Sunday, May 19, 2013

Simulated Dovetail Knurling Tool

One of my blog readers suggested a subject regarding knurling in the lathe. He had watched one of my YouTube video's where I ask viewers to submit their metalworking problems. If I think the problem is of general interest to the community and will make a good presentation I'm all for it.

The first problem I ran into on this request was I don't actually have a knurling tool holder. I have never bothered to buy one because their expensive and don't get used that much. Typically I will put a gripping surface on a knob or handle with a different method, partly because I don't have a knurling tool. Your classic catch 22 self fulfilling prophecy.

What I was able to do to move forward on this project was to borrow a smaller knurling tool holder and make a new quick draw simulated dovetail tool block that fits my large Aloris tool post.
Here is the knurling holder I  was able to borrow. It fits an baby AXA sized tool post and my lathe uses the Conan  arm breaking CXA size. Aloris in their wisdom at least made the knurling head separable from the tool block probably so they can do the same thing I was planning on doing. 
After dissecting the holder you can see how it was attached to the AXA tool block with two cap screws and a pair of locating dowels. Now all I need to do is make a CXA sized block that has the same bolt pattern in it. 
Scrounging around the steel bin I found some likely accomplices for the tool block. The larger round bar is for the height adjustment knob that rides on the stud in your typical Aloris tool holder.
A few months ago I wrote an article about this Skeleton tool holder concept. I made this one to hold my button indicator in the lathe so I didn't take up a valuable tool block to keep an indicator set up all the time. This is when I had the four jaw mounted on the lathe for a long period of time. The rods that interface to the Aloris toolpost are .500 diameter. When spaced correctly with my handy dandy rod spacer they form a facsimile of the dove tail cut in a normal tool block. My reasoning for doing it this way is one, I have some smaller material I can use right now to make a block, and two cutting large dovetails like on a CXA tool block takes a long time. I figure for a tool that I won't use that often it will be just fine.
I had to add some to the front face of the new block so the dowel pins would have some meat around them. Welding was a quick way to widen the face instead of the alternative which was start with a much larger piece and hog off most of it. I didn't have larger piece so this is it.
Here is the block all welded up with the simulated dovetail rods. Time for some knob action.
So here is the catch 22 part. I don't have a knurling tool so I added some circular cutouts to provide a gripping surface to the knob. I suppose I could have waited and knurled the adjustment knob as the first test part. The stock Aloris tool posts use a 7/16 stud of all things. I only had 3/8-16 studs in stock. I like to use long set screws for fixed studs like this. They are easy to bottom out in a tapped hole and get tight with the internal hex drive. The ID of the knob is tapped to fit the stud to provide the height adjustment. Incidentally the knob is 1.38 in diameter. I held it down with a single 10-32 screw in the center to do the fluting. I mention it because most machinists would probably prefer a larger screw. When torqued down a little 10-32 can give over a thousand pounds of clamping force. The fluting cuts were done with a 1/4 inch end mill. 
So here is the finished product. Now I can set up to do the knurling video demonstration. Sometimes its easy to find the long way around. I like to think of it as a nice walk in the woods before you get to your destination.

Thanks for looking.

Monday, May 13, 2013

What are friends for?

The planets finally aligned for a friend of mine recently. While scanning Craigslist for interesting items I found something that caught my interest. The price was a little steep but it looked like a nice specimen. The listing didn't have a phone number so I sent the seller an email inquiring about the item. I always include my phone number in the hope that the seller will respond likewise and include theirs. To my surprise the seller called me. We spoke for a while on the phone about the machine I had written about. After talking for a while he mentioned some other equipment he wanted to sell. I quizzed him on the other machines and struck pay dirt. Well almost pay dirt. A friend of mine has been looking for a 2 axis CNC Prototrak milling machine. This guys wanted to sell one. As soon as I got off the phone I called Marty and gave him Kent's contact information. This was the best situation you could ask for. It was not actually on the market yet so there was not a line of competitors going around the corner. I threw the whole thing over the fence to Marty and let him run the touchdown for the score.

 A couple of days later I get a call,  "So what are you doing this weekend? Want to help me move a milling machine?" Heck yes I do was my instant reply. Tell me where and when. Marty made the deal and now we are on the hook to get this large milling machine out of a little rats nest of a shop No offense to Kent but his busy shop is loaded with tools, equipment and materials and not much air space. In fact it took a week of prep work on his end just so we could access the machine that Marty bought. Sounds like an adventure to me. Mentally I started my list of tools and equipment that I would bring to the party.

The day started with an excited friend pulling a trailer arriving. I had my pile of gear ready to go but Marty convinced me a lot of it wasn't needed. A little voice in my head was telling me to just go ahead and load it anyway. But the lazy guy won out. At least the adjustable head prybar made it on the truck.

As we pulled up to Kents shop my riggers eye was surveying the slanted driveway and low garage door opening. Kent's shop is located in his one and a half car garage and extends into the basement and crawlspace of the three story house. I hopped out of the truck to guide Marty into the garage and noted a drainage swale and asphalt rim right at the entrance to the garage.

Ok I don't know about you but what kind of architect designs a driveway sloping into the garage without proper provision for runoff? This seems like house design 101 to me. Water has to go somewhere and its usually down hill. The pipsqueak swale the architect specified apparently is easily overwhelmed during a good rain. Kent did what he had to do to defend his shop from flooding by adding the asphalt rim to the undersize swale to protect his garage from flooding. All this is just complaining on my part because we had to deal with the drainage swale and rim while trying to move a 3200 lb machine.

You know the job is starting out on the wrong foot when the owner tells you, "Oh by the way we need to move this lathe out of the way first" On top of that we cant disconnect the power from it either. Ok, lets move the lathe first.

I didn't get as many pictures as I normally would like. I gave the camera to one of Kent's buddies to shoot progress pictures while we worked. I guess he is from the film camera era where you only get 24 shots per roll. He came up a little light on quantity but I'm glad he did what he did.
Moving the Tuda lathe wasn't too bad. They already had it most of the way up when we got there. All we had to do is lift it a little higher and get the Hilman rollers Kent had under the machine. We barred it as far out of the way as the electrical would let us to give us room to work on the mill.
 The general idea was to raise the machine enough to get a pallet jack under the mill. We used a bar and my wood wedges to slowly elevate the machine. I'm doing the bar work and Marty is slipping the wedges under the machine. The wood wedges are great because they are infinitely adjustable unlike a pile of wood scraps. The angle of the wedges is low enough that there is no slippage under load. These are just doug fir four by fours cut at an angle. Hardwood might be better but I like to see the machine bite into the wood a little.
Once we had the machine raised enough for the pallet jack we sucked about ten years worth of chips and cat litter out from under the machine. Once the mill is on the pallet jack you can move it around quite easily and safely. This particular mill is quite heavy. Its a 10 x 50 with box ways and a 40 taper spindle. Bridgeports are like drill presses compared to this machine. It really is a two person show to move one of these.
It took a couple of tries with the pallet jack to get the right center of gravity. This oversize mill is heavier on the front side because of the massive knee casting. Once we found the spot where the machine was stable one person could push it around easily. We danced around the garage for a while trying to get the machine lined up with the trailer. There was a lot of backing and filling to orient it for the tug into the drop bed trailer.
My empire for a come along right about now. I really wanted to just gently winch the machine into the trailer with a controlled simple setup. When Marty picked me up in the morning I had everything we would need all laid out. When we started talking he had some of the rigging equipment already and had spoken to the seller, Kent who had a bunch of stuff also. Red warning beacons should have been going off in my head.

OK, here is my wisdom for all eternity. Take everything you will possibly need to do the job with you when you leave. Pretend your going to the moon and there will be nothing available to use except moon dust. Marty convinced me to break my rule and we suffered because of it. Kent didn't have a come along of any kind. What he did have was a Harbor Fright 12VDC cheapco winch. The winch was attached to a section of thin wall pipe with U bolts. To operate the winch we had to attach a battery charger to the leads for the 12V supply. Definitely a jury rig.
Well what are you supposed to do? You cant stand around and whine about it. Just start and get cracking. We strapped the winch to the front of the trailer with some motorcycle straps to reinforce the weeny winch assembly. There was a up slope going into the trailer because of the driveway. We managed to span the swale after a dozen tries backing the trailer into the garage. Marty's truck is a diesel so that operation probably took a few years off my lifespan.
To my surprise the cheapco winch actually pulled the machine up into the trailer. It was a bit herky jerky with the battery charger as the power supply but not bad compared to my expectations.
So I know Marty is feeling better about now. The machine is safely in the trailer and fully under control. We took it off Kent's pallet jack. Here is where it would have been great to leave it on the pallet jack and block and strap it down. It would have saved us two machine lifts if we would have brought my pallet jack. This is where the adjustable head pry bar earned its price tag. With all the trailer structure around you couldn't use any kind of a long bar. It really saved the day.
Thanks to the machinery gods the road trip was very un-eventful. Just the way you want it when your hauling iron like this at sixty miles per hour. Now for the exhausting part.
Marty's garage is west facing so it gets the full brunt of the afternoon sun. The weather was nice and warm in the eighties for this next part.We must have lost a few pounds of water weight unloading the mill.
Everything was a tight fit at this end of the job. I think Marty had an inch or two to back and fill between the telephone pole and the garage. He looked tired when I asked him to move the trailer over a few inches to the left in this picture.
Finally back on the ground. All we need to do now is get my wedges out from under the machine. Once we got it down you should have seen the look on Marty's face when I said, uh-ohh. The head was looking mighty close to the garage door.
I call that close but no cigar for Murphy. It clears by a whole inch and a half. Good thing this is not a drawbar machine.
You cant tell from this picture but this is one happy guy. All the hard work is worth it when you get to this point. It was almost as good as getting a new machine myself. Well not quite that good. That's what friends are for, to share some fun and enjoy a job well done.

I learned my lesson,

I hereby promise to take every bar, chain, strap, jack, wedge and scrap of lumber necessary to complete the job from this day forward.

Thanks for looking.

Friday, May 3, 2013

What makes a Journeyman?

Every now and then somebody asks me what I think the definition of a journeyman is. For such a simple question I find it can be a difficult concept to explain to people outside the trades. There are many aspects of the relationship between the apprentice and the journeyman, and the journeyman and the master craftsman that people cannot easily relate to. There are some close professional parallels, but the differences are enough that full appreciation is not an easy concept for me to explain.

 If you could wrap up the definition of a journeyman in a tidy bow, it might read that its a certain number of years of experience at a given occupation or that the person has a particular set of skills in a their chosen trade.This is the simplified explanation that I give when asked to explain what a journeyman is to curious people.

What is typically accepted as minimum requirements for journeyman status is 10,000 hours of direct work experience in a particular trade. That time is spent working with established journeymen and master craftsmen with roughly ten percent of that total time in an actual classroom setting such as college courses or accredited vocational training.

 Here in the United States for many trades there are no established standards as to what makes a journeyman. Peer review and demonstrated knowledge of the trade is generally accepted for many occupations. Another rough rule of thumb to attain journeyman status is a minimum of four years combined with four different jobs. In the building trades written testing and state licensing are used to establish accepted journeyman status.

One of the key distinctions of a journeyman is that their broad work experience and practical skills allow them to teach and train others in their chosen trade. This giving back of knowledge is one of the most important contributions we as journeymen give our trade. We all stand on the shoulders of the people that have gone before us, so part of the requirement of the title is to help the less experienced.

A true journeymen will have enough trade knowledge and experience to work unsupervised. They have the earned the trust and autonomy to decide how the work will be handled and processed. This trade knowledge has been gained through more than a single work assignment. A single organization with average turnover does not provide the necessary critical mass of new ideas and the deep cross section of problems to create true journey level experience. The true journeyman has absorbed the experience through hours of training and work that now enable him or her to function maturely and independently on a wide variety of problems and situations.

Through years of work and observing others in our trades journeymen will continue to learn and can adapt their skills to the changing methods, materials and economic trends of the world around them. In the "olden days" the journeyman actually traveled around the country honing their craft and expanding their trade knowledge working for, and being vetted by several master craftsmen.

For me it has a much deeper, and emotional meaning. It is much more than a checklist of accomplishments completed. It is an attitude and ethic as well as a deep commitment to the craft, not just a simple toolkit of skills and a pile of time cards related to a given trade.

In the martial arts the relative ranking of the students is highly visible from the color of their belts. Talk to any black belt and you will be surprised to hear that the black belt is really just the beginning instead of the more popular belief that it is the highest achievement. The black belt in the martial arts and the journeyman trades person share that same starting point.

Just like the martial arts, the trades demand a similar level of humility and respect for the craft. You start at the bottom for a reason. This right of passage teaches the key ingredients in a way that bonds the person to the trade and the more experienced crafts people by common shared experience. Without the humble beginnings of every journeyman's career one cannot fully share and appreciate the journey. True journeymen are bonded together through the work and mutual respect of their achievements. The ability to cope with crappy work assignments, obnoxious co-workers and dismal working conditions is part of the tempering process that the apprentice goes through on the road to being a journeyman.

The title of journeyman must not be handed out casually. It reflects badly on all the people who's shoulders we are standing on to allow an apprentice to be awarded journeyman status, or a journeyman to be deemed a master craftsman without the proper depth and breadth of experience required for the title.

Early promotion and relaxed skill requirements handed out by the uninitiated diminishes every craftsman's gift of knowledge to the trade. The promotion without jury or real peer review does a tremendous disservice to the trade when its allowed to happen. Just as we would not want an unlicensed and untrained doctor performing surgery, or an airplane pilot with limited flight experience in the captains seat we don't want to promote inexperienced trades people just to placate a lack of patience and appreciation for the path our fellow craftspeople have left for us to follow.

Chop wood, carry water, clean the shop for a few years. And if you don't complain, we might let you pick up a tool and lend a hand. So if you really want to be a journeyman and a master craftsman follow these simple rules.

Suck it up.Work really hard. Learn to love your work. Be proud to let it define you .You wont be sorry.

Thanks for looking

Tom Lipton