[HakBot]

Hello,

I am currently running Mach3 with a Gecko G540 driver board using a touch-n-go technique for plasma cutting. My plasma cutter is a Miller 375-xtreme. I am noticing that sometimes my cuts are perfectly fine and perpendicular to the material but then other times the cuts appear at an angle.
From what I have read this may be caused by the material not being completely level to the torch height at all times. Are there any more things that would cause this? If the torch height is the issue would it be possible to add a torch height controller to the system? Any help would be appreciated.

[ajclay]

I'll get the ball rolling....

There really isn't any way to get good cut results without having an operational DTHC system on your plasma.

The Torch height needs to be adjusted constantly during an operation. Metal not being flat due to it being warped or because of slag on slats causes variations in cut height.

It's just not possible to get the cut results like some have achieved. You can get job done but you will have to scrape and or do a little grinding on the dross.

It takes a little time too, to get all variables straight in your head. (never happens for me)

Here's a hint. If the torch height isn't at the perfect height there will always be an angle on the cut. If you are cutting a square, the angle will be the same and mirrored on all four sides.

If the angle is different on two sides and good on the other two... that has to do with the torch being square to the plate... It changes a little from operation to operation because of slate and plate problems.

A few degress on the angle is considered normal for plasma.

I'm sure there will be a bunch keeping the ball rolling so get ready!!

Read this publication by Hypertherm, it will get your foot in the door for sure:

http://www.awningandsheetmetalbr.com..._reference.pdf

Aj

[HakBot]

Thanks for the reply. The majority of my cuts are done on thin sheet metal, usually no more than 1/8" so this isnt a huge problem but one that I would like to fix. What makes me thing that it may be a torch height issue and not a torch alignment issue is that the cut angles are not consistent. IE if cutting a square I would expect the angle cuts to me on two of the sides however this isn't always the case.

Are you able to add a DTHC to any plasma cutter? I would really like to avoid having to buy a new unit as mine does suit my needs.

[ajclay]

There is no way I'm knowledgeable enough to answer that question.

The DTHC is a fairly deep subject with more than just one piece to add. You'll need a good understanding of the electronic workings of your machine.

Your best bet is to go back to who ever made your machine and or supplied the parts and get with them for help.

aj

[BBchevy396_]

C & CNC offers a very good low cost thc, "LCTHC", that will interface with your 540 in a snap! Their products are top shelf, and the service is unmatched.

http://www.candcnc.com/

[travmc1]

I had just about the same setup. I had a G540 controller and a Hypertherm 380 pretty much the same as the Miller 375. I bought the MP3000E DTHC II from CandCNC and added the DCP-01 and RAV-01 to my plasma cutter because it did not have a ARC OK signal. It was about $700.00 but well worth it. You could get the LCTHC and save $325.00 but to me was well worth the extra money to be able to change the setting on the computer and save each profile so the next time just select the material and go. plus it have a little more control. Either way will work good. I could get perfect cuts on 3/16 steel. 1/4" was good too but at 20ipm had a little dross.

[HakBot]

travmc1,

The units from CandCNC look like they will fit the bill perfectly. I checked with them and it looks like I do not have an ARC OK signal either. I know its kind of a bad question but was the unit you purchased very difficult to install. I took a look at the instructions and they were a bit hard to follow however I imagine once I have the hardware and get into the install it might be a bit easier to understand.

[travmc1]

travmc1,

The units from CandCNC look like they will fit the bill perfectly. I checked with them and it looks like I do not have an ARC OK signal either. I know its kind of a bad question but was the unit you purchased very difficult to install. I took a look at the instructions and they were a bit hard to follow however I imagine once I have the hardware and get into the install it might be a bit easier to understand.

The hardest thing to do was to understand the directions because they give all kinds on documents for other applications. But once I figured out which ones to read for my application it was fairly easy to do. The longest thing to do was to install the RAV-01 Card inside my plasma cutter. Just figuring how to mount it. The rest was easy. If you need any help I will help you out and I can also take some pics of what I did the setting in Mach3 are a little tricky too because it depends on what type of z axis you have ( threaded rod, rack gear???). I believe the miller machine you have is identical to mine just different name and color.

[Torchhead]

Epilog: We have a cable that snaps in our MTA150 card (external interface card that comes with the MP3000-DTHCII) and lets you plug in the G540 directly. All of the computer interface and wiring is to the MP3000-DTHCII. There are a multitude of differences between the LCTHC and the MP3000-DTHCII including the fact the MP3000-DTHCII has an advanced BoB with Port Expansion so you get all of the Inputs (9) you need from one parallel port along with expanded outputs (8 total) The DTHCII is the only THC that offers a single cable connection to the Hypertherm 45/65/85/105 series and we are the only vendor that has an RS485 interface for controlling the Hypertherm current and air pressure FROM SOFTWARE.

Here is a chart that will show you the comparison between the LCTHC and the MP3000-DTHCII.

We will be announcing our next addition to the SMART-KUT (tm) technology that adds Dynamic Current Control to the Hypertherm 65/85/105 with the RS485 option. That will be followed by out DEEP-PIERCE feature in a few weeks.

TOMcaudle
www.Candcnc.com

[tjb1]

Isnt cutting angle also related to direction of cut? As in CW or CCW and the direction of the swirl.

[Nacs Fab]

We traded a few posts on your build thread, but I will add here once I get my machine set up. I have the same controller box you have, so the LCTHC controller board will fit right in the front panel with modifications.

http://www.cnczone.com/forums/plasma...available.html

I bought the CandCNC Interface Card that plugs directly into the G540 outputs and man it was slick to put together! Going between their interface card and their controller was a simple and provided RJ45 CAT5 cable! In their initial controller pricing, they include the Cat5 cable, a 12vdc power supply for the controller AND the THC Sensor card that hooks up to your Plasma Cutter!!!

I have my control box built and somewhat tested but have not finished the THC Sensor card installation to my Hypertherm 1250. That will be the next item I will post about in my thread above. Im merely down to mounting the THC Sensor card in a project box from Radioshack and routing a 2 wire connection as well as a 4 wire connection on the Hypertherm board.

[Nacs Fab]

Epilog: We have a cable that snaps in our MTA150 card (external interface card that comes with the MP3000-DTHCII) and lets you plug in the G540 directly. All of the computer interface and wiring is to the MP3000-DTHCII. There are a multitude of differences between the LCTHC and the MP3000-DTHCII including the fact the MP3000-DTHCII has an advanced BoB with Port Expansion so you get all of the Inputs (9) you need from one parallel port along with expanded outputs (8 total) The DTHCII is the only THC that offers a single cable connection to the Hypertherm 45/65/85/105 series and we are the only vendor that has an RS485 interface for controlling the Hypertherm current and air pressure FROM SOFTWARE.

Here is a chart that will show you the comparison between the LCTHC and the MP3000-DTHCII.

We will be announcing our next addition to the SMART-KUT (tm) technology that adds Dynamic Current Control to the Hypertherm 65/85/105 with the RS485 option. That will be followed by out DEEP-PIERCE feature in a few weeks.

TOMcaudle
www.Candcnc.com

Tom,

I do not have my manuals in front of me at this time, but wanted to make sure it is required to have 12 volts DC to BOTH the G540 Interface Card as well as the LCTHC controller board. I used separate packs for each board, but do not like the fact that when I kill my E-Stop, i still have power to these two boards due to the separate connections.

Lastly, does the THC Sensor require any external voltage? I am getting ready to get it all hooked up to the PC board and did not see any requirement, but wanted to be sure.

Thank you!! Looking foward to using your products!

[Nacs Fab]

Not sure how to get Tom to reply to the above question as his PM box is full, maybe I'll ask the question on their yahoo group.

I did manage to plug in both packs to my 110v outlet on the back of my control box and now I can kill everything in the box with one e-stop.

I tested my motors and got Mach3 all set up to run each motor properly and actually ran a "test" piece and the motors seem to move correctly. Its a nice feeling to see it all working and no blue smoke!!!

Still have not messed with the LCTHC portion as this is just bench testing and not testing with the PM 1250. I will report back soon!

[Torchhead]

We support our products on the CandCNCSupport Yahoo Forum. A post there gets answered in hours (sometime minutes) There is also my direct e-mail off of the website. I spend hours every day answering e-mails. This list is more about users sharing and a place to give out general information. If I happen to see a post here in my stroll through every day or so I will answer it here.

TOMcaudle
www.CandCNC.com

[Nacs Fab]

We support our products on the CandCNCSupport Yahoo Forum. A post there gets answered in hours (sometime minutes) There is also my direct e-mail off of the website. I spend hours every day answering e-mails. This list is more about users sharing and a place to give out general information. If I happen to see a post here in my stroll through every day or so I will answer it here.

TOMcaudle
www.CandCNC.com

Thanks for your quick reply over on the Yahoo group! We will be up and running real soon.