I've wanted to build one for a while. I used to have a customer with an automated Behringer cold saw and watching that thing slice through thick walled pipe was inappropriately arousing. I decided I needed one, but couldn't find anything on the market that was in a hobbyist's budget. Shortly after, the Evolution cold saw was released. I thought about buying one but it's just a cheap abrasive chop saw (stamped base) where they used a low speed induction motor instead of the screaming universal motor. It didn't stack up against the saw I had imagined to build, so I didn't buy it. ...nor did I build the saw of my dreams.... It's still on the to-do list.
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- Thread starter nsaspook
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Yeah I thought of going that route, kind of, but was going to add another speed reduction to a abrasive chop saw, making a spacer and toothed belt to keep the blade direction right. But I had a brand new 2HP motor sitting on a shelf and some insert type ball bearings so started to design one. Bearings like these but 1" shaft-
https://www.grainger.com/product/36...umRoCQ3EQAvD_BwE:G:s&s_kwcid=AL!2966!3!264955 That type bearing with an extended inter race, snap ring and set screws allow things to be built easily. I have a 6"x48" belt sander I built too made with them. I also have a big stock pile of used aluminum plate that I bought over the years from a scrap yard that I use for the rest of the build.
I even took the time to make some pretty nice sheet metal guards for the cutoff saw. I too wanted one after using them at work.
Here is something my paternal grandfather used to do. He was the "Master Mechanic" (repair shop engineering supervisor) for the Georgia Coastal and Piedmont Railroad back in the steam engine days. One of the things they had to do in the shop was the lettering on rolling stock. Using a Pantograph from an original stock font they could enlarge it to any size needed. It would be redrawn on card stock like that used in a manila folder. Once the card stock was lettered, it was pin pricked about every 1/8 to 1/4" along the outline of the lettering. The card stock would be placed over where the lettering was needed, and a small bag of talc dust would be tapped along the outline leaving small dots of dust on the surface to be lettered outlining the letter. Once all the lettering was dusted onto the surface a mixture of very fine gold dust and shellac would be used to fill in the lettering outlines or just plain paint as needed.
Pantograph - Wikipedia
Pantograph - Wikipedia
I have an idea that I've been planning to try, before committing to building a large CNC plasma cutter that takes up the same shop floor real estate as a car, using that Pantagraph concept with my CNC mill. In your picture above, the "fixed point" would be a robust anchor into the mill column, the point labeled "original" would be a bearing pivot assembly bolted down to the mill table, and the point labeled "copy" would my torch head, floating in the air somewhere out in front of the mill. I would set up a temporary table underneath the extended torch head; something that could be folded up and stowed away so as not to permanently own a space. It probably wouldn't be "CNC accurate" but it would probably be a lot more accurate than my hand, and good enough for just about anything I do.
Interesting that you described it as enlarging a stencil, which is the same way I want to implement it. Most descriptions of this concept put it forth as a method of shrinking, not enlarging. For example the Pantagraph engraver, which makes tiny engravings from large patterns/stencils.
I remember playing with it years ago and it was tricky to use. Not at all easy. They seem to very popular for quilting of all things. Also, for routers and engraving. What you're talking about is similar to what was used for ganged oxy acetylene burners on a table to cut out multiple identical pieces at the same time from sheets of plate steel using a small model piece to trace around. If I remember right, it had 6 to 8 ganged torches. I had a hard enough time lighting and trimming out 1 torch so was in awe that they could get that many going at once in unison. I still have the old man's wooden "tool chest" with some of the pricked-out letters and the talc dust bag along with a few envelopes of gold dust. Don't remember what happened to the pantograph but was probably thrown out long ago as it was in pretty sad condition due to its age.
Where I served my apprenticeship we had a pantagraph cutting torch but they don't work or look like the copy pantagraph Sam showed. They use a pattern cut out of sheet metal, we used 1/8" plate, and it gets mounted to the stand on an arm above the torch. Then ther was around magnetic rod driven by a motor that would move around the pattern. The torch head was mounted so it and the magnetic rod are on the same center line. so the torch would then cut out the pattern on the metal.
Ours looked pretty much like this homemade one -
I came across those when researching Pantagraph operations/applications, and while they're cool and I'd love to have one, I think they're not really the same thing despite what the DIYer in the video called it. I think the commercial machines he emulated are called "pattern machines" or "automatic cutting machines." Here's one such, maybe the similar to the ones you worked with.
The pattern machines have similar geometry, but with an actual Pantagraph, I think the requirement described by the DIYer of offsetting all the edges by the torch radius is not required.
No, they are not a "true" pantograph except for the fact that the "model" for the cut does not have to be the same size as the cut piece. Never used one (was a welder/fitter, not a burner except as needed for fitting miscut parts) but would think the model was a fixed size reduction like 1/4 scale or such. The big difference is the pantograph is scalable to whatever scale you want and not fixed.
That actually looks more like what we had. They go by different names pantagraph, pattern machine, ect. Some of them are what the maker called them and others are what operators called them. Never saw one that you didn't need to under size the pattern though. The 2 hinge geometry is one of the reasons for that, but the big reason s are the diameter of the magnetic follower and the diameter of the torch kerf. Those have to be considered. We only had one size of follower but depending on the thickness of plate we figured in the size the torch removed when cutting.
In reality though the term pantagraph should only apply to what Sam showed. A way of using a parallelogram to enlarge or decrease the size of a item. I also at the last place used a manual Deckel pantagraph mill to make carbon electrodes for EDM work. Then they bought a CNC electrode maker. Like this one -
Here is another very interesting tool similar to the pantograph. Proportional Dividers from K&E. I have a set of them around here somewhere but never really found a use for them. There is a thumb screw on one side of the joint to loosen the pinion and another on the opposite side to then turn the pinion on the rack in the divider legs to the engraved proportion scale setting. The front side shown is machine engraved 10 - 110 and has an engraved veneer to interpolate between the leg engravings. On the back of the case is chart for ratios and the settings for them to use on lines, planes, and solids. Also settings for miscellaneous ratios such as miles:kilometers and etc. along with radius:chord. Or "For other ratios the setting equals 2000a/a+b where a is the smaller term and b is the larger term of the ratio." Just incase you wanted something other than the standards. This particular set has much finer points than mine but they were replaceable and available in different sizes.
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That technique is kind of fun to scam people. With camera firmly positioned, you photograph a sketch on a sketch pad. Then you tear off the sketch and record the hands moving down a blank sheet of paper. Then a bit of patience and Photoshop you add in parts of the first photo. It is much easier to do looking like a printer so you always have the straight edge instead of trying to fill it in like an artist would.
another version is to take a photo of something like a bunch of grapes. Then using Photoshop, dab at them to blur to remove some detail, then erase each grape little by little completely. When the page is empty, record the whole process backwards and it looks like you can paint a photo-quality still-life. Some people start out with a filtered photograph so it looks like a watercolor or oil painting to begin with. Usually, it's done with a photo of something on a white background to minimize the complexity of layers in the image.
The artist who owns that channel definitely has the video editing skills to do that, but I believe they also have the artist skills to do it legitimately. You should check out some of the other videos. If only just to call their validity into question one by one also (go ahead, don't expect me to debate each one).
Are you talking about a pantograph/CNC sewing machine? I dated a woman that was a quilter, and on a really good quilt she would send it to a place that did that sewing. An expensive quilt has a pattern sewn into it to keep the batting in place. For an every day quilt they usually just stitch around the edges of the squares to keep the batting in place. She did a few quilts for some customers that the CNC sewing was worth it to them.
I'd love to have a set of those. The big thing they are used for and were from what I know were invented for back in the 16th century(from what I've read) was to make drawings that adhered to the "Golden Mean". That was a really big thing for a few centuries in furniture, painting and gun stock making, for the carved design on the stock. That's what I'd want them for. I have a couple of flintlock rifles I started on but then life got in the way. Still on my bucket list to finish at least one of them before kicking the bucket. I did get the locks them selves made and the barrels fitted with the breach plugs and into the stocks but....
