# Bending Brake issues

Discussion in 'Workshop Tips and Secrets / Tools' started by 12notes, Nov 4, 2017.

1. Nov 4, 2017

### 12notes

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I build a bending brake last night, similar to this one, except the hinge:
http://www.biplaneforum.com/pdfs/brakeplans.pdf

I used 2x2x1/4" steel angle for the main components, and 2 pieces of 3" long 1/8" wall 1" DOM tubing and a 3/4" bolt for each hinge. The hinges are centered on the 1/8" gap between the two pieces of angle iron. I welded everything together. It's 78" long, with a bending area of 66".

The hinges are true, it swings freely without distortion. The small test pieces came out fine, including a 6" piece of 22 gauge stainless.

So I put in a 40" long piece of .040" 2024-T3 to bend a stringer, and the brake doesn't even start to bend it. Increasing pressure just causes the movable angle iron to bend away from the fixed angle iron in the middle well over 1/2". I'm not sure how this is even possible, it's bending in the direction slightly between the "legs" of the angle where the angle should be most resistant to bending.

The welds are good, the bolts haven't bent, and there doesn't seem to be any other problems. Has anyone ever had a problem like this, or even heard of one? This design has been made many times by many people, and they seem to work up to 8', mine is much shorter, so I can't understand why it's not even close to working here.

2. Nov 4, 2017

### Hot Wings

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If I'm understanding this right what you are seeing is kind of to be expected because of the hinge substitution. The full length Piano hinge is what keeps the movable angle from bending away from the fixed portion. Having only the 2 end hinges lets the angle flex under load.

Since it's already built and you have a welder adding a truss along the movable angles handle might be a reasonable option?

3. Nov 4, 2017

### TFF

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.040 is pretty thick on such length with a homemade brake. .060 is almost impossible on a store bought one. That is why big brakes are such tanks. The hinge line cant flex any.

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4. Nov 5, 2017

### Little Scrapper

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Put a longer handle on it. Leverage.

5. Nov 5, 2017

### BBerson

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I never bent anything more than .032" on my 2000 lb 10ft Whitney brake.
It would need a huge bend radius

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6. Nov 5, 2017

### Turd Ferguson

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Your brake is not rigid enough for the material you are bending. Look at the bulk of a commercial bending brake........there is a reason for that.

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7. Nov 5, 2017

### Hot Wings

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If you are serious about building a good brake get this guys plans:

http://www.macsmachine.com/

Not cheap (It is compared to a store bought one of the same capacity) or quick but it works.

8. Nov 5, 2017

### Pops

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My old friend and I built one from plans. Very good 8' brake. Bent wing spars for 3 sets of Bearhawks wing, flaps and ailerons from it and been using it for 5-6 years. Will bend .040 X 8' of 2024-T3.

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9. Nov 5, 2017

### Angusnofangus

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Nice looking brake.

10. Nov 6, 2017

### gammaxy

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I believe Hot Wings is right. I built an 8' brake from the same plans using this steel piano hinge: https://www.fastenal.com/products/details/0163489 I riveted it on using steel cherry rivets (CCP). Drilling all those holes wasn't much fun.

8' long bends in .025 is no problem. I've also done plenty of 3'-4' bends in .032 with no problem along with some shorter bends in much thicker aluminum. I suspect .040" would also be no problem.

11. Nov 6, 2017

### 12notes

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I've ordered a similar hinge from Wicks (all specs are +/- 0.01" from the hinge in the link you posted), I'll see how that does when it arrives. I'll weld it on so I don't have to drill all those holes through the angle, but I'll still need holes through the hinge for plug welding.

I can't swing the money or time for the larger brake, and I found that many builders of the Hummelbird substitutes 1/16" x 3/4" x 3/4" angle for the 40" stringers (used for alignment, not structural) I was trying to bend. I'll use that for the stringers since I'd have to stop work until the hinge gets here otherwise. I'll modify this brake next weekend, do some test bends (I have 4 already cut stringers that I'm not going to use), and report back what this thing can actually bend. I may reattach the end hinges and add the truss work to the handles as suggested, too, it depends on how ambitious I'm feeling when I start working on it.

Thanks, everyone.

12. Nov 6, 2017

### Victor Bravo

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All of the large, heavy "old school" brakes, Roper Whitney and Pexto etc. were designed to be capable of bending mild steel. To bend steel they needed to be huge and thick like that. A brake for bending .040 aluminum probably doesn't need to be a 10,000 pound boat anchor like the old school machines.

But IMHO many builders are overlooking other viable solutions to these tasks. You can go to a local air conditioning fabrication shop and have them do the big, long, difficult bend for a lot less time and money that you can build a (worthwhile) home-brew brake to do the three or four "major" bends on your HBA project.

In many other cases, you can have a bend put into a piece of sheet metal using a large press brake, then AFTER the bend is made you can trim the aluminum to the correct dimension. I've heard of people trying three and four times to get a piece bent to the right dimensions,a nd they threw away $100 worth of aluminum because they didn't have the setback and bend allowances right... and one side of the bend was .040" too short. In no way am I suggesting that having a brake in your shop is not worthwhile. I would sell my soul to have a big nasty old "boat anchor" Pexto 8 foot finger brake in my hangar. and I'd love to build one of the homebuilder's brakes onto a workbench. But no matter what, there could be some bends in a sheet metal homebuilt project that I would be better off having done on a huge$150,000 hydraulic machine in somebody else's shop.

13. Nov 6, 2017

### Hot Wings

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Probably the best option for a one time builder - PROVIDED - you make sure the shop can, and will, bend with the proper bend radius. Not all HVAC shops are up to speed when it comes to structural parts and proper bend radius.

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14. Nov 7, 2017

### BBerson

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I ground a nice radius on my Whitney brake. But most HVAC shops will not do that for you.
A press brake is for thicker metals. Or use extrusions.
I suppose if only a 1" flange is needed, a simple brake clamp might work. The Whitney brake can bend any width of flange, so is a massive cantilever beam from end to end.

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15. Nov 7, 2017

### Winginit

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We have had discussions on HBA before about the wisdom of buying certain tools or attempting to make them. One of my favorite sayings is "Knowledge is of little use until experience has given it meaning". Welcome to the experience side of making your own tools. I think one of the true joys of building is making something from scratch, or modifiying something to suit a purpose. It may be a tool or an actual part. Not all attempts work out well, and often require a second or a third attempt to get it right.
You also have to consider your investment in both time and money. Someone like Pops has lots of experience, but he also has lots of accumulated stuff to work with. He can pull off the building of a brake because he understands the need for ridigity and he has lots of scrap steel laying around and he has been fabricating things his whole life. Someone new to fabrication usually has to spend quite a bit of time and money and then finds that while the brake looks nice, it doesn't function as planned. Since you made the brake longer at 66" but can't get a good bend at 40", I really doubt that changing to a different hinge is going to solve your problem. Hope you prove me wrong, but I think its not going to work well.

I do admire fortitude and the desire to create things. Lessons learned usually help with later decisions. I'm reminded of Dirty Harry's well known phrase..."A man's got to know his limitations". Well builders can only learn their limitations by trying new things. Then they learn about the limitations of those new things. I have said many times in the past that I think its not a good choice to build a brake. To build a proper brake will cost almost as much to purchase the materials as it costs to buy a USED factory made brake. When you are done with the brake, the home made unit is lucky if you can get your material costs back. No one wants them unless you did a super job building it. The Used Brake is still worth what you paid for it and often you can get more than you paid. If it was 30 (or more) years old when you bought it, is it going to depreciate even more.

I realize not everyone has room for a lot of tools, but a 4 foot to 6 foot brake should be storable for most people.

Here is a brake currently available on the Evansville Craigslist which is near Louisville. https://evansville.craigslist.org/atq/d/1904-sheetmetal-brake/6354456919.html The fellow is asking someone to make him a reasonable offer. Probably $500 or less ($300) will get this brake. 10 years from now its still gonna be worth that much.

I have a 10 foot leaf brake...takes up a lot of room, but I got it for $800 at an auction. I also have a Chinese knock off of a "Heavy Duty" Tennsmith finger brake. After a little judicious buying and selling of some brakes that were adequate to decent, I stumbled on to this one for a bargain price. Don't remember exactly what I gave for it cause I bought several items, but it was less than$500. By the time I sold my old brake and a couple of the other items (slip roll and shear), I was way ahead of the $curve. What I'm trying to convey is that buying certain older tools like a brake is/can be a tempory investment, and in the long run they can end up costing a builder virtually nothing. You have to look at the long term picture rather than the short term expenditure. These things do take a little patience and planning ahead. Try to get these tools because you know you are going to need them rather than waiting until you have to have one and none are available. OK, thats my rant for the day. I hope 12notes brake works out for him, but I think other builders should learn from his experience. Last edited: Nov 7, 2017 Sockmonkey and Pops like this. 16. Nov 8, 2017 ### Pops ### Pops #### Well-Known Member Joined: Jan 1, 2013 Messages: 6,906 Likes Received: 5,818 Location: USA. I agree. Keep your eyes open for good deals on good used tools. My airplane building buddy for 40+ years got a deal about 4-5 years ago. An airline repair shop was moving out of state and had some equipment for sale. He bought a 4' stomp shear, a 4' slip roll, a 4' finger brake, a large pedestal mount alum shrinker / stretcher and a large pedestal mount Beverly shear. All good condition HD commercial tools for$200. Everything together weighed at least 5K-6K pounds.

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17. Nov 9, 2017

### 12notes

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I appreciate the advice and encouragement, but there's an implicit assumption about the availability of space and money that the advice is predicated upon that don't fit my (and many other's) situation.

Please don't take any of this as malicious, I'm just respectfully disagreeing and explaining why. There is absolutely nothing wrong with your philosophy on tools. I'm working on a different philosophy which is just as valid, but has different methods and conclusions. Neither is right, just different.

I've fabricated my own tools for a while, this is not a new thing for me. I do not have a large amount of money or time in this brake, which was my main reason for building it - $75 in steel,$4 in bolts, and about 6 hours of time on a Friday night. I'll spend maybe another 2 hours mounting the piano hinge (which was $75 with shipping), so I'll have 8 hours and$150 in this brake. I've already used it for a few dozen brackets and small parts, so it's been worth it to me as it is. I've seen brakes of the same design with similar hinge to what I've built, so I went with that first since it was cheapest. I assumed since the 8' version in the plans I posted was used for building aircraft out of aluminum sheets, that a shorter one with the modified hinge would have no problem. The only thing I didn't anticipate was that 66" of 2x2x1/4" angle would flex 3/4" (when I really leaned on it) before 40" of 0.040" aluminum would bend, which, without analysis, seemed to be reasonable assumption, even though it is wrong.

I don't make a lot of money, and I've spent nearly everything I've had on aviation for the last three years. Although spending money and horse trading to get a better deal may work for you, it's a complete non-starter to me and many others. Not everyone has $500 they can throw at a deal at the drop of a hat. In many things, it takes money to save money - if you have the cash you can get the deals, if you don't, the deal will be gone by the time you have the cash. Spending a day at an auction hoping to find a deal, while it may be fun or worth it to you, is not worth my time or effort on a "maybe". The item may go for more than it's worth, or just more than I can afford. Either way, it's wasted time and effort. And I find auctions and negotiating tedious (not a judgement call, I'm sure you'd be bored by many of the activities I find fun). For me, the time spent wheeling and dealing would be much better spent working on the plane. I don't like trying to sell things, it's always a pain in the rear for me, and I wouldn't sell any of my tools anyway, they always seem to be needed later on. If I decide I never need the brake again, I can cut, drill and grind to have about$70 worth of angle and a $50 hinge to use on other projects. I'd be out the$25 shipping costs for the hinge. I'm out my time, but I'm sure we've all spent 6 hours on a Friday night on much less admirable pursuits before (please don't take that as an invitation for everyone to recount their personal stories, the server doesn't have enough storage space for that thread!)

I also do not own a working truck. While it's easy to borrow a truck to pick an occasional item up in town, a 4+ hour round trip is another story. And scheduling a mutually agreeable time between myself, the friend with a truck, and a random craigslist seller can get problematic (believe me on this, I've been there for weeks at a time in the past).

I am looking at the long term, the long term is that it's quicker, easier and cheaper for me to build this brake then it would be to wait until I have the money for a nicer one and then wait to find a deal. I rarely need a brake beyond this project, I still needed a larger bend radius for the smaller pieces, so building it kept my project moving. Sometimes it's better to have a crappy tool you seldom use but can afford than stopping work until you can afford a nicer one. Buying tools in anticipation of using them in the future can be advantageous, but if you have limited room it can also be a good way to get a lot of tools that never get used because there's no room in the shop to build anything. 4 years ago, building a plane wasn't even a consideration. 3 months ago I didn't even have a construction method, let alone design, decided. If I'd bought a nice set of torches for a tube and fabric plane, it wouldn't be what I needed now. And my local hackerspace just got a TIG welder last month that I can use for free, so I wouldn't have even needed torches for the landing gear and other steel fittings.

I don't have a lot of room in my garage, there's just no place to put a larger floor brake, and even a smaller roll around one would just be in the way for the 99.9% of the time I wouldn't be using it. The one I built bolts to my table when needed and I can store it under my toolbox, I have absolutely zero interest in trying to make room for a floor mounted design. They're great if you have the room, but, while technically I do, it would just be in the way and need to be moved around often.

Will this brake work better with the piano hinge? I don't know. Since no one here has offered any experience with this type of design on this particular material, we'll find out when I throw it on, probably this weekend. I've found a way around needing to bend a 40" piece, but there's other, much shorter .040 parts that need bending, so it'll be useful even if it can't bend the 40" long piece.

18. Nov 9, 2017

### Winginit

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I thought I would explain how I go about finding good deals on things. First there is the customary Craigslist search and an Ebay search filtered by "distance". You can also do a Nationwide Craigslist search and limit the distance/range of the search. (https://www.searchtempest.com/) I monitor the local Craigslist on a daily basis...even when I don't need anything.

Then there are auctions. The best auctions are when the government is shutting down some facility. Bargains galore...unfortunately these are not as common as in past years, but if you find one, there will be bargains.

Industrial Auctions. This is probably where you will currently find the best bargains...especially if they are closing some business in an older part of large cities. They don't even have to be large companies, many small shops use the older types of equipment. Hole-in-the-wall shops often have lots of small (expensive) tools. From attending a lot of auctions I have found that auctions often have a "personality". It reflects on the "type" of people who have chosen to attend and bid. Some auctions have lots of dealers purchasing used equipment and prices tend to go high. I attended an auction last year that a "survivalist" passed away and he had more stuff on his farm than you could imagine. It was well advertised and people were parking as much as a half mile down the road and walking in. It was so packed, I knew there would be no bargains. I have attended other auctions that all bids were extremely low. It really depends not only on the number of people, but the "type" of people. That being said, at a lot of the larger industrial auctions, the high dollar buyers aren't interested in small stuff and you can still get some good buys. You just have to go and see who else showed up.

When bidding, I have found a couple of rules of thumb that usually prove to be valid. If there are say 3 almost identical items that are going to sell, but there are six people who want them.....the first one sold is usually the cheapest one. Many buyers think since there are two more to be sold, maybe they can get one of the others cheaper. Usually though, the second and third items go for more than the first one because people get more desparate. Not always, but usually.

Second thing is when to bid. Many many buyers fix a number in their mind that they won't exceed. If they decide something is only an acceptable deal at $200, then$201 drops them out. Its suddenly no longer a good deal or its gonna break their budget. Usually its a "round number".....like say $100 or$150 that they have set as their maximum. Try to time your bids so you are the person who makes the "round number" bid. Then be willing to go one or two bids past that round number you fixated on. The willingness to go past the round number by one or two bids has served me well over the years.

Learn to recognize when someone else may need that particular tool for a business and must have it, or the old farts who have plenty of money to spend and aren't going to be outbid. You learn from attending auctions even if you don't buy anything. Look in the classified ads of your sunday paper for auctions. Search the internet and look for industrial auctions. (Myron Bowling etc) Even if you don't buy large tools, you can find lots of handy items that would be too expensive to buy new for a home shop.

I saw an ad on Craigs list for end mills for my milling machine. The guy was at a local flea market when I called. I rushed down there and he had a bunch of them. Maybe a hundred of them. Wanted $3 apiece and if you bought 50 or 100, he was willing to give an even better price. I bought ALL OF THEM. Seems like I paid about$180 or so for all of them. While I was making the deal, another guy showed up with his son. He had driven farther than me, but had decided to stop for a McDonalds along the way. You snooze...you lose. If its a good deal, you need to get your butt in gear and go get it....don't procrastinate. Many of the end mills I bought would have cost $50 each, but even the smaller ones are$10+ each.
While I'll never use all of them, I also have more than enough to last my lifetime for a minimal investment. The point I'm making is that you have to put some effort into searching out bargains and be willing to act on them quickly...rather than just "thinking about it". I've missed out on a lot of good bargains. I'm still kicking myself for not raising my hand and bidding on a 36HP Kubota Tractor with 40 hrs that went for $14K recently. Here are some pictures of how I got my current 4 foot sheetmetal brake. I bought this first little brake at a car show where they were offering a deal on them. It worked OK and I bent a lot of things with it. Not the best equipment but adequate for many things. Paid about$500 for it and sold it when I acquired the next brake at an auction. Pretty well made up my mind I was gonna buy it (be high bidder) unless it got rediculous. Had to do a little bidding but I got it reasonably, and then sold the little red brake. Probably sold it for about a $150 less than I purchased it for. Kept the second one and it worked well. I reccommend one like this if you can find one. Anyway I kept it until I found the heavy duty Chinese Tennsmith clone. Got a great deal on the clone along with a 4 foot slip roll and a Niagra foot shear. Had to decide whether to keep the well made but older Niagra shear or a Jet shear which I purchased new about ten years ago and has been babied. Decided to keep my Jet and resold the slip roll, the Niagra shear, and my current 4 foot brake. In the buying and selling, I actually made a substantial profit. If you take that profit from the Niagra shear, the slip roll, and my old brake and offset it with everting I spent for my new (at time of purchase) Jet shear,and my Tennsmith clone brake, I have nothing invested in them. Now being a confessed toolaholic, any profits went into other tools. Any builder can at the very least purchase equipment for use that can later be resold to recoup the original investment. To me that is the best way to get the major tools someone wants/desires/needs. I admit that others find that making tools works for them and I respect their decision to do so, and wish them well. I just think that once someone tries to emulate what I do, they will find that it can work for them too. Here are the brakes I acquired while always looking for something better. And then the bigg dawg..... Start searching for bargains before you actually need them...they are out there. Last edited: Nov 10, 2017 Pops likes this. 19. Nov 9, 2017 ### Winginit ### Winginit #### Well-Known Member Joined: Jun 13, 2016 Messages: 811 Likes Received: 242 Location: x I don't take any offense at what you said, and hopefully you don't take offense at what I posted either. I respect what you and others do, and I always wish outcomes to work out well for them. We must have been composing our posts at the same time, as yours was not online when I started mine. When I was younger, I struggled to make ends meet and didn't have the proverbial "pot to pee in". I'm not rich now, but I can usually afford something if I want it . I have learned that accumulating tools and things takes time. I used to work on a really nice 33 Ford sedan in my driveway till I got tired of getting tools out and putting them away. Finally was able to build a 2 car garage with a little sweat equity. Built my next house with mostly sweat equity(volunteered my free work for a couple of weeks with a friends construction crew just so I could learn something about homebuilding) and left one end unbricked....so I could add an attached garage later...with more sweat equity. About 10 years after the attached garage was completed, I decided I wanted a pole barn. Didn't want to spend the money (get a loan), so way more sweat equity was spent. Now I have a nice shop that I'm proud of. All I'm trying to do is to encourage others to see that they can have a good well equipped shop if they are willing to put time and effort into getting there. Please don't think for one minute that I'm putting you or anyone else down for choosing to go a different way. One of the things I have enjoyed most in my lifetime is using my hands and my mind to create things that work for my purposes. I have cobbled up many things in my lifetime that couldn't be purchased. If you saw my shop you would find many things that might surprise you. So Yes, I not only respect what you are doing but I applaud your efforts and hope they work well for you. My apologies if my writings don't always convey that. Here is my current project. I wanted somewhere to be able to paint without dealing with all the overspray and stuff. I also could use some more room for storing some easily moved large items. I went to an auction and purchased a complete large automotive size paint booth. One of the local schools decided auctioning it would save them from paying someone to take them down. They had bids of$5K/$10K for removal. I bought a whole booth for$140.
Then the school started telling me that certain things were not included in the sale, even though they were bolted inside the booth and shown in the pictures when the auctioneer said "this is what you are buying...as is where is". It was still a heck of a deal but I didn't like the way they behaved over the situation so they refunded my money. I expected to spend maybe a thousand dollars for help to disassemble the booth, so it was still a good deal....but they pissed me off when the auctioneer lied...even though it was recorded. So, I decided to build my own version of a spray booth, and since it will be used sporatically, I will use it for storing a vehicle and a bunch of easily moved (on rollers) tools and things. When I want to paint something I'll just roll them outside and spray away. The odd design with the front extensions will house a compressor on one side of the door and a home made water separator on the other side. A small half wall will shield them from most of the elements and allow dry air for this building and the one next to it. There is a large sandblaster in that small building and the air compressor will serve both buildings. The sandblaster was culled from a government auction as an empty carcass. Again, a little sweat equity and not much money. All I'm trying to say is that if someone desires to have nice tools with a minimal investment, they can do so with a little hard work. Make that a LOT of hard work...but its doable if you work at it even with modest means. I also realize that some people really don't want all of this stuff and prefer to stay modest in their dreams. Whatever path anyone chooses, I wish them well.

Well, its a nice day and I've got to get back to work putting the rafters in place.

Ohh! Just to show you that I think homemade things are great additions to any shop, here are a few of my creations over the years.

Last edited: Nov 10, 2017
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20. Nov 9, 2017

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