Friday, November 30, 2012

Yam Farming Adventure

People that have been following the blog know I've been hunting for a decent lathe for the shop. Over the last few months I have looked at a few but not made a decision on any of them. Either they were too small or too far outside my budget. I missed a nice one that the company sold to an employee on the day I was supposed to look at it.

Finally a lathe appeared that was in my price range and had the right features and tooling with it. One of the requirements for the lathe was the size. I need a longer lathe between centers than a typical tool room lathe. This is so I can machine some large rolls for an etching press project I'm currently designing. Of course like all things the process didn't quite go as smoothly as planned which is why it makes a good story.

It all starts four years ago when I bought an old navy surplus Doall vertical bandsaw at a high school auction. I had grand plans to collect equipment as it came up and carefully store it away until I had a shop space built or rented to put it all in. My good friend Don offered some long term storage space for some of the collection and is where the story gets going.

When I put the saw into storage It had a little accident. Actually I'm lucky it didn't kill me in the process thinking back on it. The saw weighs over a ton and I put it into a cargo container by myself with a drop trailer and a come along. During this ill advised activity I managed to knock the saw over and break the cast iron table mounts. On closer inspection of the saw it revealed there were some parts missing from the variable speed drive that would also need to be replaced to bring the saw into working order. It was quickly turning out to be one of those deals that's not such a great deal. Fast forward four years. I have found another saw in better condition and my long term storage welcome has been thoroughly worn out. Time to move some machinery.
It all started with a perfect weather day. Up in the hills behind Lick Observatory we loaded the Doall using the Ford tractor with forks instead of a bucket. Relatively uneventful. One down one to go. The lathe I found was out in the central valley near Turlock. I had to get outside the bay area away from all the dealers and competition to get a decent deal on a machine. We arrived at the shop where the lathe was only a half hour behind schedule. Not bad so far. The owner of the lathe was anxious to get it out of the shop since he had drug the machine up to the door right in the way of everything. The drag marks led from the back of the shop to where the lathe was sitting in this picture. Nice.
When I came out to look at the machine a few weeks ago I asked the owner if his forklift would lift the lathe. He told me no problem. I took the model number off the lathe and did a little homework on the internet. It turns out that one of the satellite shops at work has nearly the same machine so I was able to borrow a manual and look up the detailed specifications of the machine. It actually weighs about 4700 lbs. When we first got there I asked the owner if he would let me drive his forklift to load the machine. He was slightly puzzled and asked me why. I told him if he had to drive the forklift then I would give him the money once the lathe was on the trailer and not before. If he dropped the machine it would still be his which was either an incentive to do a really careful loading job, or let me do the driving. Just my luck he said fine go ahead and drive the forklift.

Before I hopped on it I asked it there was anything I should know about before I got going. Oh yeah, the brakes don't work was the only thing I needed to worry about. Its okay he said, the parking break works great. Here we go was all I could think of.
I test drove the forklift around the parking lot to get used to the hillbilly brakes. The parking brake did work good you just had to remember to keep your hand on the lever all the time. For moving this job I spent a little time and fabricated a special dolly for moving the lathe in tight quarters. I wasn't sure the owner would have it out near the door so I was prepared to move it into position with the my new three point lathe dolly. The large wheels are off a pallet jack and the front is a roller bearing skate that I added a swivel pad to.
When I hop on the forklift somebody has stenciled the capacity on the mast in big black letters. Capacity 4000 lbs maximum. Oops. The lathe weighs 4700, Houston we have might have a problem. No choice but to do a little test lift. Fortunately it seems to be fine. I sucked up as close to the machine as possible and it seemed to be stable and not light on the rear end of the forklift. So far so good. Notice the big mitt on the handbrake. We still have to get it on the trailer.
The moment of truth is coming up. I'm hating that stupid handbrake right about now.
Whew. I sure felt better once the lathe was up on the trailer. In fact I think somebody had de-rated the forklift when they stenciled the capacity on it. I was able to pick the machine  up near the end of the forks to get it more centered on the trailer. Notice the slats of thin plywood on the forks. This is a trick to keep the machine from moving on the steel forks when you least want it to happen. A greasy steel machine on a pair of greasy steel forks it almost as good as a ball bearing but not quite. A thin layer of wood or even cardboard will keep the load from shifting on the forks. I'm feeling pretty good right about now. Everything was going as planned even with a few wild cards thrown in for fun. This is about the time Murphy pops his head up and says hello.
As were tying the machine down to the trailer I notice some stuff I'm not too excited about. Keep in mind we have already loaded a one ton saw and a two and a half tons of lathe and tooling on the trailer. What kind of hillbilly junk is this? Double nuts on an egged out hole wasn't too bad compared to the other end where,
it was really lovely. Geez, now I stressing out again. My buddy Don just brushes it off and tells me this trailer just hauled a load of steel to Santa Barbara and it was fine, besides he has some extra bolts in his toolbox just in case. Oh, that makes me feel much better.
You cant see them but there are some white knuckles on the steering wheel. This was my view for the next three hours. I even started to feel optimistic when we made it over the Altamont pass without any problems.
Time changes everything. As we headed down into Livermore I noticed what I thought was a puff of smoke from the right side of the trailer. I shrugged it off as some dust that kicked up when the wheel got close to the fog line. The next few minutes were fine so I started to relax again. Dang, there it is again. A little puff of what looked like smoke. Now I'm on alert and keeping a close eye on the right side of the trailer. On the third time I knew we had some kind of trouble because I got a whiff of tire smoke with the visible puff of bluish smoke. I called Don on the phone and told him to pull over at the next exit. Turns out one of the leaf springs actually broke so only one set of springs was carrying the load. This caused the tire to touch the frame of the trailer and put out a little tire smoke. The machinery gods are laughing.
A machinery movers best friend is a smartphone and Jacks trailers in CastroValley. They had a couple of sets of leaf springs with the right eye centers for the sick trailer. These guys were great and saved the day. If you ever need anything trailer related call these guys and get fixed up like we did. They got a big old lab shop dog and don't take credit cards.
Well after the minor detour of replacing the leaf springs on a trailer with nearly 8000 lbs of steel on it we made it back to the shop. Took two guys on the high lift jack to notch another click into it. Time to fire up a real forklift not some de-rated brake less junk and unload the trailer before it cracks in half. Ernie the shop dog is supervising the rigging operation.
Almost there. It was a relief to get the lathe on the dock after all those hours of excitement and anticipation. We used the new three point dolly to move the machine into the shop.
On the rough concrete of the dock it took a little persuasion with a bar to get the machine moving. Once we were inside on the smooth warehouse floor one person could push it pretty easily. In fact its hard to stop with all the inertia once it was headed in the right direction.
Here's a shot of the front skate wheel and swivel pad. The tube is used to steer the skate as it rolls. With a three point system the machine always stays in contact with the ground even when there are dips and humps.
All in all a very successful trip. I got a nice lathe and spent some quality time with friends. Special thanks to Don and Uncle Gary from Hill-Tech engineering for supplying the very finest machinery hauling services and equipment. I know I owe you big time now which has got me really worried. If everything went perfect I wouldn't have a good story to tell and know what to look out for next time you trot that trailer of yours out. I did have fun and learned a few things in the process. Thanks for looking.
I almost forgot. The old Doall went on Craigslist the next day. A guy from Santa Rosa came down in the rain and picked it up the other night. He was all excited to get a nice name brand saw for a song. He's looking forward to getting it up and running again.

Wednesday, November 28, 2012

Bantam Jeep Factory Tour

This last Saturday I traveled south to the secret Bantam jeep factory restoration center. It sits hidden deep within a heavily guarded forty acre compound somewhere south of San Jose. Actually the factory is a barn that belongs to my friend Bill Spear of WSD. Bill is one of my oldest "Internet" friends in years known and actual age. We met for the first time at a metalworking get together to take patterns off a prototype sports car as part of a internet metalworking group project back in 2001.
 We quickly became fast friends and share ideas back and forth regularly. This is the season for car work for Bill. He lives part of the year near his design studio in Juneau Alaska and part of the year near his workshop barn here in California.

Bill is one of those guys that is interested in everything. One of his passions is the history and restoration of what we know of as the "Jeep" The story is quite interesting because most people don't even know there was a army sponsored competition to find what prototype would become the iconic jeep. The first jeeps were not built by Ford or Willy's they were built by the American Bantam Car Company.
This is a picture of the first prototype built for the Army competition by the American Bantam Car Company.
There are only a handful of these first amazing prototype jeeps still around.
The secret factory barn somewhere south of San Jose. Bills barn is almost a dream shop with the exception of all the car projects in the way of machinery. He likes cars and I like machines. So I tell him to move cars out and put more machines in and he just puts more cars in. His cool man barn is located close enough to the house to prevent any excuses for not working in it, but at the same time far enough away from the living quarters and any pesky neighbors to not disturb anybody with the sounds of serious metalworking or howling engines on the test stand.

I met Bill because of a common interest in compound sheet metal shaping. These are the kinds of three dimensional curved shapes you find in automobiles and aircraft construction. My interest came from a project I had worked on that involved compound shaping of steel for a barbeque prototype. Bills interest is purely automotive. Since our first meeting Bill has steadily put together a pretty well equipped shop. As Bills personal machinery shopper I'm responsible for furthering the amount of tonnage that his wife will have to unload if he keels over one day.  She should just be thankful he's not into steam locomotives is all I can say.
The machine shop bay of the barn. Standard milling machine that gets used for the restoration work of Bills car collection. The bags are covering a couple of engines waiting for assembly.
A year or so ago we found a nice Grob vertical bandsaw to cover the sawing needs in the barn. The picture on the front of the machine has a story to it. One of the first machines Bill got for his shop was a South Bend Lathe.
I was looking at old magazine advertisements on eBay one day and ran across one from WW2 that had the exact model of Southbend lathe that Bill has. In the text of the ad it said something like, "At 10 degrees South and 150 Degrees East its fix it or sink" It has a picture of a couple of navy machinery mates working on a South Bend lathe repairing a part for their destroyer steaming to attack. I thought this was a neat picture so I mounted it on foam core and gave it to Bill as a shop warming gift. I noticed its been in the shop long enough now its getting a nice machine shop patina on it after all these years.
This is one of the ways Bill keeps his creative energy flowing. Imagery is great for keeping the creative fires going.
One of the few remaining Bantam jeeps. This is a major restoration project made more difficult by the non-existence of most of the parts.
Bill has more than one car project going at a time. This is a more creative effort to re-body some old car with new sheetmetal. The wire form and screen provide an armature to create a three dimensional shape to work out the proportion in full scale and full context on the car itself. This is very hard to do on a computer screen.
Once the shape is frozen then a more permanent fitting buck was created to actually accurately develop the patterns and parts for the fender. This one is made from plywood and some bondo to fill in the more complicated areas.
This is the sheet metal and welding bay of the shop. Bill is using his old forklift to move a new punch acquisition into the stable. His forklift clears the sill of the door by less than an inch.
Some of the shaping equipment used for compound work. The elm stump is a nice one. It has several contours carved into it that make quick work of roughing out shapes.
Bills welding area. Yes I already gave him some heat for the mess. I caught him by surprise during my surprise inspection visit so he didn't have any time to spruce the place up. The large C frame is a converted English wheel that will become a bead roller.
This is one of the new cars in the barn since my last visit. Its a hellish two stroke machine made by Suzuki. The engine is a two cylinder two stroke motorcycle engine connected to a four wheel drive transfer case. Wheel base is less than 80 inches making this similar in size to one of those farm utility vehicles. 
Its a screaming terror with the two stroke engine. There is room in the engine bay for something more interesting and modern. Maybe a GSXR motor or a small steam engine perhaps. I'm sure I will hear more about this one.
Another collection of small cars at the test grounds of the secret Bantam factory. Bill sponsored several events of Cyclekarts at his place to promote the idea of a car project that was small enough and inexpensive enough to not be out of reach of the casual hobby builder.

Hope you liked the tour.

Additional links about compound metal shapingBantams  Bantam BRC

Friday, November 23, 2012

Interviews with Journeymen 1

Perhaps ten years ago I really started to think about all the potential knowledge stored in the heads of some of the journeymen I have met and respected. It was around that time that I started seriously thinking about capturing some of this knowledge for the benefit of the trade in some other form than a balding head with a loud mouth attached to it.

Listening to Charlie and Doug tell stories and describe tricky jobs they had to do was a delight. Just listening to these guys spin a yarn would fill your mental toolbox with new things to think about and learn from.  The oral tradition is still strong in the trades. Many of the most valuable life lessons I have managed to absorb were learned in the cold dank recesses of a metalworking shop not from any book.

Engineers and scientists write books, give talks and publish papers so their discoveries and knowledge are accessible to their peers and adds to the craft as a whole. Trades people don't do that much writing in comparison. The internet has helped, but we lose valuable hard won life lessons each time one of these old codgers dies. This was recently brought to the surface again as a close friend died recently that was a master at his craft with an encyclopedic knowledge and memory to go with it. Everything he knew is lost now. All that remains for the apprentices seeking knowledge is to study his work output and try to glean some understanding from reverse engineering his finished products. This process is less than perfect and much more difficult than just asking the right questions when you had the chance when he was available.

What are the right questions? I cant really answer that fully. It depends on where you are on your journeyman's path. Half the battle is just knowing there are always questions that can be answered now and used to fill in the chinks in your knowledge.When you think you have all the answers then beware.

The subject of this article is an attempt to test drive one way of capturing some of this trade knowledge and experience so the trade grows and becomes stronger. My thought is not a new one but perhaps the subject matter is. I thought it would be interesting and beneficial to interview some of the journeymen I know and respect just to see what comes out of it. I know from my own experience that just listening to these guys is fascinating and educational at the same time. Like listening to the tribal chief around the campfire and passing some of that hard earned lore from generation to generation.

What follows is an attempt at the first journeyman interview that I hope grows into something useful. So please forgive me because I decided to test drive the idea on myself. What follows is an interview of me conducted by my wife. It was a little weird since she has heard all my stories a thousand times so we pretended that we didn't know each other for the interview. I think I might have even surprised her with some of my answers. Which goes to show you never know what you might learn.

If you like the idea let me know by commenting to this article. There are quite a few journeymen out there worth hearing their stories and experiences. If there is something you think I should ask then let me know.

Interview #1
Tom Lipton. Years of experience in the trades, 40. Specialties, Sheetmetal, Welding, Manual and CNC machine work, Mechanical Design, Shop management, technical writing.

How did you get your start in the trades? That's a long time ago. My dad got me interested in working in the garage with him on stuff. It just grew out of that I guess. How old were you then? Well the earliest thing I remember is working in the basement when I was maybe six or seven years old. The only thing I can nail a date on was when I learned how to weld.
You learned how to weld when you were six or seven years old? No, I was nine when that happened. I was scared shitless when I had to do it. That's probably why I remember it so well. Was your dad a welder? No, he was a chemist. He worked for Shell Development in Emeryville. You reminded me about that. I got a tour of Shell Development when I was pretty young. Definitely before I leaned how to weld. The place was so cool. All these really smart looking guys running around using some complicated looking mad scientist equipment. So, I have to ask, why does a chemist have a welding machine in his garage. Was he working on an invention or something? No, he had a little business in the basement making ceramic potters wheels for artist types. There was a part that needed a small weld on it to connect it together. Also back then any self respecting dad had a workshop in the basement even if all it was was a Shopsmith and a bench vise. Kind of an early American man cave.
Did your dad have a shopsmith in his workshop? He has a Craftsman radial arm saw that still scares the crap out of me. I don't know how those arm lopping saws got so popular. He also had a big Miller welding machine in the basement which is the one I learned to weld on. So would it be fair to say that your dad was the reason you got into the trades? I guess. He never pushed me that hard in the direction of the manual trades. One thing he told me from around that time that stuck in my head is a guy that could weld, and do machine work would never be out of a job. Did that influence your career? Not that I recall. The thing was we had this family friend that was super cool. He was a welder and machinist that built a boat and did commercial fishing. real mountain man stuff, in fact the welding machine in the basement was his. He was storing it there while he pulled up stakes and went to work on the Alaska pipeline. You have to remember that this was the age of the hippies and this guy was as far from a hippy as you could get. He built stuff out of steel and aluminum, not some hippy redwood burl crap. I can see you like the image this guy portrayed. Jeremiah Johnson with a welding helmet. Close. I wanted to be the James Bond that was in Thunderball.  What about school? Did you take shop class in high school or college? Yeah. In high school I thought I wanted to do electronics. The electronics teacher was such a pompous ass that I got out of it and went to metal shop. I stayed there the entire time I was in high school. I guess the metal shop teacher was better than the electronics teacher? When I was a freshman the metal shop teacher we started with was totally old school and a real task master. He made us file a cube of cold rolled until our hands bled. The files were so bad that when you found a good one you hid it so you could use it the next day. The couldn't give you guys some new files? It wasn't that at all. Mr Sly was old school and made you work for it. If you could do the job with a crappy file then a new one was a piece of cake. He was the same way with the hacksaw blades. If you asked for a new one he would run his thumb along the blade near the handle or the opposite end and say, "There's plenty of life left in this blade. Shorten up your stroke." What kind of things did you guys build in metal shop? Its funny but I can't really remember anything other than an aluminum meat tenderizer. We made these cubes of steel with a file and a square, and I think there was some of the classic lathe turned diameters that had to be spot on size. Typical high school metal shop. I was a teachers aide so I helped a lot of other students with their projects. What kind of equipment did the shop have? There were two welding area's. One for stick welding and the other for gas welding. It also had an aluminum foundry, a natural gas forge and anvil, vertical milling machine, and three Rockwell lathes. I just remembered we made a cold chisel in the forge out of O-1 or W-1 tool steel. It was octagonal which is a weird shape of tool steel you don't see too often even today. Do you still have it? I don't think so. I think I tossed it after trying to use it on something and it was way too soft. I must have heat treated it wrong. Did you get a job in the trades after you got out of high school? I already had a job. I worked at a motorcycle shop after school and then got my first real metal working job while I was still in high school. So you got a metalworking job while you were still going to high school? How did you get that job? Boy that's a tough one. I think it was some friend of the family long deal type of connection. It was in a different city so I actually had to commute some to get there. What kind of things did the shop build? Mostly wrought iron fences and gates. Lots and lots of pickets and small steel tubing. Every once in a while we would do something else like build a truck lumber rack. Were you able to learn anything there? Sure. You always learn something. The main thing I learned there was what a crappy boss looks like.The owner was a lazy jerk and bullshitter. He told me some stuff that turned out to be total garbage. Is that the main thing you learned at that shop? Pretty much. I did learn a couple of valuable things that I still use. One is how to space pickets out uniformly along any length really quickly and the other thing is how not to hold your arm when you MIG weld. How do you you hold your arm when you MIG weld? Out of the spray of sparks by tucking it in closer to your body. You learn real quick or you end up with scars to prove it. And yes I still have some scars from that place. Did they have any machinery there? A few things like an iron worker, a nice Kalamazoo horizontal band saw, decent welding machines, and a nice welding table on a hydraulic lift. How long did you work there? Maybe a year. I left as soon as I found another metal working job. In fact when I found the new job I didn't even bother to go and pick up my paycheck from the old place. My dad finally made me go back there and get it. Ouch, how did that go? It sucked. At first I thought he was going to let me off easy but then he let me have it. It was a lesson in facing the music. He waited until I reached out to take the check out of his hand before he laid into me. Where did you go after you left that place? I quit for a job closer to home. A friends brother hooked me up at a place that made four wheel drive accessories. I stayed there for a couple of years. Any unique memories from that period of time? I just told a story the other day about the owner of that shop. He had smashed his finger in between something and had a big hematoma under one of his fingernails. He had been whining about it for a few days and he finally decided he was going to drill through the nail to relieve the pressure. Youch! That makes my fingers ache just from your description. How did he drill it? It was great. He got the smallest drill in the set, a number 60 and chucked it in the drill press. On this drill press you had to change a couple of belts to change the speed. While he was changing the belts he banged the same sore finger in the guard of the drill press and was howling like a little kid. We were all cracking up. Was this guy a wimp or something? Not really, more like a melodramatic poser. He looked like one of the guys in ZZ top with his little cheap liquor store cigar, the kind with the white teeth gripper. This was all sticking out of a huge red beard. So what happened with his finger on the drill press? Oh yeah, he finally gets the speed set after hopping around for a few minutes and he proceeds to slowly drill through his fingernail dead center of the hematoma. The pain must have been intense. It took him a couple of tries to go all the way through. The best part was when he finally broke through. The internal pressure spurted blood all over the drill press. He let out a sigh of relief like he just finished having some great sex. What was the next  big learning experience for you? I wanted to work in an oil refinery. I was trying to get a job at the Chevron oil refinery in Richmond. At the time I thought I wanted to weld full time and my dad worked there. When I was looking there they weren't hiring any welders. They needed operators with refinery experience. Did you start welding full time? In a roundabout way. I went to a vocational school to become a qualified welder. I could already weld but so many people asked me if I had any certifications I thought that it was necessary to get certified. Did you get your certification? Yes. Actually I ended up with several when I graduated. The school offered me a job before I graduated. That's pretty smooth. You got your wish to weld all the time. Actually it was a huge learning period in my career. We had to teach in the classroom as well as teach actual welding on the shop floor. When you have to show somebody how to do something three different ways you become pretty good yourself at demonstrating and explaining verbally. The classroom was the hardest part for me. What did you teach in the classroom at a welding school? There were different modules for the different kinds of welding. Each module had roughly a third that was classroom theory and book work. We taught blueprint reading, welding symbols, shop math, drafting. It was a lot of preparation for the instructors. Which one did you teach? All of them. We rotated through the modules so you ended up teaching everything. The shop math is the one I had the most trouble with. At the time I was pretty lousy at math. Did you overcame that deficiency? It was one of the most valuable lessons I ever learned. I figured out that it wasn't that hard to stay ahead of the class and never ever give an answer to something if you don't know. That was the real lesson I learned teaching in the classroom. How many students were in your class? In one module there might be twenty to thirty students. Six modules, makes a hundred or more students per shift. There was a day shift and a swing shift. Two hundred plus students at any given time at six grand a pop to enroll. It was a major operation. We really burned some welding rod there. What other things come to mind when you think of your time there? Balloon tests and no fingerprints. Ok you got my attention on that one. Tell me about balloon tests and what you mean by no fingerprints. Was it some kind of criminal operation? (Laughs) No it wasn't criminal other than what they charged to attend the school. The fingerprint thing was from the TIG welding module. The more senior instructors would snag the better modules, and the TIG module was the best out of all of them. One of the things you end up doing a thousand times for each class is sharpening tungsten electrodes.
 The students contaminated tungsten's like drunken sailors drinking shots on shore leave. We issued them one at the beginning of the module but this quickly became so short that it was difficult to grind. The instructors ended up grinding a lot of electrodes. They get hot when you grind them and your calluses start to smooth over from rotating a hot cylindrical object between your fingertips. You end up with big smooth pads instead of fingerprints. That sounds painful. Its really not. You hardly realize its happening. At first it might feel hot but on the hundredth zillionth tungsten you can almost handle them red hot.  So I'm still wondering about the balloon test? The balloon test became a grand tradition for the incoming students in the oxy fuel module. The welding gasses can be dangerous so we used to do a demonstration with a small balloon filled with acetylene and oxygen. A small six or eight inch diameter balloon would break fluorescent lamps and knock the clock off the wall from the shockwave.  It was intended to make the students respect the hazards of the materials. One of my friends there used to relish doing that demonstration.  

I can tell watching this video that these guys didn't have the gas mixture quite right. When you get it right it is a much sharper sound and even more energetic. We actually got really good at doing this since we did it a couple times a month. How did the students react? Oh it scared the shit out of them. In fact it was almost too effective. In that module its really common when the torch pops if you get it too close to the base material or the torch tip is dirty. The normal pops had these folks shaking like leaves after the balloon test. It took a few days for them to calm down and realize the popping was normal.Would you say this was a pivotal place in your skill building? One of them. The school built confidence. Getting up in front of a bunch of guys, many older than you and showing them how to do things and have them thank you is pretty empowering. That early confidence was a great tool to put in my toolbox. So I would say the time I spent at the school and when I first got into sheetmetal were the real important times in my early apprenticeship. At one point did you switch to sheetmetal? I didn't really switch. It all happened at the same time. My first sheetmetal job was pretty humbling. I was a good welder which is how I landed the opportunity, but I sucked at sheetmetal. Its a good thing the first job I did as a sheetmetal worker was a huge welding job. What were you welding? They were stainless fuse enclosures. Hundreds and hundreds of them. 14 gauge three feet long, fifteen inches wide and maybe twelve inches across. The shop was filled with them when I started. Sounds boring. How did you feel about it? It was all new to me at that point. I just got in there and welded for months. The first couple were pretty rough but an English guy named Tony helped me early on. After that it was rock and roll. I was fortunate that I got that production job first. All the other guys in the shop didn't want to do it so there was no competition from the established guys while I got better flying under the radar. They also left me alone because it was a miserable job. By hanging in there and not complaining  I cemented a reputation without having to fight for it. Was your reputation that important there? Its important everywhere. Its how the pecking order is established. This was a union shop so there were different journeyman levels which each carried a level of respect and a definite pay differential. What was your reputation? Old school, hard worker, good welder, means what he says. Most of those I get. I know there is a story about "means what he says". You would be right. I told a guy I would hit him with a hammer if he put his finger on the steel table I was working at. He wasn't convinced the first time so I educated him a second time. Did you get in trouble for hitting him with a hammer? Hell no. He would have been more embarrassed if he went and went crying to the foreman than the pain of any hammer hit. His posse would have laughed him out of the shop. You hit his hand twice? No, the second time I hit him in the head but that's a story on its own. Do you ever wish you did something else? No way. This is the best thing I can imagine. The only improvement I can think of involves cheerleaders and a good Vietnamese restaurant next door that delivers. What skill would you like to have? That's a good question because so many things interest me. I guess I would like to learn more about precision grinding and EDM work. This is something I have not done very much of that's on my shopping list. What is your weakness? Some people mistake my enthusiasm for the trade for being a know it all. The truth is I don't like it when I hear people that should know better giving out bad, or misinformation. I feel its part of my duty to correct bad advice related to the trade. And let me tell you the web is loaded with it. When did you know this was what you wanted to do? I think it was in high school shop. Before that I thought I wanted to be a welder. Shop class opened my eyes to some other metalworking areas like machining. At what point did you not have to think about the basics? I'm not sure what you mean by basics, but I do remember a point where I didn't have to have my full attention focused on what I was doing just to do it. For example when somebody would ask me a question when I was welding and I could think about what they were asking and give them a meaningful answer without stopping. What is the first thing you notice when you go into a new shop? Smell. I always notice the smell. Every shop has a signature aroma to it. It is related to the cutting oils they use and the materials the shop works with and in some cases the food the shop people eat. The smells get blended together into a unique combination. Not always good by the way. Do you have a favorite material? It depends on what I'm doing. If its sheetmetal I like copper a lot because of its warm rich color, and its smell. If its machine work I guess I like 8620 steel. It produces the most amazing blue purple chips you have ever seen.  
 What kind of toys did you play with when you were a kid? The usual ones a kid in the sixties and seventies had. I had a Mattel helicopter on a rotating arm that I really liked. Also my mom gave me the saw off the aluminum foil box to play with. I ended up cutting into her furniture with it. The great part was she blamed herself. Duhhh, what do you think a kid would do with a saw and no adults around? How many tools do you have? A lot. Its one of the things I really like about the trades. Each trade has its own set of tools. I like the look and feel of all of them. What do your tools mean to you? When I look at my tools I feel unlimited potential and possibilities. They stimulate my imagination and desire to create things. Did any of the mentors you worked with ever give you a tool? Yes, Doug gave me an old English cross pein hammer that I really like and Charlie gave me all kinds of stuff but my favorite thing is a toolmakers microscope that he made before I was born.
 What other trades people impress you? All of them. I think there is something to be learned from all of them. None are inherently better than any others. I would add that I do have preferences. In your experience what is the worst task in this craft? What I really hate is being interrupted when I'm in the zone out in the shop by some human maintenance need. Human maintenance? What I mean by human  maintenance is having to sleep or go to the bathroom or stop to go to some kind of social function. Having to wear lots of protective equipment to do some icky operation is probably on the list also. What is your most favorable memory of a job or project you did? It wasn't a job it was an auction I went to. I spent four days crawling all over the Mare Island shipyard crafts shops. It was a historical event like no other you can imagine. At the time I would have killed for a better digital camera. As for actual jobs there are lots of projects I'm fond of with new favorites happening all the time. Probably one of the more recent ones I really enjoyed was one we called the death star.  
 What is the most negative memory of something in the trade? This interview. Just kidding. I don't have one yet. There are things I didn't like when they happened but they are all part of what I am right now. Without them I'm not sure what I would be like. Do you give back to the trade? I write about what I do so there is some kind of durable record of the knowledge. I also train young people by volunteering and giving talks about the work. What is your idea of perfect happiness? Buying the whole Mare Island shipyard and all its equipment before it got dismantled and inviting the best and brightest craftspeople from all over the world to come over and play. Second to that is what I have right now. I'm a pretty lucky guy.  
 Are there any historical figures you look up to? Probably Richard Feynman. He wasn't a metalworker but I think he is my idea of somebody that obviously loved his work and didn't care what anybody thought. He worked on things that interested him for the fun of it.  Do you have a motto? "Nothing too strong ever broke". I borrowed it from my friend Doug. If you had a chance to change something you did during your career what would that be? I would try to protect my hearing more carefully. I could have done better on that one. Never sell any tools or equipment.

If you had to condense any advice to someone learning the trade what would that advice be? Learn everything you can about everything you can. Your skills are your protection and the key to your satisfaction and security. If your young move around every few years so you learn how other people do things. Be humble. There will be plenty of time to be cocky. What is your favorite hand tool? Obviously you haven't seen my tool collection. I don't just have one I have two. The file and the hammer are probably my most favorite. Did you ever get a nickname? Not that I know of, at least none ever stuck. I never gave a crap what anybody thought of me. I cant do anything about what other people think, so I don't waste my time worrying about it.  Lots of guys I worked with got some pretty bad nicknames like my buddy laser beam. 
In your career what is the thing you are most proud of? An excellent question. I think it is when the my old mentor Doug said something to me that really felt good and made all the hard work worth it. I had recently finished a difficult compound shaping job for a kettle barbeque prototype. I was showing Doug some pictures of how I had attacked the problem. He told me I had really come far and was doing things he never got to do. He also said that he would have struggled with the job if it had been given to him. Keep in mind this is coming from a guy that built his own fifty foot sailboat in his backyard from the ground up. It swelled me with pride that he thought that much of my abilities.   
 If you had to rate your career how would you rate it? So far so good. I cant wait to see what happens tomorrow.

Saturday, November 17, 2012

Simple Six Axis Adjustment system

Ever get tired of slotted brackets and crummy set screws to provide some kind of a precision adjustment? Many times mechanical designers are asked to provide a low cost precision adjustment to locate a component or assembly in relation to something else. The tired cheap fallback systems of slotted plates and shafts with set screws lack the design elegance that mechanical designers would strive for. Time and cost considerations sometimes make these less than perfect adjusters the default choice when the time runs out and an idea is needed. Stacking multiple expensive precision linear slides orthogonally is a brute force approach to solving the multi axis precision adjustment problem. I have seen this approach used more than a few times and it always looks a bit like a gift wrapped rhinoceros. A lot of effort is spent on designs to solidly locate components in space and provide some kind of intuitive adjustment that doesn't break the budget.

What this article is about is a simple system that provides kinematic support and adjustment in all six axes of movement. To refresh your memory on all the possible movements , there are three translational movements that most machinists are familiar with, X, Y, and Z. and three angular which airplane pilots are familiar with are pitch, yaw and roll. These are defined by rotation about one of the translation axes. In an airplane the orientation of the angular movements is determined by the direction of flight. Each branch of technology has a convention for "normal" positions of the axes to further confuse us poor mechanics on the six degrees of freedom.
At work we use a six strut system to locate beamline elements and provide a simple way to adjust and maintain their alignment. This setup is simple and clever and more than likely has uses outside particle accelerator construction. The basic parts are just glorified garden variety turnbuckles. Instead of real turnbuckles we use stiff precision rod ends in our six strut systems to rigidly isolate sensitive equipment from vibrations transmitted through the floor. At the same time the six strut system provides precision adjustment and allows us to position equipment in all six axes to less than .001 inch easily.
This is a small example of the six strut alignment system. Its hard to get a picture of all the struts at one time but trust me there are six. In fact the six strut system is not overconstrained and if you remove any one of the struts from the component it will fall down.
Here you can see all six turnbuckle struts There are three that typically support the load vertically or in the direction where rigidity or vibration isolation needs to be highest. The struts are oriented orthogonally which makes it very intuitive to adjust. A similar system that many people have seen in the popular press are variations on the Stewart Platform. Sometimes it is also referred to as a hexapod. Hexapods are also a positioning system that locates parts fully with six degrees of freedom. Its main drawback is higher expense and practical implementation for day to day applications. Furthermore, it lacks the easy intuitive adjustability of the turnbuckle six strut system.
 These simple strut systems have the ability to carry and align heavy loads. Not sure of the weight of this undulator structure but I wouldn't want to drop it on my foot. For maximum rigidity and vibration isolation we use crimped and swaged rod ends or off the shelf commercial rod end units that are split and a clamp screw is added.
One of the other advantages to this simple precision adjustment system is its scalability. Some of the larger six struts support loads in the multiple ton range and the smallest one I have seen used #4 screws through the rod ends. Typically the struts are the "turnbuckle" type which means they have one right hand thread and one left hand thread. In special situations we fabricate differential thread struts where both rod end threads are right handed but the thread pitch is different. Differential same direction threads cancel each other with the net movement coming from the differential between  the two thread pitches. Very small per turn movements can be designed with the proper choice of threads. The choices in thread pitches are limited if you stick to standard rod ends but for special situations they are simple enough to modify or custom order from the manufacturer.
Here is an example of a off the shelf rod end that has been split and a clamp screw added. This particular unit is a female thread rod end that has a simple custom stud fabricated to turn it into a differential strut. The opposite end has a same hand thread but a different pitch.
The female thread in the strut body is a split collet that is welded to a tube of the length required for the design. The collar is not used to lock the strut into a fixed length which might be your first instinct looking at the assembly. It is adjusted so that it can be moved easily with a pin spanner, but tight enough to not move if accidentally bumped or turned by hand. This preloading eliminates any wiggle in the threaded connection and keeps any bozo's from turning the strut when they put  their hand on it absentmindedly.
Here is a picture where you can see the collars and the pin spanner holes in the strut collets. Incidentally if you look underneath there is a hexapod stage mounted to the bottom of this chamber. Its takes a computer program and position encoders to adjust the motorized hexapod system on this manipulator. The six strut in contrast is adjusted intuitively by hand with feedback provided by dial indicators if necessary.
Here is a small six strut stage that I set up a little demonstration with. I actually ran out of indicators that I could put on the thing for the demo but I think four gets the point across. I started by scrambling the stage in all six axes out of its initial position by around a half inch measured at the ends of the tube clamped to the stage. I was able to re-aquire the indicator zero in less than five minutes to within a grand of the starting position.With the dial indicators as a feedback device the adjustment was straightforward.
In the next example you will see the range of motion even a small six strut system is capable of.
This example shows the misalignment of two pipe flanges. You can see the initial position is pretty far from where it needs to be.
The alignment of the two flanges is actually off in all six axes of possible movement. You can see the small slit in the flange actually has to roll into position for good alignment. The struts on this little stage are 10-32 thread turnbuckle type.
A few minutes of twiddling the struts produces an alignment close enough to insert fasteners into the holes.

So if you want to try this odd looking but clever system out here are a few general guidelines.

Keep the struts orthogonal to one another. Three in the one direction where rigidity is most important, two in the second direction where you need some translational control, and one in the direction of least need of rigidity and translational control. Use the longest struts that are practical. This reduces the crosstalk between the axes of movement from angular changes. Mount the rod ends of the part that moves so that their centers are in plane with the features you are trying to align.

This is a very forgiving, inexpensive alignment system that is capable of superb accuracy and control. Next time your backed into a corner and have your back against the wall, pull this clever solution out of your hat. Or better yet when somebody throws a hexapod out as a possibility drop this into the discussion. At first pass it looks a little wacky but trust me it is tried and proven a thousand times over. From a design point of view it is simple and elegant with no more parts than is necessary to get the job done. When is the last time you could say that about set screws and slotted plates?