Production Techniques Made Easy...PartIII

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Hey guys,Ok, here's another installment of production techniques for those who work in production/job shops. These techniques are to help you understand the concept of producing multiple products with repetitive consistency & how to construct a jig or fixture per your application. Almost every jig/fixture is designed & constructed using an already finished part so that your construction is of exact dimensional specification for the parts to be assembled to be the completed piece.This particular part is called a "rigidizer" that is used to tie-in & strengthen a 4-way panel intersection with our office systems. These are a cast aluminum we got from a casting company in Pittsburgh. They used our dies to make these & some of the dies were made to be able to cast (2) configurations. These dies cost in excess of $250,000 each. The casting company suffered a total loss with the massive flooding in Pittsburgh in '06. My boss, the owner, was in panic mode as we used 400-600/mo. Sooooooo, he calls me in the office & asks what I could do to convert the straight parts into 3-way & 4-way parts. I told him I needed a day or so to take a couple parts home to see if I could convert easily & productive. The next day, I went into the office & told him I had a cure & needed some material to take home to make some jigs. He told me to take anything I needed & log all my time at home as he would pay all my hours/expenses.That weekend, I made the (2) jigs & cut the legs off the straight pieces to be fit in the jig to attach to another straight piece to make a 3-way or 4-way. Since we had 25,000 straight ones, I had sufficient stock to work with. I did all our aluminum welding in my home shop as we didn't have a spoolgun or another MIG at work & the owner didn't want to spend any more $$$ to buy me one for the metal dept. Yup.... I got to work at home & he paid for all my hours & furnished all the wire/gas I needed. When I took the (2) prototypes in the following Mon., he was elated to say the least & it enhanced my year-end bonus.Ok, the pics will show several jigs & some of the variant types toggle clamps that one can use for securing parts in place. You will see the shields I made to keep the aluminum spatter from covering/sticking to the toggle clamps. Also, the box of cutoffs ready for the next job. These were virgin castings that were really clean & only needed a light brushing with a SS brush to prep.. I welded with MIG using  .035/5356. I had a hotplate next to the welding table with (8) pieces getting pre-heated to 250* that made it a snap for MIG.Anyway, I hope this may give you some ideas for your shop if you do a lot of multiple pieces. Don't hesitate to ask a ???.  Gonna need (2) posts to get all the pics on....PLEASE WAIT TILL BOTH POSTS ARE ON!    Thanks....Denny Attached ImagesComplete Welding/Machine/Fab. ShopMobile UnitFinally retired*Moderator*"A man's word is his honor...without honor there is nothing.""Words are like bullets.... Once they leave your muzzle, you cannot get them back."
Reply:2nd Group:These show the setup & could be configured to make either 3-W or 4W pieces. The finished piece is ground to finish & ready to prep/paint.Denny Attached ImagesComplete Welding/Machine/Fab. ShopMobile UnitFinally retired*Moderator*"A man's word is his honor...without honor there is nothing.""Words are like bullets.... Once they leave your muzzle, you cannot get them back."
Reply:Looks good!  Coming from a carpenter's world into welding, Jigs were second nature.  I had fabbed jigs for routing and repetitive cuts for years.  They can save alot of time.
Reply:Nicely done Denny. It's amazing sometimes how one can have better facilities to do things at home than at work. I found this true several times in my career.I've got some grills I've got to build for the horse stalls in the barn that I will have to jig up. I'd like to get your thoughts on jigging them up. I find that when I've done this in the past I run into issues with the verticals varying slightly. I've seen examples of where people have drilled out holes on the top to account for the variation and welded just the bottoms.Thoughts?GlennSign on East Texas payphone: Calls to God 40 cents......it's a local call...
Reply:Denny,   Thanks for the post. Where do you get the green handled "over center" clamps?Stampeder, I have often been frustrated because I didn't have the facilities to do something at work that I am set up to do at home. I think it is a common problem.
Reply:daddy,Toggle clamps.  Available all over the place.  Handy gadgets.As to where Denny specifically got those small green-handled toggle clamps, I have no idea.  http://www.use-enco.com/CGI/INSRIT?P...&PARTPG=INLMK3http://www.grainger.com/Grainger/DES...WX4?Pid=searchhttp://www.mcmaster.com/#hold-down-t...clamps/=afisrshttp://www.fastenal.com/web/products...3162998&ucst=tOr probably about a thousand other suppliers.    The best laid schemes ... Gang oft agley ...
Reply:Hey guys,Glad you find these techniques interesting. As far as the toggle clamps, hmmmmm, back 8-9yrs ago when I was working for my company, I got them to order me different size ones as per needed usage. I got on E-Bay & found them so cheap, I ended up buying about 150 of them in different size & configurations. I was buying the small ones for .50/ea & the large ones for $1-$1.50/ea. & they were the good ones, all USA mfg.. They really are so handy & quite strong, even the little ones. I know that some of the USA companies went to China & there are imported ones fairly inexpensive, & just more loss of good products. Maybe the name brand ones, if made overseas, will still have good quality..... hard to say. Hey Glenn:  Post a couple pics of the units you need to make so I can get an idea of what would make it easier for you. For large items, you gonna need a table capable to hold it all in place. Show me what you have....DennyComplete Welding/Machine/Fab. ShopMobile UnitFinally retired*Moderator*"A man's word is his honor...without honor there is nothing.""Words are like bullets.... Once they leave your muzzle, you cannot get them back."
Reply:Nice tutorials Denny!I jig and/or fixture whenever I can, but some things just refuse to play nice...(pardon me if I'm polluting your thread)These are signs for a bank. They hang from a wall by their edge, with the two "face sides" each facing a direction of traffic.This image shows the raw shells. The two fabricated halves of the sign, constructed from .125" aluminum. The tops, bottoms, and faces are all curved, while the remaining flat surfaces contend with a 3/16" lip formed by a continuation of the face material. The actual top of the sign is the closest surface to the camera. Multicolored lexan occupies the large empty spaces and the copy below, forming the bank's logo. Fluorescent lighting and a steel supporting structure round out the build.The best part is that the one half of the sign has to hinge open for service, with just a handful of countersunk screws for closure. This means the seam between halves has to be flawless, and that all of the structural and lighting aspects are forced into the fixed half. Many, many people tried to build them with forms and fixtures. "Boat builders" I'd call them, because of the typical wooden cradles they would almost always try at first. Even when a seemingly workable contraption was made, it was never repeatable from half shell to half shell. Turtle power!I was suitably frustrated myself. But in the end I decided to exactly replicate my movements through the whole process for every shell, from fabricating the individual parts to tacking and welding them. Not too super impossibly hard usually, but any time you throw a radius into the mix, and subsequently a hand cranked slip roll...  FML.No one else was able to make two halves that would fit together competitively, so I whipped up 40 half shells that were mostly interchangeable. I was happy to make 3 complete sign shells a day which was plenty fast enough to keep everyone else busy. With a suitable fixture or set of fixtures no doubt the build time could be reduced substantially. But because it is eighth inch aluminum, any excess clamping or holding pressure, once released, ends up distorting the product just as bad as a weld.And now I've learned that this same bank has taken over another, adding some 100 locations. All in need of new signs...Suggestions?Please!!
Reply:Coming at it from the woodworking angle... box building... how about set up the pieces to be welded into a complete shell and then build a jig to plasma cut the shells into two perfectly matched parts...
Reply:Hey ncfh,Glad you found the tutorials informative. You definitely have an interesting project there & quite nicely done. Since you have a finished item, you need to build around it.  Looking at it, couldn't you build a frame with bowed straps w/correct radii, to set the sides in place & clamp together to allow tacking? You using MIG or TIG?  I'll try a couple experiments with some 1/8" alum. & see what results I get.  Sounds like you have your work cut out for you.DennyComplete Welding/Machine/Fab. ShopMobile UnitFinally retired*Moderator*"A man's word is his honor...without honor there is nothing.""Words are like bullets.... Once they leave your muzzle, you cannot get them back."
Reply:NCFH;When I first saw this my first question was.....where are the oar locks for the oars so the slaves can row.....Hee Hee......Nice work though....I agree with Pandinus about the box building approach. I have done lots of woodworking over 30 years and every time I have a structure like you are working on, it always turns out easier to build it as a complete box unit then cut it in half. Perfect fitting every time and will save you time in the end. You can even install stuff in it before you cut it in half.Good luck and keep us updated. Looks like fun......Glenn.Last edited by Stampeder; 01-12-2011 at 03:38 PM.Sign on East Texas payphone: Calls to God 40 cents......it's a local call...