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Longeron Dies
- Thread starter JEG
- Start date
engineerofsorts
Well Known Member
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Larry Buller posted information on his bending dies--check the Longeron topic. I bought a set from him and found them generally pretty straightforward to use.
Larry Buller posted information on his bending dies--check the Longeron topic. I bought a set from him and found them generally pretty straightforward to use.
NDrv8r
Well Known Member
longeron dies
yep I have them is stock ready to go.
paypal $45.95 (includes usps shipping) to the u.s. to [email protected]
email me for other payment options.
Larry Buller
yep I have them is stock ready to go.
paypal $45.95 (includes usps shipping) to the u.s. to [email protected]
email me for other payment options.
Larry Buller
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MacPara
Well Known Member
Ah, I found it. Paypal transfer completed. I give up after 3 days of back and forth on the center bend on just one longeron. Call me impatient but I can't take this any longer ... When I matched the bend, the vertical plane wasn't straight. After adjusting the vertical plane, the bend was messed up. Come on!
NDrv8r
Well Known Member
What the longeron dies do.
The dies apply equal pressure to the vertical and horizontal flange of the angle reducing the tendancy to twist. The slot that the horizontal flange is in also keeps the bowing to a minimum, but as a result the angle may get tight in the slot. Some grease on the angle helps things out a lot.
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The dies apply equal pressure to the vertical and horizontal flange of the angle reducing the tendancy to twist. The slot that the horizontal flange is in also keeps the bowing to a minimum, but as a result the angle may get tight in the slot. Some grease on the angle helps things out a lot.
Kyle Boatright
Well Known Member
When you bend longerons, clamp them together and bend both at the same time. That greatly reduces their propensity to twist.
With the assistance of a vise (with cushioned jaws) you should be able to knock both of 'em out in an hour.
Kyle,
I find it irritating when statements like this are made, with no regard to the experience level or skills inventory of the person who will be attempting this. I was a first timer, with average mecahanical skills, and it took me several terribly frustrating work sessions to bend these things, and after completion they looked like they had been through a war. At one point I was ready to give up on the whole project because of this task.
Make no mistake, this is a very hard task. I suggest to first time builders that they obtain whatever assistance they can, preferably from an experienced builder (through EAA or other sources). If these "dies" really work I wouuld have given my eye teeth for them back in the day.
John
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Jetguy
Well Known Member
These things work!
John I bought a set of these dies after I was done with my RV12. After receiving them I can tell you they will make this task a lot easier. For the first time builder maybe not 1 hour but it shouldnt take much more then 2 and no beating with the hammer.
John I bought a set of these dies after I was done with my RV12. After receiving them I can tell you they will make this task a lot easier. For the first time builder maybe not 1 hour but it shouldnt take much more then 2 and no beating with the hammer.
Kyle Boatright
Well Known Member
John, Sorry you had a hard time with these. I was a first time builder with average skills when I bent mine 13 or so years ago. Using the method I suggested, it took less than an hour to bend both of my longerons back in the day, and the method I suggested has the benefit of more or less eliminating the twisting problem mentioned in the thread.
I find it irritating when people complain after others say: "Here is a method that worked well for me.". I'm not sure what the point of these forums is if we don't share that kind of information.
Kyle,
Maybe "irritated" is the wrong word. I am thinking about the poor guy who is struggling with a task. He is not an engineer, maybe has never worked with metal before. He is very frustrated, partly because the techniques to get something done, as instructed in the plans (ie "beat on it with a hammer") do not work for him. He needs help.
Then somebody tells that poor soul how easy the task was for them, "You should be able to knock both of 'em out in an hour."
That just makes the guy feel stupid. I remember already feeling dumb enough at that point with having it reinforced.
Longeron bending was a daunting task for me, and I feel this guy's pain. I think the difficulty of the task is highly dependent on one's skills and experience. Van's instructions, while generally exceptionally good, are poor for this task. As an example of that, how silly is it to specify the amount of twist in tenths of a degree? Who could achieve that level of accuracy using "simple hand tools?"
JMHO
John
Maybe "irritated" is the wrong word. I am thinking about the poor guy who is struggling with a task. He is not an engineer, maybe has never worked with metal before. He is very frustrated, partly because the techniques to get something done, as instructed in the plans (ie "beat on it with a hammer") do not work for him. He needs help.
Then somebody tells that poor soul how easy the task was for them, "You should be able to knock both of 'em out in an hour."
That just makes the guy feel stupid. I remember already feeling dumb enough at that point with having it reinforced.
Longeron bending was a daunting task for me, and I feel this guy's pain. I think the difficulty of the task is highly dependent on one's skills and experience. Van's instructions, while generally exceptionally good, are poor for this task. As an example of that, how silly is it to specify the amount of twist in tenths of a degree? Who could achieve that level of accuracy using "simple hand tools?"
JMHO
John
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vernhendershott
Well Known Member
Hi John,
He is very frustrated, partly because the techniques to get something done, as instructed in the plans (ie "beat on it with a hammer") do not work for him. He needs help.
Yes he could use some help, but many are not willing to ask for help. There are many EAA Tech Consolers and other people who have built Van's kits that would be pleased to help if they were just asked.
Then somebody tells that poor soul how easy the task was for them, "You should be able to knock both of 'em out in an hour."
Well I guess you would have us lie to him and tell him that he must just get on with it as it is a "right of passage" when in fact there are several ways to do the job in about an hour with very good results and very little frustration. It does take skill or tools but why should the person suffer with frustration when all they must do is ask for help.
Longeron bending was a daunting task for me, and I feel this guy's pain.
I am sorry you had a hard time with this task and as we have talked about the solutions on this list several times I would hope by now that everyone would know that for some this is a hard task and that they may need help just as some find the fiberglass a new and hard task to be feared.
I have not tried the dies talked about above myself but they should work just fine, I use a shrinker/stretcher and can do the longarons in less than an hour with less than 1/32 variation from the template part and have done so for several of the RV-12 builders locally and I am willing to help any others who live near enough to come by my hangar.
I hope that all will learn to ask for help instead of cursing the darkness.
Best regards,
Vern
He is very frustrated, partly because the techniques to get something done, as instructed in the plans (ie "beat on it with a hammer") do not work for him. He needs help.
Yes he could use some help, but many are not willing to ask for help. There are many EAA Tech Consolers and other people who have built Van's kits that would be pleased to help if they were just asked.
Then somebody tells that poor soul how easy the task was for them, "You should be able to knock both of 'em out in an hour."
Well I guess you would have us lie to him and tell him that he must just get on with it as it is a "right of passage" when in fact there are several ways to do the job in about an hour with very good results and very little frustration. It does take skill or tools but why should the person suffer with frustration when all they must do is ask for help.
Longeron bending was a daunting task for me, and I feel this guy's pain.
I am sorry you had a hard time with this task and as we have talked about the solutions on this list several times I would hope by now that everyone would know that for some this is a hard task and that they may need help just as some find the fiberglass a new and hard task to be feared.
I have not tried the dies talked about above myself but they should work just fine, I use a shrinker/stretcher and can do the longarons in less than an hour with less than 1/32 variation from the template part and have done so for several of the RV-12 builders locally and I am willing to help any others who live near enough to come by my hangar.
I hope that all will learn to ask for help instead of cursing the darkness.
Best regards,
Vern
skydiverlv
Well Known Member
Vern, How 'bout creating a UTUBE video while forming the longerons for those of us that have not had the opportunity to perfom the task? Would be much appreciated by many.
vernhendershott
Well Known Member
I would be pleased to but I have no video skills, if someone in the Central Florida has the skill to make such a video and someone has a set of longerons that need doing I would be happy to give it a try.
Best regards,
Vern
Video....
Now THAT is a great idea! If I lived in Florida I would volunteer to help. I sure wish I had had a video to watch!
Also wish I had had a mentor who was experienced in metal work - but everyone around these parts seems to work on rag and tube planes.
BTW Vern, what is a "shrinker/stretcher"?
Now THAT is a great idea! If I lived in Florida I would volunteer to help. I sure wish I had had a video to watch!
Also wish I had had a mentor who was experienced in metal work - but everyone around these parts seems to work on rag and tube planes.
BTW Vern, what is a "shrinker/stretcher"?
vernhendershott
Well Known Member
Hi John,
There are a number of videos on UTube this is just one to let you see what it is and how it works.
http://www.youtube.com/watch?v=GvaFtmAzxNk
Best regards,
Vern
yankee-flyer
Well Known Member
I'm with John
I spent several days bending, twisting, and "opening up" (94 deg?????) those things and was never happy with the result. If I hadn't bought the entire kit at one time I might have given up. Come to think of it, those &*^*&%&^% longerons may be why 143WM takes excessive rudder trim. I'd gladly have paid for pre-formed longerons.
Wayne120241
I spent several days bending, twisting, and "opening up" (94 deg?????) those things and was never happy with the result. If I hadn't bought the entire kit at one time I might have given up. Come to think of it, those &*^*&%&^% longerons may be why 143WM takes excessive rudder trim. I'd gladly have paid for pre-formed longerons.
Wayne120241
Vern,
Just watched the video at http://www.youtube.com/watch?v=GvaFtmAzxNk That's amazing! Never knew such tools existed. I can just image how easy that would make the longeron bending. No wonder you can do them in an hour! Problem is, most of us novice builders have no clue about advanced techniques and tools like this.
Others with "Longeron Frustration",
Strongly suggest you find someone in your area with building experience, or better yet, someone with these kind of tools.
John
Just watched the video at http://www.youtube.com/watch?v=GvaFtmAzxNk That's amazing! Never knew such tools existed. I can just image how easy that would make the longeron bending. No wonder you can do them in an hour! Problem is, most of us novice builders have no clue about advanced techniques and tools like this.
Others with "Longeron Frustration",
Strongly suggest you find someone in your area with building experience, or better yet, someone with these kind of tools.
John
Dgamble
Well Known Member
... don't have access to, or the dollars required to buy, tools like that for a one-time job.
I got through my longerons at the cost of a few hours of frustration and a broken vise (I found opening the angle to be more difficult than the bending), and I have no problem with having had to do so, but I do marvel at some of the inconsistencies in Van's decisions as to what we should do for ourselves versus what they will do for us with their high-end production machine tools.
I somewhat tongue-in-cheek refer to their part-time hole dimpler, who only shows up to dimple holes that 1) I could have done myself, and/or 2) I wish they hadn't dimpled for me because I would like to have been able to break that edge. In comparison, I would have traded those dimples for a formed pair of longerons in a heartbeat. With a production set-up in place, they could form those longerons in seconds. Considering the importance of those two parts in strength and alignment of other parts of the airframe, it would seem to benefit all involved if they did.
E. D. Eliot
Well Known Member
Business Opportunity
There are a lot or RV builders out there who would like to have his/her longerons bent for them. Someone who already has an RV assist business already set up seem ideal. Bending them might be easy and inexpensive to do but the shipping might be the expensive part of that business. Wonder why Van's doesn't offer this 'option'. like the fuel tank?
There are a lot or RV builders out there who would like to have his/her longerons bent for them. Someone who already has an RV assist business already set up seem ideal. Bending them might be easy and inexpensive to do but the shipping might be the expensive part of that business. Wonder why Van's doesn't offer this 'option'. like the fuel tank?
WingedFrog
Well Known Member
I had the opportunity to meet with Jean-Marie Longeron who was from an old French aristocratic lineage. They dropped their noble patronym after the French revolution, before that they were known as the Counts "Longeron de Fuselage".
I just learned that Jean-Marie died after a life full of twists and blows, it is a sad story but it is good that he is memorialized in the VAF forum, he would like it because we have lots of respect here for the Longerons, particularly if they are Longerons de Fuselage.
I am of Fuselage lineage, my mother's family coming to this country from said village not far from Versailles.
I was on a tour bus in Versailles, and had the opportunity to meet The Baron du Fuselage Longeron- he is from the lesser known side of the lineage, and informed me that he still is not on speaking terms with the rest of the family. He then bought me a croissant.
Dgamble
Well Known Member
I met him. He was pretty rude. I told him to "get bent," and the rest is history.
MacPara
Well Known Member
A new entry to the recommended tools list!
Let me copy some text from my blog to share my experience I had with the longeron dies in action. One longeron I abused with a mallet, the other one was done with the dies. The short summary is: I consider these dies at least a recommended tool if not a required one.
"I had finished the left one before and now it was time to do the right one - this time with the help of the bending dies I had received a few days before. A first trial fit session where I used a piece of scrap cut off the longeron showed that the back die (the one without the cut out for the flange) was too tight. I filed it a bit wider and polished it with a SB pad to allow for easier removal of the angle after bending. I also added a marker on both dies that indicate the center line where the bend is being added for easier positioning with the markers on the flange of the longeron.
I was first worried that I wouldn't have that much control over the bend as with the mallet (well, 'control' is not a good word here) as I couldn't immediately verify the shape with the template while the longeron is in the vise. The dies make a direct positioning impossible and I had to remove the longeron after each bend to check if it turned out ok. I did this by clamping it into my second, smaller vise attached to the second work bench. Although this sounds awkward and slow, it turned out to be way superior over the mallet "method". And that is because I never had to go back to a previously bent spot. There's no vertical bend when using the dies. I checked it multiple times and there just wasn't anything to remove! I also developed a good feel for how much pressure was needed to accomplish a certain bend angle and so I hardly had to rebend a particular spot.
After the procedure the longeron looks pretty good. Not like it was salvaged from a shot down plane like the other one did. And it matched the template better than the mallet-treated one, too.
It took me 1.75 hours to bend the center area and the aft 4 degree angle, including the weight reduction cut. Boy, I so wish I had had those dies when doing the left longeron!"
Let me copy some text from my blog to share my experience I had with the longeron dies in action. One longeron I abused with a mallet, the other one was done with the dies. The short summary is: I consider these dies at least a recommended tool if not a required one.
"I had finished the left one before and now it was time to do the right one - this time with the help of the bending dies I had received a few days before. A first trial fit session where I used a piece of scrap cut off the longeron showed that the back die (the one without the cut out for the flange) was too tight. I filed it a bit wider and polished it with a SB pad to allow for easier removal of the angle after bending. I also added a marker on both dies that indicate the center line where the bend is being added for easier positioning with the markers on the flange of the longeron.
I was first worried that I wouldn't have that much control over the bend as with the mallet (well, 'control' is not a good word here) as I couldn't immediately verify the shape with the template while the longeron is in the vise. The dies make a direct positioning impossible and I had to remove the longeron after each bend to check if it turned out ok. I did this by clamping it into my second, smaller vise attached to the second work bench. Although this sounds awkward and slow, it turned out to be way superior over the mallet "method". And that is because I never had to go back to a previously bent spot. There's no vertical bend when using the dies. I checked it multiple times and there just wasn't anything to remove! I also developed a good feel for how much pressure was needed to accomplish a certain bend angle and so I hardly had to rebend a particular spot.
After the procedure the longeron looks pretty good. Not like it was salvaged from a shot down plane like the other one did. And it matched the template better than the mallet-treated one, too.
It took me 1.75 hours to bend the center area and the aft 4 degree angle, including the weight reduction cut. Boy, I so wish I had had those dies when doing the left longeron!"
The Dies Work Great
I received my dies this Saturday. On Sunday ( with no previous longeron bending experience) we knocked out both longerons in about 90 minutes. I have previous metal working experience, but the dies make the process quit easy in my opinion.
i would hate to put the inventor out of business but why can't we have a few sets around for builders to use and pass on to the next builder for the price of shipping? Unless you are building more than 1 aircraft you should not need them again.
I received my dies this Saturday. On Sunday ( with no previous longeron bending experience) we knocked out both longerons in about 90 minutes. I have previous metal working experience, but the dies make the process quit easy in my opinion.
i would hate to put the inventor out of business but why can't we have a few sets around for builders to use and pass on to the next builder for the price of shipping? Unless you are building more than 1 aircraft you should not need them again.
randyintejas
Well Known Member
Really??
I hear what you are saying but, dang! the man is selling them so cheap that it will cost half the price to just ship them! Just buy and be happy with the fact you are not beating the !@# out of your aircraft parts with a dang hammer!
I hear what you are saying but, dang! the man is selling them so cheap that it will cost half the price to just ship them! Just buy and be happy with the fact you are not beating the !@# out of your aircraft parts with a dang hammer!
The frugal part of me hears you loud and clear, but given how useful they are and the low cost, I will gladly pay the full amount to the gentleman to reward him for his contributions to the community.
NDrv8r
Well Known Member
longeron death
I heard he commited suicide after atempting to fabricate airplane parts out of 3/4" angle using a vise and hammer
Every time I see this thread I wonder, who was Longeron and how did he die?
I heard he commited suicide after atempting to fabricate airplane parts out of 3/4" angle using a vise and hammer
rv9aviator
Well Known Member
I did mine according to the Orndorff video and did them both at the same time in a cushioned vice. Worked like a champ and maybe took a little over an hour. I really like the two in the vice trick and measuring between both pieces to get the proper bends. They came out exactly alike and worked great. Just another way to get good results.
I think part of what motivates folks to put their genius into motion is the prospect of getting paid for their efforts. Fork out the $35 and thank the man abundantly for making your job easier.
Threetracker
Active Member
I beat my longerons to submission...
I wrestled and beat the longerons in N124CS into submission a couple years ago now; if I build another RV-12 I'll make a purchase of Larry's dies.
Thanks for your efforts, Larry.
Jay Sluiter
N124CS
Albany, OR (S12)
I wrestled and beat the longerons in N124CS into submission a couple years ago now; if I build another RV-12 I'll make a purchase of Larry's dies.
Thanks for your efforts, Larry.
Jay Sluiter
N124CS
Albany, OR (S12)
WingedFrog
Well Known Member
All Set Now!
For what it's worth, I ordered my dies yesterday and my wing kit and fuselage kit both arrive next Tuesday. I decided that I didn't want to destroy too much aluminum with my hammer. After all the talk and struggles had by others, and Don's comment on how quick it was with the dies I placed the order.
For what it's worth, I ordered my dies yesterday and my wing kit and fuselage kit both arrive next Tuesday. I decided that I didn't want to destroy too much aluminum with my hammer. After all the talk and struggles had by others, and Don's comment on how quick it was with the dies I placed the order.
agirard7a
Well Known Member
Bending easier
I thought I would add regarding bending the longerons. Regardless of using the dies or not.
I took the drawn curve on the plan and traced it on 8.5x 11,
that was taped together. Then spray mounted the paper on to a 1/4" peice of luan plywood. With 3m spray mount from a hobby shop. Cut out the curve and used the plywood template to match the curve in the angle alum. Mark the the key measure points on the plywood template.
The important part is laying the angle down on a straight tabel to make sure the bend is correct on two planes. Otherwise twist is a nightmare. I did not use the dies and they came out fine. However, I'm sure the dies save a lot of time in reducing that dreaded twist.
I thought I would add regarding bending the longerons. Regardless of using the dies or not.
I took the drawn curve on the plan and traced it on 8.5x 11,
that was taped together. Then spray mounted the paper on to a 1/4" peice of luan plywood. With 3m spray mount from a hobby shop. Cut out the curve and used the plywood template to match the curve in the angle alum. Mark the the key measure points on the plywood template.
The important part is laying the angle down on a straight tabel to make sure the bend is correct on two planes. Otherwise twist is a nightmare. I did not use the dies and they came out fine. However, I'm sure the dies save a lot of time in reducing that dreaded twist.
woodsideraff
Well Known Member
stretcher machine
I looked at the video of the stretcer/lenghtener. Basically it looks like one flutes the part. I wonder about any structural weakening that may occur using this method vs. the actual bending.
I did my left longeron yesterday and it was quite a challenge --- especially the opening of the angle. I ended up purchasing a 2 lb. hammer and using another angle over the longeron and still have some marks at the vertex. Perhps a bigger vise?
The deformation in the perpendicular plane was less of an issue, although it took a few iterations to get it right.
Had I done the research on the dies, I would have definitely ordered them, but I'm halfway there already. I hope to do a better job on the second one today.
Finally, one thing still bothering me is the tolerances on the twist and angle opening. 0.1 degrees is not for hand tools!
Cheers,
Rafael
RV12 at the longeron stage
RV8A purchased and flying
I looked at the video of the stretcer/lenghtener. Basically it looks like one flutes the part. I wonder about any structural weakening that may occur using this method vs. the actual bending.
I did my left longeron yesterday and it was quite a challenge --- especially the opening of the angle. I ended up purchasing a 2 lb. hammer and using another angle over the longeron and still have some marks at the vertex. Perhps a bigger vise?
The deformation in the perpendicular plane was less of an issue, although it took a few iterations to get it right.
Had I done the research on the dies, I would have definitely ordered them, but I'm halfway there already. I hope to do a better job on the second one today.
Finally, one thing still bothering me is the tolerances on the twist and angle opening. 0.1 degrees is not for hand tools!
Cheers,
Rafael
RV12 at the longeron stage
RV8A purchased and flying
Gagarin737
Well Known Member
I used a pipe coupling and a (steel) vise. No damage and the opening is easy to control:
woodsideraff
Well Known Member
AHH! A bigger vise, not a bigger hammer
Thanks, will try this.
Rafael
Thanks, will try this.
Rafael
Dgamble
Well Known Member
Which, as the owner of a ruptured vise, I suggest doing!
http://www.schmetterlingaviation.com/2010/08/taking-longeron-way-around_22.html
Be VERY CAREFUL of overstressing a vice! I did that once straightening some aluminum angle and had the head of the vice break. Because of the tension, it flew--within and inch of my face. It landed 23 FEET away, outside the garage, through the open garage door. It still scares me to think of it even now. I will never again own a cheap vice.
Bob Kelly
DonFromTX
Well Known Member
I had a similar experience with another cheap trick. When opening up the angle, I chose a nice (slick) deep well socket. Worked like a charm, crank down on the vice, and the angle appears like magic. Suddenly however the socket slipped out under pressure, shot a nice hole in the garage door insulation, glad I was not in its path.
woodsideraff
Well Known Member
Longerons are done!
Tried a shorter nipple with the same 6" vise. It was a struggle, but the angle finally yielded. I believe I came close to breaking the vise!
Getting the right curve was another matter. I did get it within the 1/16", but this is much too big a tolerance for the .020" skin thickness. After 4 hours of bending in both planes, finally decided it was good enough.
What worked for me was drilling the ends, clecoing, drilling the middle, and then the rest of the holes. It ended not perfect, but close.
So far, this has been the biggest challenge in the build.
Cheers,
Rafael
Tried a shorter nipple with the same 6" vise. It was a struggle, but the angle finally yielded. I believe I came close to breaking the vise!
Getting the right curve was another matter. I did get it within the 1/16", but this is much too big a tolerance for the .020" skin thickness. After 4 hours of bending in both planes, finally decided it was good enough.
What worked for me was drilling the ends, clecoing, drilling the middle, and then the rest of the holes. It ended not perfect, but close.
So far, this has been the biggest challenge in the build.
Cheers,
Rafael
