general question about height control

[grogmeister]

Presently we're using the hypertherm PHC height control but i also noticed some machines do not have a height control,you set the torch height
and thats it ,sort of like using the torch by hand.
Would like to hear from people with manual height control and a 2 axis machine

[Scratch]

I can't believe I'm going to admit this....
I'm actually pretty embarrassed to say it...
It's not something I'm at all proud of...
I probably should just keep my trap shut...



eh... what the heck, I don't really care anyways.

"I do not have any type of automatic torch height control on my table!"

I sit next to the table, on a milk crate, with a shade 10 goggles on, holding a stupid pendant with an up and down button on it. Pity me.

I had always planned on getting one, but heard bad things about Practicals THC so decided to save the 2 grand and get one later. It's been like 5 years or so and I've gotten used to it now. Not sure if I ever will get one. I think I'd get all spoiled and stuff if I did.

Whilst sitting there, watching that magical spark float across the vastness of total darkness in my shade ten lens... It gives me time to reflect on the fragility of life, and the true meaning of Cap'n Crunch cereal.

[trucks1948]

You turn out some really nice things that way too scatch.I too have a praactical table ,but i put a cand cnc height control on it and i love it.Mainly tho i believe its getting to know how your own table works and working it the way it works for you.

[elkriverfab]

Scratch.......

Don't feel bad by any means.

My My plasmacam has height control and I do the same thing you do without it.

This crappy steel bows all over the place and if I don't watch it, it "WILL" catch!

I figure it this way, If it cuts clean and straight It's good enough for me.

I am not in the position to get a DHC2 and mine is fine.

I will be thinking about that cap'n crunch along with you!

[plain ol Bill]

I built my own machine and use CandCNC electronics with it. I have their THC unit and love it. You can watch the Z axis motor twitch up and down following the material height within a very few thousandths. The arc voltage read out will vary 1 volt during cutting. I also use a water table and that REALLY helps with material warpage. I don't see how you can cut a complicated item with a lot of intricate cutting in light gauge material without drastic warpage unless you use a water table but I have seen you guys do it.

[trucks1948]

I'd love to have a water table,but mine would freeze solid about 2-3 monthes a year Jim

[grogmeister]

Thanks guys , i see now that the height control is not a big thing ,a nice to have but a spot for it to act up.
When you use a hand torch and a torch follower your height is set and you just follow the 1/4 ply pattern
nect thing you have your cut out BUT with cnc more intricate cuts take place so a 2 zaxis ,achine and a method of raising and
lowering the z axis is required .
possibly a z axis but not configured that way you have manual control.
Thanks again

[jimcolt]

I think you may have read these posts incorrectly....height control is a big thing for mechanized plasma cutting, and is necessary if you expect repeatable cut quality and long torch consumable life. A plasma torch needs to pierce at a higher height than it cuts at....this is to prtect the nozzle from molten metal blowback. one pierce too close, and the nozzle orifice is damaged, and you will have varying cut angularity and slower speeds for all of the rest of your cuts. Once the plate is pierced...it is necessary to control the torch to work distance accurately (plus or minus .005" of the torch manufacturers height specs is good) , if the height varies during cutting, the cut edge angularity will vary and dross formation will vary.

There are some cnc machines avaialble at low prices without THC. They are good for one at a time cuts, or if you are just severing metal and expect to do a lot of secondary grinding, etc to make you parts fit up. Height controls for plasma are necessary if you expect high quality cutting with repeatable results, and low costs (long consumable parts life).

Jim Colt

[jeeplogic83]

I have had a machine with THC and one without but had manual control. Jim (like always)is right it is important to have some type of control. I was like Scratch I had to sit by the machine with goggles on and manually lift and lower the torch head with a pendent. once I did the CandCNC retrofit I have a working THC and it is spectacular I can walk away from the table and do other things in the shop while the machine cuts. If you have a machine with no control at all you will crash your torch head and break stuff (been there done that). Also if you have no control and you pierce thicker material from the wrong height you just destroyed a 5.00 tip. To sum up you have to have some type of height control either manual or automatic. hope this helps

[torchhead]

I can't believe I'm going to admit this....
I'm actually pretty embarrassed to say it...
It's not something I'm at all proud of...
I probably should just keep my trap shut...



eh... what the heck, I don't really care anyways.

"I do not have any type of automatic torch height control on my table!"

I sit next to the table, on a milk crate, with a shade 10 goggles on, holding a stupid pendant with an up and down button on it. Pity me.

I had always planned on getting one, but heard bad things about Practicals THC so decided to save the 2 grand and get one later. It's been like 5 years or so and I've gotten used to it now. Not sure if I ever will get one. I think I'd get all spoiled and stuff if I did.

Whilst sitting there, watching that magical spark float across the vastness of total darkness in my shade ten lens... It gives me time to reflect on the fragility of life, and the true meaning of Cap'n Crunch cereal.

Use the palm of your hand and slap your forehead while you realize you have been sitting watching the pretty arc for 5 years to save less than $750.00. The MP3000-DTHC WITH a MACH license is less than that and we have a special PCNC adapter card that lets the MP3000 plug directly into your PCNC power box. You could have been using a real THC for along time. We just released a software upgrade for the MP3000-DTHC that adds "Smart Cut". It will automatically set the proper Arc Volts (preset) based on the first few inches of a cut. It automatically compensates for different material and changes in consumables. We also will announce this week our new Digital Current Probe that slides on the workclamp lead and measures the actual cut current and displays it on the MACH screen. It can also be used for getting the ARC OK and/or warn the operator if the cut current is out of range for the material being cut.

After hundreds of hours cutting for our Plasma Cutting business I found any time sitting and watching the machine cut was wasted productivity. I used the time to clean and debur the pieces and get them ready for powder coat or plating. I realize a lot of this is hobby cutting where production time is not a factor but we had to make money on every piece we cut or I did not eat (it was my single source of income for 4 years). I learned all kinds of tricks both in software and in the cutting process to speed things up.

Anyone that tells you you don't need a THC for plasma cutting either does not do it much or they don't have a cost effective solution.

TOM caudle

[Scratch]

Like I said Tom... It's not something I'm proud of. If and when I do get THC, you are the one I was planning on talking to.