DT software-cut height on small holes

[Bigrhamr]

I think I am missing a setting or don't understand it.
In the DT software if you use slowdown for small holes, and freeze THC on those small holes is there something that drops the torch to cut height after pierce? Or does it cut at pierce height? I am using the contact initial height sensing now and plan to upgrade to ohmic sensing soon.

Thanks.

[WSS]

Have you played with the button next to the torch height screen? It looks like a thin line with arrows pointing at it, if you click it the thin line will expand to indicate "thick plate cutting". If you left click on it a window pops up to show you a bunch of settings you are inquiring about.

WSS

[super95awd]

Will the thick plate pierce settings override the THC freeze for small circles? I, too, have noticed it cuts at pierce height on small holes with that setting active and haven't found a good way around it.

[WSS]

Ya, I believe it will override any code. I did some small holes today on 1/2" and noticed two things, on .825" and over it froze but moved at what looked like 100% FR. Under .80" the torch was running at the specified 60% of FR (at least it looked like it). The slower hole had less taper.

Found this on eBay:

Dynatorch Master Series 5' x 10' CNC Plasma Table - eBay (item 190495722080 end time Feb-03-11 12:51:19 PST)

WSS

[super95awd]

Yep, I've been using the thick pierce settings on pretty much everything to get it to cycle quickly to cut height, leaving THC disabled on small holes. Takes a little bit of hand coding, but I have gotten some great results with hole quality this way.

[WSS]

Originally Posted by super95awd Yep, I've been using the thick pierce settings on pretty much everything to get it to cycle quickly to cut height, leaving THC disabled on small holes. Takes a little bit of hand coding, but I have gotten some great results with hole quality this way.

Tomorrow I will post some pics of these holes. If you have some pics of the holes you are cutting, it would be great. i am constantly working on getting better holes in thick plate. I can gaurantee .015" right now. It takes alot of work. I find that changing the consumables before they oval or pit too deep helps reduce lost parts. If I see a hard pierce, down it goes, swap parts and back to it. I try to get a few sets ready for rotation. I would say I could go 50 pierces and swap,not necessarily new parts go in, but just looked at and brushed off. I have this 10x magnifier that is lit that helps me decide. A cool tool would be a magnifier with a scope type etching or grid with a go/no-go scale. Probably can go 75 to 100 pierces before they are too oblonged or pitted.

I do like the DT THC. It is very customizable. Tied twith the we-cim, I can get nice clean and round holes. I have quite a library of burners in my we-cim configurer.

WSS

[WSS]

Here are some pics of parts done today. I experimented with water based anti-spatter. The results were good but clean up for painting was tough. I will play with it some more.

Material is AR500 1/2" holes are spec'd at .8125" +/-.015"

The ding on the hole in pic three was removed with a low speed die grinder and a hard wheel, takes about 5-10 seconds per hole. Holes were .805-.810 consistently.

WSS

[jimcolt]

You are doing the right things to improve plasma cut holes. # 1 priority is a good torch height control.....pierce height is critical to the life of the consumables, and you need to be at cut height before getting off the lead in and into the cut contour. I have a .pdf file that talks about best practices for hole cutting...if anyone wants it email me, and I'll send it to you. Here are some holes done with my Powermax45 on a few different materials: First two are of holes starting at .188" dia in 1/4" steel, 3rd pict are 1/2" dia holes in 1/2" plate, last are holes that were plasma cut at .188" in 1/4" plate, then drilled to .201 and tapped 1/4"-20.

Jim Colt Hypertherm

[super95awd]

Kind of crappy pictures, but the first picture is the front side and second picture is back side. Material is 1/2" A36 and the hole is .500".

Also, WSS... I found that a short radial leadout that closely mirrors the radius of the hole will eat that last little bit of ding out. Might not be the proper way to do it, but it works for me!

[WSS]

Can you get the specs of the lead out or maybe a picture? We are using we-cim to generate the leads (nesting too) and I have library of lead parameters for different materials. I will try to get a screen shot of the actual leads. The lead out is hardly larger than the kerf with a degree or two tighter angle/radius. The lead in is 90deg.

I believe a ramp down of power on the plasma generator helps. Does anyone know if that is possible with a Hypertherm/DT combination?

WSS

[jimcolt]

The plasma (Hypertherm) ramps down every time it is shut off. The best lead out for a hole is an overburn.....stay on the hole radius and extend the part program past 360 degrees for about .200". Use an advance plasma off....that extinguishes the plasma while the motion is still going. The worst thing you can do is to stop motion and plasma at the same time....if the motio stops and the plasma is still ramping down...there will be a big divot.

Jim