Technical Optical burning table

Maybe you guys can help with some technology or terminology for searching what I’m looking for.
Long time ago an every shop I worked in had a torch burning table with an electric eye optic follower. You draw full size what you want, put that under the eye, light the torch and go.
I want that exact set up but plasma. No computers, no programming, no files. Just cut what I draw, drew, or traced. Simple as simple gets but I can’t find it.
Anyone know the correct technical terms to search, maybe the supplier of such alien technology I seek?
Thanks

 

I believe they're referred to as optical trace burners.

 

On another note, I took a large pattern/ hammer form I made out of wood to a machine shop. I wanted a copy of it made in steel. (It’s 2-1/4” thick). All it does is flip a fancy flange for a wheel arch that holds a skirt. It’s got to be nearly perfect bends. My form works perfectly but only once because the edge gets ponded too far. Maybe I’ll make a couple hundred or so.
He said he needed a CNC file plotting every point along the radius, costing a fortune for that because some actually needed to measure my form and plot those curves.
I told him I made the wood pattern off the skirt with a pencil and a washer. He knows of know way to make what I need, no pantographs, no Bridgeport pattern followers, and he’s old school guy.
Just silly

 

https://theequipmenthub.com/product...tracing-machine-cnc-plasma-cutter-pantograph/

Old technology so probably out of stock permanently.

Any decent CAD programmer should be able to plot what you want easily.

 

My son is a CNC programmer/operator. I've presented him with a couple of "What-ifs", usually to be frustrated with the answers.
CNC ops are 'fascinating' to an old codger like myself, but I've worked the 'Dark Ages' of the auto trade.
Ah, @K13... The pantograph. We had one at the large trailer company I worked for.
Larger table, 10 ft. square. Could cut whole side panels for steel belly dumps.

 

Id buy it tomorrow!

 

The CNC stuff makes no sense for onesie twosie parts. The extra time and expense I’d just hand cut and be done with it like I’ve been doing and get it quicker.
Make 10 it’s probably worth creating the CNC program

 

If you know what you are doing it makes perfect sense. You make it sound like it takes hours to program. Unless you are doing super complex parts most fairly basic stuff can be programmed in a couple of minutes. Then if you ever need to make it again you have the file ready to go.

 

I'm too young to know exactly what you are describing, but it sounds pretty neat. Like an automated optical plasma pantograph basically?

The problem with modern CAD and CNC stuff is that you can't just fudge geometry. It has to be able to be described to the computer mathematically. It is lines, arcs, splines, surfaces, etc and a bunch of different ways of making the computer understand how to read that between different software, hardware, and file formats. Again, no room for fudging the numbers. My SOLIDWORKS software goes out 12 or 16 decimal places when it calculates stuff. If it can't calculate something (due to user error) it has a total fit.

Some shops can still use a tracking or cutout, but time has to go into cleaning up the geometry to make it actually work in the computer.

I would get some cheap or free 2d cad software that's easy to learn that can export a .dxf file that any plasma / water jet / laser shop can import and work with. Draw, print on paper to compare the shapes. Once you are happy send the file off and wait for your parts to come in. Once you get a hang of it going back to the old ways is pretty tough.

 

I once converted a line tracing torch to CNC plasma. The parts to maintain/repair the line tracer were no longer available. I had built this first:

http://www.accuratepower.com/Torch/ It's CNC and uses a hand torch. As usual, I was on a budget (I built it for ~$1500, all in. Including torches & tanks. Everything.)
A friend saw it and asked if we could use CNC to fix his tracer. It moved the torch around using servo motors and gear racks. Between the eye and the motors there had to be some processing going on. I never saw the box that used to run it though. It wasn't purely mechanical, there was a rudimentary computer in there somewhere. You could go purely mechanical with a pantograph and templates, probably not lines on paper.
To set a CNC machine up and use it you will have to use the computer. You can write G code without CAD though. It's coordinates and commands (G code only has a handful you need to know). You can write it in Notepad and change the .txt to a .cnc (or whatever) and run it. If you know the coordinates of everything, then you can write it. The CNC shop's problem with curves is that G code can read a center point, radius, start point and end point. Just an arc segment. The problem with a random curve is that it goes in as a zillion line segments, start x-y end x-y and so on. My CNC software won't accept a "spline" out of CAD (a sort of flowing curve) for this same reason. You can scan it and use software to extrapolate coordinates or use a digitizer to find them all. Or, your drafting table and a ruler to plot the lines manually.
Look for line tracing stuff in the robot realm, they use it too (with a computer). Mike

Edit:

I know what you are saying. But, there is no way I can hand torch like this:

I only made the one steady rest.
http://www.accuratepower.com/Rest/

 

When I worked in the tool room at EMD, GM’s locomotive division there was a Gorton mill and at some point it had a manually operated tracer attachment added, long before I got there. I imagine it dated from the 1940’s. Gorton later updated their tracers with hydraulics to make life easier on the operator.

Obviously that would be too small for a project like @31Vicky with a hemi has but that was some early technology from the days B.C., before computer.

 

So you started your statement with “IF”

In My world, I realize other peoples worlds are different, but in my world something always starts with me being under a car, paper scissors, pencil. There’s no drawings for this kind of stuff in my world.
The paper goes to cardboard or Masonite or luan plywood. That then goes to full mockup in place adjustments made, interesting curves or shapes added then I go trace that to steel.
Taking my hand drawn parts that might have a 4.477554” radius into a 1,8765 radius so it fits and throwing that to a cad guy to figure out and interpret my pattern into computer program seems dumb.
I’ve already got everything into the pattern, cutting it quickly and cleanly is all I need.

 

In the early ‘70’s my dad would take me to equipment shows. One I recall had a torch setup that mimicked a pattern. The torch was in a holder, a wheel/follower followed the pattern. I was to young to figure out how it stayed on he pattern, but there were many identical pieces of metal cut out on display.
I’m thinking now some type of spring loaded jig was used? We only watched it following the pattern, I guess the demonstration was over with. But I thought “damn that’s neat”.

The pieces cut out were fairly intricate as well, things like animal profiles, etc.

 

I used to use one of these in our fab shop at work-draw a thing on cardboard go to the machine and trace your drawing on to white paper and line a "magic eye"to a curve that led to your lines ,try it once to make sure you were on your piece of metal,spark up the plasma then press go!!! It was brilliant.......they scrapped it :-(

 

https://arcdroidcnc.com/en-ca/produ...le-top-plasma-robot-ships-from-asia-warehouse

I saw this on Finnigans you tube Channel. I thought it looked pretty slick until I looked up the price. To me it would only make sense in a commercial application.

Phil

 

I could have generated a dxf file for you for free, in an hour or two, working from no more than a good, substantially square-on photograph and a few basic dimensions — and that working from the other side of the planet!

 

All you/I need is a clear photo, without any angular distortion and a scale. I usually put a ruler in the picture. I import it into my CAD program, but that's just an image. So I measure, scale the image to make it 1:1. Then I trace the outline of the part and any holes or details. It's not that hard to do. You can download free 2D drafting programs and do it at home.

 

Do you want to try tomorrow?
It’s 48” x 16” x 2-1/4 thick
I’ll get those good pics tomorrow

 

Sure — if my wife doesn't have the entire day tied up already!

 

Used one in a fab shop I worked in about 15 years ago.
It used both plasma and a cutting torch. We had a draftsman draw the patterns for us.
Pattern had to lay flat and have crisp dark lines for the electric eye to follow.
You had to manually start and stop each cut.

 

Right, sometimes they had a lead in and lead out line too. That left a little titt to grind off vs a pierce hole

 

Back in the late 60's to early 70's I worked in a shop that had what was called a 'red-eye' system. It seemed pretty wild at the time as it somehow followed that pencil line.

 

Years ago, Hot Rod or maybe R&C had an article on how to build a tracer pantograph burner. The pattern was secured to the middle of the tracer follower and a motor controlled by a model railroad power supply pulled the pantograph arm, following the pattern with a toothed gear.
Several similar builds:

 

The problem you're faced with in your project is the thickness.... thinner material can be cut with plasma using a hardboard template to follow. (For you guys that will disagree, I'm talking about accessible, affordable cutting systems, I'm not looking for a pissing contest, I'm trying to help @31Vicky with a hemi )
But.... being in Cleveland, you may have access to fab shops that do have the type of optical-eye torch burner you need. They were very common in shops for decades until plasma and laser came into being. Try locating an old-school fab shop in your area...
Good luck!

 

Look into a “Vectorizing” app for your phone. It will cost you a few bucks but will allow you to convert a high contrast pic into a .DXF file. I downloaded “Vector Converter” recently for $10 with no subscription. Here is a water pump impeller that I happen to have a pic of, and the steps to turn it into something useful. I’m not suggesting that anyone needs to buy CAD/CAM software, but rather letting you know it is possible for the vectorized photo to be used by anybody with a CNC plasma table

original pic;


Vectorized;


Trim off what you don’t want and create geometry that closely follows the original contour. In this case I created 1 vein then copied the other 3



Then scale down to a useful size;




DUN!

 

That one project in thick, (so far)
I think I’m going to have a go at making it by laminating 3/16” plates then working the bevel by hand with flap discs. 3/16 because that’s what my plasma cutter can do fast and clean, plus (maybe he can help) there’s a guy down the road who can water jet 3/16 plate. He usually sticks to artwork type stuff but willing to help. Also said he can scan 8-1/2 x11 parts directly to file and press go. We will see.
The center most 3/4” of my 2-1/4” project is flat no bevel and could be aluminum because it doesn’t have to be anything but a spacer.

The other things I’m always doing is usually just flat plate out of lighter stuff. And usually notebook sized paper.

 

The most popular optical tracer by far is the Westinghouse HL-90. When Westinghouse stopped making them, I think it was Koike Aronson who continued to make and service them for a while. They're now discontinued but some NOS ones are still available for $5000+ {for just the tracer head}. There are some companies around that advertise repair capabilities for used ones. Usually flat rate prices in the $3000 to $4000 range. Obviously only a worthwhile purchase for someone who's currently operating a burning machine and needs a replacement part or repair.

The tracer really wouldn't be a good option to use with a plasma cutter. The max speed is about 40 inches/minute which is way too slow for a plasma on any type of thin material. Airco probably built more tracer controlled burning machines than all the rest combined and all the ones I've seen are cantilever type machines. The design has too much mass to be able to just speed it up to plasma speeds because the changes in direction would cause shaky operation that would result in inaccurate cuts.

I've had a 2 torch Airco with the HL-90 tracer for 25+ years. Probably been 10 years since I've used it, but I'm very familiar with the tracer's capabilities and drawbacks. If I had a current need for plate shape burning, the first thing I'd do is strip off the tracer and retrofit a cnc control to the existing mechanicals. For sheet burning, I'd look for a bridge type cnc machine that's more compatible with plasma cutting.

I'm pretty much retired now, but for the last several years prior, I found laser cutting to be so cheap and accurate that I'd have a tough time justifying in house shape cutting on anything within the capacity of the local laser houses.

 

Thanks, that was extremely informative.

 

Maybe something like this would work? This looks really cool. Looks like about 12k for a 4x4 table with the tracer.
https://arclightcnc.com/product/auto-tracer