Anatomy of a Router Plane - The Stanley No.71

Stanley No.71, disassembled, explained, and reassembled, ready to make shavings

Let my demystify the anatomy of the metal bodied router plane. I'll use my Stanley No.71 - an open throat router plane. The No.71½ is a closed throat version, the same in all other respects (as far as I can recall). Veritas and Lie Nielsen both make similar router planes, arguably to a better standard, but my fettled Stanley works just fine for me.

The video shows all the main points:



Main considerations for good performance:

• A flat sole
  Prepared by lapping on a surface plate, hand scraping, or sanding on top of a flat reference surface.
• For open throat router planes, the accessory throat closure should lie in the same plane as the main sole.
• Well prepared iron
  Since the iron is bevel up, the bevel angle will directly affect the angle of attack during a cut, and therefore you can tailor the angle to suit the work in hand.
  My video, Sharpening a Router Plane Iron, shows how I achieve a consistently honed iron.
• Blade parallel to sole
  Essential to achieve a level depth of cut. Inaccuracy can be corrected by either working on the tool post or the blade. Since this is a multi-blade tool, the tool post faces should be filed perpendicular to the sole, and then all irons ground so that their edges fall parallel to the sole.
• All sharp corners and edges eased - to prevent injury to either work or user

In Use:
More passes, taking thinner shavings, will achieve the best results, rather than struggling to control the plane because the cut is too deep to make comfortably.
Because of thread backlash and coupling gaps, adjustment of iron height can be counter intuative to begin with. Rather than forcing the iron down with the screw adjuster, it should be held back by the adjuster. Having released the clamping collar, the iron is advanced by applying pressure on it's top, whilst letting it down in a controlled way with the adjuster. After a little time, this becomes second nature.
With grain planing should be in the direction that causes least tearout. Cross grain planing is best achieved with the 'snow plough' shaped iron, or by skewing the plane (in which case one direction of skew is likely to be better than the other).
To work further from a reference face, attach a ridgid sub-base that extends far enough for good support.
Attaching a sub-base with a long fence will give much better control for straight cuts than the standard fence.
To achieve an angled bottom in a groove, attach a suitably angled sub-base to the plane.