klandin |
Newbie |
Keith Landin |
Connecticut |
teacher |
you mean other than woodworking? |
Male |
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Thursday, June 1, 2006 |
Saturday, March 11, 2017 8:47:11 AM |
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Dan, is this for your personal use or for your classroom?
Without getting into a full-on treaties on sharpening I'd say forget the diamond stones. They are too expensive and they don't last long enough. Also, diamond plates aren't available in grits anywhere near fine enough for final polishing. I do like diamond plates for such specialty tasks as sharpening card scrapers, initial flattening of the backs of new chisels and plane irons and for touching up my turning tools, but for day to day tool sharpening tasks they can't hold a candle to other more traditional abrasives. For my personal use I prefer water stones. Nothing puts as fine a mirror polish on a cutting edge as an 8,000 grit water stone, especially when used with a nagura stone. But water stones are way too delicate and fussy to be used by kids. I've tried traditional synthetic oil stones with my students but when used frequently (as I instruct them to do) the stones quickly became hopelessly dished out. Instead I now use self adhesive abrasive sheets on plate glass. I made two separate sharpening stations. One station with 3 different grits for rough work (320, 400, 600) and one station with 3 different grits for fine polishing (1000, 1500, 2000). By using an inexpensive honing guide with these sandpaper sharpening stations my students are able to quickly and consistently produce razor sharp edges on their chisels and plane irons. With this system there is no worry about keeping the stones flat and whenever an abrasive sheet becomes dull I simple tear it off and stick on a replacement. In use these abrasive sheet sharpening stations work the same way as traditional stones so the skills taught are exactly the same.
Another good way to go for the classroom is a Tormek sharpening machine. These machines are kinda pricey (about $400) but they work very well and they are nearly fool proof to use. The edge that I can get on my Tormek may not be as good as what I can get from my water stones but it is plenty sharp enough for most student needs. My one complaint, and the reason that I don't use it with my beginning students is that when you learn to sharpen tools on a Tormek you aren't really learning how to sharpen. Most people will never own a fancy expensive sharpening machine. Instead they will go out and buy themselves an affordable set of stones. Therefore I'd be doing my students a disservice if I didn't teach them how to sharpen with traditional stones.
Keith Landin Woodshop instructor, Woodstock Academy "Mens tua sit implementum acerrium in fabrica"
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Tom, As I'm sure you know the primary source of belt heat is the friction generated where the sanding belt rubs against the steel platten between the front and rear rollers. I have found that replacing the OEM steel plattens on my belt sanders with graphite impregnated pads works wonders for reducing belt friction. This simple expedience significantly decreases heat build-up in the belt, thus extending belt life. It also takes a heck of a lot of the load off of the motor, thus extending the life of the tool. I have done this to all of my belt sanders both at school and at home. I would not dream of handing a belt sander to some ham handed student without first having swapped out the sander's OEM platten for a graphite impregnated pad.
Keith Landin Woodshop instructor, Woodstock Academy "Mens tua sit implementum acerrium in fabrica"
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I had the exact same problem a couple of months ago and nothing that I tried worked. Even gorilla tape had no effect. In the end I had to throw them all out and buy new ones. My take home lesson was that even good quality sanding belts expire sometime after twenty years - not so unreasonable really. If there is a fix I'd love to know about it.
Keith Landin Woodshop instructor, Woodstock Academy "Mens tua sit implementum acerrium in fabrica"
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As far as I can tell The WCA is either a failed effort that no one has bothered to officially bury, or it's a scam. Here are my experiences with WCA:
Thinking that by aligning my curriculum with the skill standards set by this organization I could better justify my program, I ordered a hard copy of their "Manufacturing Skills Standards" book. At $75 this book was ridiculously expensive and as it turns out a complete waste of money. The edition I bought (V1.0) wasn't even complete. Entire sections were left blank because they were still being developed, and what was there was so daaa obvious that it left me feeling duped. They should never have charged money for a work in progress.
That notwithstanding, I still hoped that aligning my curriculum with a nationally accredited program (even a lame one) would lend my program the validity that I was looking for to help justify my program's existence, so I forged on. The next thing that I did was to contact the good folks at WCA to see if I could sign up to receive the training to become a certified WCA skills assessor. In theory this would have allowed me to award WCA credentials to my students as they mastered specific woodworking skills. These efforts went exactly nowhere. I spoke with my local trainer several times but he never would arrange for a specific time and place where I could go to receive my training. He was always very clear about how much money he wanted up front, but everything else was always alarmingly vague. The further I delved into this the more it began to feel like an elaborate scam. Has anybody else out there had a more positive experience with this organization?
Keith Landin Woodshop instructor, Woodstock Academy "Mens tua sit implementum acerrium in fabrica"
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There aren't so many of us in this vocation that we can allow a brother to pass unnoticed. God speed Mr. Roseling.
Keith Landin Woodshop instructor, Woodstock Academy "Mens tua sit implementum acerrium in fabrica"
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I found this link on the Popular Woodworking site. It may be a bit long winded, but it is also the most carefully crafted argument in favor of what we do that I have ever read. Please share this link with your administration and spread the word.
http://www.popularwoodworking.com/article/were-letting-down-the-next-generation-of-woodworkers?et_mid=742977&rid=249251392
Keith Landin Woodshop instructor, Woodstock Academy "Mens tua sit implementum acerrium in fabrica"
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I think that the key to success is setting fairly tight design parameters up front. ie: maximum size of the finished project, maximum board feet used, specific type of object (box, table, clock, etc.). Don't let a design project become a free for all. My point is that your students don't know what they don't know. If you give them too much design latitude then they're very likely to take on more than they can handle. The instructor's job is to set appropriate limits so that this doesn't happen. But don't think of design parameters as being limitations. Think of them as goal setting tools. Once you've set the project parameters, and everybody is more or less on the same page, then you can start to design your lessons and demonstrations to meet the specific construction challenges that you anticipate are likely to occur. Of course, none of this means a thing unless you've already provided your students with a solid foundation in the basics. There's no point in branching off into design skills if they're not already competent with the basic tools and techniques of the craft.
Keith Landin Woodshop instructor, Woodstock Academy "Mens tua sit implementum acerrium in fabrica"
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Here are a few useful websites that I have found:
http://www.onlinedesignteacher.com/furniture_design/furniture_design%20history.html#.Utvzv_tOnGg
http://rifa.art.yale.edu/
http://www.fourcenturies.org/
Keith Landin Woodshop instructor, Woodstock Academy "Mens tua sit implementum acerrium in fabrica"
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Speaking from experience I'd say that if your cyclone is blowing sawdust out the top, then that almost certainly indicates a serious leak between the cyclone and your collection bin. In order for the cyclonic separator to function properly there must be no air being drawn up through the cyclone from your collection bin. When this happens it creates an updraft that prevents the sawdust from settling into the bin as its meant to do. Instead the sawdust gets ejected out the system's exhaust port. In order for the cyclone to work properly the seal between the the lower part of the cyclone and your collection bin must be absolutely air tight. By the way, you will probably find that this fixes your other problem as well. If you seal up your bottom end leak then it will force the fan to draw all of its air from the other end of the system, resulting in more suck where you want it.
Keith Landin Woodshop instructor, Woodstock Academy "Mens tua sit implementum acerrium in fabrica"
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Yep, we started up today as well. Three days of pointless PD, and then the kiddos arrive. What happened? Wasn't it just early July? Oh well, here's to a happy, productive, and accident free new school year.
Keith Landin Woodshop instructor, Woodstock Academy "Mens tua sit implementum acerrium in fabrica"
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