Cambered Fore Plane

[Bill Haumann]

I recently purchased a 17" Marples plane, never used. Anxious to put it to work I sharpened the 2 1/4 inch iron with no camber and put it to work. It took nice broad shavings right away, but the shavings continually stuck in the throat and I had to stop every other pass or face a very jammed throat.

I tried a thinner shaving with no difference. (I was avoiding cambering the blade simply out of laziness - I had no idea it was related to the throat clearance issue.) then while staring into the plane's throat in annoyance, I realized the throat was never meant to clear a 2 1/4 inch shaving.

I ground a camber (about a 12 inch radius), sharpened the iron, set it fir a more rank cut, put the same board down, and held my breath. I had to stop after two passes again, but thus time in amazement. Not only did the thicker shavings (still over an inch wide - I haven't measured), not jan in the throat, but they flew completely out of the throat to land on the bench. Hundreds if passes and a few minutes later, I had two boards roughly flattened on both faces, and not a single jammed shaving.

I haven't seen throat clearance as a reason for cambering before, though I bet I just read past it. Ithus was a real turning point for my understanding of wooden planes.

- Bill

[george wilson]

If the plane is a traditional wooden plane with the angled escapement in front of the iron,many times,the owners would cut away the escapement some to let shavings not jam.

I'd need to make a sketch to show this,but don't know how.

[Larry Williams]

My guess is that the camber forced moving the cap iron back from the edge and the cap iron is what was causing the choke. You could work on the cap iron to at least partially fix this but I think moving it back is fine. Cap irons cause more problems than they solve.

[john brenton]

Almost a year ago I bought a barely, if ever used, Salman jack plane (beautiful condition, European red beech...a real beauty) and had the same problem. I guess that just like tools today, these tools were mass manufactured and not all were tuned up as they should be. Sometimes I think I expect all oldies to be perfectly tuned up as they are. I figure that perhaps someone had bought it and had the problem and never fixed it and that's why it stayed so cherry.

I thought about opening up the throat but instead I also put a heavily cambered, big ol' fat monster Buck brothers iron in and never had a problem. I have another plane that I use with uncambered irons and keep the Salmen jack fitted with the cambered one. It's great, and I use it all the time.

[Bill Haumann]

Thanks for the replies.
I was considering filing the throat open a bit before the camber resolved things - good to know that wasn't an uncommon adjustment.

It may have been the cap iron placement as Larry said. I did have the cap iron very tight to the cutting edge and the camber did require that it be moved back. If I ever put a no camber iron back in, I'll watch the cap iron placement.

- Bill