Plasma cutting detailed cut-outs

After years of wanting one (much of which was caused from reading this NG) I got a Thermal Dynamics Cutmaster 51 for Christmas. I have a lot to learn and so far I've only read the manuals and played with it a little.

I have been reading old posts and surfing the Web for things about using templates. I can see how a non conductive template would work with something less detailed like a five point star or a rectangle out of sheet metal. How are folks cutting out more detailed items with a hand held torch? I realize skill is a factor but I don't get how that intricate a template could be followed. I tried cutting over paper but it caught the paper on fire. That was probably a lack of skill though.

By the way, I asked for this particular machine based on what I've read here over the years. I'm pleased so far and appreciate what I've learned over many years of reading this NG. I wish I was more skilled so I could share it as so many posters have done for me.

Reply to
sgf
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I plasma cut with a handheld torch and can honestly say that it will be hard to do very detailed pieces. you will need a templete which you can rest the side of torch against, and glide the torch along smoothly at a steady speed. also you will need something to keep a gap between the workpiece and the torch tip to minimize drag.

most metal pieces that you see with nice cutouts are done with CNC plasma , laser or waterjets, where a machine moves the torch , or the torch is fixed and the metal table gets moved around at a steady speed with very precise movements.

also, anything you do with handheld torch most likely will have a semi rough edge. which will need to be cleaned up .

Reply to
acrobat ants

I have a friend that has one - We both have Hypertherm 600's. His wife is the welder, she went to school... - Husband is a professor... She tried a wood cutout as a sample on the first day and that was after her deft hand moved the torch down long cuts.

Her wood whatever didn't get burnt - I think browned.

If you want a nice line - use an angle iron that is clamped down tightly - and use it as a guide. Run fast - you can re-trace. Fast typically means 1. low dross or 2. not cutting through.

The next tool if you don't have one - is a 4 1/2" angle grinder - to grind the dross off.

I have had great luck on some with a heavy hammer and a quality steel chisel. It will knock the dross off - start at a low spot or a corner... Comes off in long lines.

Martin

Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH & Endowment Member NRA Second Amendment Task Force Charter Founder

sgf wrote:

Reply to
Martin H. Eastburn

Personally, I cut things out with a hand held torch freehand. I've never used a template, but instead I draw a design directly on the metal with white or yellow paint pen, then just trace it with the torch tip.

If you would like to see how detailed you can get with this method, you can see some work on my personal site at

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Check out the little animals I call the Plasmites. Each of the critters is 5"-6" tall, just for perspective.

When cutting things with detail on the plasma torch I would say there are three main concerns: 1) Speed - you need to travel as fast as possible while still making a complete cut. This reduces the dross, which means less clean up. 2) Steadiness - you need to be reasonably smooth and steady with your cutting motion. This will only come from practice... but it will come! 3) Kerf - When designing your detail you must take into account the width of the actual cut. Depending on your torch, the kerf could be

1/8" wide. That, combined with your skill at tracing your pattern, is ultimately what affects your ability to do fine detail.

Hope this helps,

John P.

PS- Paper will catch on fire no matter what you do. And tape or other adhesive backed materials will melt and cause a huge mess. You must use a paint pen or chalk.

Reply to
John P.

I'd like to see the torch you are using to do these John. Is it water cooled ?

I have made accurate (

Reply to
Steve

Steve,

This is just a plain old Hypertherm PowerMax 1000 hand held torch with the standard tip.

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No water cooling or anything, but at this thickness (1/8") of material the torch has a 100% duty cycle so I can cut all day.

I've just ordered the Fine Cut Consumables Kit as I believe I could cut more detail into my art if I could just have a finer kerf. Allegedly this kit will do that... we'll see!

John P.

Reply to
John P.

snip

Let us know how the fine cut consumables do for you.

Reply to
mrbonaparte

I usually cut out the figures i do , sillouttes of ravens etc, and then transfer that to the steel using soapstone. I have the TMX600 and its works great. I just need to learn how to be consistant and perfect my cutting.

John,

Am thinkiong abt the wee kerf kit myself. Let us know how it does for you.

BR =========

Reply to
Blueraven

It will by far.

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8/14/05 10:42 PM 5820 Hypertherm_600_fine_cut_copper.txt 8/18/05 9:45 PM 86296 Hypertherm_600_fine_cut_copper1.JPG 8/18/05 9:40 PM 47603 Hypertherm_600_fine_cut_copper10.JPG 8/18/05 9:37 PM 33516 Hypertherm_600_fine_cut_copper11.JPG 8/18/05 9:44 PM 68057 Hypertherm_600_fine_cut_copper2.JPG 8/18/05 9:42 PM 92904 Hypertherm_600_fine_cut_copper3.JPG 8/18/05 9:38 PM 39609 Hypertherm_600_fine_cut_copper4.JPG 8/18/05 9:32 PM 31626 Hypertherm_600_fine_cut_copper5.JPG 8/18/05 9:34 PM 29458 Hypertherm_600_fine_cut_copper6.JPG 8/18/05 9:35 PM 35610 Hypertherm_600_fine_cut_copper7.JPG 8/18/05 9:36 PM 26719 Hypertherm_600_fine_cut_copper8.JPG 8/18/05 9:39 PM 79011 Hypertherm_600_fine_cut_copper9.JPG

in very short note: Cut 2" lines using various speeds.

50 ips clean cut .055 kerf - approx via optical rule 100 to fast - did not cut the length - used heat from pierce to cut some. 75 ips to fast - did not complete the whole line - last 1/3 didn't cut final hole did. 25 ips very clean now .08 kerf but likely to slow. 40 ips .08 clean chosen speed as it is slightly better than 50 due to consistent square slot. 0.025" kerf [ a small paper clip wire will not enter the slot.] 100 - to fast misses some near the end - like the first one. 75 ips still to fast - does better than 100, but does not complete line. 25 ips - CLEAN and nice cut. still a thin 0.025. 40 ips - clean as 25 - a little clearer cut line that 25. >cooled ?
Reply to
Martin H. Eastburn

I will definitely report back when I get the kit. I'll try to do a detailed report including actual kerf width, before and after, as well as dross comparison and anything else that seems different.

John P.

Reply to
John P.

That is great information Martin. I'm really looking forward to getting my kit now!

John P.

consistent square slot. Put on a new fine cut set. Re calibrated height. Same series next to it and two words.

wire will not enter the slot.]

Reply to
John P.

Buy some 20 and 30 amp tips if you want the thinnest kerf you can get with the SL60 torch.

Reply to
svande48

Thanks for all the input. It sounds like a lot of this (like most things) is a matter of skill and practice. I am hoping to do some things like the ones in these links for myself and friends.

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this
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attended an event where some folks were selling items like the ones pictured. One man was doing them with a CNC machine. Another, who I spoke with, did all his by hand. Some were even more intricate than the ones in the links. They were also very clean. Based on the responses I've recieved, my grinder or maybe my little pneumatic grinder with 2" abrasive disks, will be a necessary evil. from Steve's pictures, etc, it looks like all this is doable by hand though, yes?

SGF

Reply to
SGF

___________________________________________

Thanks for the info. After reading your post I went to the welding store. The normal (experienced) guy wasn't there. The person I dealt with said he's never heard of 20 and 30 amp tips, only 40's. He said if I had the part number he could check on it. Does anyone have a P/N for these tips for a Thermal Dynamics SL 60 hand torch?

On a semi unrelated note. My plasma equipment came from a local supplier. Probably not the best price but I asked my wife to get it there for no other reason than to support the local shop where I might go to ask advice. The store was empty and all it would have taken to answer this was a phone call to a supplier or Mfg. For those who wonder why the local shops (of all kinds) aren't supported, this is why. If the service is no better than it would be from an unknown on-line supplier, why not get the discounted price. You can bet I'll mention it to the other employee, who I believe is the manager.

SGF

Reply to
SGF

These two pieces are definitely done by machine, and based on clip art.

Certainly. Practice is the key. But if you are going to be doing this kind of stuff I'd take back my recommendation on that 115v plasma cutter. I'd recommend a 230v unit which will require a good size compressor to go along with it. If you are going to want to cut out stuff that is this intricate, and do it by hand, it's going to take you a little while. The little plasma cutters simply don't have the duty cycle rating you're going to want. They're not designed for this kind of work.

I'll also advise a few other things:

- Have you found a supplier (or scrap yard) for the sheet steel yet? You're going to want to know what the prices of material are going to be. Also, most new suppliers sell in 4'x8' sheets so you need to have it sheared down to whatever sizes you can manage. There are usually additional charges for shearing.

- If you're going to sell the things you produce they are going to have to be very professional looking and different from what is already out there. You aren't going to be able to compete with the CNC machines that can cut that horse out in 60 seconds - perfectly and with no clean up required.

- Can you weld? Cutting out a shape without being able to attach it to something is going to be exceptionally limiting. I'd argue it's not even worth doing if you can't weld.

Take care,

John P.

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Reply to
John P.

Here is the 30 amp ones.

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The 20 amp one I will have to look up. The orifice size is the same as the 30 amp ones, so I would try the 30 amp ones first. The 20 might put you in a speed range for smoother pulls?

Reply to
svande48

20 amp 9-8205 30 amp 9-8206 40 amp 9-8207 I use the 40 amp tips at 30 amps and get a fairly narrow kerf (.030) at 135 inches per minute cutting 16 gauge CR. Here is where I buy mine. I gave up on my local supplier when they sold me some old style HF start consumables and later claimed they didn't.
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Reply to
its me

These two pieces are definitely done by machine, and based on clip art.

SGF> I'm sure your right about these items being done by CNC. I do hope I will be able to do similar projects, realizing the clean up will more and that it will take longer.

SGF> I have a Thermal Dynamics Cutmaster 51. The Input Power is 208 / 230V, Single Phase, 60 Hz, 39 / 37 Amps with a Duty Cycle of 40% at 40A. I also have a capable compressor.I believe the Cutmaster 51 is rated to cut 1/2' material but probably more realistically 5/8".

SGF> I haven't bought sheet metal in years so I can't say if I a good deal or not, but I bought a 2'x10' (half sheet since their fulls are 4'x10') of

16 guage sheet metal and a bunch of 20 & 16 guage scrap pieces. The scraps would make up about the equivilant of about 2'x6'. I can't locate the receipt but I think he charged me $75.00 for the sheet and $50.00 for the scraps. I thought he could have done me better on the scrap pieces. I know these prices vary throughout the country.

SGF> I can't say I plan to sell anything but I wouldn't rule it out. What you say about the CNC makes perfect sense.

SGF> I can weld. I wouldn't want to submit close ups of my welds to this group but I'm capable enough that I made a box truck ladder rack with walkway from scratch five years ago and it's still holding up without incident. On an unrelated note John, I looked at your Website from end to end; nice work.

Reply to
SGF

I cut out 5 pointed Texas Stars on the CNC all of the time :-)

Maybe what you want to try is to cut the star - with maybe the inside corners not cut - but all others and lines. In other words - route out with a router the star but when the router comes to the center - stop and skip over a bit - so the star can float on these 5 internal areas. Make the routed lines the width of the nose detail of the plasma torch you are using. So it fits down and glides around. Something like that.

Martin

Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH & Endowment Member NRA Second Amendment Task Force Charter Founder

sgf wrote:

Reply to
Martin H. Eastburn

Until one year ago I had never touched any piece of metal working equipment. I can assure you that if I can master the Plasma torch you can too. :-) It honestly just takes time and patience.

That torch will work just fine! Personally I find that even cutting

1/4" is normally too thick for art. 1/8" material or slightly thinner is usually best. Especially for pieces that will hang on the wall. (weight ya know...)

That sounds pretty high to me. Especially for the scraps. Man, $50??

In Dallas we have a place called Gold Metal Recyclers. It is basically a big junk yard, but they buy metal by the pound and they'll sell it the same way. Anyway, I purchased over 1000 lbs. of sheet stainless steel for about .30 / lb. It was all in sheets of 2'x4' to

4' x 4' and they were obvious scraps from a laser cutting facility. You need to see if you can find something like that anywhere near you. In essence I paid about $10 per 4x4' piece.

Having said that, even when I purchase mild steel new it's far less than you paid. You might want to start inquiring about how much they are charging per pound and do your comparative shopping that way.

As long as you can make the metal stick together it's all good! That will allow you to put hooks and standoffs on your work so that it mounts on the wall or stands on tables nicely.

And thanks for the compliment on my stuff. ;-)

John P.

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Reply to
John P.

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