Bending Steel With Plastic Tools

my dad has this $20 Harbor Freight sawzall and somehow he lost the blade guard for it I've always wanted to try to press form sheet metal using 3d printed forms I haven't really ever seen that done before and it seems like a fun project so I'm gonna see base just on photos I can find out what the blagger looks online design one cut the sheet metal and then hopefully design some forms that'll let me make a functional end for it so let's see if we can do it this is the best picture of the blade guard I could find and it looks like it's made of two parts riveted together the blade guard is where all the hard features are it has bends all the way around the perimeter which isn't too bad but they're right next to a hole and that's something you really try to avoid in sheet metal because it's very difficult to get the bend made without distorting the hole and then inside the hole you probably can't see in this in this photo it's formed with a radius all the way all the way around the edge and that you can't do with normal bending that is a some kind of punching or forming operation and so I took some dimensions off off the sawzall came up this and just for reference this is a cross-section of what the form feature looks like and this is the part I'm most concerned about for pressing with 3d printed parts because this is a lot higher pressures and forces than you would get for a simple Bend because you're actually compressing and stretching the steel a lot more and so I'm worried that I'll either just shatter the the die or smush it or something like that I'll make some some drawings and we'll go cut them out I'll be cutting the parts out using a CNC plasma cutter I'll be cutting them out of 16 18 gauge steel and if you haven't seen a plasma cutter before it actually cuts conductive metals using electricity and the way it works is it creates a jet of ionized gas in the case of mine it's air and this allows electricity to flow from the nozzle to the workpiece and the electricity basically forms an arc which delivers an enormous amount of heat to a very small area which just cuts through the metal and they're super fast and super handy for work like this I 3d printed this die or former I don't know exactly what you would call it but it's basically the space below the sheet metal part that I want after it's been folded and it has a registration feature on top so that I can take the sheet metal that I just plasma cut and it'll hold it in the right spot and then when I bend it it will wrap around this block and have the right bends in the right spots with the right angles now to bend it around this form I need another form or Die which goes on on top of it which has basically the space of the air or whatever above the part and that's this so it has a cavity in it which has the shape of the space above the part and then I'll put this in the press and shove it down really hard and hopefully it'll bend this thing to the right shape now there's actually still a problem if I just try to set this on top and press it it's not going to be in the right spot and so I made this extra little frame so this is a pocket which I can put the lower form into and I'll hold it in the right spot I can put to this upper form has bushings that go around those rods and this will locate it correctly in space take it over to the press and give it a smash and see how it how it does all right looks like the forum is mostly undamaged is in there tight this is okay there's actually damage or poor bending at the top this is actually to be expected generally speaking when you're making sheet metal parts you do not want holes in your bends because you have this problem that the it distorts the part when you try to bend it I think I can actually change the design of this too to mitigate that by pressing this before I start folding it to lock it in place this part was pretty difficult to get out of the upper die and the reason for that is it's not actually square it the flanges are bent out a little bit you might be able to see it if I put a square against it and that basically wedged it into the mold when I when I was done and the reason for this is it's a it's material property of the metal the metal has some springiness to it before it will actually Bend and so I'm bending it to a 90 but then it pops out a little bit if I want an actual 90 I have to bend it beyond 90 which I can't do just by coming straight down with the press because there's no clearance to get under it so one of the neat things about 3d printed tooling is that it's a lot easier than with machine tooling to get some kind of action that can fold the flange under and then come back out because I can print whatever geometry I want without having to do really more work than a little bit of design so here's a quick demo of the spring mecha I was talking about I have a vise which is acting as half the form I have some aluminum which I'm forming and then I have the top of the form which is just a piece of aluminum bar just like the steel it's wedged in and you see it Springs out I just can't get a 90 degree Bend with anything that yes tissa t alright top div' - and this one's pretty similar to the previous one and the main difference is it has these two big holes in the top which allow some pretty stiff Springs to pass through the die and the way that this will work is I will epoxy this little plate that I cut on top and then the springs will go into the holes and then I have this other plate which I need to decide how I'm going to attach it I'll probably just weld it maybe although I'm a bit afraid of annealing the springs I'll probably just glue it it'll be on these Springs and so when this comes down to to form the part I first have to compress these Springs which should firmly clamp the part and prevent that top from bowing up and giving me this very undesirable shape that I have very nice very very nice nice clean bends there's no doming or flatness on the top significantly improved 3d printing tolling seems to work pretty well for making bends and sheetmetal but what I really want to do is make a formed feature and so a lot of stamped parts and and if you look looking at the photo for this part online there's actually a formed lip around the inside of the part and I want to try to form that so I made another set of dies this one actually has a opening where I will try to press the sheet metal into this hole and it has a radius all the way around and hopefully I can smash it in there and get a radius on the part and I have a matching die which hopefully does the Smashing I don't have high hopes for this I I've seen dies before that do this and when I visit factories and this doesn't seem quite right it's uh it's definitely going to put some serious strain on the part and so I'm gonna actually start with a much thinner piece of galvanized steel excuse the really terrible cut quality I haven't actually cut this before and don't have the Settings tile but the the slot in the middle is is generally right so this will set on top of this die and we will smash this die into it well it would appear I installed my diet wrong [Music] so I made a giant error when I was going to press that I installed the upper die backwards so the die smashed into basically a wall which the press completely demolished now the ease with which the press demolished it was shocking but also probably indicates that this material just isn't gonna work but I kept on smashing just to see if I got anything out of it kind of there's a bit of a formed edge in there I'll have to reprint this but I'm gonna try it again with some slightly thicker material because I don't care if I destroy this this jig so I've got some 18 gauge steel here let's go throw this in the press all right I just pressed that off-camera because it's the same thing that I've done every time so it actually looks like it formed most of the feature it's pretty decent looking actually it doesn't look like other than the damage I do to the form with the press it doesn't look like actually damage to the form either bottom form is looking good as well Wow so it's looking at this partner I just realized I made a big error in the design of the form so this form is only designed to basically put a radius on the slot that was already formed in the part the slot will get a little bit wider because it has to to form a radius but it doesn't actually really widen it there's not enough material to stand it up straight which is what I was going for and it's because I just designed it rolling this this needs to first form the slot to be wider and then radius it and so I need to make a tool that does that unfortunately I don't have a 3d printer available right now so I'm going to machine these just see if it works because I'm really curious to see if this work all right you got some stock in the mill I'm gonna make it have some aluminum bar stock and hopefully this works [Music] [Music] we have ourselves a die now given that my original goal was to see if I could form sheet metal with 3d printed parts this is cheating just a little bit it's only half cheating because I'm still going to use a 3d printed half of the die I just really want to try this and this only took maybe 15 minutes to machine on the CNC so gives me that great sense of instant gratification that I'm seeking back in the press we have the aluminum die in there everything's oiled up so let's see if we can get some forming done there goes the die although I think I might have gotten it formed before I exploded the die this is a lot more carnage then and I thought so it looks like what happened is that I exploded the inner die which exploded the the outer die so that that dies toast but this looks pretty nice so did you look at this looks like I formed the future before I exploded the die I'm pretty sure I could do this on a 3d printed die the this die the machined one is loaded totally under compression and so I don't see why it wouldn't survive the process this one is loaded under attention it's trying to be pulled apart by the sheet metal that's probably what broke it apart I could probably also survive if I just made this a bit thicker or made it out of maybe a different resin with a higher yield point yeah success half cheating just need to bend this into the final part and I will call it a success reviewing the footage of the press I think I understand why the tool broke and I don't think it was due to the pressures and forces of forming at least not the outer tool the inner tool might have broken from the pressures it kind of looks like it did but the outer tool when I was pressing it it was actually cocked a little bit and I think what was happening was that the bushing was camming onto the guide rod and what camming will do is it doesn't matter how hard I push with the press here it will not slide I can literally push with infinite force it won't slide harder I push friction is generated here that's more than the force and that's it so I think the press just snapped the tool in half all right so to finish off this formed piece I took the original form and milled a pocket in it to make space for this because I don't have a form that will hold this the normal intent would be to first do the bending then form this feature but since I destroyed my form tool I have to do it out of order all right due to the complete and total failure of the one minute epoxy I've reconfigured the spring press a different way well see how we did so we have a nearly totally flat top with a formed in feature nice bends nice I am really happy with this part the second part of this blade guard isn't it very special I can bend it normally so I'm gonna just bend it in the vise break we've got our two pieces just gotta build them up now so there we have it a 3d printed form bent complex formed and it looks great the only thing I really want to do after I make sure that it actually fits the saw is to powdercoat it so overall this process is quite promising I think with the few tweaks I could have some tooling that I'm printing that would allow me to make maybe a hundred or more of these and that's really the point of making the toning it really doesn't make sense to make the tooling to make a single one finally one of the single one I probably just would have actually machined it out of a piece of aluminum or something rather than trying to make it a sheet metal it's a pretty cool concept and the things I would like to do in the future is fully 3d print the molds so 3d print this this forming operation here all right scratch that I really didn't feel right saying this was a victory when I only have one that actually sounds a whole lot more like first-place loser to me so I printed another set of forms and I actually noticed a small interference when I was looking at the CAD between the interface of this form in the face of this form and it would tend to split the this form apart like a log splitter and I think that might be would actually split the form apart before so fingers crossed I hope it'll work this time I got everything else fixed up and very presumptuously three blanks ready to be pressed so let's give it a try we're starting off with the side bends with doing things in the correct order this time [Music] well so much for the epoxy yikes I realized that my super optimized even lower bottom form was bottoming out the whole press assembly before I could get a full stroke so I've put a previous form underneath in we're gonna finish off this press alright that operation looks pretty good so I'm gonna go for the inner form now this is the setup that was intended it's pretty cool because you can have the part you leave the part as it is and just replace the top die I have my new mini die insert it in here and I'm gonna give it a press sounds like I exploded the die bummer so it's definitely presumptuous to cut three three blanks here's the broken apart form it's pretty cool how perfectly symmetric it broke here's the part it just about worked the front edge is slightly and completely formed but I'll call this almost a win I would use this part it's it's basically good and I think this is a good stopping point you certainly can 3d print forms and form relatively thick gauge sheet metal with it at least once I think you could do it more than once with maybe a bit more section a resin with a higher UTS or maybe modifying the future a little bit or doing in two passes so it's less aggressive this tool was definitely very aggressive but overall I'm pretty happy with the results and I feel like I got a good feel for what you can do I'd really like to make a form that has some kind of action on it either to get 90 degree walls or some other complicated feature hopefully you enjoyed this if you didn't I have no idea why you're still watching this and I'm out of here Thanks

Channel: Stuff Made Here

Views: 1,342,640

Keywords: sheet metal, 3D Print, forming, dies, rapid prototyping, 3d printing, 3d printed, 3d printing ideas, press brake tooling, 3d printer, sheet metal forming, how to, hydraulic press, plasma cutter, 3d printed tools, metal forming, 3d printing business, metal forming processes, metal forming press, press brake, press, stereolithography, SLA, press brake dies, sheet metal forming machine, sheet metal forming press die, sheet metal forming die, metal bender, bending sheet metal

Id: WuY2-OrT9ig

Length: 20min 2sec (1202 seconds)

Published: Wed Mar 04 2020

Reddit Comments

[u/AdditionalWrongdoer]

Great video: no music, no unnecessary intro’s, great explanations.

Please make more videos.

Do you have a channel?

[u/danny_ish]

You should say your channel name in your videos, or drop it in comments. Also, how about a shop tour one day? Cool videos, ill look forward to seeing more

[u/Br0kenrubber]

Awesome stuff, I enjoyed watching that. Now I need to watch all of your other vids, keep it up!

Also what plasma cutter is that?

[u/Gold_for_Gould]

Wow, loved the video. I learned a lot. Hope you keep making the great content. This would probably be appreciated in r/MechanicalEngineering too. Cheers!

[u/nitram_gorre]

Kudos on the process. I'ld be curious to see if this can also be replicated to some extent using an FDM printer.

[u/22plantmom]

I was hoping to hear you say that die died

[u/shpider]

You have a CNC plasma cutter... Why not cut the hole after bending?

[u/Iguessimanerdnow]

Why not just mill the die out of aluminum?