DIY CNC Press Brake in Action

Patreon Link: www.patreon.co...
Instagram Link: / craigsmachineshop
Please direct all correspondence to:
Craig's Machine Shop
2753 E. Broadway Rd Ste. 101-PMB416
Mesa, Az 85204-1570

[@14768]

This may be one of the most impressive things i've ever seen built in a home shop. Makes my home built tools look like garbage. Kudos sir.

[@37yearsofanythingisenough39]

Dustin do not put down your work. 90% of people cannot build anything.

[@craigsmachineshop2040]

Wow, thanks Dustin! Probably one of the best comments on my channel!

[@teddytavernier7522]

the edges are flared because you are air bending. The lower die is not making contact on the notched corners. Swapping to a smaller width lower die would help (you could just skim material off the top surface on the dies you already have) this will increase bend force , so consider how much tonnage you have to spare. Alternatively you could reduce the size of the notches, at least on the ends of the part, the smaller notch would let the die make full contact up to the edge. you would still be dealing with the issue on the middle notch since you need full depth to get it to fold upon itself. The best solution would be switching to a coining operation where the dies are machined to 90* ( or slightly over) and the die set completely bottoms out.

[@craigsmachineshop2040]

Thanks Teddy! Yeah, I think I decided to go with bottom bending with spring back. The bottom bending and coining will put the tonnage over the limits of my press. I ordered a 36" length - 3/8" VO 90 deg no bottom radius from Midwest Press Brake. I will machine my punch to 90 deg with a sharp point. I hope that will do the trick.

[@ultra4suzukisamurai679]

I built a press brake too, I use I micro switch that the ram hits at the bottom of its travel. The switch controls an air valve that cuts air to the pump. The switch is mounted to a fine threaded slide for adjustment and different angles.

[@user-lj4hv3ye6r]

The flare up its normal, u can make a smal slip in the corners or u got special dye check out rolleri presbrake dye. Verry Nice build.!!!

[@craigsmachineshop2040]

Yeah, I have been eyeing those recently. Maybe later this year.

[@rosswoolley2854]

Yes, KZbin finally came though with this recommendation. Craig hats off to you on the build!

[@craigsmachineshop2040]

Thanks Ross!

[@rickfazzini22]

Looks like you could give yourself more surface area making contact with your guides when cutting if you did the center notch first then the knock off the 45s Awesome set up! My son and I are building motorcycle parts out of our garage and we find we have to make a lot of tooling

[@testdevice989]

Nice setup! The puckering you noted at the end of the bend is occuring where the metal is not supported on both sides of the bend. The shiny lines left by the bottom die are an indication of where the material is properly supported during bending. Since the metal is cut on an angle that crosses this shiny line area, the bend is not fully supported for this last increment, so in puckers. If you prefer the angled cut, then the cure is to hold a block of metal inside the bend and lightly hammer the metal into shape. As a general rule, always support the metal for the full width of the bottom die, on both sides of the bend to prevent puckering.

[@craigsmachineshop2040]

Thanks! I ended up going with bottoming dies. They are both 90 degrees with no radius. The puckering is mostly gone now but I am over bending by 2-3 degrees. I think I may need to put a slight radius/chamfer on the punch.

[@JohnDoe-rx3vn]

TL;DR: A leaf brake is perfect for avoiding those flares, is cheaper, and you can fine tune the bend radius The flaring is where the material is unsupported by the bottom die. As the top punch presses down, it forms a roll or radius where the material is compressing. When you have an extreme angle inside the edges of the bottom die, the unsupported section has nothing to grab it and roll it, so it stays somewhat straight. The flare will become more extreme as the angle of the material increases. The pucker on the last bend is from the metal leveraging itself outward due to extreme pressure and proximity. Fancy software like Solidworks compensates by removing material where it comes together. You can alleviate the edge flare in a few ways: create a square shoulder that follows the edge of the bottom die, or create a tiny cut along the bend line starting where the metal starts to 'leave' the bottom die. The result for the first will be a properly bent edge (with an ugly square shoulder). The second will be a perfectly bent piece with tiny open corners where the flare would be. Neither is a perfect solution, but it is what it is. A leaf brake is the right tool for bending angled pieces with no flares, and for your application it would probably be preferable If you 'coin' the material in a 90 V die to press the flare flat, it will work but you will gouge a softer bottom die over time. Ask me how i know!

[@EZ_shop]

Hey Craig, a crack will develop in the corner unless you relieve it with a round cut where the corner would be. This will also alleviate the flaring issue in the corner. I suggest you drill a ¼" hole where the corner will end up. Good luck. Ciao, Marco.

[@craigsmachineshop2040]

Hey, Marco thanks! How is it going? I can't really make any holes in it for appearance reasons. I think I got it figured out though. I have to go to a 90 deg punch and die and do bottom bending instead of air bending. From what I have read, by using a sharp punch it will over bend slightly and form a 90 with a 90-degree punch and die. Ciao, Craig

[@b2manufacturing]

Gotta drill a small hole in that corner before notching it so it all closes up without that little bulge in it. When I use sheet metal software to Cnc plasma cut a 2d box to be bent in a press brake, it automatically cuts a tiny circle in the corner to prevent that bunching in the corner.

[@bad_mo_fo_24_74]

I wasn’t sure if anyone answered this. The flaring is from lack of support under the work piece. You’ll need a larger bottom die, but the solution we used was to have a backer plate. Basically bend two pieces at the same time and your flare will not occur. Alternatively, to save that extra material, you can hammer the with piece down to a die in a vice.

[@craigsmachineshop2040]

Thanks. I started notching after the bending to avoid the problem but the price of steel became too high and I had to abandon the new product line. Maybe in the future, if the prices come down.

[@Twistedstar0320]

4 months now, this channel still active? I find this very entertaining. Hope you make more videos on stuff.

[@craigsmachineshop2040]

Sorry, we are in our busy season. I hope to start making more videos around the holidays. Thanks.

[@Stefan_Boerjesson]

An impressive build. Working in the industry for many years and later designing heavy, high power stuff I know well the demands for operator safety. I hope You develope Your machines in the respect of operator safety, especially the hands.

[@craigsmachineshop2040]

Thanks, Stephan! Yeah, I plan on adding a laser on it somehow. Not much room. I will have to drill a hole in the channel for it. It will cut the supply of air with an air switch that is normally closed.

[@Stefan_Boerjesson]

@@craigsmachineshop2040 Thanks for Your reply! You obviously have huge skills in electronics and electrical matters but look at time 13:58. A light fence would have difficulties not knowing if it is Your hand or the object. I would suggest You to "two hand start", using both hands, well apart, for starting the activity. Your mechanical skills will surely quickly create clamping or holding devices that can fixate the object properly, before activating the press.

[@BorisSpark]

The flare that you was talking about, leave the thickness of material on that edge rather than a sharp 45 degree and it will cure that "Flare".

[@maholet]

Hi, nice device. To eliminate the flare you can swap operations, bend 90 degree the angle, then cut corners and then bend again.

[@craigsmachineshop2040]

Thanks! I think someone had mentioned that but I dismissed it because I was thinking I couldn't fit it on the shear after that. I guess i can take the tip of the notcher up to the bend.

[@SmallPressBrake]

great job

[@JAMESHOPKINSIBXCNC]

Ok first nice job!! Second your flair is part of sheet metal work. You can reduce the flairs by changing to a coining process. Usually a set of dies with a Vee of approximately 87 1/2* will produce a 90* bend. Basically you apply more tonnage/pressure to squeeze the material out to a 90. The squeezing will flatten the flairs some.

[@craigsmachineshop2040]

Thanks, James! Just the information I needed to hear, thank you so much! Do you know the tonnage factor for coining versus air bending? I am at around 6 tons for 18 gauge at 24". My press is 20 ton. What VO would you recommend for coining? I am at 3/8 for 18 gauge now.

[@JAMESHOPKINSIBXCNC]

@@craigsmachineshop2040 your V throat may stay the same but your tonnage is going to increase quite a bit. sheetmetal.me/tooling-terminology/coining/ try that link and see just what the differences are in coining verses bottom/air bending.

[@craigsmachineshop2040]

@@JAMESHOPKINSIBXCNC Thanks, that's what I was afraid of. Oh, I found a good PDF on Cincinnati's website. Says I can get by with 1 1/2 to 2 1/2 X if I use spring back bottom bending. That is, a 90 Deg punch and die but with a sharp point punch. I guess the sharp punch causes it to overbend a bit within a matching 90-degree punch and die. Page 3 - wwwassets.e-ci.com/PDF/Products/press-brake-capacities-brochure.pdf

[@JAMESHOPKINSIBXCNC]

Craig's Machine Shop bottom bending is not coining!!

[@fredbloggs4829]

Craig, mate, great video. I was quite amazed how important the thin gap between the two punches is. Could you share the reason why you want to make these corner pieces. But what quite a lot of want to know is, how you would make a complete box, not just a corner section. I really liked your CNC back stops. I think for the press you need an X and Y CNC stop, so no guessing how to align the centre. Really, a great video.

[@craigsmachineshop2040]

Thanks, Fred! They are pole base covers. They have to be 2 piece to be able to put around the pole after it is lifted into place. Yeah, I thought about using multiple backstops. I made the shoe 6" wide which should work with the products I plan on making. I don't have an extra axis since I will have to use 3 on the notcher.

[@luispablomartiz]

To much congratulations is amazing job… may i ask a question??? How do you control the lower/bottom limit to avoid hit and breake the bottom die??

[@MachinistDom]

I normally just hammer the puckering flat with a flat panel beating hammer and a lump of steel on the inside as an anvil. Comes out perfect.

[@craigsmachineshop2040]

Thanks, Dominic! That's a good idea. In the long term, I may need to go with a bottoming die but that may get me by in the meantime.

[@EasyFold007]

We miss you Craig :)

[@craigsmachineshop2040]

Thanks! I hope to make some videos soon.

[@homemadetools]

Very cool! We posted this video, and the other related one, on our homemade tools forum this week :)

[@craigsmachineshop2040]

Wow, thanks!

[@homemadetools]

@@craigsmachineshop2040 You're very welcome, this is a great build. Feel free to email me at "jon" at our website url, and I'll give you a coupon code so you can join our forum for free and post your videos whenever you want. Looks like you're one of us :)

[@n0rth3rnlight]

Regarding the press brake Craig. Imagine Your endstops with inductive limit switches and a light or better yet them hooked up to the cnc controller. Now that would be bad ass :)

[@craigsmachineshop2040]

Yeah, that would be pretty cool! I will have to think about that. Thanks!

[@elviralengersdorf4086]

The end 5mm cut. Later welding and pollish

[@craigedinger9629]

Thanks!

[@dean4075]

when i was in the fab shop years ago your dies thick dies for plate ,1/2 to 3/4 for light sheet like you are using , half the time we used a j hook die for two bends close to each other

[@revgro]

Another good build.

[@roylucas1027]

Nice video. Looking at your flair issue and having no idea what I'm talking about I'd suggest the following. Put the flares on an inside die and tap with a hammer till smooth. There, I've solved all your problems. Sorry I can't be of any real help. Thank you, take care.

[@craigsmachineshop2040]

Thanks Roy! I think I got it figured out. I will have to change the bottom die to 90 degree and machine the punch to 90 degree and do what is called bottoming with spring back.

[@alaskanken2132]

Great build 👏

[@funone8716]

Nice project. You need a DRO on the press ram for accurate repeatability.

[@craigsmachineshop2040]

Thanks, yeah I thought about that. The problem is that the air over hydraulics pushes in like .050 increments. I have to have a way of stopping the ram from moving past the needed point. Having the DRO might be nice though to know exactly where it's at for changing to different thicknesses and dies. Thanks!

[@kmcwhq]

@@craigsmachineshop2040 Perhaps you can eventually change up to a reg. Hyd. pump. Or a couple of large ball screws to provide the force. There are large presses that are ball screw operated.

[@CNCCookbook]

Be sweet if your stop on the press brake was a switch instead of a stop that cut out the foot pedal when you reach the stop. Very nice project and video. Thanks for sharing!

[@craigsmachineshop2040]

Great idea! I will keep that in mind! Is that The CNC Cookbook?

[@CNCCookbook]

Yes, it's Bob Warfield from CNC Cookbook.

[@craigedinger9629]

@@CNCCookbook Hey Bob! I nearly doubled my production recently when I realized (After Checking G-WIzard) I could run a 3/8" 4 flute rougher (Lakeshore Fire Plug) at 4200 RPM on my Tormach 770!

[@patobanion]

Very nice work!

[@derekchaplin2867]

Do you mind sharing where you bought the dies and die holders? I’m designing a shop press and would like to add a brake press setup like this as well

[@GregsGarage]

Slick stuff Craig. I don't know what the pucker is from. I'm interested to find out what others have to say.

[@greysky1252]

Just grind it off and call it a day.

[@craigsmachineshop2040]

Hey Greg! Thanks! I think what Ohmcrazy2 said seams correct "Problem is the “lever arm” goes to zero at that point and the force required goes to infinity thus no bending at the end where the radius starts"

[@craigsmachineshop2040]

@@greysky1252 I tried that. Somehow I don't think my customers will approve.

[@kylezellmann6811]

Well Done

[@FISHBREATHH]

Craig very nice job on your tools. Nice fit up on finished product. As far as that small area that dose not form up when you bend to 90 deg I think you may have to sand that smooth/flat or you may be able to use a brass hammer. hopefully someone else will have an answer. I would like to hear more about your business and the products you fabricate. thank you for the video. Dave

[@craigsmachineshop2040]

Thanks, Dave! Yeah, I tried grinding it down but it doesn't look right. I may go the route of a brass hammer or something til I change the punch and dies. I think I may need to go to bottoming punch and dies. The punch and die basically flatten it out. I make covers for light poles.

[@carman32377]

Very Nice Set up you have there. This has me modifying my plans. A suggestion to get ends of the bends flat. You could try a small relief, without having to change your set up, drill a small hole, the size of the inside radius right where the two flanges intersect. Same thing on the ends. Try to center the drill as close to the inside bend line as possible. That should help eliminate the blowout. If you would like me to draw up a sketch to better understand what I mean, just reply with a email address and I will send you sketch. Anyways, very impressive set you have. Hopefully you have information about the air motor and such in your link. Thanks for sharing.

[@carman32377]

Here is a example of what I was referring to. kzbin.info/www/bejne/e4aVqWSXp7d3atE

[@craigsmachineshop2040]

Thanks Donald! Not sure how I can add the relief holes while scaling production. I guess i can have them laser cut in but I was trying to make them with a notcher to make them as inexpensive as possible.

[@craigsmachineshop2040]

I got the air motor from redline engineering.

[@craigsmachineshop2040]

www.redlinestands.com/catalog/shop-equipment-c-327/general-shop-equipment-c-327_335/cylinders-pumps-c-327_335_366/redline-re20ta-replacement-shop-press-pump-p-2590

[@douglasdarby8584]

Very impressive. Thanks for sharing.

[@craigsmachineshop2040]

Thanks, Douglas!

[@ultra4suzukisamurai679]

Where did you purchase the die holders?

[@banger355tw]

Would it be an idea to make a 90 degree dolly with a toggle clamp to hold the already formed corner bracket in position and give the flair a sharp wrap with a hard plastic hammer? It might lower it without creating any excessive marring of the part.

[@craigsmachineshop2040]

Thanks, yeah I thought about that and had a few comments also. I'm trying to reduce the number of steps in the production process. I am going to be trying to cut the angles after bending and see how that goes.

[@salahzenieh2515]

Your channel is intriguing and mysterious. I have watched few of your videos but I cannot tell what you do. It seems you make a product(s) of a sort, but I cannot tell what it is. Or are you a job shop? Would you take on small batch manufacturing of parts? How do I contact you? Do you have a website, if you do sell a product. I am subscribed and will continue to watch maybe I will figure it out as I do. I certainly like the way you make your tools and how you experiment.

[@craigsmachineshop2040]

Oh, sorry. I haven't been keeping up on the comments. No, we don't do jobshop work. We make electrical parts. Thanks!

[@3dkiwi920]

Very clever, although you could drive it all with a $10 arduino :)

[@elong70]

Nice work !

[@craigsmachineshop2040]

Thanks Eric!

[@brianm5684]

Couldn't you 45 the ends after you make the bends? That way the material is there for making the bend. I know very little about bending, just was watching your amazing video

[@craigsmachineshop2040]

Thanks! The sheet metal is cut on a shear. I can't cut it on the shear after its bent.

[@robertcarr5846]

Hi Craig do you have a computer model of the machine to share?

[@kelvinlennox2038]

hi craig im certianly no expert on this type of work but would putting a bit of oil on the die help with the problem?

[@craigsmachineshop2040]

Thanks Ned. I think I may have to use a different style of punch and die call bottoming that will flatten it out in the bending process.

[@washingtonrider211]

@craig Would you be interested in having a Zoom interview? I teach welding and robotics at the high school level and I'd love to talk to you about your journey and background!

[@craigedinger9629]

Wow, I'm kind of shy and not that well-spoken, I guess I could give it a try.

[@washingtonrider211]

Awesome! If you want to send me an email at [e-mail] we can link up and figure out the logistics. Its not a formal interview by any means, I'm just a high school teacher, but I wanted to provide content for my kids and talk to a cool guy about how he got where he is. Look forward to hearing from you!

[@craigsmachineshop2040]

@@washingtonrider211 Sorry, would love to do it but my concussion has been acting up. I will have to decline.

[@stewartfrye]

bigger hammer is always the solution, sorry duct tape works well too!

[@craigsmachineshop2040]

Or maybe both. Lol.

[@neffk]

There's a fancy type of rolling v dies that can solve your problem. kzbin.info/www/bejne/qHK6o6yHZa11nMkm34s