :lol: ...so I keep looking at articles and jim holt gives a lot of info. I try to do everything he says. (Gauge at the back of my 45xp, table is grounded good, I've got shims to check my torch height) everything seems to be checking out good. I was cutting this 3/16 last night and my cut height was .06 pierce was at .15 with .5 sec delay.. but how am I getting this bad of a pierce with these numbers :o This is not a high end table I'm working with (saving up for a bulltear) but it seems to stay pretty consistent with its accuracy. These were new genuine tips. Air pressure never dropped below 120psi. And these are the regular 842 and 941 tips (non finecut) what would you all look into? I could
Possibly get some pics of my tips tonight and post here. The holes did plug on my shield. But it was quickly replaced.

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Millermatic 252
Hypertherm 45xp machine torch
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Pat4rd
Posts: 68
Joined: Thu Apr 06, 2017 6:32 pm

Re: Ewww pierce points...

Postby Pat4rd » Tue Nov 07, 2017 6:58 pm

I also did change the pierce height in increments up to .18 and did not see any major change. I also changed pierce delay to .06 and again nothing really helped.. the slag comes off so easily but this is a problem I need to address, and I've been buying tips like crazy!!
Millermatic 252
Hypertherm 45xp machine torch
Eagle 4x4
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tcaudle
Posts: 788
Joined: Tue Feb 28, 2012 6:47 pm

Re: Ewww pierce points...

Postby tcaudle » Tue Nov 07, 2017 8:59 pm

Do you have yourr workclamp clipped to the material?
Have you disable the THC and tired a manual (no THC cut?
Are you using the right consumables for automated cutting?
Have you used Single Step mode in MACH to do each line of code for a touch off and the move to the different heights is it REALLY piercing at .150?. Those are really ugly pierces and have too much back splash and will ruin tips.

Pat4rd
Posts: 68
Joined: Thu Apr 06, 2017 6:32 pm

Re: Ewww pierce points...

Postby Pat4rd » Tue Nov 07, 2017 9:48 pm

I'll run through those tonight.. i reset my offset on my switch to make it dead accurate. I run my codes and type in M00 to make the Mach3 stop so I can take an accurate measurement and everything shows a definite .06 and .15.. thanks for other stuff to check into. I'm going to try running a clamp to the material tonight. But the table has been grounded good as far as making sure all contacts are clean and plenty of surface area to make a good ground. I'll do some more testing tonight! Thank you
Millermatic 252
Hypertherm 45xp machine torch
Eagle 4x4
Mach3, sheetcam, adobe il, inkscape
Proma 150 floating head, Quincy 5hp 60gal, 3 stage dryer.

Pat4rd
Posts: 68
Joined: Thu Apr 06, 2017 6:32 pm

Re: Ewww pierce points...

Postby Pat4rd » Wed Nov 08, 2017 1:04 am

Hooked up a new ground clamp wow what a difference.. it's start points are so much cleaner. I was thinking on my way home how I put my ground on the leg of the table and now I realize I need to move it to the water pan. I'm guessing it was trying to ground through the bolts that hold the leg on. Dumb mistake lol thank you!
Millermatic 252
Hypertherm 45xp machine torch
Eagle 4x4
Mach3, sheetcam, adobe il, inkscape
Proma 150 floating head, Quincy 5hp 60gal, 3 stage dryer.

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acourtjester
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Re: Ewww pierce points...

Postby acourtjester » Wed Nov 08, 2017 6:45 am

With many thing the shortest path is the best, Here is a clamp I made for my table. It attaches directly to the metal being cut, surface rust and mill scale can cause some problems. cleaning the spot the clamp is attaches removes all this just a quick and simple action after mounting the metal. :)
ground clamp.jpg

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tcaudle
Posts: 788
Joined: Tue Feb 28, 2012 6:47 pm

Re: Ewww pierce points...

Postby tcaudle » Wed Nov 08, 2017 10:54 am

Pat4rd wrote:Hooked up a new ground clamp wow what a difference.. it's start points are so much cleaner. I was thinking on my way home how I put my ground on the leg of the table and now I realize I need to move it to the water pan. I'm guessing it was trying to ground through the bolts that hold the leg on. Dumb mistake lol thank you!

No you need it ON the material, First, its not a GROUND clamp. Its the POSITIVE side of the plasma voltage (Workclamp) table grounding is for noise not cutting. Its all about getting max current flow at the exact spot of the cut. You are depending on water conducting to the slats and up to the material and then across the material to the cut. At high current it does not take much resistance to cause the actual power in the cut to diminish. Water is not a conductor....onyl the impurities in the water conduct. Slag is a poor conductor. Rust is a non-conductor. In plasma constant current is critical. every other parameter (like torch volts) depends on the current staying constant.


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