Showing posts with label Basic. Show all posts
Showing posts with label Basic. Show all posts

Saturday, February 19, 2011

Wood Turning - After the Basic Tools, What Then?




Wood turning is an old craft. In fact, Egyptian pictures on the sides of pyramid tombs indicate a history of at least three thousand years. Most of the basic tools such as cutting tools and the wood lathe itself have not really changed since then. At the same time the tool catalogues are full of a bewildering array of accessories, add-ons and gadgets. Here are some thoughts on what may make turning more enjoyable.





First of all there are the myriad numbers now of project parts. In days gone by, people either made some of these such as potpourri covers or had them made by other craftsmen. Now they are readily available from various suppliers. Obviously, if you wish to make a pen, you will need pen parts. Simply buy project parts from reputable dealers and you will be fine.





Less obvious are some of the accessories, including safety items. One of the first things to buy is a face shield. Most woodworkers will already own and use safety glasses but there is a fundamental difference between a wood lathe and most other shop power tools. Most of our tools have rotating or otherwise moving blades that cut through a piece of wood that is advanced to them. Wood lathes hold wood and move it toward us while we use sharp tools on it. If the wood is released for some reason it can fly out and hit a turner in the face. While this is rare, it does happen. What is more frequent as a turner advances in knowledge and begins to use more decorative wood with bark inclusions and other bits, is that shavings, bark and wood chips are thrown at the turner. A face mask is almost a requirement.





To go along with the face mask is the sanding equipment and dust mask that is needed. A simple piece of sandpaper will work for a long while, but sanding pads powered by electric drill or some other means speed up work. They also kick up a lot of dust and lungs should be protected with a dust mask. Look for one with an N95 safety rating to protect your lungs.





While chucks are a topic in themselves, many wood turners like to use four jaw chucks to hold wood on the lathe. While these are not necessary, they are very convenient for a lot of uses. Get a good one. They tend to hold large and heavy blocks of wood that should not be allowed to fly out from the lathe. Remember that these are very young in the history of the craft and may cost more that some beginner lathes.





One of the great additions to the turner's arsenal in recent years has been the use of cyanoacrylate glues, sometimes called super glues after one of the first marketed to the general public. They come in various viscosities or thicknesses. Many turners will find plenty of uses for both the thin and medium types. They are handy for holding some work, attaching pen or other project parts, filling cracks that would otherwise spoil a piece of work and the list goes on. These are available from most woodturning and woodworking suppliers.





While there are other always other things to consider purchasing in the never ending game of tool buying, once the basics are on hand, this age old craft is a great provider of all kinds of enjoyment. Even though many new tools and accessories may be bought or dreamt of, woodturning only needs the basics for good craft.


Monday, February 14, 2011

Basic Wood Carving - Carve a Dish




In the beginning choose something simple like a leaf shape. Look at some trees and select a leaf shape to your liking, Choose a wood which is not too hard but with a firm close grain-mahogany, chestnut or walnut and later ash and maple. Draw the design on paper first, as it is so much easier to modify or change a drawing than wood after it's been cut. Think twice for one cut, is the carpenter's motto.





Tracing your design onto the wood let it run diagonal or parallel with the grain, next cut out the shape of your leaf close to the outline with a fret saw. It should now be glued to a larger piece of wood than the work and of inferior quality that can be used many times for this purpose, which is for holding it down to the bench. In order that the work might be separated when the face has been carved, a sheet of newspaper was inserted between the two glued pieces, this will make it easy to separate them on completion.





The recommended gouge about No 6 or 7, and start shaping the inside from the direction of the grain, which is the easiest method; unfortunately it is easier to carve into wood than to carve out of wood. When cutting into wood the fibres are being compressed as they are cut, but in cutting out the fibres are being opened up and torn apart.





The effect is similar to trying to sharpen a pencil with a penknife, and starting from the point and cutting back toward your self, instead of cutting towards the point which is much easier and safer. So don't carve from the nearest side but take a small chip from the furthest side of the work from yourself and continue until all that you desire is removed. Finish by sand papering down and vanishing.


A Basic List of Hand Tools Needed For Kids to Get Started in Woodworking




You can buy the tools that you don't already have as you get to them in the book or you can go ahead and buy them all at once. In the article below I give suggestions as to sizes and styles that can help children get the most out of their use. The advantage in having all your tools ahead of time is that it will save you from having to run around trying to find what you'll need the day before you start a new project just to find out it's sold out. Another advantage is you can often times find all the tools you need online at one site. This can save you time and money.





Here is a list of tools you'll need. Use this to compare what you already have to what you'll need to purchase. You can buy each child their own set (which would be nice since one of the first projects is a tool box) or they can share tools. (But getting kids to do that is an entire book unto itself.)





A. Measuring Tape (12') they make measuring tapes that have the fractions labeled on the tape to make it easier to read especially if your child is just learning about fractions.





B. Ruler (12") wooden ones are easier to read than the clear or colored plastic ones.





C. Hammer (7 - 10oz for smaller children, 16oz for older children with better hand eye coordination)





D. Screwdrivers: flathead and Phillips





E. Nail set





F. Handsaw (western or Japanese style)





G. Coping saw





H. Block plane





I. Brace Drill (Hand drill)





J. Rasp





K. Sandpaper (100, 120, 150, 180 grits)





L. Glue (white or yellow) water proof for outdoor projects





M. Screws and nails (a box each of 1 ¼" and 1 5/8" drywall screws and a box each of 3d, 4d, and 6d finish nails will get you through most projects in this book).





N. Clamps (See the lesson on building the step stool for information on clamps).





O. Safety glasses (it may take some extra effort, but find a pair that fits your child. They will become frustrated quickly if every time they start to swing a hammer they have to push their glasses back up on their noses. Manufactures do make child size glasses it just might take some looking around to find them.)





P. Combination square





Q. Speed square





Again, this isn't a complete list of the hand tools needed to build any project imaginable, but it's a great start. Armed with the above list of hand tools you can conquer all the projects in our book, "Woodshop 101 for Kids"


Saturday, January 29, 2011

Basic Pattern Making In The Hobby Foundry




Success or otherwise in your hobby foundry will depend to a large degree on your skills & ability to create simple patterns, i.e.


Patterns that are easy to mould, lift or separate from the sand


mould after a gentle rap.





A pattern that has incorrect draft on vertical surfaces, badly finished corner fillets, or a pattern that has not been finished to an ultra smooth finish will be difficult to work with.





Pattern making is an art in itself, pattern making


apprenticeships take around three or four years to complete, before you are given your "Trade Ticket".





The average hobby foundry worker most likely won't have the time, or the patience to get involved with the art of pattern making to that extent.





But the basic skills are worth the effort to learn, because


without them you wont get far with your hobby foundrywork, unless you PAY to have all of your patterns made for you, but that would take all of the fun out of it, and also cost you a sizeable amount of money.





Construction costs of professional pattern making can vary from a few hundred dollars for simple patterns, up to several thousand dollars for complicated pattern designs.





I happen to a know a pattern maker who designs and builds patterns & core boxes to make alloy & cast iron cylinder heads, it is not unusual for pattern & core costs to be around $20,000.00 AU before you even think about melting & pouring any metal.





If you are a legacy of the old tech school system of the sixties


& seventies, there is a good chance that you still remember how to skilfully use woodwork hand tools.





Some of the finest foundry patterns were made using basic hand tools. More than likely you still have a chisel set tucked away in a drawer, or a spoke shave, wood plane & handsaw, plus


a host of other tools that could be used to make excellent patterns in the home hobby shop.





And if they happen to be a bit rusty, then get them out again and bring them back to life, re-grind the cutting edges and hone


them with an oil stone.





Remember what your trade teacher always told you; "sharp tools


give the best results."





Do the same with the wood plane and any other tools, such as a small set of carving chisels you could use to carve intricate shapes in wood.





You'll need some good pattern timber or lumber as it's called in the states... doesn't matter, it's all wood isn't it. There are many types of timber suitable for pattern making, but, you'll probably be limited to what's available in your area or region.


Quality pattern timber is expensive to buy, so ask for off cuts at the local timber merchant, which you may get for a considerable discount





You'll be looking for a soft timber that doesn't splinter, has a straight grain, is easy to work or carve, and finishes to an ultra smooth finish.





One of the easiest timbers to use is jelutong, this timber comes from the Philippines, I don't know whether it is from plantation timber, or old growth forests, but it is great to turn on a lathe, or shape and carve with sharp hand tools.





Some of the other pattern timbers in use are cherry wood, mahogany, maple, white pine, and many others.





Quite often a master pattern can be made from timber, and then a replica mould is made using RTV 585 silicone, this is a quick method to remake replica production patterns.The replica patterns can then be mounted onto a match plate along with the runners & gates, this method will enable you to mould & cast multiple parts at the same time.





With a little practise you will soon know enough to make reasonable quality patterns that create good sand moulds.





There is one important pattern making tool that will make you wince when you purchase, but it is an important tool to have if you want to make accurate patterns where shrinkage rates are concerned.





The tool is the "Pattern Makers Rule", this is a ruler about 500mm (20")long. Made by Rabone Of England. No B5. And the graduations are marked as: 1/30-1/40-1/60-1/80,





The graduations represent the amount of shrinkage allowance for different types of metals. The pattern makers ruler provides a built in shrinkage percentage, which means you don't have to calculate the final measurement or size of your pattern, you simply take your measurement from your shrink rule, and transfer the measurement to the pattern being made.





The system is quite clever in the way it's all been calculated.





For a quick example, the 1/30 scale measurement seems to give


the correct result with patterns used for cast aluminium items.





Machining allowance on specific parts of a given pattern may also need to be considered, generally your own judgement can be used to judge that.





Pattern making can be quite a challenge for the hobby foundry worker, but once you learn the basics and develop your skills, with a little practice your patterns will get better and so will the overall casting quality.





If you intend on making lots of patterns, the investment in a shrink rule is well worth the money.





And while you're at it buy a good book on pattern making, it deserves a study all on it's own, but it forms an integral part of foundry work, and because you're the boss of your own workshop, you have to learn to wear the hat of the pattern maker & that of the sand moulder & founder.





Sounds like a whole lot of work doesn't it, but you'll soon learn what will work best for you. Spend the time to learn all you can, and you'll be rewarded with encouraging results.


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