Is a THC really needed?

[Degrom]

Hi.

I am in the process of building a CNC plasma cutter. The main purpose of the machine will be to cut sheet metal.

Do I need to have a THC or will it work if I manually set the torch height?

(I know that if I want to set it manually I will have to be sure that the sheet metal is level)

Any advice would be appreciated.

Thanks.

[DSL PWR]

The thinner stuff will warp and you will need to stand by and adjust the standoff.

[TAProwler]

Well I am definitely no expert, but I have been learning a lot about CNC plasma cutting on this forum. I have read a bunch of posts by Jim Colt and he is obviously very knowledgable with plasma cutting.

This post is in reference to cutting holes, but pretty much sums up plasma cutting in general. Refer to paragraph 3. in particular:

http://www.cnczone.com/forums/showth...35579#poststop

Hope this helps. It has convinced me to find a THC solution for my table.

[Edwardo]

I,ve had my cutter running for 8 months now and i mainly cut 1/16 metal. In a perfect world all of the sheets would lay flat against the slats and wouldnt warp as you cut them, but they dont, some are better than others but the majority of them are bowed to some degree. I have THC on my cutter and i really cant imagine trying to cut this thinner material without it, i still have problems sometimes when peircing as the torch pushes the metal down, then the metal springs back up and is touching the nozzle when it tries to fire, so i have to realy watch it when peircing and if this is happening i have to push down on the metal to keep it away from the torch until it starts to cut and the THC takes over, once cutting the torch follows the contours and isnt a issue but i cut up a 4x8 sheet the other day with almost 1200 peirces alone so it took some doing. I just seen a new option from Dynatorch called DASH, its a digital height control for peircing were the torch doesnt touch the sheet for peircing, its a grand US but i think i will invest in it when i get the coin, especially for cutting this thinner steel.

EDD

[Edwardo]

I forgot to mention also that to get a good clean cut on thinner material your torch cutting speed can be in excess of 100-130 inches per minute, trying adjust torch height and watching for tip ups and everything else thats going on while the torch is flying around the table would take multi tasking to a new level i would think. Just my 2 cents though, good luck on your build and post some photos if you get a chance.

EDD

[Big John T]

No, THC is not required. Is it good? Yes. I've been cutting for a year now without a THC on material from 14 gauge to 1/2". Do you have to take extra precautions to make sure your material is flat? Yes. It all depends on your needs... are you needing to run production 8hrs a day 5 days a week? Then you need THC! If your just doing it a few times a week then you can "get by" without it. I equipped my machine with a Z axis and a touch off switch. I use that to "find" the top of the material and move to the correct pierce height before starting the cut.

Attached photo of my Z setup. Also, I might mention that I'm in the process of building a THC into my setup just to make it more automagic...


John

[Degrom]

Thanks for everyone's replies. [Big John T] I think you are asking the right questions...

A THC makes a huge difference and I will eventually get one. But for now my biggest goal is to get that first few cut's done. The machine will not be used a lot but I know how it goes.(It will end up being used for everything... :P )

Thanks again for all the info.

[TAProwler]

Nice looking set up there Big John T! Who's machine torch is that?

[millman52]

Originally Posted by Degrom Thanks for everyone's replies. [Big John T] I think you are asking the right questions... A THC makes a huge difference and I will eventually get one. But for now my biggest goal is to get that first few cut's done. The machine will not be used a lot but I know how it goes.(It will end up being used for everything... :P ) Thanks again for all the info.

You can't even begin to imagine how many 1 off parts you will make just because it's now easy to do so.

I've whipped out loads of simple things like new holders for water at all my grinders. Consisting of a small piece of flat plate cut with nice rounded corners then a ring just the right size tacked to the top for a butter bowl to fit.

Just last week I burned several small brackets for mig gun holders. Same deal there I had washers tacked to everything for that purpose. Now I have brackets that are made just for the purpose & look like parts factory made.

The list goes on & on

Now that I have a table a second that doesn't look quite as home made will be much easier to do.

[Big John T]

Originally Posted by TAProwler Nice looking set up there Big John T! Who's machine torch is that?

Mine! or did you mean who made it Hypertherm.

John

[Big John T]

Your inbox is full...

more pics here

http://s47.photobucket.com/albums/f1...asma%20Cutter/

John

[Degrom]

Originally Posted by Big John T Your inbox is full... more pics here http://s47.photobucket.com/albums/f1...asma%20Cutter/ John

Thanks John, I cleaned out my inbox.

Thanks for the link to the photo's... The machine looks really nice!!!