Archive for the ‘treadle lathe’ Category

Treadle Lathe – Machined Crank Details

Thursday, January 30th, 2014

Lathe builders in 1805 didn’t know Roger Davis. They’d just have a blacksmith make them a simple crank and be done with it. I didn’t know Roger either when I built my lathe. He saw the blog entry showing the (pathetic) wooden crank I made, in the absence of a blacksmith, and suggested it wouldn’t last long. It didn’t. He then made me one that will never fail. It is solid!

Roger Davis is a fellow Hoosier with the good sense not to move to New York, a frequent visitor to the Sawmill Creek forums, owner of “a very complete machine shop” and self-proclaimed “lack of good sense,” an aerospace engineer by education (Yay Purdue!), former high school teacher (physics, cemistry, algebra), a builder of scientific instrumentation (start to finish) as his paying job, a builder and user of muzzleloaders as one of his hobbies, and variously proficient in gunsmithing, blacksmithing, woodworking hand tools, A&C furniture, cooperage and who knows what else. Bottom line: a generously good guy.

So, why am I telling you all of this? Josh, from the previous post, wanted more information about the machined crank, as did Matt in the comments on the post about Stephen Shepherd’s kit of parts.

Photos and a drawing tell most of what you need to know to make one. If you have the metal working equipment to cut a block of steel, cut a slot in it, drill accurately, and tap some screw holes, you can make one similar. For what it’s worth, the distance between pivots was simply an estimate (a little more than a tenth the diameter of the flywheel) and has worked very well. Roger didn’t specify the size of the cap screws, but they look to be 1/4 by 20 by 1 inch long. The only other thing not shown on the drawing, that’s very visible in the photos, is a dowel pin that retains the crank pin. The retaining pin is probably not needed on this particular crank since Roger built it to such close tolerances that the crank pin probably took several tons of pressure to seat as a “press fit.”

When installing on the flywheel axle, be sure to go back and forth between the two screws, as they each affect the other’s tightness until they are really tight.

This crank has been very solid. I’ve got hours and hours of use on the lathe and ZERO, Nada, NO slippage from the crank. It simply works! Thanks again, Roger.

photo of flywheel crank - 1 photo of flywheel crank - 2 photo of flywheel crank - 3 photo of flywheel crank - 4 drawing of crank arm as always, click any photo for a larger version.

Treadle Lathe Compilation

Tuesday, January 28th, 2014

One of this blog’s followers, Josh Delmonico, compiled a Word document that includes many of the posts for the Treadle Lathe category. The result is a single document that describes building this lathe.

I browsed through it quickly, and found that it covers all of the construction related posts. There are a few posts not included, such as ones published after construction that are related to some of the things made on the lathe. Omitting those is logical for someone wanting to build a lathe. The focus is on the build.

The included web links work too! Josh captured the photos at sizes that fit comfortably. You can see larger versions of most of the photos by clicking through to the actual blog pages and then clicking on the images.

For someone wanting to build a similar lathe, this is a GREAT compilation that gets all the construction related material in one place. Highly recommended.

THANKS JOSH!

Download >>>—> Treadle Lathe DOCX (about 8MB)

Update (1/31/2014): Josh updated the document to include the recent post about the machined crank. All build details are now fully up to date.

PS: For those (like me) who don’t have Word or abstain from the MS suite, you can find a variety of DOCX readers with your friend, Google.

 

Treadle Lathe – Parts Update

Wednesday, October 23rd, 2013

Any of you who followed my treadle lathe project know that most of it was based on Stephen Shepherd’s drawings of an 1805 Turning Bench. You might also remember that I stalled for a long time while searching for a blacksmith … who apparently fled NY’s wonderful tax system and literally headed for the hills.

I recently heard from another lathe builder who was also looking for certain parts, all the metal bits. Good News…

Just in! Stephen Shepherd has just pulled together a hardware package for people building the lathe. The hardware lets one keep the authentic nature of the machine with fittings that match the original plans (with a very minor size difference here or there). From Stephen’s description, the fittings look great and I see the price as very reasonable.

Highly recommended! see: http://www.fullchisel.com/blog/?p=4425

 

Carving on a Turned Object #2 – Lathe Enhancement

Friday, December 14th, 2012

Sometimes, there’s madness in my method. Back when I made the adjustable tool rest, I used a certain shape in anticipation of these carvings.

51+w65WS2cL._SL500_AA300_Inspiration for this pair of turnings comes from yet another Frederick Wilbur book, “Carving Architectural Details in Wood: The Classical Tradition.” A little rosette appears in the lower corners of a very ornate picture frame. It’s a classic rosette that’s frequently seen on period furnishings. Besides its appeal to me, it is sometimes carved from a turned base, one of the reasons I built a lathe.

photo of drawing and book images

As with many carvings, I like to draw the item a couple of times myself. It helps be get a better feel for the object, for knowing the turning profile, and for having a fair idea of how to create the result.

photo of steps in tutning the baseThe turnings are of walnut. Because the dominant features are on the face, these need to be mounted for faceplate turning. I used a small “Easy Wood Tools” faceplate, to which I screwed some sacrificial pine. To that, the walnut is attached by the technique of gluing a layer of paper between the pine and walnut.

The turning is straightforward. Walnut works very easily. The only unusual aspect is that I have not yet made a tool rest specifically for faceplate turning. So, I improvised by F-clamping the existing tool rest across the lathe’s ways in the only way it would fit … backwards.

photo of 4 steps of carving and completing the rosettesAt my level of ability, carving is about two factors, grain and sequence. Feeling grain interaction with tools is almost second nature now. The real consideration for grain on these pieces was orientation with respect to features. I decided to place the leaves between the pedals on diagonals to the grain direction. My hope was in minimizing the likelihood of breakage. That worked out great. Sequence is the other aspect that I find challenging. What to cut first? My instinct was to set in the spaces between pedals first, and to do that with cuts that minimize the pressure on what will be the sharp ridge of the leaves. That worked out OK. The rest of the carving was to remove everything else that’s neither leaf nor pedal. :-)

photo of enhanced tool restLastly, I drilled the back of each rosette with a 3/4″ hole the depth of a metal nut, and additional 1/4″ hole to accommodate a screw. The nut is set in a pool of epoxy. The whiteness of the epoxy is due to a filler.

Finish: simple boiled linseed oil.  NO sanding harmed either this carving or me!

The result is… some classy knobs to replace the ugly wing nuts on the adjustable tool rest!

Carving on a Turned Object – #1

Sunday, November 11th, 2012

The running dog caught the car. Now what?  I built a lathe. Now what? My first interest in building the lathe was like that running dog’s, “Just do it!” “Gotta make one of those!”

Along the way came carving and a fascination for carving on turned objects. Let’s go.

photo of book coverThis first turned object carving is a challenge piece, a skill builder. I selected it because it has several different sorts of carving on one piece. It is a combination of two pieces from Frederick Wilbur’s “Carving Classical Styles in Wood.”

Pineapples have long been used in architectural decoration as symbols of hospitality. Like the running dog needing a car, I really don’t need a pineapple or a symbol of hospitality. Call me hermit, not hospitable. Yet, it is a challenging carving project. My interpretation takes the form of a small finial about 6 inches tall. There a photo of one in Wilbur’s book. To that, I added a ring of beads just above the pedestal’s cove … for more challenge. I omitted the leaves at the top … to accommodate the blank I had on hand. I sketched up a drawing and headed for the lathe. The wood for this project is Northern Basswood from Wisconsin. It is moderately soft and has a very straight and even grain, excellent for carving.

photo of the finial on the latheTurning was relatively easy after all the firewood making beads and cove practice. I dulled the points of the outside calipers, and worked to the measurements from my sketch. Most of the surface was left as cut by the turning gouges. The only places I sanded were areas that will not be touched by carving tools, the base pedestal and the large half bead below the leaves.

Layout for carving is the fun part. I’ve watched Mary May’s amusement at the engineers who are frequently her students (myself included). She does layout the way an artist does, estimating spaces and proportions with a very keen eye. Engineers use scientific techniques and tools. Wilbur suggests leaving the pineapple in the lathe and using an indexing head to mark out 16 segments. photo of making and using a 13 segment rulerMy lathe doesn’t (yet) have an indexing head, and besides I wanted 13 segments … because nature does it that way. More on that shortly.

How to get 13 segments? The enginerd way, of course! Wrap a piece of paper around the turning to mark off the circumference. Strike 2 parallel lines indicating the circumference. Connect with a base line. Lay a ruler across the parallel lines in a manner to divide into 13 segments. Mark each. Drop a perpendicular at each mark. When done, cut off a strip to use as a ruler. Wilbur’s “in the lathe” advice is good for one part of the layout. I put the pineapple back in the lathe and used the tool rest for drawing axial lines. Next, laying out the field of diamond segments.

Here’s where nature comes in. All sorts of things in nature grow in spirals: pine cones, pineapples, sunflower seeds, flower petals, leaves around a stem, and on and on. Often they grow in double spirals. Look at a pine cone or pineapple from the end to see the effect, or watch this Vi Hart “Doodling in Math” video. The double spirals in nature always use a pair of adjacent numbers in the Fibonacci sequence. (1,1,2,3,5,8,13,21,…) Our lovely pineapple often uses 8,13. Thus, my interest in 13 segments. Now, how to lay out the other spiral of 8? That’s where my head started hurting too much and I decided making both spirals as found in nature would be one too may challenges for this project. Apparently, most who create pineapples for pediments and other architectural purposes agree. Those pediments all have symmetrical diamonds.

My solution for marking off the spirals was to fetch an image of a protractor from that world wide web thingy, strike off a 135 degree angle, glue it to a magazine cover for a little more substance, cut it out along the baseline and 135 degree line leaving a strip about 1/2 inch wide, and use the resulting flexible ruler to mark the spirals. No photos. Doing such required 5 hands and a monkey to obtain a smooth curve and manage the pencil, leaving none for the camera. Aren’t enginerds clever?

photo of workpiece in an f-clamp, in a viseOK. now how do we hold it for carving? The vise on my carving bench doesn’t have enough extension to hold the piece securely. Both vises on my 12 foot work bench have plenty of capacity, but that bench is way too low for carving. Oh, my aching back. Bingo: F-clamp! I turned a small cup for the pointed end of the blank. Secured all in an F-clamp, and clamped that in the vise of my carving bench.

The rest was all carving. “In the zone” carving. Time disappears. Shapes emerge. Until…. other time-sensitive projects are demanding attention. photo of partially completed finialSo, I’ll stop for now. My learning goal has been accomplished. In addition to the enjoyment, two notable carving points stand out:

Treadle Lathe – Show-n-Tell 2

Tuesday, October 30th, 2012

Despite Andre’s concerns, it actually works.