Pantogragh style tracing torch project

This project is a pretty much forgotten way to duplicating parts with a cutting torch or a plasma now that CNC has become the in word of the day.
Never the less I miss my old Victor DC2400 with its magnetic knurled stylus that would cut out any shape I could possibly conceive as long as I made my templets correctly.

My whole reason for building the tubing/pipe holder for my Craftsman lathe was to make this project.
This is the cad rendering of what I am building.
Attachment 5104
Starting off with a plate laid on top of 1 of my handy work stands I began placing the pipes into position
One of the tools I frequently use for projects like this is my bander. I find that using a steel band to hold things together is 10 times faster than tacking a lot of scraps to a plate to make a jig if I am only making a one-off When fabricating multiples then a fit up fixture if the only way to go.
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The steel banding also makes it easier to pull something square when you have half a dozen or so loose parts to contend with.
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And we hardly ever think of the simple innocuous jack screw as a real homemade tool since we mostly just grab a nut and a bolt with a short length of pipe to force the final piece to where we need it
No matter how close parts are cut it always seams to me at least that one corner needs a bit of prodding to get it just right. in my 150 odd years of doing this kind of stuff (well 50 odd at least) I bet I have used a million of these simple little tools. I actually saw some for sale at a machinist supply once and my question was WHY?
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First arm fabricated ready for clean up
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Thanks for posting this. Not everyone has the resources to acquire, or build, a CNC machine.

Hello Frank S,
It would be nice to have some dimensions posted.
I am thinking of all the things I need/want to use this for!

D.King
Nice and simple often makes the most useful tools.
Don't believe me? Just look at a hammer sometime.........:)

d.king ordinarily I just think up a probable size that I want then start hacking out what I want. In this case though I want to be able to burn 36" diameter circles and or parts up to 60" long since my old Victor DC2400 was very limited in the size department I am making this unit quite a bit larger. the arms will be about 25+" long at the bearing centers their separation distance is not at all critical but I decided on the primary arm to be 12" tall the torch arm or secondary arm will have to be sized to pivot around the primary
I am making my main post out of 3" oilfield pipe because that is what I had on hand also it will be much more stable than the factory torch was with its little 1 1/2" OD stem
these may help you out
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Attachment 5166
just click on the pictures for a full size view

Eventually after I get it built I will be making a burn table for it and most probably do like I did on the one I took to Kuwait and left there. I will mount the torch on a gantry that travels the length of the burn table. Doing that even allows for converting to a CNC burn table later on if I desired
this is what I have in mind with the burn table I will be able to place a 4x8 sheet on it and move the torch anywhere over the sheet I found on my old one that it really made things easy to make multiples of the same parts or change out the templets andcut up a whole sheet without moving it
Attachment 5167

For the bearings temporarily I will be using 2" OD 1" ID stamped flanged ball bearings the same ones I used in my rough terrain welding cart and my torch cart mod. these are not the best quality for the job but I have an abundant supply of them, they are also less than $2.00 each on Ebay. Later I will change them out for true angular contact bearings.

Frank S.
I see your not afraid to build your pantagraph on the sturdy side. I look forward to more photos as you progress. I have a pantagraph table "partly" underway. I have an old dentist's light arm I want to use after I add new bearings. After seeing yours I am eyeing my 2 1/2" pipe out back though. You have a good writing style too. Not bad for a 150 year old!

Thanks for the good ideas.

Bob from Canada

Bob; one of the main failings of my factory built Victor DC2400 was the post and the adjustable legs it came with. of cours it was also a much smaller rig than I am, constructing. I may wind up with a duel pattern support system due to the expected large patterns I could conceivably use on it.
Vertical movement while cutting due to vibrations or whatever is a huge enemy to the finished product. That is why I opted for 2 braces in each arm and the way over-sized post
Good luck on your pantagraph project. If you are talking about the arm assembly used to hold the big reflector-ized light over the dentists chair then it should be fine as long as the vertical movement parallelogram arms are locked.
As to the 150 year old part some days I really feel like I have been doing this type of stuff for that long LOL

A little time today to make some progress on my pattern torch
I had welded 1/2" thick ends to teh short pipe pieces then chucked them in the lathe and did a minimum clean up on them then with a 5/8 bit in the tail stock I drilled all the way through
Attachment 5186
then I used a " drill I drilled all the way through 1 part then on the second part I stopped about 1/8" short of going all the way through the reason for this will be explained latter
Attachment 5187
A few items for helping hands to hold the parts square to each other
Attachment 5188
the completed arm except for the ends that will eventually hold a drive motor and what ever torch I use
Attachment 5189

Life always finds a way of getting in my way when I want to build a special tool that will involve more than a few minutes time to construct.
then there is the Frankinizing factor which has plagued me since before I was hardly old enough to walk when I used to sit on an old blanket in my dad's garage playing with worn out engine parts as my toys to keep me occupied.
I started out just going to build this to have a simple round stylus on the top and to hold which ever torch I wanted to use IE ox-act or plasma. InitiallyI was not going to go to the trouble of making a proper drive motor for it. That was going to come later but I started thinking about a DC gear motor that I knew I had off an old satellite tracking system Sure enough it turned out to still function I counted 40 RPM on 12v Since the power requirements will be low I figure I can get away with up to 40vdc
which would probably yield upwards of 150RPM nearing the max voltage. So time to start looking around for a suitable power supply. all of te ones I could dig up out of my stock of recyclables proved to be way too large I for sure do not need a DC supply that is capable of a 50 AMP output
OK bite the bullet and buy a small 120vac to 40 VDC 5 amp power supply from Ebay and a DC motor speed controller both for under $25.00 I think. Anyway enough about that stuff for now.
Today I finally had a few minutes to do a little more work on the unit.
I found this cylinder rod clevis lurking in one of my parts bins that looked like it was begging to be used. Ok I kne wit was made of malleable iron but the stuff takes to a cutting torch well enough and welds just fine besides it meant I didn't have to cut out and drill a couple of parts just cut it up and grind the ends to fit my mounting post collar.
Attachment 5404
Attachment 5405
these are the bearings I am using they will be more than adequate for this machine and they only cost about a buck each
Attachment 5406
2 7/8" OD oilfield tubing and 3" ID pipe for the post and collar the set bolts are 1/2" gr 5 with flanged nuts welded to the collar the picture doesn't show but there are 4 of these welded to the collar
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Attachment 5408
this is the motor I plan on using
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All is left now is to mount the motor make the magnetic drive and the stylus plus the torch mount
Attachment 5410

Jon I'm glad you drug this one out of the vault. I tabled the project while we were making our move and just the other day managed to dig it out of the storage trailer.
Basically it is ready to use with the exception of a suitable means to make way to magnetize the stylus. I have tried cylindrical hollow centered magnets but they don't magnetize a stylus well enough to hold it against a pattern
Any suggestions would be helpful at this stage

Currently I am building a cutting table for it which will have a gantry for the torch to mount on this way an entire 4x8 sheet can be cut up without having to move the sheet of steel

Did you figure out how to make the stylus?

I have been following this build with great interest, as I am keen to build something similar so I can quickly cut multiple parts “in house”.
Good job!

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Originally Posted by NortonDommi

Did you figure out how to make the stylus?

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funny you should mention that.
I bought 100 round magnets with a 1/2" hole in them. I was hoping to stack several together and use a 1/2" steel rod turned down at one ends and knurled but even with a 3" high stack of them there was not sufeincent magnetism concentrated into the bar to cause enough traction.
Then I found a small round neodymium magnet without a center hole when a 1/4" bolt was stuck to the end the bolt seemed to have quite a lot of magnetic attraction to the side of the bolt. This prompted me to order a 1" diameter 1" long Neo 52 magnet when I stuck a bolt on the end of it I could pick up a 10" crescent wrench with the side of the bolt. So I am thinking that pressing that magnet into an aluminum housing that I can push a turned down knurled cylinder of iron bar into the end will do the trick. The only problem is I put the magnet up somewhere and haven't laid eyes on it in a few months :headscratch:
I get a lot of these projects started only to have them tabled by something else that comes up then it takes me a while to ever get back to them.
Even now I an seriously considering adding another 30 by 35 ft. addition to my shop building for steel storage. and a sepperated 40xy 50 tented area to vehicle storage between a couple of van trailers. because I have to get someplace covered for the CT electric my 49 chevy pickup Ed's 59 Ford and a couple of my Mack trucks so we can work on them without having to bring them into the shop

In the 70’s I had a similar pantograph with the knurled magnetic stylist you have mentioned. In fact, the stylus was easily removable so you could add a bigger diameter stylus to create the same pattern shape but larger. I think I had 3 of them. 1/8, 1/4, 1/2. They are great for making circles (or washers) of different diameters using only one pattern.

Anyway, I got tired of making metal templates so the magnet would stick to the pattern. One day I was in a terrible hurry and I cut a pattern out of particle board with a coping saw, sanded and cleaned up the edge. I just held the magnetic stylus against the wood pattern with my finger. As the stylus revolved I simply held slight pressure against the stylus and rolled my finger with it as it revolved. Voila! A perfect part! From that point on I rarely needed the magnet feature of the stylus. All of my stuff was prototype, usually one piece or rarely two. After that the only time I made a metal pattern and used the magnet feature was for producing a lot greater than 5-10 pieces. It also depended on the complexity of the pattern and how much time I wanted to spend on it in wood or metal. I say don't get hung up on the magnet. Try it with a dowel pin and see how you like it. YMMV! :-)

Edit . . . I forgot to mention my parts were small. My cutting table was maybe 2-1/2 ft x 3 ft so I could stand right next to the stylus and reach over to press against it. Probably wouldn't work on a 4 x 8 ft table. All the best

Edit, again . . .! If you put one of those rubberized sleeves over the stylus (like used on some tubing, or vacuum covers on carburetors) the dowel pin might have good traction against the pattern with slight finger pressure.

Did you ever get it to work? I see you building a table for it but can't find a shot of the finished setup.

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Originally Posted by Sleykin

Did you ever get it to work? I see you building a table for it but can't find a shot of the finished setup.

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I have used it manually without a drive on it but getting around to finishing the drive motor seems to be one of those round to its

At long last I finally got fed up with having the Pantagraph torch taking up space and not being reliably useable. I started building this thing back in 2015 a couple years ago a built a burn table for it last year I made the drive motor this week I really needed to finish it. I made the controller for it complete with on off Sw forward reverse Jog and speed control. Thinking everything was good to go the stylist shaft with the neo magnet in it turned out not to be straight and it didn't have a good grip on the magnet between the bottom of the shaft and the top of the shaft so it slipped half the time I made a new shaft to fix that then having bought a machine torch a long time ago, from who knows where, turned out not to have either of the 2 US standard oxy fuel hose fittings Every welding supply I talked to said the same thing it either has the A size or small one or the B size larger one those are the only 2 sizes there are. Ha-ha-ha, fat lot any of those guys know. The threads on this torch were larger than the A actually they were of all things 12 mm but 20 threads per imperial inch What the heck kind of fitting is that? Sounded like something a very confused person would come up with, I filed the threads of to as round as reasonable then cut off 1 end of the standard hose splice couplings drilled them out and silver brazed them to the torch Problem solved Take that MR confused person.

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It works just fine you can see the controller at the top under the pattern
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<div id="blocks"> <div class="block b1 pngfix"> <div class="bimg"> <div> <a href="https://www.homemadetools.net/homemade-pantograph-cutter"> <img src="/uploads/261394/homemade-pantograph-cutter.jpeg"/> </a> </div> </div> <div class="head pngfix"></div> <div class="left pngfix"></div> <div class="right pngfix"></div> <div class="blockover b1 pngfix"> <div class="title"> <a href="https://www.homemadetools.net/homemade-pantograph-cutter">Pantograph Cutter</a> <span> by <a href="https://www.homemadetools.net/builder/Frank+S">Frank S</a></span> </div> <div class="tags">tags: <a href='https://www.homemadetools.net/tag/pantograph'>pantograph</a>, <a href='https://www.homemadetools.net/tag/cutter'>cutter</a> </div> </div> </div> </div>
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Out of idle curiosity, I spent 10 minutes looking at pipe thread tables. Both ISO & BSP have 19 tpi at that size, but I think the latter would be over13mm

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Originally Posted by Philip Davies

Out of idle curiosity, I spent 10 minutes looking at pipe thread tables. Both ISO & BSP have 19 tpi at that size, but I think the latter would be over13mm

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The thing about fitting sizes is to make things proprietary it seems there is always some little something which sets one type of fitting in its own category be it diameter of pitch or possibly even pitch angle. Manufactures seem to love to create their own standard of measurement sometimes combining 1 unit of measurement with another.
It's a moot subject now since I have converted it to the US standard torch hose fitting size.

A couple years back I ran across fastener which was 5/8 12 TPI. my first thought was it had to be a 14mm bolt with a 2.125 thread. It clearly was not since a 14mm nut wouldn't even start over the bolt and a 14mm bolt was loose but bound after a few threads due to the differences in the pitch. SO I ordered the factory bolts and bought a 5/8-12 tap Like TM51 stated who knew that 12 was and odd number.

I have been building several tap and die sets with strange TPI I have a set that is all 40TPI now up to 1" 24TPI up to 1" My 12 TPI set currently goes up to 1-5/8" in 1/16" steps A lot of Hydraulic JIC fittings use the 12TPI above -12 size

Here is a good one 37°and 45° flare fittings share the same threads up to -10 or 5/8" (7/8-14) from -12 or 3/4" ( 1-1/16"-12 for the 37°)(1-1/4"-12 for the 45°)and above, the 45° fittings are 1/16" larger in diameter than their similar dash sized 37° fittings but sitll 12 TPI all the way up