Bending Thick Steel with 3D Printed Tools - Prusa PLA 

I have my printer setup for polycarbonate since I often need functional parts. Would that be better than PLA? It would probably last more cycles at least. Replying to an old comment I know.

@@paint4pain polycarbonate is superior to PLA I think in every way, IIRC it has a higher hardness and tensile strength. Probably your main consideration at that point is just the cost of different filaments.

@@EdKohlwey Thanks! That's about what I thought, it does cost about 50%-100% more per kilo, print speed is also way slower than PLA and you have to dry it to prevent hydrolysis.

I think that the misconception of PLA strength comes from assuming that its strength is kind of a "von mises" (aka. plastic materials (in the sense of deformation tolerant materials)), but actually is more akin to "mohr coulomb" (brittle materials, as unreinforced concrete, rocks, etc) with good compressive strength but really weak in many ways that other plastics are strong. (I am avoiding to say "brittle material models" vs "plastic material models" because it would introduce noise of definitions)

I really didn't expect the tools to perform as well as they did either.

Thanks for watching!

You just got to up your youtubing skills, there’s been videos on this for a couple years now

@@albertvillalobos1377 Please point me to a video bending steel this thick as I have not seen it.

I agree, printing the part slightly smaller and then attaching the first bent sheet to the part would massively improve life span.

I've already designed some radius attachments that just slide on to existing tooling but there will still be a need to print the entire tool out depending on the part. For example if you need to form a part similar to the part in the very beginning of the video. It already had flanges formed up so the tool needs to have that exact spacing to fit between the two flanges. Normally we would need to grind down existing tool until the part fits. The issue with prototypes is that the flange distance is likely to change and then a different tool would need to be made.

If you were going to make a tool with replaceable tips, it would probably be better to machine the base tool, then with the variable/consumable bits being softer than the base, you would probably never have to recreate the base. If you needed to make things only slightly wider, I would imagine you could probably get away with making the tips slightly wider than the tool as well, before you have issues.

I might start doing more videos in the shop to try to balance the electronics vs mechanical videos.

It looks like you're using the default 0.4mm nozzle - it'd be very interesting to see if a 0.8 or even 1mm nozzle /line width would significantly improve strength. It would certainly improve print time!

Have you tried annealing the PLA parts once printed? They say makes it stronger and more heat resistant. Some of the wear you noticed can be heat related as metal warms when bending it.

@@GroovyDrifter I did consider annealing but after doing some research, I'm not sure I want to deal with the the shrinkage that occurs as a result. I could use a thin rubber film that we normally use to reduce the tool marks caused by regular tooling to increase the lifespan of the printed tools.

@@UnreasonableSteve CNC Kitchen has a good video showing layer heights larger than 0.2mm actually get weaker. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-fbSQvJJjw2Q.html

@@UnreasonableSteve a much larger nozzle like you suggested may make a difference though

if your going to be hammer forming with the dies your probably gonna want to make them out of nylon . Or abs at a minimum...not guite as much tensile strength as pla but much tougher far as impacts go.(if have a decent compressor be sure and test out some homemade hammer heads for an air chisel...your shoulders and hands will love you!)

That's pretty impressive!

PLA is great when the characteristic you need is rigidity.

People think that pla is weak. Its not. It just have this fail curve where it does not do much of plastic deformation before failing. But its a strong material.

@@HidekiShinichi PLA is rigid (and brittle) af. if you need dimensional stability (unbending, unyielding), PLA win all other 3D printing materials

@@VuLamDang well.... Not that we have continuus carbon fiber or other simillar materials right? I wouldnt go as far as to say that pla is absolutly best from all availble for that. But it is certainly one of the best and probably the best if it comes to standard ones.

@@HidekiShinichi ha ha yes, I was hyperbole. I was refer to the common stuff, ABC, PC, PETG. Idk if PEEK is more or less rigid, although it is certainly not common

I have even designed custom printed back gauges for the press brake when you have a strange profile that you need to register off of.

It will definitely work, I would just put the bottom v die inside a steel tool holder that has walls on all sides. This would allow smaller printed tools without worrying about the v splitting.

Not sure about glass but the negative for carbon fiber is it becomes abrasive so not for mating parts

@@albertvillalobos1377 Its true that all reinforcing fibers are abrasive. For high friction/wear zones moly disulphide can be used to improve wear characteristics.

How is the filler added? I've never done 3d printing.

@@TheArtificiallyIntelligent Its melt processed in large batches. Molten plastic heated to temp is added to fillers (fibers with a de-clumping agent and compatibilizer). This is then blended until the fibers are evenly distributed (homogenous). This is then pelletized. The pellets are fed into an extruder. The filament comes hot out of the end of the extruder into a water bath and once cool and dry is wound onto a spool.

Hi Zach!

I think I will really print out my version of same thing, consisting of five separate pieces (one model printed four times + one model to hold two sets apart at exact distance) and give it to maintenance guys. It's so simple it can be printed even at high speeds with no problem, there are no overlaps and layers are situated correct way, so threaded rod which holds everything together shouldn't break it even when they tighten it too much.

Pla shouldn’t really be used for industrial applications, these guys got lucky because it’s a one time thing, but it’s better to reserve pla for artsy projects

@@albertvillalobos1377 Sorry, you are mistaken. Experts in the field are also using PLA for this application: www.thefabricator.com/additivereport/article/additive/need-a-custom-press-brake-tool-try-printing-it

We use it just as holder for bearings, result is practically XY positioning "table" out of smooth rods. In center are attached 3D printed parts to direct air from compressor into proper direction and they are moved in circular direction. There's practically no load, just weight of smooth rods, some thin aluminium frame and those 3D printed parts to direct air. But that's not important when holder breaks after slightly pressing one screw in hole.

Have them try out Markforged, you can get crazy strength from 3D printed tooling

That would most likely be a waste of time for a prototype or a small job for a part that we might not ever make again. Also, because it is a prototype, it is very likely going to change. The part size could change and/or the inside radius could change and then that tool becomes worthless. If it is a job that will be made over and over again, we would just order a real tool.

The tool that broke was 8 perimeters, 20% infill, 6 top/bottom layers. The first two tools were also printed like that and didn't but the forces were a bit easier to handle. The gooseneck tool that didn't break was 12 perimeters, 20% infill, 8 top/bottom layers. You could go 100% infill and it would probably bend even thicker steel but I would stick to at least 12 perimeters, 20% infill as a minimum starting point if you want to try to make your own tools.

@@ProtoG42 Thank you. Indeed, perimeters are more important than infill, at least in my tests.

@@ProtoG42 You don't need to go higher than 60%.. 100% infill makes the part shatter easily.. there is no flex.. you need a bit of flex at least.. 60% is a lot when you look at the density.. 3D infills also help with lateral forces.. Prusa Slicer has cubic that works wonders in all directions.. i'm an amateur anyways, but have tested a few things myself..

Thanks Peter!

¡Muchas gracias Gustavo!

Bending a 1" wide section of 10 gauge steel with a 1" V die requires 1580lbs. I'd rather keep going thicker than waste 12 times as much metal and plastic. The values obtained with the smaller forming tools allows me to calculate how wide of a flange I can form given a specific material and thickness.

@@ProtoG42 so keep going thicker man!!! I'm interested to see where this goes!! Lol 🍻

I totally agree! I will definitely try embossing sheet metal with this process and other types of forming.

For skilled people in manufacturing, 3D printing feels like a natural and well needed extension of our abilities. 3D printing is for everyone but it really shines in our hands, unfortunately the industry has been fogged up and not given the respect it deserves due to the likes of 3D printing nerd and anything making benchies. Since the Stone Age we’ve needed one tool to form a specific shape until now, that’s the power or additive, it re-writes our entire rule book.

@@albertvillalobos1377 completely agree. The amount of toys and crap that are printed are astounding. As a CNC machinist and gunsmith, I have tons of useful jobs for mine that's coming in the next couple of days.

The bottom die is less important unless you are coining which involves forcing the metal to take the shape of the bottom and top tool. All the bending in this video is referred to as air bending and the radius of the bottom die does not affect the part. For air bending, only the bottom opening affects the part. Most custom tools we need are the top forming tool. For most jobs, the bottom tool just needs to be wide enough such that it doesn't interfere with the forming. You want to use a bottom V-die opening of around 6-8 times the material thickness. You can cheat and use a smaller die, but generally we try to avoid that. For example, if you want to form a 0.25" flange on a part, you can't expect to use a bottom V-die with an opening of 0.75" as the flange will not be supported at both ends. Also, the top tool is more commonly the tool that needs to be as close to the width of the flange as possible and in the beginning case, the tool needs to fit between two other flanges that were already formed. I could have used any length section of bottom tooling and it would have worked. The other parameter that is always affected by both the top and the bottom tool is the amount of stretch that needs to be built into the flat pattern. Bending a 2 inch long strip of metal exactly in the center will not produce two 1 inch flanges. The length of the flat pattern will vary depending on the tooling used.

For sure, we already do that. Even for the radius tool, we would normally cut bar stock, turn down rod stock to the right diameter, cut them to size, and weld them together. This is just another tool in the holster to take advantage of. Read the articles I posted above and you'll see some of the other use cases.

Thanks for watching!

The gooseneck offset would be better with more infill but the other 2 tools in the video wouldn't benefit from more infill. 12 perimeters at 20% infill seems to be a great setup for non offset tooling.