# Hollows and Rounds



## Ocelot (Mar 6, 2011)

Last year I started down the slippery slope with hand planes - and since then have bought 20+ bench planes, one rabbet (rebate) plane, and a Stanley 148 tongue and groove match plane.

Continuing down the addictive slope, I'm looking at hollows and rounds.

As a aside, if anybody has too many hollows and rounds and not enough Bailey 5, 6, 7's we might could arrange a swap. I have five No 5's, four No 6's and four No 7's. I could let go of half of those.

I've read a little - particularly this treatise on hollows and rounds.

I think what is called a "half set" would be plenty for my needs.

I've been looking at this very inexpensive Chinese-made set offered on ebay, which is less than a half-set, but a pretty nice assortment for only $12/plane delivered.









I posted on another thread (HPOYD) an inquiry about these inexpensive new planes but got no response.

American or English made sets from days of old go for several times that price - and right now, I'm not going to spend hundreds.










I'm interested in hearing other woodworker's experiences with this type of plane. (I used the word "other" implying that I too am a woodworker, and I hope you cut me some slack for that)

What say Ye?

-Paul


----------



## dyfhid (Jun 4, 2015)

I've bought planes from that eBayer before, and they're OK. Shipping takes a while, obviously.

Lee Valley has what looks like the same set for $249 so the eBay price is right. Lee Valley also sells them individually and in pairs. (Traditional Asian Hollow & Round Planes)

Regarding Hollows and Rounds in general, I think they are very useful planes to have. I have been collecting the English type one at a time for years, and have gathered together about half of a good 'half-set'. (I've gotten a few dogs in there which are only decent now for being small pieces of beech to use for other things 

Like chisels and router bits, I would be leery of getting a set; you might find you've paid for dust collectors. Of course, getting them singly or in pairs, if you do end up finding you need/use what would be an entire set, you'll end up paying more than if you bought the set to begin with.

Have you looked up Matt Bickford? He's a treasure trove of information on molding planes, and the use of Hollows and Rounds. (http://msbickford.com) His book and DVD are awesome, and his blog has lots of free information too. (http://musingsfrombigpink.blogspot.com) He has been a little light on content on the blog this year, but go through his archives. Like I say, a treasure trove.

Also highly recommended, both Traditional Molding Techniques: The Basics and Traditional Molding Techniques: Cornice Moldings. Don McConnell goes into some fascinating detail on using these Hollows and Rounds in these DVDs.

Finally, on the choice between the Chinese and the English sets - I think they both cut Hollows and Rounds in wood about equally, and in actual use there probably isn't all that much difference between them, so I say go for it!


----------



## MLWilson (Jun 28, 2015)

At that price, they may well be luthiers planes. Very small. What some call "finger planes". I bought a pair of compass planes of that size from a Chinese outfit on eBay. The size was what I was looking for. And they were sharp out of the box. I also have a couple of very old Filibuster Planes, one of which is missing its outrigger/fence. If you'd like to see them, email me at [email protected] for photos.


----------



## Ocelot (Mar 6, 2011)

dyfhid,

Thanks for your reply.

[ I have my wireless router set to switch off at 10:30pm. Although I set it up for one of my children, it also keeps me from lingering too long on the internet. You sent your message at 10:22, I didn't notice it for 10 minutes so I didn't reply last night.]

I was particularly pleased to see you had bought a plane from that seller and it turned out to be OK. I'm leaning toward ordering that set.

I don't "need" any planes at all. I'm a hobbyist, so I will use he tools I have in any case. I might do a project a particular way just to use a particular tool.

Thanks for the links to some good info on using molding planes. I'm sure amongst that is info on sharpening. There is no point in buying planes that I can't sharpen. I figured that for the smaller ones, I could build a fixture to hold the iron at the bedding angle (actually 90 degrees from the bedding angle) on the drill press, and sharpen the smaller hollows with a conical diamond hone - that I bought to sharpen hollow mortising chisels. I don't know what to do yet for the rounds or for "flattening" (rounding) the other face of the hollows.

I'm moving toward hand tools not for any philosophical reason, but mainly looking toward involving my children in woodworking and wanting a safe gateway. My Dad was a shop teacher at one time in his life, but never taught me - probably because Mom didn't want me to cut my hands off.

Thanks also to Mark Wilson. I think I can get a sense of the size of these planes because I know the widths of the irons. I think they are a little on the small side, but not tiny. I'll look carefully before I order. Perhaps the Lee Valley site has measurements.

Well, time for breakfast. I've got to move my laptop out of the way to make room for a plate.

-Paul


----------



## Ocelot (Mar 6, 2011)

Well, I ordered the Chinese set.

I still don't know how to sharpen them.

I can flatten the backs.

For perhaps the smallest hollows : 1/4, 3/8 and 1/2 I can sharpen with a pair of diamond cones I got from Lee Valley (about $13) for sharpening hollow chisel mortising bits. Lee Valley also sells a larger pair of cones for sharpening up to 1 1/4" hollow mortising chisels (who's strong enough to use such a thing), but I would need 2 1/2" diameter cone to sharpen the 1 1/4" hollow, since the width is equal to the radius.

Hmm now that I think about it, I could only sharpen the smallest hollow (1/4) with the cones I have since they are designed to sharpen up to 1/2" hollow mortising chisels. I have to remember that the radius is the same as the width on standard hollows.

I need to do some research on sharpening these things. The larger pair of diamond cones are $32, and would only take me up to the 1/2" hollows. I still don't know what to do about the rounds.

DMT also makes some 1/2 cone "stones" but even the largest of these would not have a 1 1/4" radius. Also they have a "wave" sharpener - but matching the radius seems problematic.

I'm talking to myself here. It seems I might have to spend more money on sharpening gadgets that I've spent on the planes.

-Paul


----------



## DLK (Nov 26, 2014)

For hollows and rounds you can use doweling or molding with the right diameter or profile with sand paper or infused with honing/polishing compound. For hollows you can also use slipstones or Round Arkansas stone files or other the stone shapes used by carvers.


----------



## Ocelot (Mar 6, 2011)

If you use a dowel with sandpaper to hone the hollows, how do you provide a relief angle (bevel)?

-Paul


----------



## DLK (Nov 26, 2014)

> If you use a dowel with sandpaper to hone the hollows, how do you provide a relief angle (bevel)?
> 
> -Paul
> 
> - Ocelot


By tilting freehand at the correct angle. The idea of the sandpaper is to make your own slip stone, but achieve the same results as "scary sharp".

But see this article which says "you never want them to get so dull" so that they can not be resharpend by honing alone. Then honing compound on leather should I guess conform to the the blade shape.

See also this discussion.


----------



## paratrooper34 (Apr 27, 2010)

For my set of hollows and rounds, I use slipstones to sharpen them. It is tedious and makes someone have appreciation for using a plow or other type of straight bladed plane for removing as much stock as possible before using the hollows and rounds to save on sharpening iterations for them.
I do not hone a bevel on them. I have never seen a hollow and round blade sharpened like that.


----------



## dyfhid (Jun 4, 2015)

As others have said, you don't need to match the radius exactly with your sharpening tools. Think of the woodcarver, with his many shapes of gouges. If we had to match every radius of the hundreds of gouges available carving would never be done because of the expense!

The articles Don linked to are great to help learn from. I would add to those one of Matt Bickford's archived posts, Sharpening: A window into my basement

Just like everything else, a little practice will get you there.


----------



## Ocelot (Mar 6, 2011)

Ok I've got some reading to do!

If you tilt the dowel (or the blade with respect to the dowel), the profile will be elliptical. Maybe the deviation from circular is too small to matter. I'll try to do the reading this afternoon.

Thank you for taking the time to advise me!

-Paul


----------



## DLK (Nov 26, 2014)

> Ok I ve got some reading to do!
> 
> If you tilt the dowel (or the blade with respect to the dowel), the profile will be elliptical. Maybe the deviation from circular is too small to matter. I ll try to do the reading this afternoon.
> 
> ...


O.K. I see your concerns. You can either shape the dowel to fi as you want, use a smaller dowel and move it around to address all the surfaces, or pad the the dowel with leather so that it confirms to the hollow and use honing compound. Traditionally we use slip stones.


----------



## DLK (Nov 26, 2014)

Incidentally conic sections are ellipses too. And it looks to me the shape of the bevel on an hollow is actually elipitic. At lest the ones I have appear so. However the angle that make when they meet the wood to be cut causes the bead cut to appear to be a cylindrical. I have not really thought about this mathematics before I just sharpen with a slip stone.


----------



## DanKrager (Apr 13, 2012)

If you take a 45° section of a cylinder, it is an ellipse. If you want to produce a cylindrical cut using a cutter at 45° then the cutting edge has to be elliptical. The surface of the bevel, however, is another beast because relief is required at every point behind the cutting edge. If you look closely, I think you will find that the bevel angle at the tip of the cutter is much shallower than the bevel angle of the highest point of the ellipse in the cutter. This is confusing because the relief angle may well be constant behind the cutting edge, but to achieve that, the bevel angle changes because of the slope of the cutting edge. Relief angle is measured from the path of a point on the cutting edge to the face of the bevel. Bevel angle is measured from the face of the cutter to a line tangent to the curve and perpendicular to the face. Two wildly different angles at the peak of the cutting ellipse, but almost the same angle at the tip of the cutter. That makes it difficult to visualize a jigged sharpening technique because the bevel angle is different for every point on the cutting edge.

To illustrate specifically, lets set the cutter by itself on a surface so that the straight bevels at the tip of the blade are resting flat on the surface. The face of the cutter will not be 45° to the surface because of the relief angle of those bevels. (If the blade were raised to 45° then the angle between the bevel and the surface is the relief angle, commonly 15° just like on a straight plane blade.) The bevel angle of the curve at the tip of the cutter can be seen resting on the surface, and that will represent the relief angle, perhaps as much as 15°. If you could measure the bevel angle at the peak of the ellipse you would find it to be approximately parallel to the reference surface. So the relief angle is a constant 15° but the bevel angle changes from 15° to 30° and back to 15° as you progress along the cutting edge from tip to tip.

The surface of that bevel is best matched with a conical section at a very careful match to the angles. One must rotate the matched cone rather than slide it back and forth being careful to keep the original matched position. By checking the marks on an original factory edge, this is not how they were ground in the first place. I cannot speak to that from experience. The closest I can imagine is a wheel with an elliptical shape on the edge and the cutter jigged to present the cutting face to an appropriate "section cut" of the wheel.

It's helped me to think about it, so thank you for enabling that process.

DanK


----------



## Ocelot (Mar 6, 2011)

Thanks for the replies, Don.

I used to work as a graphics programmer, so I don't have too much trouble visualizing what happens when you slice a cylinder or cone. I think using a slightly smaller dowel and moving it around in a conical movement might do the trick. As you say, a wheel with the right elliptical profile could do the factory grind. Sharpening on a cone by hand (not a rotating cone) would obviously be difficult since there actually only one location on the cone which matches the profile and relief angle of a particular iron. You would have to move the iron back and forth over a very small distance - and still it might not be very satisfying. But a rotating cone would do fine if the axis of rotation passes through the point at the center of the radius of curvature of the edge of the iron and is at the bedding angle of the plane. You would still have to set the depth exactly right so that the section of the cone which rubs the iron has the radius you want on the iron. Aaack. A picture would be worth quite a few words here.


----------



## Ocelot (Mar 6, 2011)

Well, Sketchup makes lousy cones, but still I can see that I was wrong about this.

Maybe I'm not so good at visualizing after all!

Maybe I'll ask an old friend who still is a graphics programmer. Now it's a challenge! I can't let it go!


----------



## DLK (Nov 26, 2014)

Good explanation Dan K. (I see our names are being confused again.)


----------



## Ocelot (Mar 6, 2011)

Oh! I apologize to both of you! Dan and Don.

Thanks Dan for the explanation!

-Paul


----------



## DLK (Nov 26, 2014)

> Oh! I apologize to both of you! Dan and Don.
> 
> Thanks Dan for the explanation!
> 
> ...


Its O.K. we're twins.


----------



## DanKrager (Apr 13, 2012)

I think a spinning cone is the simplest geometry to create in a home shop. If you want a 15° clearance, then you want a 15° cone with a sufficient range to cover your cutter sizes. Then, holding the blade at 45° to the axis of the cone snuggle the bevel to a good fit and sharpen or hone depending on the abrasive in use. Gotta try that.

DanK (aka Don) Aw shucks. Said I wasn't gonna bring it up again!


----------



## theoldfart (Sep 9, 2011)

^ twin sons of different mothers!


----------



## DLK (Nov 26, 2014)

The hamming distance between our names is only three. (Don Kreher vs Dan Krager) Half the time when I tell someone my name they write down yours. Quite remarkable we both frequent the same threads.

Also I'm liking the cone idea.

We shall call it the cone of sharpness


----------



## theoldfart (Sep 9, 2011)

Maybe you two should have a joint avatar!


----------



## Ocelot (Mar 6, 2011)

> I think a spinning cone is the simplest geometry to create in a home shop. If you want a 15° clearance, then you want a 15° cone with a sufficient range to cover your cutter sizes. Then, holding the blade at 45° to the axis of the cone snuggle the bevel to a good fit and sharpen or hone depending on the abrasive in use. Gotta try that.
> 
> DanK (aka Don) Aw shucks. Said I wasn t gonna bring it up again!
> 
> - Dan Krager


That's what I thought before I looked at the sketchup and thought some more. We want the iron to sweep a circular arc when moved along a straight line. The cone would only do that if we intersect it at right angles to it's axis. But since the iron sits at 45 or something (I don't actually know what angle these planes hold their irons, 'cause I don't have them yet.), if we grind/hone at right angles to the cone, then tip the blade to 45, the sharp edge of the iron won't be a circular arc any more. If we hone at 45, the cross-section of the cone that it cuts is not a circular arc (which I believe you Dan (or Don) stated way up above here) and I don't think it's the right ellipse either. I don't know. Maybe it *is* the right thing.

... but I think we need something else. I think an elliptical projection of some sort would do the trick. My graphics programmer friend (George) hasn't replied yet, but I did write to ask his opinion. He could probably solve the problem mathematically or geometrically or algorithmically or something. ;-) I should be able to do this, but I'm tired and rusty and maybe a little old etc. and my tooth hurts.

-Paull


----------



## groyuti (Oct 12, 2015)

[No message]


----------

