Workholding Jig

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I found this video and decided I have to have this...We have another member here who did this, but I cant find the thread. Anyway, I have a basic question that some of you more knowledgeable welders could answer, but please look over the jig video so you can answer...Steel Balls come in lots of different grades. You can get mild steel, machinable, tappable or you can get higher carbon hardened case, meaning only the outside is hardened. Or you can get chromium with other alloys that make the entire ball hardened. I want to make this jig so that its very easy to use. My first thought is, can we use mild steel balls and have them drilled and threaded all the way thru the ball so we can add whatever we want easily? Would the mild steel eventually wear unevenly or be a problem? Keep in mind that instead of Aluminium, I have 3/8" mild steel plates.So if you veterans think that the mild steel ball is a bad idea, what would be your thoughts on how to weld a short shaft on the end of the ball to receive vise grips, another rod of various size, etc. What kind of welder do I need? Which grade of ball? I have an SP175 Lincoln Mig that I really want to use, but maybe its not sufficient?Thanks all! I get a lot out of being a part of this forum!
Reply:Here are a couple threads to get you started:http://weldingweb.com/vbb/showthread.php?t=61670http://weldingweb.com/vbb/showthread.php?t=48154
Reply:yes. Acoutjesters post was the one that really helped the most, but my questions still stand. Thanks for posting those.
Reply:Check this guy... he has a bunch of styles. Any ball should work. Steel, brass, aluminum should all be fine for the application.http://stores.ebay.com/ToolSupply/Th...sub=1485291013
Reply:There are various ways to do this. I had a friend at the local welding shop CNC plasma machine make me up 20 sets of 3/8 inch, 4x1.5 inch plates with 3/4 holes. If this jig is going to follow our 'Tinker Toy' philosophy, we want to have many different vise grips, rods of different sizes, etc to make it useful. Our plan is to use HEX rods machined for this use so we can put a wrench on the rods to tighten them. The steel balls is our problem right now because as beginner welders, we arent sure if you can weld hardened steel balls with a mig, or if we use mild steel balls will they hold up? If we go with mild steel balls we can mill threads all the way thru the ball and make this a lot easier? We just could use opinions at this point.
Reply:For that project I see no problem MIG welding the hardened balls to the rods. If your  Welder is on the smaller side you might want to preheat the balls a bit.Personally if it was my project. I would use aluminum plates and mild steel balls that are tapped to fit the rods. This is going to give you a much larger range of versatility because you can simply change out the threaded rod for a longer or shorter one. The aluminum plates being softer than the steel balls are going to wear and not gouge the balls (nobody likes gouged balls  )I don't really see the advantage of using a hex rod over a cheaper round rod. If for some reason you need to twist the rod simply use a pair of curved jaw vice grips.If you cant fix it with a hammer, it must be an electrical problem."Boy, everyone starts with a full bag of luck and an empty bag of experience. The trick is to fill the bag of experience before the bag of luck is empty."-Grandad circa 1990ish
Reply:I already have the 3/8" steel plates so from what I understand you would recommend go with higher strength balls then. Without being able to tap the balls, we will create a 3 inch or so shaft with female threads to accept any male threaded part, welded to the ball. Does this make sense?
Reply:Originally Posted by DeveI already have the 3/8" steel plates so from what I understand you would recommend go with higher strength balls then. Without being able to tap the balls, we will create a 3 inch or so shaft with female threads to accept any male threaded part, welded to the ball. Does this make sense?
Reply:I would weld 1/2-13 coupling nuts to the balls, they are longer.Millermatic 251Century 180 migSpectrum 625 Syncrowave 250DX
Reply:This is a good idea, but in actually looking at the pieces, 3/8 would be better. More range of motion and plenty strong enough. This idea would also self center the ball for welding. So where do you get couplers like that? My local hardware store doesnt have them. McMaster again?
Reply:Did you miss the link I posted with the threaded balls? Attached ImagesLast edited by forhire; 07-26-2012 at 08:37 PM.
Reply:no, but that would mean they are machinable balls thus softer than the plates. Since the 3/8" mild steel plates were created using a CNC plasma, this hardening the holes a bit, my thinking is I need the case hardened balls. I am going with 1-1/4" balls. does that make sense?
Reply:No offense, but machinable don't mean crap. Where I work we have 3 CNC setups that machine stainless all day every day. Plasma cut mild steel and that heat treating, if it exists, is still softer than the stainless. The base material itself is key. Maybe the balls are work hardened from the machining? Call them and maybe they can let the tooling dwell a bit and harden the surface a little.Bruce
Reply:Originally Posted by forhireDid you miss the link I posted with the threaded balls?
Reply:I ordered 5 of these and 5 of the 1-3/8" of the same grade to test them before I buy the rest. I plan on welding these to grade 5 1/2" bolts with my Lincoln SP175 Plus Mig. I also ordered 1-3/4 coupling nuts to see if that will work out for the connections. Any tips or suggestions would be appreciated. I am a very new welder and have lots to learn. Thx9528K44E52100 Alloy Steel Ball, 1-1/4" Diameter, Grade 25, packs of 1
Reply:IMO, you'd be much better off with a case-hardened ball.  Welding 52100 should be done with pre and post heat and ideally in an annealed state.McMaster-Carr lists case hardened balls up to 1" and may be able to supply larger.http://www.mcmaster.com/#catalog/118/3658/=im8066"USMCPOP" First-born son: KIA  Iraq 1/26/05Syncrowave 250 w/ Coolmate 3Dialarc 250, Idealarc 250SP-175 +Firepower TIG 160S (gave the TA 161 STL to the son)Lincwelder AC180C (1952)Victor & Smith O/A torchesMiller spot welder
Reply:ok, I am REALLY new at all this. Annealed? And my problem is I cant find 1-1/4 and 1-3/8 *havent decided the size until I see them) in McMaster or anywhere that seems reputable. All the help I can get is much appreciated. If I preheat the balls I have on order, can I use a propane torch? It says they are grade 25.  The bolts are grade 5. Is this an apple to apple comparison? Like the ball is actually 5 times harder? My welding shop owner friend says I can do it, but to put the SP175 Plus on max heat. This connection needs to be pretty darn strong. Im worried. I also noticed if you can find them outside of China, there is a such thing as UNhardened mild steel balls. But again, cant find a place to order them and worry they would be strong enough anyway.
Reply:Annealing refers to "soften" the metal. And no, I do not think a propane torch would produce enough heat.  What exactly are you planning on holding with this thing? In the video it shows a sheet metal fender, I see the rods bending and flexing before a weld gives away. I understand wanting to do it yourself and some good research before diving in. But if it concerns you that much, perhaps you should have someone with more experience and a proper setup weld it up for ya.  Hell, send them to Zap...he gets ALL the fun jobs If you cant fix it with a hammer, it must be an electrical problem."Boy, everyone starts with a full bag of luck and an empty bag of experience. The trick is to fill the bag of experience before the bag of luck is empty."-Grandad circa 1990ish
Reply:the motion picture, photography, and sound industry have used these types of clamps for years with out fail.  Some of them being able to hold very heavy loads while in use.  I think that in my opinion only, that sometimes we fail to look around us to see what is in use everyday by others that might have high use in our own industry or others.  and while we fail to see the eveyday things in use, we want to try and come up with something that is unique and unthought of by others when the wheel has already been refined. the clamps that photographers are made with very heavy duty clamps and arms that would work as jigs for most projects that would need to be accomplished in welding shops from day to day, with out having to spend tons of money having others mill, drill, and search, for the items that already out there for us to use.   Now I am not ranting or putting down anyone thought process, because I know 1st hand that I fall into the same trap of not being able to think outside or the box due to depresion or some other thought blocing process.  but if you want google articulating arms and clamps and a bunch will show up, some being made by the bogen manfroto company, I only know this as in a former life I dabbled in photography, now I hope this has a little help so i will shut up now.By
Reply:I have been paying alot of attention to what else is out there and I dont want any plastic in it because I may end up getting a torch close to the system. I like Lazze's professionalism when it comes to using aluminium and everything machined so nicely. But I am thinking 1 inch balls arent optimal. Im thinking 1-3/8 or 1-1/2 for a better range of motion. I had my plates cut to 1.5x4 inches so I could play with this theory. Just having fun and learning new things. I dont have an O/A Torch but I can understand why preheating would be a good idea. I purchased a few balls to play with to see what I can do. If I get too discouraged, I will ask someone else to do it. I can understand heating the work up before welding but how do you soften (anneal) the metal? Or is that that same thing? Thanks all for your patience. I learn so much from you all.
Reply:for a really heavy duty version trailer hitch balls are pretty darn good.  I've made some similar but larger clamps with them.  they will support small bench vises etc..wether or not the balls are hardened are almost irrelevant to the functionality.    deburr the holes if you dont want to scratch the heck out of the balls but actually havig a little scratch and bite will make the clamping more secure than if you have chromed or very hard balls.balls having threads doesnt mean they are what you call "machinable"    some really insanely hard stuff gets machined.  much stuff gets hardened  after it's machined.the system is so basic you can freehand cut the plates and end up with good working clanmps. you dond need CNC or a mill or any of that.  just some steel plates and rod, few cheap hitch balls, and some hardware.Last edited by dsergison; 07-30-2012 at 11:06 AM.
Reply:So I have the 3/8" plates made with 3/4" holes to receive the balls. I also beveled them so they seat nicely. I then decided on 1-3/8" balls after looking the 1-1/4" ones over and decided they need to be bigger for range of motion issues. Now its time to drill the center hole in the plates and I was given some nice grade 5 allen head 1/2" x 13 bolts. Question is, do I use them? Wouldnt you rather use fine threaded bolts for this? How much does fine vs course threads really matter? Thx
Reply:Bearing balls are number graded according to precision.  It has nothing to do with the strength or hardness.If you weld on those 52100 balls, you may have cracking issues and a brittle area in the heat affected zone.  You will affect the hardness in at least part of the ball.  You could heat the ball hot enough with a propane torch to reduce the hardness somewhat.Here are some somewhat rough 1 3/8" steel balls that might work fine.  As long as they are round the texture might actually grip better.  Not bad for $1.09.http://www.kingmetals.com/Catalog/Ca...ogDetailId=226"USMCPOP" First-born son: KIA  Iraq 1/26/05Syncrowave 250 w/ Coolmate 3Dialarc 250, Idealarc 250SP-175 +Firepower TIG 160S (gave the TA 161 STL to the son)Lincwelder AC180C (1952)Victor & Smith O/A torchesMiller spot welder
Reply:It turns out the 52100 grade 25 steel balls from McMaster-Carr welded up very nicely without any problems at all. I went to alot of trouble testing this, slamming the welded balls on the concrete, hitting them with a large ball peen hammer, etc.. Nope, the weld is great. The only concern I have now is the threads on the plates. You have to really tighten the crap out of the plates to get the balls to stay tight. I tried course thread 1/2-13 and it stays tight and doesnt give problems, but when I tried 1/2-20 hoping the finer threads would be more secure, it felt like I could easily strip the threads. Turns out the fine threads arent as deep into the metal. You use a 29/64 bit to make the fine threads, but a 27/64 to make the course ones. So the fine ones would be easier to strip out but have a finer tighening ability. Go figure. Cant win there! I guess I need to stick to coarse?
Reply:Why not weld a nut to the plate instead of tapping? I believe 1/2-20 develops more clamping force than 1/2-13.. But I'd have to check the handbook. Hell I'd weld a nut tap the plate through the nut for even less chance of stripping.. Sent from my Galaxy Nexus using Tapatalk 2Miller: 200dx, Bobcat 225, Passport, Powermax 45, Milwaukee: Dry Saw, MagDrill, grindersWhy not press a wheel stud through the plate and then use a good nut on it? Can go with fine thread and if you use a lug-centric nut upside-down, you've got lots of contact area.Bruce
Reply:Please do check the handbook. Where do I get such a handbook? I 'could' weld a nut to the plate but only of its necessary.
Reply:Bruce thats a great idea for this project but I dont have a shop press nor do I know how to prepare the plate to accept the stud. Im new at all this. I think at this point I will try new hardened bolts with fine thread and see how long the threads thru the 3/8 plate lasts. Then if I strip out the plate, go with something else.