[jason_alex]

Hey guys I am looking for some advice and was hoping you could help... I am trying to reduce the divot left by the plasma as it shuts off.

I have a HD 3070 with a burny 5 we are working on upgrading the table as we go right now I am running a .1 lead out I think a lot of it is I am running 80A on 12GA plate with tips that have 1500 in the consumables topping 290 IPM. any input would be great!!!

[jimcolt]

There are a lot of different types of cut anomalies that may be called divots. Pictures certainly would help. Depending on where it is it could be a backlash (mechanical) issue, a height control issue, and arc off timing issue, a part program issue, a CAD drawing issue, and many more.

Jim Colt Hypertherm

Hey guys I am looking for some advice and was hoping you could help... I am trying to reduce the divot left by the plasma as it shuts off.

I have a HD 3070 with a burny 5 we are working on upgrading the table as we go right now I am running a .1 lead out I think a lot of it is I am running 80A on 12GA plate with tips that have 1500 in the consumables topping 290 IPM. any input would be great!!!

[jason_alex]

Here are some pictures. This is in 1/4" plate running 80 Amps and 108 IPM. We are looking at upgrading the machine a step or two at a time to newer components(right at the moment we are looking at new nesting software, and have plans to do that cnc, THC and plasma power supply soon). We have ran the pen test and have not noticed any problems with backlash but there could be. It is always on the back side of the plate.

Attachment 242354
(this is a picture from the back side outside profile.)

Attachment 242356
(back side of a hole)

[jimcolt]

The divot you are showing is occurring at the shutoff point of both the plasma and the machine motion. The HD3070 plasma has a "ramp down" timing event at the end of every cut cycle....meaning that for around 100 miliseconds the amperage and the plasma gas (oxygen) do a controlled ramp down...this is necessary to achieve good consumable parts life with an oxygen plasma.

On most systems that divot can be eliminated by programming your holes with an overburn (stay on the hole radius) that goes past the lead-in kerf by about .200". Then, if your Burny cnc control has the function (some do, some don't) set an advance plasma off time that extinguishes the plasmajust prior to the lead in kerf crossing. This allows the plasma ramp down to occur while the torch is still moving.....which eliminates the divot. Your divots are occurring because the motion stops...yet the plasma takes 100 ms to extinguish.

The newer Hypertherm integrated plasma systems using our cnc control have this timing fully automated....you do not need to experiment!

Jim Colt Hypertherm

Here are some pictures. This is in 1/4" plate running 80 Amps and 108 IPM. We are looking at upgrading the machine a step or two at a time to newer components(right at the moment we are looking at new nesting software, and have plans to do that cnc, THC and plasma power supply soon). We have ran the pen test and have not noticed any problems with backlash but there could be. It is always on the back side of the plate.

Attachment 242354
(this is a picture from the back side outside profile.)

Attachment 242356
(back side of a hole)

[jason_alex]

Thank Jim, when I get a new controller that I can actually get into the setting of it i will give it a go. We are looking at upgrading our cnc controller in the next few months, followed by a THC soon after that and hope fully by this time next year depending how it all goes going to a new HD power supply my guess is it will be a kaliburn or a hypertherm system.

Not sure yet if it will be a Hypertherm or burny controller, thc, or plasma.... decisions decisions.

[Kerryfisher]

Sound advice as always from Jim there, I have also been using the new feature from Sheetcam & Candcnc to control turning off the torch while the machine is still moving, it's well worth using for holes and small inside cuts.
This is on 8mm, not perfect I know, but getting there.
Powermax 45

Attachment 245122

Attachment 245124

[plain ol Bill]

OK Sean I'll bite - what is that part anyway?

[Kerryfisher]

It's a part of this kit
:: Weldon`s - John Deere Commercial & Domestic Dealer ::

[jason_alex]

What type of coating is that you put on it?

[Kerryfisher]

Zinc plate and passivated I believe, I'm cutting and assembling.

[plain ol Bill]

Interesting equipment Sean. I have a love/hate relationship with my mower and catcher - mostly hate