Hollows and rounds have no fences. They have no depth stops. They are difficult to steer and harder to correct. They have edges that take more skill to maintain than a straight edge.
I know what you're thinking. “I wish there was one wonderful thing that can take care of all three problems. I wish it only took one tool. And I wish that a video showing how to do it is easily accessible.”
THERE IS!
Rabbets, Rabbets, Rabbets
-Hollows and rounds have no fences...Rabbets create a series of chutes on which the planes travel.
-Hollows and rounds have no depth stops...When laid out correctly you will plane until the rabbets are gone (or you're leaving plane tracks on both sides, but this occurs when cutting greater than 60 degrees of an arc so we'll get to that some other day.)
-Hollows and rounds take more time to sharpen than a normal straight edge... Rabbets remove most of the material.
Steering
These planes are difficult to steer. When they start heading in a certain direction it's difficult to change. If a plane has a single point for its sole to ride, the chance that you end up with the beginning of the molding equaling the end is slim. The chance of the beginning equaling the ending and equaling what you want? Good Luck!
These planes are steered by giving them two points to ride.
Let the rabbets and chamfers dictate the direction the planes are presented because it is easy to change these.
Let's look at some real life examples now.
Do you want an ovolo at 30 degrees? One hollow--one chamfer at 30 degrees
Do you want a cove at 30 degrees? one round--the tips of two rabbets at 30 degrees
Do you want an ogee at 30 degrees? one hollow and one round--one 30 degree chamfered rabbet for the hollow, the tips of two rabbets for the round, also at 30 degrees
Do you want an ogee at 45 degrees? Look at the differences in the rabbets below vs. above. Everything is laid out at 45 degrees here.
Do you want a reverse ogee at 30 degrees? Again, look at the different layout. Same tools, different results.
Do you see any features above you recognize in the previous two moldings at which we looked?
Additionally, look at how much material is being removed by the profiled planes in the perfect world of google sketchup. It's minimal.
Next week we'll look at how rabbets serve as a depth gauge.
One last thing: I am not the person to speak to regarding design. I am a copycat when it comes to my craft. This is the reason I bought my first antique planes--to copy. Anybody looking for elements regarding design should check out Lie-Nielsen's library. I've heard very good things about a few of their dvds, including those by Don McConnell, Larry Williams and George Walker. They are each extraordinarily knowledgable in the subject.
PS I wish I was in Warren, ME this weekend. Have you seen the line up at the Lie Nielsen Open House?
Thank you so much for this post. Really helps demystify the proper usage of these planes.
ReplyDeleteI have to agree with David as your post really helped me as well. Thank you Matt.
ReplyDeleteSome time I wish i was closer to all the woodworking "shows" and tool makers!! ho well, sait la vie!!
ReplyDeleteCheers and thank you for all the great info!!
David
Very informative and helpful. Thank you.
ReplyDeleteGary
what is the best size rabbet plane to get? There seem to be quite a few different widths out there - some differing by only fractions of an inch? What do you recommend?
ReplyDeleteAnon,
ReplyDeleteI rarely make rabbets bigger than a 1/2" or 5/8". I use a 7/8" rabbet for nearly everything I do. There are times when I will use a 5/8" to knock a corner off in a tight place. These time are rare. A 7/8" rabbet will do everything from 7/8" down to <1/16".
Matt
You explain things clearly . Very helpful! Keep up the good work!
ReplyDeletematt, i am reading your blog for the first time. i acquired some h&rs as a gift (galootaclaus from the oldtool list) last year, and i am using them to cut a molded edge to some vise faces (in mahogany).
ReplyDeletemy geometry isn't exactly the strongest. my profile is going to be a cavetto, similar to your 30deg cove above but without the bottom step. i understand the use of the rabbet, but i cannot figure out how you know just how high to cut the rabbet so its point determines the bottom of the hollow *and* does so at the correct angle. hopefully it's something simple, because i feel *so* very nearly there!
thanks for a great blog, very, very helpful to a neophyte molding-maker.
Draw the profile you want on the a piece of paper. Take a straight edge and connect the edges of the cove with a line extending past. Draw a rabbet that terminates on the arc and connect the the arrises that the round will sit upon. If the two lines are parallel, that's your rabbet. If they are not, erase the rabbet and draw another.
DeleteI wish I had some geometrical answer for you, but I doubt one is quicker. Do this 10 times with 10 different angles and you'll start getting it within two attempts.
Execute those 10 different profiles and you'll learn to steer the planes to the extent that close enough is good enough.
ah, the old "trial and error" method! *rubbing my hands together* excellent...http://www.youtube.com/watch?v=YKUOB8MN4Kc
Deletei'll take a picture when i'm done. thank you very much for your swift reply!
Matt, I got my rabbets cut to do a simple 45 degree cove with a 5 round. Set up seemed good. Shavings were light. But as I was getting close to done (rabbets were converging) I noticed that the cut was"diving" at the far end of the board. I.e. I was cutting deeper into the bottom and less so at the top, compared to the near end of the board. Another way to describe it is that there was a twist in the cove from right to left and top to bottom. Does that suggest anything to you?
ReplyDeleteThank you for any help you can provide.
E
E,
ReplyDeletemaking an accurate rabbet is important, but it's not everything. Make certain that you are applying pressure to both arrises evenly. People starting out will often put progressively more pressure on the lower arris throughout the length of a cut. This will rotate the plane, which is what you did. Check your progress often. Errors can be corrected by steering. The sooner you recognize your errors, the less steering will be warranted.
Matt