Single Pass V-Groove?

admin

Does this joint look like it could be completed in one pass? Every piece of literature I have from AWS and AISC fail to really touch on this.Is there a formula available that would give an idea one way or the other? Our goal is one pass, but engineering is willing to go two in absolutely necessary.*Edit- We are GMAW with 0.045" Lincoln L-59Thanks!
Reply:You can figure the square inches of weld if you know the length of the bevel from root to top of plate (depth is close enough).  Then just figure out the circumference of the weld, and multiply by the length of the bevel.  This ought to get you pretty doggone close for actual strength.  3/8 is close enough for the width of the bevel.  3/8 (pi x diameter)= circumference in terms of square inches of weld.I don't see that as one pass either.
Reply:Lincoln states that L59 has deposition rate similar to metal core. If that's true you could do it in one pass. Tack up some coupons from plate or flat bar, get in some practice to dial in your settings and have at it. I'd be concerned about lack of fusion with solid wire so cut up a good looking coupon for macro inspection and show it to your engineers as argument for a two pass weld if need be. I think I'd rather see the root pass done with 035 wire or maybe use dual shield for the whole job.
Reply:Will the weld machined?
Reply:I'm no pro but that looks like a LOT of heat to be putting into the part in one pass.
Reply:The big question here from the usual lack of all information, will this be welded by a machine on a fixture or manually?  If it's going to be robotically welded its probably plenty do-able. by a human hand... 2 passes with .035" wire would be my recommendation.  Three threads on this and we only get small driblets of info in each.
Reply:I would be curious as to the reason (reasons) why a single pass weld is being promoted as an answer to a weld joint such as is shown in the drawing. I suppose, in theory, that it could be done. But sometimes things that look so wonderful from behind the desk look different out in the shop. One thing to remember is that it will take a certain amount of time to fill the joint with the weld deposit. With .045 wire as per the specs, it is possible that completing the weld in two passes will almost be as fast as trying to do it in one pass. The difficulties that could be encountered by a one pass method will likely outweigh the ( possible) time gain.But as always, the world is a big place, with many different and varied circumstances. Sent from my E6810 using http://tiny.cc/Forums_reader
Reply:Originally Posted by 12V71The big question here from the usual lack of all information, will this be welded by a machine on a fixture or manually?  If it's going to be robotically welded its probably plenty do-able. by a human hand... 2 passes with .035" wire would be my recommendation.  Three threads on this and we only get small driblets of info in each.
Reply:Originally Posted by CAVEMANN But in his defense, maybe the engineering department doesn't know anything.
Reply:I'm trying to stress that if we're going to want consistent welds since they have to be manual, ontop of the size of the groove a two pass minimum is needed and they don't want to budge. Sadly this is a redesign of an area because of failed welds.
Reply:Manually in a very hard to get position.
Reply:Our design engineers happily admit they know nothing about welding. I'm the weld Manufacturing Engineer that is being dragged into this and future projects. They want to argue every suggestion I give so I'm looking for an outside opinion to verify that I'm correct. But they're concerned with production time. Right now the unit is so big we will be manually welding these joints and they won't let off this one pass bs. The whole purpose of the design was because the previous design had a 100% failure rate on test units that didn't use cast steel and was welded in 3 passes.
Reply:You're exactly right. They think after I do an FEA simulation that it's good enough. I tell them we need to verify and validate but they think the software is final say. So I'm trying to make sketches to get a better idea of what I'm dealing with, without giving away anything of the unit it goes to as it's not on the market yet and 5 different NDA's I have.The sad part is, they just designed this cast piece so we have no real way of testing it yet. Just knowing it has a 6,200lb (well half that because there are two of these cast hubs) limit that it must be able withstand.Last edited by SP4NKH4RD; 5 Days Ago at 10:01 AM.
Reply:It'll be manual welded, at least in the beginning.
Reply:If they know nothing about welding then they should leave the welding to the weldors, it sounds like the pieces are going th be welded on the assembly or after it's installed, honestly, how would they ever know if it was one pass or two passes unless they're standing there watching, heat can be controlled by skipping.IMPEACH BIDEN!NRA LIFE MEMBERUNITWELD 175 AMP 3 IN1 DCMIDSTATES 300 AMP AC MACHINEGOD HELP AMERICA!“Freedom is never more than one generation away from extinction.We didn’t pass it to our children in the bloodstream".RONALD REAGAN
Reply:Originally Posted by villageblacksmithI would be curious as to the reason (reasons) why a single pass weld is being promoted as an answer to a weld joint such as is shown in the drawing. I suppose, in theory, that it could be done. But sometimes things that look so wonderful from behind the desk look different out in the shop. One thing to remember is that it will take a certain amount of time to fill the joint with the weld deposit. With .045 wire as per the specs, it is possible that completing the weld in two passes will almost be as fast as trying to do it in one pass. The difficulties that could be encountered by a one pass method will likely outweigh the ( possible) time gain.But as always, the world is a big place, with many different and varied circumstances. Sent from my E6810 using http://tiny.cc/Forums_reader
Reply:Originally Posted by CAVEMANNIf they know nothing about welding then they should leave the welding to the weldors, it sounds like the pieces are going th be welded on the assembly or after it's installed, honestly, how would they ever know if it was one pass or two passes unless they're standing there watching, heat can be controlled by skipping.
Reply:Originally Posted by 12V71The big question here from the usual lack of all information, will this be welded by a machine on a fixture or manually?  If it's going to be robotically welded its probably plenty do-able. by a human hand... 2 passes with .035" wire would be my recommendation.  Three threads on this and we only get small driblets of info in each.
Reply:Originally Posted by flushcutI'm no pro but that looks like a LOT of heat to be putting into the part in one pass.
Reply:I didn't realize I wouldn't be able to edit the original post so I'll try to clear some things up here.I've been a weld manufacturing engineer for 6 years, and minus some military time I have always welded and even grew up in a weld shop.I've only been at my current company for a couple of months and don't have a lot of pull when it comes to anything. I am the ONLY weld ME at my location and I work for a very large international company with 40 robot weld stations and 300 manual welders here onsite.At my previous employer I was one of 8 weld ME's and we had 2 weld engineers that came from MIT (finally not Ohio) so they had everything covered.At my current employer, we don't have a weld engineer so instead they come up with a design and come to me supposedly because I did all the FEA and weld simulations at my last employer. They come to me and it seems like they just want me to agree with them and that's it. So I joined this forum for backup/support on what I'm trying to get across to engineering.I apologize I was lacking some basic information. Usually when I'm on a forum I'm usually on one that I've been on for 15 years asking if anyone is having the same issue with a Motoman that I am.
Reply:The posts can only be edited for a time, I havent totally figured it out yet but I think when you close the site you lose the ability to edit, but I'm not sure, it may be time based. I have gone back after some time to initiate an edit, but the site was never closed as I usually open a new tab.IMPEACH BIDEN!NRA LIFE MEMBERUNITWELD 175 AMP 3 IN1 DCMIDSTATES 300 AMP AC MACHINEGOD HELP AMERICA!“Freedom is never more than one generation away from extinction.We didn’t pass it to our children in the bloodstream".RONALD REAGAN
Reply:Seems to me that solid wire mig is not the most appropriate process for this joint. Is there any reason why you can't go dual shield? Sounds like the previous failures were lack of fusion with solid wire.
Reply:Originally Posted by WoznmeSeems to me that solid wire mig is not the most appropriate process for this joint. Is there any reason why you can't go dual shield? Sounds like the previous failures were lack of fusion with solid wire.
Reply:I've been retired from the trade for quite a while, I know things change, but I would run a root, and two hot passes myself.Miller Dialarc 250Hobart 140HTP 220 MTSMiller Legend AEAD 200LE  Gas drive
Reply:Originally Posted by SP4NKH4RDIt'll be manual welded, at least in the beginning.So far, and forgive me, this has all been crap.  Is the weld failing, or is the assembly failing?  What hangs on the assembly that might make it fail, and the questions keep on rollin'.Does it sit there, look up at you, and self destruct...........does it fail in use.......does it just want to go to Mexico on a vacation???????????Cracks after welding...........not pretty enough............................................  ..................................................  ...................what's actually happening???????No pics of the fail (shrug)
Reply:I guess I'm being a jerk about this, but so far........it's been a guessing game for all participants.
Reply:Originally Posted by farmersammmSo far, and forgive me, this has all been crap.  Is the weld failing, or is the assembly failing?  What hangs on the assembly that might make it fail, and the questions keep on rollin'.Does it sit there, look up at you, and self destruct...........does it fail in use.......does it just want to go to Mexico on a vacation???????????Cracks after welding...........not pretty enough............................................  ..................................................  ...................what's actually happening???????No pics of the fail (shrug)
Reply:Originally Posted by 123weldspankhard, let me introduce u to our most persisitant member (sam), who refuses to throw in the towel,untill all options are exhausted, wheter its  steel or a rubber tire (or anything in b/t).    the jabber aint cuttin it anymore , and  breaks/destruction evidence  is the next step'to be  evaluated.
Reply:I mean I'm pretty late to the party here, but I might as well put my few cents work in.There is no way the joint configuration can be reliably welded with complete fusion into all plate in a single pass if it is to be welded in at flat (1G) position, even with an 800 amp submerged arc setup it would be iffy.if it's a round part that can be welded on a rotator then I can see it being possible to full fusion with .045, have the operator weld at the 2 o'clock position so they are always welding "uphill" so to speak, and with alot of very precise manipulation I can see it being possible, getting that reliable with a manual operation is another thing though, and this is completely ignoring the grain structure problems with having a single large pass that will decrease the welds ductility and crack resistance.Honestly with solid wire I would say that this is a minimum of a 2 pass operation if it's on a rotator, if its in the flat 1G position then this is a 3 pass weld.
Reply:I would like to see pictures of the failures and pictures of th welded joint after welding . Personally looks like a poor joint design by no welding the fillet weld on the outside of the joint a 1 pass weld like that with that high of deposition rate without proper post weld cooling would be a very high stress point I would think.
Reply:Machine the hub square to fit the plate hole (press fit if necessary). Get the casting made with a wider flange and bolt it in. Add dowel pins if you think it needs them. It should then stay in perfect alignment. When Sam is out doing hay he's got lots of bolted assemblies that are loaded way beyond 6200 lbs. multiple times all day long and they don't shake loose. It would also make the parts replaceable when they wear out.---Meltedmetal
Reply:Originally Posted by SP4NKH4RDI didn't realize I wouldn't be able to edit the original post so I'll try to clear some things up here.I've been a weld manufacturing engineer for 6 years, and minus some military time I have always welded and even grew up in a weld shop.I've only been at my current company for a couple of months and don't have a lot of pull when it comes to anything. I am the ONLY weld ME at my location and I work for a very large international company with 40 robot weld stations and 300 manual welders here onsite.At my previous employer I was one of 8 weld ME's and we had 2 weld engineers that came from MIT (finally not Ohio) so they had everything covered.At my current employer, we don't have a weld engineer so instead they come up with a design and come to me supposedly because I did all the FEA and weld simulations at my last employer. They come to me and it seems like they just want me to agree with them and that's it. So I joined this forum for backup/support on what I'm trying to get across to engineering.I apologize I was lacking some basic information. Usually when I'm on a forum I'm usually on one that I've been on for 15 years asking if anyone is having the same issue with a Motoman that I am.