Tuesday, August 7, 2018

Various Features of Dedicated Moulding Planes, 7/16" Roman Ovolo

This 7/16” Roman Ovolo plane I introduced last week is easy to use, straight-forward to sharpen, and creates a profile that is simple to include in your work. 

When familiarizing yourself with this plane and its use, one must first address a few aspects of its design that can greatly affect the way the plane shall perform.

This dedicated ovolo is sprung and shall be used only at the angle for which it is designed. The angle that this plane is to be held is defined by the ‘Spring Lines’ on either end of the plane, 30 degrees from vertical in this case.

Aggressive, easily seen spring lines make the plane easier to use.

A dedicated plane that is not sprung is designed to be held vertical.

Both of these planes produce the same profile, the one on the left in both images is sprung.

Why is this plane sprung? There are a few purposes to having a plane that is sprung. The first is that the plane's sole and profile does not go as far up into the plane’s escapement. This allows for a mouth that is both tighter and more uniform across its width.

The sprung plane is on the left again.

Additionally, there are benefits to the iron’s cutting geometry when a plane is sprung. In this case, the cutting edge of the sprung plane is never far from perpendicular to your force. This results in more of a shearing cut. The scraping action of the unsprung plane greatly reduces the longevity of a sharpened edge. 

Adding a spring to a plane is an example of technology that is in the tool and often overlooked. The height of the fence is another.

Why does the plane have a wide fence?In addition to the plane being sprung, it also has a tall fence. When the fence of this plane is tall you are able to remove more material with your chamfers. (think Bulk Waste Removal.)

The plane on the right has no reference surface for the fence. Therefore, the same chamfer will not work

A tall fence allows a wide chamfer. A small fence demands a smaller chamfer. A small chamfer means more passes for your profiled plane; which means more use, additional maintenance, and increased sharpening of an edge that is seemingly difficult to address.

Note the difference in material that must be removed.

When considering the purchase of a plane, new or antique, all of these considerations shall be taken into account. 

SOLD OUT (More available in early September, email to put your name on the list): I still have a few of these 7/16" Ovolo sets available. They are $295 plus shipping.These planes will arrive sharpened to the extent that I use them and come with an appropriately sized hard Arkansas slip stone for future maintenance. Email matt@msbickford.com with questions or requests.

As always, you can check out my FAQ page for some general answers

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