Wed 26 Nov, 2008
Tags: Design, Ruby, SketchUp, Software
Wed 26 Nov, 2008
Thu 20 Nov, 2008
SketchUp 7 is released and can be downloaded at http://www.google.com/sketchup/download/. I have played with the new version for about a day now and have come to a few preliminary conclusions;
1. We SketchUp 6 users should all rejoice! There is still a free version called SketchUp 7. The professional version is called SketchUp Pro. By and large, SketchUp 7 is still the great 3D drawing package we have grown to love.
2. There have been very few significant changes in the free version for woodworkers who use SketchUp primarily for creating furniture models and shop drawings. Yes, there are some new icons to let you sign in/out to your Google account and work seamlessly with 3D Warehouse. But I don’t consider them significant for the woodworker.
3. One change that is significant is the way crossing lines are treated. Lines that cross are now split at their intersection, that is, at the point where they cross. Therefore, two intersecting lines become four lines. I will show how this can be significant in some situations, but in most cases this is a more logical handling of lines.
4. Inferences appear to be more robust and the clues appear to be more obvious, though I would have a tough time demonstrating either. It just seems so.
5. While I can’t vouch for all Ruby scripts, those that I use frequently appear to be compatible with version 7. Though I am sure over time we will discover some that are not.
6. Most of the major changes in version 7 were aimed at SketchUp Pro, Layout 2 and Style Builder. If you are a Pro user and need to interface to Layout 2 and/or Style Builder you will find many improvements in both functionality and compatibility.
7. A very significant change in the Pro version is the ability to create Dynamic Components. Dynamic components can take on behaviors and attributes. For example, a staircase might be defined such that, when enlarged for greater floor spacing, will automatically add steps but retain step height and width. These components can only be created in the Pro version. A limited number of Dynamic Components are provided in the new Component Options dialog box, but they are not particularly applicable to furniture design.
8. There are a few quirks that existed in version 6 with the Tape Measure tool that didn’t get fixed in version 7. There are also many non-obvious behaviors of Push/Pull in version 6 that changed somewhat in version 7, I believe due to the change in the treatment of lines, but that were not directly addressed in version 7. This post is primarily about these issues.
When I first started using SketchUp I came across two behaviors I thought were either software bugs, or at least illogical tool behavior. I discovered that to get the very most out of SketchUp a modeler must think a few steps ahead, like a chess player. Otherwise you go down paths that lead you to attempt recovery by cleaning up unwanted lines. Sometimes this works, but all too often it makes matters worse.
The first behavior has to do with the Tape Measure tool. The tape measure tool can be used to create a construction line parallel to any line or edge by clicking on a point on the line or edge and moving away from it, in one of the two orthogonal axis, a desired distance. The result is a true construction line, that is, a dotted line that does not render in a model, but can be used with other lines or edges to create an intersection and a tool tip that indicates an Intersection. In addition, when you move along the construction line with, say, the Line tool, you get a tool tip that says On Line.
Another way to use the Tape Measure tool is to start at and end point and move a desired distance away. It is most useful when moving along an axis but can be moved in any direction. This produces a dotted line with a Guide Point at the destination. The dotted line however is not a construction line. Other lines, edges or construction lines intersecting it do not produce an Intersection tool tip. Nor do you get an On Line tool tip as you move along the line with the Line tool for example. This is either a software bug or an unfortunate design choice. It still exists in Version 7. Download the SketchUp 7 model Tape Measure Tool and examine the various type lines using the Line tool. See the difference for yourself. You might want to also download the Draw Construction Lines tool discussed below. Refer to the picture at left for a description of each line type (click to enlarge).
Fortunately there is a very good Ruby that solves this problem entirely. It can be downloaded at Draw Construction Lines and produces all the desired results. It comes with a pencil icon similar to the Line tool but yellow with a dotted line under its point.
The second, more seriously bad behavior, has to do with the Push/Pull tool. The Push/Pull tool can probably claim on its own the reason for SketchUp’s success. It is a very powerful and unique tool in the 3D drawing and modeling tool bag. But it also has some flaws.
Look at the picture at right which is generated using SketchUp 6. I start out with six identical objects except each has a different rectangle drawn on the end. My goal is to see how many times I have to “use” the push/pull tool to get an object that is not going to change as I push further along. That is, the shape will no longer change, though the length will. I start with the Push/Pull by clicking on a face, moving it until the face will not move further. I call that one “use” of the push/pull tool. I then click on the same face and push again with the Push/Pull tool until it stops. Each time it stops I count it as a “use” of the Push/Pull tool. Some of these objects will only require one “use” and others multiple “uses”. The number of rows after the first represents the number of uses of the push/pull tool before I reach “equilibrium”. When I first wrote Dave it was curious to me that along the way I got faces that had lines dividing them, but I could only select the largest face to go forward, not either of the smaller faces; this changed in version 7. The other goal of this experiment was to see how much cleanup is left afterward. There may be other combination of interest, but I found these to be the obvious ones.
If you are a woodworker, you would expect Push/Pull results in each case to be similar to that produced by a mortising bit (a square drill bit) driven parallel to the X axis through the material. These results are quite different and not obvious. Note also that some of the surfaces are turned inside out, a clue as to what is happening. If you study the pictures carefully it becomes obvious what is happening and it is quite predictable. Still, one would hope that the designers would have made the boundary conditions more useful.
You can download the SketchUp 6 Push/Pull Model I used to experiment on your own by clicking here. Be sure to open it with version 6. I grouped each object in the model, so to modify them you will have to explode each group.
First notice that the second object from the bottom left row now only requires one “use” of the Push/Pull tool to reach “equilibrium” but with a very different end result. The fifth object from the bottom in the first row still requires two “uses” but can have two outcomes, both different from version 6. This is because the new splitting of crossing lines now produces two possible surfaces to push with the Push/Pull tool. The sixth from the bottom first row now only requires two “uses” instead of three but can also have two possible outcomes for the same reason. Only the third from the bottom first row produce an end result equal to a mortising bit.
You can download the SketchUp 7 Push/Pull Model I used to experiment on your own by clicking here. Be sure to open it with version 7. I grouped each object in the model, so to modify them you will have to explode each group.
So why is this important? Why am I nit picking as Dave would say. It often occurs that you have to make choices as to how to use the Push/Pull tool. For example, lets suppose you modeled one side of a traditional draw with the dovetails on each end, you make a copy of it to produce the other side. Now you want to create the grove in the sides that support the beveled bottom. You should think ahead, because if you produce it using Push/Pull from end to end you could get into trouble if a dovetail intersects that grove. You will be tempted to fix it by cleaning up lines and get deeper into trouble. On the other hand you could Push/Pull normal to the side and avoid all problems. This particular problem is exacerbated when combined with a Intersect/Intersect with Model operation. I point this out with an example in Drawing A Bedside Table – Part 5 for anyone interested.
I was hoping version 7 would have fixed these two situations. Unfortunately it hasn’t. But if you think ahead you can avoid the second and there is a very good Ruby to fix the first. That said, SketchUp is still the tool of choice for me and I continue to be very happy with it. Its intuitiveness, ease of use and price are unbeatable.
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Wed 12 Nov, 2008
Cutting dovetails in the shop doesn’t require dimensioned shop drawings. Heck, Frank Klausz doesn’t even measure or mark them before cutting. But for many people a drawing is helpful, and for completeness I add them to my shop drawings. That way they pop out at you when viewing a textured rendering in SketchUp, as shown in the picture at right. Since SketchUp models for shop drawings need to be drawn “exact”, we need to know the detailed pin and tail dimensions. Calculating these dimensions can be a little tricky, but with the aid of a simple Excel spreadsheet it’s child’s play. Drawing them in SketchUp can be equally easy if you follow a methodology. In this post I provide you the Excel tool and a basic tutorial. To download them click on Dovetail Calculator and Drawing Dovetails. This tutorial assumes you have a basic understanding of SketchUp at least beyond the novice or beginner level. If you do not, first refer to the Beginner SketchUp Tutorial on my web page.
Open the Dovetail Calculator and review the drawing provided which explains the terminology used (or click on the picture at left for an enlargement). I am sure you are aware that the pins are the smaller portion of the dovetail joint and the tails are the larger portion. Start with the board width you are using, perhaps for a drawer side or a carcass side. You must decide three things. First the size of a half pin; the partial pins at the ends of the dovetail joint. Second the number of tails. And third the size of the pin gap. The pin gap can be as narrow as your dovetail saw kerf if you cut dovetails by hand. You also want to choose a combination that winds up with dimensions that can be measured by you measurement tools, for example increments of 1/64″. A dimension of 1 23/40″ isn’t useful; though you can as easily draw it in SketchUp it is not useful in the shop.
In the upper left hand corner the Dovetail Calculator has a table. All cells except input cells are locked to prevent erasure of equations. Only the input cells for Board Width, Number Of Tails, Half Pin Dimension and Pin Gap are changeable. Start by inputing the Board Width. In the tutorial I use a board width of 10″, so input that. Next put in the number of tails desired. The tutorial uses 8, and we will see why shortly, so input that. I usually use a half pin of 1/4″. This is small enough to be visually pleasing and large enough to withstand normal side pressure created by a tight fit without splitting in hardwoods. This is largely a matter of taste and personal preference. If you are using a softwood, one that easily splits, you might want to make it larger. Input 1/4″ for now. Lastly input the pin gap. Some woodworkers like a very narrow gap, even as small as the kerf created by their dovetail saw. It’s a show off thing; it says “I am a really talented woodworker. See my small pins?”. But if you hand cut dovetails, tails first, this creates marking problems and almost requires you use a marking knife versus a pencil. Again it is a matter of taste. For now use 1/4″.
The results are a tail width of 31/32″ and a tail width plus pin gap of 1 7/32″ (1/4″ + 31/32″). These are usable dimensions; they can be used by your measurement devices to set a pair of dividers for example.
Now play with the Dovetail Calculator by substituting integers 1 to 10 for the number of tails (fractions of tails aren’t useful). Notice that inters 1, 2, 3, 4, 6 and 8 give results that are increments of 1/64″ which means any of these integers can be used as the number of desired tails. Integers 5, 7, 9 & 10 should be avoided, at least form the point of view of marking them with typical measurement devices used in the United States. The Dovetail Calculator can easily be modified for metric system measurement devices.
Experiment with other choices for Board Width, Half Pin Dimension and Pin Gap to get a feel for the results. OK, set the inputs as originally suggested (10″, 8, 1/4″ & 1/4″). The important results to remember (write them down) are 8 tails, 31/32″ tail width and 1 7/32″ tail plus gap width. Close the Dovetail Calculator and open the Drawing Dovetails tutorial. Notice there are scenes along the top labeled Step 1 through Step 14. Follow along with me, but don’t try to change the tutorial drawings themselves. Instead, open another blank drawing and draw your own from scratch using the explanation here and the tutorial as a reference.
Look at Step 1. We start out by drawing a rectangle 10″ wide by 26″ long. This is the arbitrary side dimensions of a drawer we are going to model. The sides, back and front will be 1/2″, but don’t worry about that for now.
Step 2. Using the Move tool bring the end lines of the box in 1/2″ on each end. Notice the construction line and green axis mark the original length of the rectangle. We are moving these ends in to account for the 1/2″ thickness of the front and back, which will become obvious shortly.
Step 3. Using the Tape Measure tool draw lines parallel to the top and bottom 1/4″ IN from the edges. This creates a half pin construction line. If you haven’t already, use the Tape Measure tool to create a parallel line 1/2″ OUT from the right end. This creates a tail width construction line.
Step 4. Using the Protractor tool start at the intersection of the top parallel 1/4″ IN construction line and the parallel 1/2″ OUT construction line and form a construction line 8 degrees from the top parallel 1/4″ IN construction line. I will explain why 8 degrees in a moment. Now, using the Tape Measure tool draw a line starting at the previously described intersection down along the parallel 1/2″ OUT construction line and make it 31/32″ long, the width of a tail. Again using the Protractor tool start at the end of this construction line marked with the construction cross and draw a construction line 8 degrees sloping upward (opposite slope to the previous angled line). You have now formed the outline of a tail.
The angles used for dovetails are somewhat arbitrary, but most dovetail markers use two angles, generally a combination of 6:1, 7:1 and 8:1 run over rise. The larger the first number the shallower the angle. Shallow angles are appropriate for hardwoods while steeper angles are more needed by softwoods. I use the 7:1 side of my marker which corresponds to an angle of 8.130 degrees or simply 8 degrees. Coincidentally this angle is also very useful for beveling the bottoms of drawers or raising door panels.
Step 5. With the Line tool outline the tail. It requires two short angled lines and one line the width of the tail. Refer to the zoomed view of the drawing. At this point you can choose Edit/Delete Guides to remove the construction lines.
Step 6. Using the Select tool with the Ctrl key select the three lines you just created to form the tail. With the Copy/Move tools and the Ctrl key copy these lines 1 7/32″ to the left and parallel to the green axis. Immediately type the characters x7 to replicate this move seven times. If you type anything after this step before typing x7 the multiple copy feature will not work. Seven is the number of desired tails, eight, minus 1, and 1 7/32″ being the tail width plus pin gap width.
Step 7. Use the Eraser tool to delete the opposite end line which will also eliminate the surface. In addition erase the short lines inside the tails. Refer to the drawing. Now select all lines and using the Move/Copy tool make a copy alongside the original. While still selected, use the context menu (right click) choose Flip Along/Group’s Red (assuming your drawing looks exactly like mine).
Step 8. While still selected move the second set of lines into position as shown to complete the dovetail outline. Now create a surface by drawing a diagonal line from one corner to the other as shown.
Step 9. With the Erase tool eliminate the diagonal line. The surface should remain. Now with the Push/Pull tool give the drawing a thickness of 1/2″, the thickness of both sides, back and front.
Step 10. Select the dovetailed board and make it a Group or a Component using the context menu. Using the Rotate tools followed by the Move/Copy tool place it as shown on the origin. Using the Move/Copy tool with Ctrl, make a copy and move it in place as shown, that is, along the green axis and 19 1/2″ from the first so that the outside dimension is 20″. With the Rectangle tool and opposing corners of the sides as extreme diagonals for reference, draw a rectangled surface as shown.
Step 11. Use the Push/Pull tool to give the front a thickness of 1/2″. Select the entire drawing. Choose Edit/Intersect/Intersect with Model.
Step 12. Move each side away from the front and with the Push/Pull tool move the tail surfaces in to create the pins. Notice I have moved some and left the others so you can see what I am doing. Do the same to the other end.
Step 13. The Intersect with Model tool leaves a few lines that should be cleaned up. Use the Orbit tool to view the back side of the front and erase the lines on the inside of the pins. Notice I have erased some lines and left the rest so that you can see what I am doing. When the lines are cleaned up make the front a Group or Component.
Step 14. Using the Move/Copy tool and Ctrl make a copy of the front. Using the context menu Flip Along/Group’s Red flip it. With the front as the reference assemble all pieces and you have your basic drawer or carcass construction.
This methodology may seem long and complex as you followed along with me, but once you get the hang of it and do it on your own you will find drawing dovetails is quick and easy. I keep a pointer to the Dovetail Calculator on my desktop so that I can access it quickly. I draw a lot of dovetails and find it very useful.
In reality drawer construction is slightly more complicated because the front and back dovetails are different in traditional style drawers (see The Design & Construction of a Traditional Drawer and The Crafting of a Traditional Drawer). I will leave it to the student to figure out how to modify this methodology and Excel spreadsheet to take this into account. Right now I am tired and hungry and am signing off.
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Fri 7 Nov, 2008
I was scheduled to pick up my new Lie-Nielsen workbench on Monday, October 6th. (See The Tool Worth Waiting For for background.) I had waited for this moment for nearly twelve months; Lie-Nielsen has a large backorder on this popular bench which I learned when I ordered it in the fall of 2007. The combination of my excitement, the beautiful October colors and a desire to visit the Lie-Nielsen facility suggested I pick it up in person. I invited Willow along so that we could spend a weekend in Maine – sort of a short vacation.
We departed early on Sunday morning, October 5th, from Lancaster, MA after spending and evening with our grandchildren – and their parents too. We guessed it would take about five hours driving time but were pleasantly surprised when it took only three and a half. I had two requirements for the trip. First, I didn’t want to miss the Patriot’s football game which began at 4 pm, and secondly, I wanted to spend most of Monday touring Lie-Nielsen and ogling their tools. Willow also had two goals. First she wanted to stay in a quaint B&B – she abhors motels and hotels – and she needed to participate in a board meeting conference call Monday morning.
So we set out to find a B&B with cable TV that received the Patriots game. This didn’t take long because there are numerous old houses which offer B&B services. We were particularly lucky to find the Weskeag Inn, located on Route 73 in South Thomaston, situated on the edge of the Weskeag estuary near the reversing falls in South Thomaston village and not far from Lie-Nielsen Toolworks Inc. The Inn was built in the 1830′s and is filled with antiques, many of which are furniture pieces that I admired and thoroughly examined for construction.
We had a quick lunch in the combination general store/post office next door and read the local papers with particular interest in the local political races. With our famine quelled we retired to the Inn’s living room to watch the Patriots beat the San Francisco Forty Niners 30-21. Watching that game must have burned a lot of energy because immediately thereafter we had dinner at Amalfi’s.
The couple that runs the Inn are our contemporaries and over a delicious breakfast the following morning they regaled us with the Inn’s history including stories of how he acquired it, its disrepair and repairs and their meeting – and discovering they were high school classmates. The stories were interesting and humorous, so much so that I almost forgot we were supposed to be at Lie-Nielsen’s.
Lie-Nielsen Toolworks Inc. was founded by Thomas Lie-Nielsen in 1981. The company manufactures and sells high quality hand tools for woodworking at a premium price. It currently employs about 90 people. Corporate headquarters, shown in the first picture above left, resides in Warren, ME. This building houses a showroom and corporate offices including sales and marketing. Manufacturing is in a building about 200 feet away where nearly all Lie-Nielsen’s tools are made. Lie-Nielson workbenches are made in a separate facility in Waldoboro, ME – about 10 miles from corporate headquarters.
We pulled into the parking lot and Willow sat in the truck where she was able to acquire good reception for her conference call while I went inside for a tour of the facilities. To this point most of my communications with Lie-Nielsen had been through Andrew Dix in the Sales Department and Darren Gilbert of the Workbench Group. After announcing myself I was introduced to Matt Blazek, also of the Sales Department, who took me on a guided tour of the manufacturing floor – safety glasses required. The pictures you see here were taken by me while on that tour. Hold your mouse over a picture to read a description or click the picture for an enlargement.
After the tour I went to the showroom to fondle and try out some of the new tool additions such as the progressive pitch dovetail saw. There is an old bench in the showroom for just this purpose. Lie-Nielsen’s entire line, including the workbench, is available in the showroom for the customer to examine and try. I fell in love with the progressive pitch dovetail saw and vowed to get one to accompany the Lie-Nielsen Independence Saw I currently use.
Willow joined me in the showroom. While I was looking at tools I noticed her talking to Andrew and filling out some papers. When I inquired what she was doing she said “I am giving you a $400 gift certificate for your birthday”. I knew I invited her on this trip for some specific reason, but wasn’t sure why until that very moment. Willow insisted I spend it right away. She said “I know you have a list in your head, so just pick the next item on the list”. I did. I got the Iron Miter Plane which coincidentally will partner quite nicely with the bench I was about to pick up.
While we were converting the newly gifted gift certificate to a purchase Thomas Lie-Nielsen walked in. I had met and talked to Tom on a number of occasions at woodworking shows but this was an opportunity to introduce Willow to him. We talked for a while. I was curious about the practical use of floats and Tom demonstrated their use to me. I told him I was there to pick up my much anticipated bench. He told the story of their surprise when they started offering custom benches and receiving a response which quickly swamped their ability to fill orders. They are catching up now, but still have a backlog of nearly 200 benches. We discussed the benefits of tools made in America and Tom indicated that he is thinking of making his own line of vises to some day replace the high quality German vises now used on his benches. You can always make improvements he said.
Famine hit again and Willow and I made for Moody’s Diner in Waldoboro, ME. I didn’t realize the history of Moody’s until I began writing this post. Moody’s is a family owned restaurant and motel which is apparently 75+ years old. It has its own cookbook called “What’s Cooking At Moody’s Diner: 75 Years Of Reminiscences” by Nancy Moody Genthner, the daughter of the founders Bertha and “P.B.” Moody. I ordered a favorite meal of mine – liver and bacon with mashed potatoes and gravy. It was delicious. The liver was tender, the bacon crisp and the vegetables cooked just right. Even the coffee seemed exceptional.
Finally we arrived at the Waldoboro shop to pick up my bench. Darren greeted us and gave Willow and me a shop tour. I recognized much of the equipment; Bridgeports, Jets and numerous dust collectors. Workbenches in various stages of build were throughout the shop, as well as large blanks and other raw material used in their manufacture. The glued up bench tops are purchased from and American supplier and customized for Lie-Nielsen. There, up against a wall, under an old factory paned window, sat my bench. I actually felt a chill when I was told it was mine, my anticipation so long and great.
Darren supplied some cardboard for the bottom of my truck to protect the bench. The trestle was disassembled and placed on the bottom, more cardboard, and then three guys loaded the top. I brought along a plastic tarp, purchased just that morning, which we strapped to the bench and truck. Rain was forecast for the trip home.
The following morning I was back at my shop with the bench in the back of my pickup. I was alone, no one around. The bench weighs 250-300 lbs. I wanted it set up and usable – now! I tried to contact my usual list of likely helpers with no luck. I committed myself to do it alone. My shop was designed with a garage door and a floor raised in loading dock fashion. With the help of an assembly bench with wheels I was able to set up the trestle and move the top in place. To place the top on the trestle I had to turn it over because it was loaded on the truck topside down. It wasn’t easy, I was careful, and it required a lot of awkward hefting. But I managed.
After approximately six weeks of use I couldn’t be more pleased. This bench is heavy, stable and flat. The vises are smooth and precise. The bench came with two sets of dogs; one metal and the other wood. They work great.
I wouldn’t be human if I didn’t find a few things I would do differently if I were to make a reproduction of this bench. First, I would probably add a few more coats of finish. It came with two coats of a 50/50 mixture of boiled linseed oil and turpentine. However, I have noticed that pencil and crayon marks that I make on milled pieces are wearing off on the bench. Maybe a few more coats would at least keep them from wearing into the top. Second, when the tail vise is fully closed there is a gap. This is apparently traditional as I have noticed when researching benches. However, looking at the bench it appears the gap width is arbitrary. I would choose a gap of 3/8″ instead of the nearly 1″ it now has. This is because most drawer sides, backs and even some fronts are 1/2″ thick and this 3/8″ gap would make it easier to cut dovetails using the tail vise. These are minor issues that can be easily remedied by the user. The bottom line – this is a top notch bench, well worth the $2,500 sticker price.
With a career in electrical engineering behind me and an avocation of cabinetmaker I am ill prepared to fully understand the metallurgy, machinery and mechanical engineering that go into the manufacture of quality hand tools. However, I have been around hand tools all my life; my father and brothers were all craftsman in the carpentry, plumbing and electrical trades (I come from a family of twelve siblings). As a child and teenager I used numerous pre-war Stanley tools and planes as well as many other quality brands. I was always taught to purchase a quality tool; tool purchases are not a time to be frugal, for good ones will last generations. With that background and my own woodworking experience I consider myself qualified to discern quality as I use such tools. Lie-Nielsen tools are second to none in design, fit-and-finish, quality and results. That, combined with the fact that they are American made is why I use almost exclusively their products.
The bench is home in its corner of my shop next to the tool cabinet that holds my hand tools, mostly Lie-Nielsen. You will notice that my tool cabinet has some space for planned future purchases, but space is not planned for a complete family. I doubt I will ever have all the planes, chisels, floats etc in the Lie-Nielsen collection. I am not a collector. I am a user who generally purchases a tool only when it is needed or will improve some facet of my work. I try not to fool myself into thinking I need a tool only to see it take up space in my shop but serve no useful purpose. But when I do purchase a tool I am particular about the brand. Lie-Nielsen has proved to meet or exceed my expectations.
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