Camber on Plane Irons 08/26/2009
A recent discussion over at the Rennaisance Woodworker got me thinking about the amount of camber I put in my plane irons. Those of us familiar with hand planes and planing typically understand each other when we say that our fore or jack plane iron has "significant" camber or that our try plane has "moderate" camber or that our smoother has "just a hint" of camber. But these terms are mostly subjective and to someone new to using hand planes, "significant", "moderate" or "just a hint" doesn't necessarily translate well. So although I don't typically measure the amount of camber I put in my plane irons, I decided to try to quantitate it in order to better qualify the meanings of "significant", "moderate" and "just a hint."  So these are the three planes I am going to talk about in order of most amount camber to least amount of camber. The fore plane in front (also called a jack plane) has what I consider "significant" camber. In the middle, my try plane (also called a jointer) has "moderate" camber. Finally, in the rear, [one of] my smoothers have "just a hint" of camber. I took all the irons out since they needed honing anyway and tried to quantitate their amount of camber.  So after some trial and error using a piece of string, a magic marker and my awl, I got a close estimate of the amount of camber in two of the three irons (no matter how much I tried, I couldn't quantitate the camber in the smoother, the radius was just way too big). In hind sight, this would be a good way to mark your irons in order to grind a specified amount of camber. Simply use a dark colored permanent marker (I used black) to color the edge of the flat face of the iron. If you have it, machinist layout fluid would work as well, but it's not necessary, the marker works just fine and is a lot less messy. Tie a small loop in the end of a long length of string. Place an awl in the loop, hold the opposite end of the string to the bench top a distance equal to the camber radius away from the edge of the iron and scribe the camber radius through the marker onto the iron. Then simply grind to this line and hone as demonstrated in Episode # 6 of the podcast.  So here are the results. They are in the same order as the planes above and you can see the resulting radii from my crude measurements. The radius of the fore plane (on the bottom) measured at about 10". You can easily see the radius ground into this iron. The radius of the try plane was about twice the fore plane at about 20" (middle). You can also easily see the radius in this edge, though it is not as distinct as the fore plane. Finally, at the top is the smoother. This iron basically looks straight, however, if you place a straight edge up to the edge, you will see a hint of light at each of the corners. The relief is definately less than 1/32" but I couldn't measure it. When it comes to establishing the cambers, I grind the camber into the fore plane and try plane irons. However, when I grind the smooth plane, I grind the edge straight. Then, when I get to the honing, I simply do some extra honing of the outside corners in order to relieve them below the center ever so slightly. Again, the iron still appears straight, it's only when a known straightedge is shown to the iron that you can notice the slight relief at the corners.  Here's the finished result. This is a picture of the fore plane after the freshly ground and honed iron has been put back in and the depth of cut set. You can see the effect that the camber has. The center of the iron will take a relatively heavy cut (maybe between 1/32" and 1/16" thick) but the corners won't dig in and leave tracks behind. You can see how this makes the plane capable of removing stock in a real hurry (about 1/4" in about 8 strokes). No fluffy shavings here. They're more like chips.  Similarly, the try plane will not leave tracks behind due to its camber. The camber is less than the fore plane's by about half so the shaving thickness is similarly about half that of the fore plane. Again, these shavings aren't fluffy. They're thick enough to bring a board face true in fairly short order, but they are still thin enough to remove the scallops left by the fore plane and prepare the surface for final smoothing. The camber in this plane also helps in squaring edges by enabling the plane to take a wedge shaped shaving just by shifting the position of the plane on the board's edge. I didn't take any pictures of the smoother as you really can't see the iron above the sole like you can with the fore and try. The smoother is set up to take extremely thin shavings to put the finish ready surface on the show faces of the "money" boards. It leaves behind a tearout free, polished surface that is ever so slightly scalloped. The scalloping is so shallow that you don't really see it, but if you run your hand over the surface, you can just barely feel it. So there is my definition of "significant", "moderate" and "just a hint" of camber as it applies to my personal planes. I'm curious now as to how my definitions of "significant", "moderate" and "just a hint" compare to yours for your personal planes. Sawing Long Stock 08/23/2009
I received a question in reference to Episode # 4 of the podcast about sawing long stock. The viewer noted that all of the demonstrations in the podcast were done with relatively short stock (which was intentionally done to make filming easier). However, the viewer was curious as to how I typically handled long and/or heavy stock that is too difficult to manage with a single saw bench. So I took a few photos that will hopefully clarify and answer this question.  In order to rip long stock, I use two saw benches rather than a single one. I use the back end of my shave horse as a second saw bench (I intentionally made the saw bench and shave horse the same height for this reason). With the stock supported at both ends, I begin the rip the same as I would for a shorter board.  Unlike sawing shorter stock over the side of the saw bench, I cannot simply keep sawing until I'm done. Instead, when my saw cut reaches the bench, I reposition the stock and continue sawing between the two benches until I reach the rear bench or until I can no longer saw comfortably in that direction.  To finish the cut, I have two options. I can reposition the stock again and continue sawing through to the end or I can start the cut from the opposite end and meet the previous cut. In either case, the "keep" stock and the waste are fully supported throughout the cut.  Crosscutting long stock can be done the same way. If the stock is manageable without clamping, I'll simply span the saw bench and shave horse and hold it with my knee. If necessary, I may also use a pair of handscrews to clamp the board to the two benches. Then just saw between the two benches and both sides of the stock are fully supported. Episode # 6: Sharpening Part 2 08/21/2009
In this episode I talk about sharpening edge tools with curved edges, like molding planes, bench gouges, carving tools and cambered plane irons. If you're used to using a honing guide you may find honing these tools a little more challenging as most can't be honed using any kind of guide. You can hone cambered bench plane irons in several of the available honing guides, however, molding planes and gouges are best done freehand. In this episode I discuss the way I do it. Design Part 2 08/17/2009
 While I don't always go through the trouble of drawing out projects in a lot of detail, I felt that my current design project was going to be fairly complex so I thought I'd do some additional detail design. So I started with my general outline from the last post and began breaking it down using some of the design tools I mentioned below and some others I have mentioned in a previous post to work out some of the smaller details of the wall unit. I started from the bottom to work out the base molding first. Imposing Ionic column proportions on the height of the base cabinet, I used the height of the column pedestal (1/5 of the height of the base cabinet) to arrive at the height of the base molding. This looked good to me so I proceeded to work out the proportions of the feet. Most pieces of this nature look sort of like a built in unit, with a solid base molding that wraps around the piece. While this looks ok, I wanted to refine my piece a little and make it stand out as a piece of furniture and not a built in unit. So I decided to give the piece the illusion of having bracket feet like a chest of drawers would have. I say illusion because I don't really want to make the cases the typical dovetailed boxes on top of frames with feet like a chest of drawers would be since most of the side feet will be hidden by the adjacent boxes. It would be a lot of extra work that would never be seen. So instead I'm going to apply the "feet" to the fronts of all the cases and the outer sides of the outermost cases only just like a baseboard molding would be, except I'm going to scroll the base molding to look like furniture feet.  To work out the design of the "foot" I played with several of the proportional tools until I came up with a design that looked good to my eye. I started by imposing the proportions of an ionic column and entablature on the height of the foot. The column and entablature are broken down into six equal parts to arive at the height of the entablature (1/6) and column (5/6). Using the proportion of the entablature, I established the height of the sticking that I would put on the top edge of the base molding, i.e. 1/6 of the height of the base molding. From here I played with some other proportioning "rules" until I got a foot that looked nice to me and seemed to fit the proportions of the overall piece well.  After playing with some proportions for awhile, this is the "foot" design I came up with. It has a similar style to some bracket feet I have seen on some antique pieces from the middle third of the 18th century and to my eye looks very appealing. You can see how a lot of the different parts of the "foot" are related to each other and ultimately the height of the base molding.  After going through similar exercises for the cornice molding, waist molding and doors, this is what I came up with. Many of the parts are proportioned based on some of these "rules", however, as I mentioned in the previous post, there were also a few "it just looks good there" moments that have no basis on geometry, common ratios or column orders. Sometimes you just have to go with what looks good to your eye. I'm still a little undecided about the top of the piece as it seems a little light in relation to the bottom. I think it's because we decided to go with open shelves at the top instead of doors. I may still decide to add doors to the top to balance out the piece or possibly add face frames to the front of the upper cases to give the top a little more needed "weight". What do you think? Episode # 5: Sharpening Part 1 08/14/2009
It's no secret that to do fine work we need sharp tools. So the next few episodes are going to be a series on sharpening all of the different tools commonly found in the hand tool shop. I have three requirements for a good sharpening system: 1. It needs to be simple 2. It needs to be fast 3. It needs to be repeatable While my chosen method of sharpening isn't for everyone, it works for me and meets these three requirements perfectly. In this first episode of the sharpening series, I cover the straight edged tools like the square and skewed chisels and plane irons. How I Design 08/10/2009
It's been kind of slow in my shop lately. I haven't really been working on anything in particular now that the built-in and my shop desk have been done for some time. Summer is always a slow time for me in the shop as my family prefers outdoor activities when the weather is nice. However, I am gearing up and preparing for a major project for the fall once the summer activities slow down some and the vacations are all but over. So I thought this would be a good opportunity to share some insights on how I design a piece of furniture. I don't work from pre-printed plans but I will use pictures and/or drawings as inspiration for just about all of my pieces. However, as my wife will tell you, the pictures are merely a starting point. So it will be with my newest undertaking as well. Ever since we finished renovating our family room, we've been making do with a cheap Walmart TV stand. Other projects and pieces of furniture have been higher priorities up until now so we've simply dealt with the ugly plastic veneered particleboard stand, knowing that we would design and build a nicer piece at some point in the future.  My wife had an idea of what she wanted, but I always like her to find a few pictures of ideas that she likes as a starting point. She knows that I won't build the piece as pictured since the factory made stuff is typically junk, but the concept is really what I'm after, not the design. So for our family room, we found several pictures like this one. Now media units like these are obviously not period pieces, however, whether you are into period furniture or modern contemporary styles, the methods of designing and constructing them are no different. At first glance, this might seem like a very intimidating piece. It's pretty tall and very wide and there are a lot of doors, shelves and possibly some complex moldings. The trick to designing and building pieces like these is to break them down into small manageable steps. In this case, I'll break this down into 6 pieces of furniture that will later go together to look like one large piece. If you were designing an 8 foot tall Newport style secretary, the process would be no different. Now, while my preference for building furniture is to use tools and techniques similar to those used in the 18th and 19th centuries, when it comes to designing, I humbly embrace CAD drawing programs. Not because they can make accurate drawings (which they obviously can), but because it's so easy for me to scale drawings, proportion parts and move pieces around without having to have a large drafting area and a lot of pencils and erasers. I'm working on my drawing skills, especially when it comes to things like carving, but for rough dimensioning and proportioning and just getting some general ideas about scale and proportion together, CAD is hard to beat.  I like to start by figuring out the general proportions of the piece. In this instance, because I needed to proportion 6 differnt cases, I started with the bottom center case for the TV. My wife and I figured out how high we wanted the case to be based on the height of our seating furniture and the distance that most of it was placed from the TV. With the height of the center case established, just about all of the general dimensions of the six cases were in some way based on the chosen height for the center case. To illustrate this, I'll describe the process I used to arrive at the general dimensions for each of the six cases for this project. We decided that the center case for the TV should be about 30" high. I decided to make the width of this case a 2/3 ratio of height to width. This made the case about 45" wide, which turned out would be a good width for the TV which is 41" wide. The side bottom cases were figured out next. Again, the height was set at 30" to be even with the center case. Using the 2/3 ratio again, this time width to height, resulted in the side cases being about 20" wide. For the height of the top side cases, I applied a 5/9 ratio (height to width) for the entire area covered by the top cases and the open space for the TV. This entire rectangle has dimensions of about 47" tall by about 85" wide, which made the top side cases 20" wide by 47" tall. Finally, I made the bridge case about 1/4 the height of the side top cases or about 12" tall.  After figuring out the proportions for the front of the case, I moved to the top view to determine case depth. A lot of this is dependant upon what will go into each case. I decided on a stepped design for aesthetic reasons as well as practical reasons. Not only does the step back of the top and side cases look nice, it aids in hiding the joints of the moldings. The cases are going to be modular to make them easier to move. Therefore, the moldings cannot span more than one case. If the side cases were the same depth as the center cases, the base, waist and cornice moldings would have a visible vertical cut line where each case comes together. This joint would be immediately obvious and not very attractive. However, by stepping the side cases back from the center cases, the moldings can meet at an inside miter, which will hide the joint much better and help it to look like one continuous mitered molding and hence one solid case instead of six separate cases. So I started with the bottom center case again since that is where the TV and A/V components will be housed. I decided on about 21" deep for this case. To arrive at the step back for the side cases, I subtracted 3" from the center case depth to get about 18" for the bottom side cases. Then to arive at the top case depths, I subtracted 6" from the corresponding bottom case depth to arrive at a 15" depth for the top center case and a 12" depth for the top side cases.  With the front and top views drawn, it was a simple matter to transfer the dimensions to create a right side view of the cases. From a drawing perspective, this is about all I will do. Going through this exercise helps me to arrive at the general case dimensions for each case. From here, I can build all 6 cases and then begin the process of fitting everything out. The doors, drawers, shelves and moldings aren't really important at this point because their dimensions will all be dependant upon the final dimensions of the six cases. All of those parts will be gauged as I go along. This allows me to make adjustments as I go as opposed to working from a cut list which makes adjustments challenging. One final note on designing your own pieces. There are a lot of proportioning ratios that generally look good to the eye, like 2/3, 5/9, 3/5, golden ratio, etc. These ratios can be used as tools for designing a piece's general proportions. However, they are ultimately just tools and your eye should be the final judge as to whether something looks right or not. Sometimes, what looks right to you just doesn't fit any kind of "rule". It just looks right, so you go with it. That's the best part about designing pieces yourself instead of working from pre-packaged plans. The final piece has your character designed into it, not some one else's. Hand Tools & Techniques Hits iTunes 07/28/2009
Well after some work over the weekend, I've finally managed to work out all of the bugs that were haunting the podcast and it's communication with iTunes. So for those of you who have been long awaiting this day, it's finally here. You can now get the podcast through iTunes. I've also made getting there a little easier since it's been brought to my attention that the little widget provided by the podcast host that was supposed to make it easy to subscribe using iTunes doesn't work like it should. So instead, I've just put direct links on the Podcast page so you can click once and subscribe with iTunes or using the podcast's RSS feed. Thanks to everyone who has waited so patiently! Hope you enjoy the new feature! Episode # 4: The Mechanics of Sawing 07/25/2009
The hand saws are the workhorses of the hand tool shop. They're used for just about every operation on just about every part of a project. So it's important to be able to saw accurately in order to be effecient. In this episode, I share three tips I've learned for making consistently more accurate saw cuts. Just A Quick Update 07/21/2009
Well, it's been pretty slow with regards to shop time in the last three or four weeks and as a result the blog and podcast have been sitting pretty idle. We've been pretty busy lately with family events, some unexpected veterinary trips, a vacation that got cut short and getting outside to enjoy some of the nice weather we've finally gotten over the last couple of weeks here in the Northeast. Email Troubles 07/08/2009
I'm not sure if it's my email or the site's contact form or if some folks are just not entering real email addresses in the contact form, but I have gotten several email replys I have written to folks returned to me as undeliverable in the last couple of weeks. So if you have been waiting for a reply from me and you have not received one, that is likely the reason why. I do read and reply to every email that I get so if you have sent an email with a question, a suggestion for the podcast or just to say "Hi" and I have not sent you any reply at all, even just to say "Thanks!", rest assured that I'm not ignoring your message. I definatly sent you a reply but if you didn't receive it then it got returend to me as undeliverable (Noel, your messages come to mind immediately as there have been several that were returned on a number of occasions). | CategoriesAll
October 2009
       
       
        
|
RSS Feed