Back bevel or higher pitch – which is better?

Posted February 27, 2015 by D.B. Laney
Categories: Uncategorized

Most of you know that I am not a big fan of honing back bevels on plane irons.  I believe that many inexperienced plane users allow themselves to be mislead, thinking that a back angle (bevel) is going to be some type of magic pill.  But after a crafts person is sufficiently confident in their ability to sharpen and maintain appropriate cutting geometry, the use of a back bevel can be very beneficial.

Several days ago I was working in my friend, Les’, shop.  He asked me if I’d take a look at his L-N #4 that he had set up with a York pitch (50°) frog.  He wasn’t very happy with the surface he was getting on a piece of cherry stock.  The stock was not particularly gnarly, but there was a grain direction change, right in the middle.  The iron was the same that had been removed from the Common pitch (45°) frog.  Les, who is always meticulous about the condition of edge tools, said that he believed the iron was sharp.  But I, “doubting Thomas” that I am, suggested that we test the edge.  Sure enough, the iron sliced a piece of unsupported paper easily.  Next, it trimmed a neat bare patch on the back of my forearm.  But upon closer inspection under a loop, it was clear that there were some tiny edge fractures present.

Cogitation began.  Increasing the pitch angle of a bench plane (bevel down), supposedly increases the tool’s ability to work in very dense and/or highly figured stock.  Obviously, either condition is a challenge to shearing tools.  And an increase in pitch causes an increase in the amount of effort required to push the shearing edge through the material.  Neither of us had ever experienced a similar problem when using an iron that was back beveled to effectively create a higher pitch.  Could back beveling be better than increasing pitch?  Turns out, yes.  Maybe.

Take a look at the following diagrams (Please note that, for the purpose of illustrating the problem, I’ve used Common Pitch (45°) and Middle Pitch (55°) for the examples.)

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When a back bevel in employed, the increased included angle strengthens the tip of the iron.  The clearance (relief) angle is kept to a minimum, thereby providing the greatest possible amount of support to the iron.

When a conventionally prepared iron (25° primary bevel, 30° secondary bevel) is secured to a higher pitch bed (frog), the clearance angle significantly increases and the amount of unsupported surface significantly decreases.  I believe that the tip section would be effectively weakened by these two factors.

It may be appropriate to increase both primary and secondary bevel angles in order to increase tip section strength and reduce clearance thereby increasing the amount of support surface.  It is common for adjustable scraper planes (Stanley 12, 112, 212) to be ground at 45°.  But these tools are rarely used at attack angles under 90°.  We need to do some physical testing, as there seems to be very little, if any, information available on the matter.  If anyone has any thoughts and/or experiences on this question, please share them with us.

Good old Henry Ford

Posted February 27, 2015 by D.B. Laney
Categories: Uncategorized

Still awfully cold here in NW Ohio.  But the sun is shining.  It’s a good day to sit around and think.

For some reason I started thinking about Henry Ford.  Farm boy with Irish roots. Pioneer industrialist.  Builder of some of the largest manufacturing complexes ever conceived.  Inventor, philanthropist, the list goes on and on.

But the thing I remember most about Henry Ford is that he paid his workers more than his competitors paid theirs, more than just “a living wage”.  Henry Ford was, above all else, a “long term” thinker.  He realized that well paid workers could be a huge, hitherto untapped, customer base.  Get a job at Ford Motor Company.  Buy a Model T.  A new middle class was born and America was “off to the races.”

Sometimes I wonder if anyone in American business or government still thinks that way?

 

Flat layout of frustums and cones

Posted February 25, 2015 by D.B. Laney
Categories: Uncategorized

First, please note that, apparently, the correct spelling is frustum, not frustrum. Hmmm….  You learn something new everyday!

Second, you might ask why am I talking about this?  Isn’t this subject more appropriate to a blog on sheet metal work?  Well, think about it.  What if you’re designing a chair with a back that is laid out as a portion of a frustum?  What if you want to make a brass lamp shade?  How about a coopered pail?  How about a dunce cap for your friends?  I mean, the potential for this method is unlimited.  Right?  Okay.  Maybe unlimited is a bit of a stretch.  But understanding this layout may help visualize measurement of these shapes (or portions of them) in a number of scenarios.  Remember diameter x 3.1417 = circumference.

If you should ever find yourself in the highly unlikely situation of having to layout a truncated cone, here’s an excellent tutorial site:  http://leonjane.hubpages.com/hub/How-to-develop-a-Truncated-Cone#

A Great Shave (requires no foam or gel)

Posted February 24, 2015 by D.B. Laney
Categories: Uncategorized

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Pardon me for obsessing.  But I haven’t been so excited about a traditional tool, that I could make in my own shop, since my friend, Jim Crammond, taught me about making travishers several years ago.  Of course, I’m talking about the pjål (pronounced somewhere between pill and peel.)  This is the simplest of tools.  But, it offers incredible versatility.  Pjåls can be used for doing rough work like a scrub plane, smoothing or detail work like a moulding plane.  It is a devilishly clever tool.  Given all that, the pjål is one of those tools that has the sculpted look of an art piece.  I’ve taken the liberty of pulling all the pics I could find on-line to create a small gallery.

The traditional carpenters (tradisjonelle snekkere) at Stiklestad have just posted another excellent video showing the use of a moulding pjål in use.

I think we’ll be seeing more information about methods of making and using the pjål in upcoming months.

If you’re interested in making your own pjål, but don’t have the capability (or desire) to fabricate your own irons, there are several traditional smiths who may be sources:

Øystein Myhre

Mattias Helje

Jon Dahlmo

Queen Anne drop leaf – a gallery

Posted February 23, 2015 by D.B. Laney
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For most of us, woodworking can be a pretty solitary business.  And, for the most part, that’s the way we like it.  But when I have the opportunity to spend time working alongside a couple of expert woodworkers I take it, gladly.

Several months ago, my friends Les and Scott, and I agreed that it would be interesting to meet once a week and work on a project together.  One of the problems working on your own all of the time is that you become terribly “hide bound” in your approach.  We decided we’d all benefit from sharing our methods with one another.  We settled on a project, a small drop leaf table with hinged apron supports.  We’re old(er) and slow(er) and once a week has stretched the project out.  But we’re making headway and we’re “in the white” at this point.  I thought it might be interesting to give a little documentation of our progress, so far.  All pictures, few words.

In way of a caveat, most of you know me as a dedicated hand tool woodworker.  Though I prefer to be unplugged in my own shop, I’m perfectly okay turning on the power when I have the chance to commiserate with guys like Les and Scott.  But visitors to my shop should not expect to see any increase in powered equipment there, actually, quite the contrary.

News from Norway

Posted February 23, 2015 by D.B. Laney
Categories: Uncategorized

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skottbenk

It’s no secret.  I’m intrigued by the skottbenk.  For those of you who aren’t familiar with the skottbenk, it is a simple machine used for jointing long boards for things like flooring, clapboards, etc.  And, if you’ve ever tried to joint an 8′ long board on a power jointer, you’ll immediately see the value of the skottbenk.  It seems to be unique to Scandinavia, specifically Norway and Sweden.  It is a design that has been around for centuries and even Leonardo DaVinci found the skottbenk so interesting that he drew up an “improved” design. But, for some reason, the skottbenk is not commonly seen in the U.S.

A Sketchup file on the type of skottbenk that Roald Renmælmo uses is available on his blog skottbenk.wordpress.com.  In the same post, Roald provides a video showing the use of the skottbenk. Many readers will find the planes used in the process of particular interest.

I’ll be starting mine, as soon as the weather “breaks”.

 

Making masts for Ma Bell

Posted February 21, 2015 by D.B. Laney
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Recently I decided that I needed a larger draw knife for chamfering seat planks.  So, I went to Ebay and was surprised to find a significant number of large draw knives (12-14″ blades, 22-24″ overall) that were available and most were in surprisingly good condition.  In the descriptions, most sellers referred to them as “mast makers” draw knives.  At first, that made sense to me.  Certainly, masts, spars and booms were made using draw knives for shaping.  What didn’t make sense was that most of these knives didn’t appear to be old enough to have been around during the “age of sail”.   In several descriptions there were makers marks that gave dates.  One example was “L.I. & J. White, Buffalo, 1837″.  The seller had assumed that 1837 was the date of manufacture when, in fact, 1837 was, more likely, a founding date for the L.I.& J. White company.  Then other tell-tale words popped out in a number of descriptions; “Bell System”, “Western Electric”, “U.S. Army”.  A bell went off in my head (no pun intended).

These days, we tend to forget that the construction of the communications and power delivery systems that we take so much for granted, are, relatively modern phenomena.  The rural electrification system was largely a product of U.S. government efforts to modernize the country’s infrastructure after the Great Depression. It became immediately clear that these “mast maker’s” draw knives were used to make the “masts” that supported the nation’s telegraphic, telephonic and power lines.  They were used to make utility poles and cross-arms.

A 24" (woa) "mast maker's" draw knife

A 24″ (woa) “mast maker’s” draw knife

A "mast maker's" draw knife with a thicknessing gauge bar

A “mast maker’s” draw knife with a thicknessing gauge bar

Today’s utility poles are manufactured with large machinery in centralized plants, then transported to the field.  In earlier times, utility poles were often made from appropriate trees removed when right-of-ways were being cleared.  Many of these “field made” poles are still in place around rural areas across the country.  During WWI and WWII, telegraphic communications were critical.  Where do you string telegraph wire, on poles.  Ergo, “U.S. Army.”

Utility companies and all braches of the Defense Department bought massive amounts of forestry and woodworking equipment and continue to do so.  And, it was always of high quality.  For example, many of us are in possession of bit braces and all-metal Yankee drills that bear the “Bell System” logo.

Kelly provided felling axes to “Ma Bell”.  Stanley was a huge supplier of all sorts of tools for the “utility” trade.  The number of well known, U.S. companies that provided tools to Bell, General Electric, etc. is immense.  Sadly, many of these firms are no longer with us.  They fell victim to the advance of technology.

Broad hatchet with hole for tightening square cross-arm bolts

Broad hatchet with hole for tightening square head cross-arm bolts (Bell System)

So the next time you pay your phone bill, give “Ma Bell” a little nod of thanks and respect.  “She” helped American hand tool manufacturers and continues to provide “unplugged” woodworkers with quality, vintage tools.

 

 

 


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