Need to clamp it in the middle of your table?

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Hello everyone, occured to me the other day to include this little tid bit for those who haven't already done something of this sort. I sometimes find that I just can't quite reach an item to clamp it down due to various obstructions and maybe a half-clamp or a wedge and dog just doesn't quite fit the bill. So, by using a block/blocks, C-clamp, and a piece of tube, angle, channel, or some other sort of structural shape you might just be able to get enough pressure on that part to serve your purpose. Best regards, Allan Attached Imagesaevald
Reply:I have done similar, but I must confess that most of the time I just tack a clip to the table and clamp off of it.  I have different sizes of angle clips and if I need to really hold something down, I weld a wedge dog or screw dog to the table.
Reply:LoL... I though he was being funny when he said he would use a dog... I guess it's an actual term for some form of clamping mechanism? Pardon my ignorance, new to all this myself
Reply:Hello DageonYar, this might help to clear up the "dog and wedge" term for you a little bit. Best regards, Allan Attached Imagesaevald
Reply:We refer to the "dog" as a "lug" when used with a wedge. Same thing just different word.Ranger 250 GXTSmith Gas Axe
Reply:perfect timing.  i was thinking to drill holes on my welding table to use machinist wedge clamp.  I will try this first.
Reply:Excellent pics and info you provided!  Thank you!Lincoln Power Mig 216Lincoln AC/DC-225/125Miller  625 X-Treme PlasmaMiller 211 Forney 95FI-A 301HF 91110Victor Journeyman O/PMilwaukee DaytonMakita  Baileigh NRA Life Member
Reply:Hey, simple.  Effective.  I like it!(Retired) Professional firefighter, amateur everything else I try to do...Oh yeah:  Go Big Red!   (You know: one of the 12 members of the Big 10 cuz we left the 10 members of the Big 12...)
Reply:if you have a steel table top even as thin as 1/8 you can tack clips to it.  the tacks are only 1/4 to 1/2 inches long.  I use a metabo to cut one tack and then pop it with a hammer and the clip comes off.  touch up the table with a grinder and move on.  for the dog, you only need to run a stitch on one side.  then drive your wedge in from that side.  if you need something more substantial, weld both sides and wedge as needed.  when it comes time to remove the dog, metabo one side and then hit the dog with your hammer.One word of caution.  if you do have a thin table top, you can warp it by aggressively using a dog.
Reply:Allan, I am sorry to have highjacked your thread.  I have used your clamp method especially if I need something quick and need to move the project around and reclamping it.
Reply:Hello Scott, I don't mind at all. Sometimes it takes a topic to bring out others. Everyone hopefully learns a little something, I know I do. Best regards, Allanaevald
Reply:Allan, I had just hit enter on my second to last post and it hit me, "you dummy,  Allan had mentioned the cantilever was for when a dog can't be used."While we are on clamping, are you familiar with key plates?
Reply:Bridgeport clamps work on the same principle as the OP's"Any day above ground is a good day"http://www.farmersamm.com/
Reply:Hello Scott, the term "key plates" doesn't bring anything to mind for me, possibly I know it by another name. Look forward to further explanation and possibly some pictures? Best regards, Allanaevald
Reply:Well Allan, FINALLY I have an opprotunity to post up something to help YOU...Here is the website:http://www.fitupgear.com/fug.htmlHere is the video page:http://www.fitupgear.com/videos.htmlHave a Good Day.Later,Jason
Reply:Hello Jason, thanks for that information. I have not seen that particular type of fitting tool before, is it typically a storage tank type of fitting tool or is it specific to any other particular industry? As to the "finally" part of your post, I have read more than a few of your responses and I have learned from you many times and you and many others have given me plenty to think about as I read through the various posts on this forum. Thanks again for including those links. Best regards, Allanaevald
Reply:allan, it is used mainly in tank fitup, but i have used them anytime i needed to pull sheet and flush it up.  I use to work for a tank company.  I have used them in non tank environments mostly.  I had a logging loader arm that I needed to pull together and flush up.  Another time I was having difficulty replacing the skin on a dump truck and used them for that.  I have found a ton of uses for them.  I have had to be creative at time when a bull pin won't fit, I will use a short wedge.  really anytime you need to pull or even push a seam, you can use them.  I made all my key plates out of 1/2 inch stock
Reply:Thanks, Scott, I can certainly see how they would be very handy for a number of applications like those you named above. Best regards, Allanaevald
Reply:Good idea Aevald, thanks for posting it.A chain passed over a push-block and then pulled tight with a chain binder will also exert a lot of down force, even though the push-block may be some distance from the chain's anchor points.Good Luck and a happy Mother's Day.
Reply:i used this method yesterday...it vorks great!
Reply:Hello Denrep, I believe this might explain what you spoke of in your response about a chain/push block/binder, although it's slightly different, it's still the same principal. Best regards, Allan Attached Imagesaevald
Reply:Denrep & Allan,I use a similiar setup, I have a piece of pipe that I modified to fit onto a 12 ton Bottle Jack...  It has another piece of pipe welded onto it at 90° that the chain passes through to contain it, and keep it ON the bottle jack as I push into the chain, and bend the structure like a bow.I will TRY to get picks of it today.Have a Good one fellas.Later,Jason
Reply:Be vary carefull with the chain and bottle jack method.   You could easily snap a grade 70 5/16" chain with a 12 ton bottle jack.Vantage 500's LN-25's, VI-400's, cobramatics, Miller migs, synch 350 LX, Powcon inverters, XMT's, 250 Ton Acurrpress 12' brake, 1/4" 10' Atlantic shear,Koikie plasma table W/ esab plasmas. marvel & hyd-mech saws, pirrana & metal muncher punches.
Reply:Hello Jason, I believe this might be somewhat along the lines of what you suggested in your post. Following what dualie posted about snapping chains with excessive tonnage, the lugs that I used for this example should really only be used for this sort of purpose as opposed to being used for transporting/moving/lifting materials, however I see it all the time in shops where they have manufactured their own devices, you just have to use extreme caution and care not to place yourself in the "bite". Best regards, Allan Attached Imagesaevald
Reply:Duallie  and Allan,Yes you are BOTH correct with your warnings... BUT, in my defense, my adapter is made with a 3" Sch 40 ring welded on to it that the chain passes through, so I have the ability to use either a single, very LARGE chain, or SEVERAL smaller chains as the application requires.  You have to realize that this design is NOT very efficient, and a lot of energy is absorbed just taking the slack out of the chain, before a real "Load" is applied... This is NOT the same as applying 12 tons of pulling force in a straight line on the links of the chain.There are inherant (sp?) flaws that can be pointed out about the components of all the designs discussed here, mine is no different.What I would suggest, is that these ideas are offered up for consideration by the members, with the implied understanding that the end user will have sufficient knowledge of the equipment being used, that he/she should be able to SAFELY use said equipment within acceptable operating parameters.If the end user cannot use my design safely without blowing up a chain, do any of you think that the end user has sufficient knowledge and experience to COMPETENTLY:1) Attempt the repair, or 2) Use a WELDER while performing the repair?As Allan has posted a very similiar idea, I will not bother posting the pics of mine.Have a Good Night eververyone.Later,JasonHello Jason, I hope that you don't take my post as being critical of your design or use of this sort of aide. That definitely was not my intention. I am always open to ideas and suggestions from others on addressing various challenges. Even "approved" devices can fail or are subject to failure if used incorrectly or without a level of common sense. As I consider various ideas and ways of accomplishing tasks I always try to ask myself if I have considered the types of failures or scenarios where someone can get hurt and when applying ideas I do my best to insure that I'm out of the pinch and if there are others present I definitely make sure that they are out of the way. I am certain that there are plenty of folks who could criticize many of the methods and aides that I have employed over my career to accomplish a job or task. I have been in the presence of failures of methods and equipment, both engineered and home-engineered. Due to dilligence, common sense, and a general lack of complacency, I have been able to avoid any major injuries to myself and others. I believe that anyone who considers another's ideas or methods has to do so by assuming their own responsibility for use and safety. Here again, common sense needs to prevail for the end user. Keep 'em coming Jason. Best regards, Allanaevald
Reply:These are the kinds of threads I enjoy having on this site, they give me access to so many ideas that I would probably never think of myself. The Denrep/Black Wolf contribution just solved a problem for the next step in my project. I'm a home hobbyist without alot of sophisticated clamping tools, but I do have some heavy chain and a small bottle jack and it never occurred to me to use them in the ways described. My problem is simple, I need to box closed some 7" channel with 1/2" plate and I want to clamp the whole thing to some heavy walled 5" square tubing to reduce warping while welding. I can clamp the ends of the channel/plate to the tubing easily with C-clamps but I have nothing to clamp in the center (channel is 60" long). Now I'll just loop a chain through the tubing, over the top of the channel and put the bottle jack in the center.Yes, all great ideas are inherently dangerous when working with metals at their melting points and put under huge loads. The liability falls back on the end user, not the presenter of an idea. I agree with Allen that we need to apply common sense and be alert while working to stay safe. Please keep the ideas coming, and also thanks to the "safety police" for the continuous reminders to be vigilant while working.
Reply:Originally Posted by aevaldHello Jason, I hope that you don't take my post as being critical of your design or use of this sort of aide.
Reply:I have been fortunate to have worked with some older men who have gained this common knowledge.  By working with them they pass it on through the practice of the trade.  What I enjoy is the variations of each of you contribute.  I have used a bottle jack with a top much like allan's, but ours wasn't home grown.  it was salvaged from another chain counter implement.  I believe it came from a truck's took kit when they were allowed to double back chain binders.Before I began life as a welder, I was a carpenter.  There are a lot of similarities, but then again they are worlds apart.  I am still learning the trade of a welder so thank you for yall's posts and reminders to be careful.  even seasoned tradesmen need that reminder.I know it is a variation to the binder and bottle jack, but if you did your fit ups on the same table, you could use a cable instead of a chain.  let's say you have a 5', 6', 7' etc. cable with spliced eyes on the ends.  you could utilize the table catches and a shackle to attach the cable to.  you will be hard pressed to snap a 1 inch cable with spliced eyes.  The top of the bottle jack could have a soft radius attachment to channel the cable.  You would use the appropriate cable for what ever need you may have.  dunno, it may be stupid, i am just think aloud at the moment.
Reply:sticky this bad boy!!
Reply:An excellent suggestion Scott....If an individual found him or herself in this situation repeatedly, your idea sounds like it might just fit the bill...I cooked up my adapter several years ago from neccessity... I was working on a building from a drilling rig sitting on a rack site, and had to force a member into place, but had no means to attach it close-by, so I build what I needed specific to the application.I have learned that this adapter is handier than I thought, and it gets pulled out of the toolbox every so often to help me do something oddball...  The nice part is, I can use it with the bottle jack in any position except inverted, and with the ring, it is like another set of hands.Had it out not that long ago and used it to pull up the lower flanges of some 12"@ 45lb  I-beam, after I had coped the webbing to fit around some 5" pipe, and tapered the webbing from the lower edge of the pipe back to the lower flange.... It is pretty common up here to have all of the Service Rig, Drilling Rig,and Rental Equipment for the oilpatch mounted on skids that can be winched on to bed trucks and winch tractors...Have a Good Day.Later,Jason
Reply:Just so everyone knows with the veer angles involved in that setup if you actually maxed out that 12 ton jack you could impart 48,000lbs+ of force into each side of the chain leg if the bridal over the jack.For reference bulk grade 70 3/8" cargo transport chain has a safe working load limit of 6,600 lbs.   I have seen chains brake, its not pretty.   My friend Joe has 3 pieces of titanium in his dome after a Grade 100 5/8" chain broke on him.Vantage 500's LN-25's, VI-400's, cobramatics, Miller migs, synch 350 LX, Powcon inverters, XMT's, 250 Ton Acurrpress 12' brake, 1/4" 10' Atlantic shear,Koikie plasma table W/ esab plasmas. marvel & hyd-mech saws, pirrana & metal muncher punches.
Reply:Aevald - That's great. You've built some nice fixtures. Thanks for posting them.Dualie - No doubt a chain has less capacity when angled.But can you share  how the chain loading of  48,000 x 2 is calculated?ThanksLast edited by denrep; 05-14-2010 at 09:47 AM.
Reply:Denrep,Well, technically the chain still has its same load capacity.    But when a chain or cable or sling is angled and not used in a straight vertical lift, the -effective- weight limit for the lifting device is reduced in the angled lift configuration compared to the vertical lift configuration.ex:  1/2 inch Grade 100 alloy steel chain is rated to 15,000 lb vertical lift (WLL, not ultimate chain rating)So two such chains could lift 30,000 vertical lift (WLL, not that you would necessarily lift 2x the weight of any single chain just by using two chains vertically).A two-leg 1/2 inch Grade 100 alloy steel chain bridle sling is rated as follows depending on the sling bridle angle:30 deg bridle angle =  15,000 lb WLL45 deg bridle angle =  21,200 lb WLL60 deg bridle angle =  26,000 lb WLLThat's for a nice even balanced load shared equally between the sling legs.  Unequal loading or non-horizontal loading changes things for the worse.It all comes about from the sine of the sling angle ( angle sling leg makes to the horizontal load).sine 60 = .866 x 30,000 lb (effective vertical lift WLL for two such chains) = 26,000 lb WLL at that anglesine 45 = .707 x 30,000 lb = 21,200 WLL at that anglesine 30 = .5 x 30,000 lb = 15,000 WLL at that angleWhat does this all mean in the real world?That 12 ton bottle jack is too much for that rusty chain.    Unless that chain is bigger and stronger than 1/2 inch grade 100 alloy steel chain.  And even then I think it would have to be condemned based on all the rust.  The theory and physics of the chain/cable over the top of the jack in the middle of the plate is fine.  But the use of the 12 ton jack is waaaay to much for that particular chain at that particular angle.  Cause looking at the chain angle it looks close to a 30 deg angle, and that means the chain WLL should be reduced in half for use at that angle.  If the chain were good 1/2 inch Grade 100 alloy steel chain at that approx 30 deg angle, a MAX 6 ton jack would be appropriate.  (good chain two legs at that angle = 15,000 WLL so that means a 6 ton jack MAX)Going to a Grade 80 alloy steel chain in a two-leg bridle configuration and desiring to use the 12 ton jack would mean using a minimum 3/4 inch chain size.  That's 5.5 links per foot and 6.6 pounds per foot of chain.  Minimum size required for the 12 ton bottle jack.http://www.ashleysling.com/cs14.htmNotice that at a 30 deg sling angle the WLL for a two-leg bridle sling is the SAME as for a straight line WLL for the same size/grade chain/cable.  (two legs at 1/2 WLL = one leg at full strength WLL)And yes, if something snaps things would go bad fast.  All that energy in the tensioned chain/cable will be released in an instant and the chain or cable will whip and DESTROY anything in its path.  Be safe.  Machines and equipment don't care, so YOU have to take extra care.btw, keep the clamping/jigging ideas coming.  But be safe.  Always be safe.  The best laid schemes ... Gang oft agley ...
Reply:Right MoonRise, I should have said a chain sling assembly's capacity is reduced, not the chain capacity itself.I understand the terrific mechanical forces that can be generated with toggle-type, or scissor-type links (which is essentially what the jack in a triangle is) but I wondered where the specific 48,000# number came from. I was thinking that maybe Dualie has a rough rule-of-thumb to share.Aevald's rusty chain? No sweat. The hooks would peel long before that chain was in danger of yielding. And actually, a qualified operator could safely use the pusher with even a 100 ton jack. After all, the jack isn't being pumped up to relief pressure. Granted, an unqualified operator could possibly manage to hurt himself using just a ½ ton jack.Good Luck
Reply:Originally Posted by DualieJust so everyone knows with the veer angles involved in that setup if you actually maxed out that 12 ton jack you could impart 48,000lbs+ of force into each side of the chain leg if the bridal over the jack.
Reply:Hey Aevald, this one sure blew up, huh?  Personally, I will stand by my earlier statement:"Hey, simple. Effective. I like it!"(Retired) Professional firefighter, amateur everything else I try to do...Oh yeah:  Go Big Red!   (You know: one of the 12 members of the Big 10 cuz we left the 10 members of the Big 12...)
Reply:Originally Posted by strube1369Hey Aevald, this one sure blew up, huh?  Personally, I will stand by my earlier statement:"Hey, simple. Effective. I like it!"
Reply:Nice thread, below is a link to the US Army rigging manual and contains load calculations about half way through. You can spend a long time studying the knots and other trivia in this thing.http://www.petrospec-technologies.co...ts/FM5-125.pdfWhen Porto-Power still made the screw together parts they had a number of attachments for their jacks to use with chain as in this thread. Porto-Power cautioned that the use of all attachments de-rated the jack by 1/2 (I suppose this was for caution).It is never smart to stand in line with a chain, cable or rope in tension. But I think as used in this thread for clamping the setup is pretty stable.This same arrangement is used to straighten things and in that case what goes wrong is a load shift and the jack tips and the foot kicks out. In this case think of the object under the jack as a "bow" the chain would be a "bow string" and the jack becomes an "arrow".Matt
Reply:Hello Mat and everyone else who has responded or checked out this thread, my full-time job is as an educator, I also spend plenty of additional time working in various aspects of the metal trades doing shop/field work and a fair amount of hobby work. I am sure that many of you are aware of the great number of folks who will be exiting our professional workforce in a very short few years. It will be coming up very quickly and without a lot of fanfare. The major downside to this exodus will be the loss of knowledge and skills as these folks transition into their retirement years. I cannot tell you how many folks I have seen retire, be forced out of their jobs by down-sizing, be replaced by advances in technology, or otherwise leave the work-force. Most all of these individuals take with them an irreplaceable amount of knowledge and skill, so if you have the opportunity, pay attention, ask questions, share stories, and if you are so inclined, share your own experiences, knowledge, techniques, and other useable information. Even if no-one specifically thanks you, you will likely have had a hand in someone elses success. I thoroughly enjoy the ingenuity displayed by the many folks who post to the various forums, everyone is likely to have a slightly different perspective and idea on how to approach a particular task. Geographic location, prevalent industries and jobs, social make-up, and so many other things will effect the responses and approaches employed by individuals with a challenge to overcome. I appreciate the diversity that comes accross when subjects are discussed and suggestions are made. Even opposing views are good for the consideration of those who are interested, if you can keep an open mind you will likely see the logic of both sides and possibly learn in the process. I look forward to reading and viewing many additional topics and learning and contributing when I feel I can. If you read this, thanks for your time and hopefully I haven't put you to sleep before you wanted to be. Best regards, Allanaevald
Reply:Good observation there Allen, even though some aspects of welding and shop work in general are strictly defined and certain rules must be followed, there still is a lot for an individual to work out by themself.When there is more than one reasonable solution for a problem that is much the same as a wrench in the toolbox by a different manufacturer. I still have my favorites but there is a plan "B" for the times I missplace or otherwise can't use it.This business of passing on or through has been going on since the start of things, I'm not that melancholy about it right now. Recently I've been getting up and discovering there's a whole new day I can screw up!!!Matt