Replies

1. 
   philip | Aug 04, 2007 12:11pm | #1

   C, ----- "does it matter what bevel angle is on the blade".
   It does matter in several ways, for example the bevel angle you put on the blade affects how sharp you can hone that blade.
   I think that even with some of the so-called superior steels that are being used today the maximum bevel angle would be around 35 degrees-definitely not more than that because sharpening or honing is not effective-it just is not sharp.
   Anything less than 25 degrees weakens the blade edge-very hard steels will be prone to chipping whilst soft steels just curl back.
   The performance of the plane is also affected- more power is needed to push the plane when the blade bevel is on the high side-like more than 30degrees.
   Note that the blade can be ground at say 25 degrees, and honed or sharpened at anything from 25 degrees to the maximum I mentioned above.
   Basically that is it-unless I have left something crucial out....or got the wrong end of the stick...

   Philip Marcou
1. 
   ctsjr | Aug 04, 2007 06:21pm | #2

   Thanks, Philip.So what, if any is the advantage of a bevel down plane? Or does it just boil down to personal preference? The reason I like the Veritas Bevel Up Smoother is the low center of gravity and the ability to push through the difficult grain. Granted, my experience is limited, but I've seen folks using bedrock style planes and bevel up planes side by side, both tuned very well, and the bevel up seemed to do better. Thanks. Tom"Notice that at no time do my fingers leave my hand"

1. 
   philip | Aug 05, 2007 12:09am | #3

   C, one advantage of a b/d plane is the relationship between the mouth and the blade: adjusting the cut does not alter the gap/tightness of mouth- it stays constant.
   With a b/u plane if you want to maintain a tight mouth then you need a (convenient) means of adjusting mouth tightness.
   There is also some debate on the rate of wear with a blade used b/u: they will blunt quicker, but this may be negated by use of certain steels, and is related to the bed angle and bevel angle of the blade.
   I am sure others can provide more details.
   Make a few planes, and you can try out all these things (;)(;). Many folk are wedded in eternal bliss to both types.Philip Marcou

1. 
   ctsjr | Aug 05, 2007 12:19am | #4

   PhilipThanks for the good information. Everything you have said makes perfect sense. I do think I'll leave the plane making to you and the other artists that turn out such working works of art. This all started one evening as I was thinking about the relationship of bevel angles, cutting angles and the different plane styles. I've been planing some lacewood this afternoon with my new 50 degree bevel blade, and had some good success. I will be glad when this project is finished, however. Lacewood is not my favorite--seems to be full of pitch and is hard as iron. The figure makes planing very difficult. Thanks again. Tom"Notice that at no time do my fingers leave my hand"

1. 
   lwilliams | Aug 05, 2007 04:52am | #5

   Hi Tom,Let me expand a little on what Philip has posted.First, these bevel up planes have confirmed for a lot of people some of what I've been saying for more years than the current BU fad. One of those things is that relatively small changes in cutting geometry over the range historically used make a big difference. Plane makers of 200 years ago and much more knew what they were doing when producing common, York, Middle and half pitch planes. The other thing the BU fad has confirmed is that cap irons really aren't necessary and have less impact on tear out than other plane features.You spoke about versatility and and the BU design. I guess that depends on your definition of versatility. If all you use a plane for is to replace your sander, I can understand that comment. If all you plan to do with a plane is remove machine marks after preparing stock with machines perhaps you'll find a BU plane to be the answer to your prayers.However, if you plan to or occasionally need to prepare stock by hand a 12º bevel up plane isn't all that functional. Just like traditional bed angles, there's a reason that three traditional planes are used for stock preparation. You need a fore plane, try plane and smooth plane. The BU plane can perform the function of the smooth plane but a smooth plane is the least used of the three in stock preparation. In fact, I think it would be a stretch to say the smooth plane is used for 5% of stock preparation work. Is a 12º BU plane all that versatile when it can perform less than 5% of the work traditionally assigned to bench planes.12º BU planes lack the clearance angle needed for anything but the lightest of cuts. While they can be quite functional for special uses, they make a poor substitute for bench planes because the lack of clearance angle limits the depth of cut. The irons are difficult to camber and the depth of cut limitation makes cambering the iron pointless anyway.The major thing really missing from the widely viewed Internet review of the Marcou BU plane is a look at the performance difference between the 12º bed angle plane and the 20º Marcou. I guess, because the reviewer only finish planes machine prepared stock, the 50%+ increase in clearance didn't make much difference in such a limited examination of the Marcou plane. The Holty 98 has a bed angle similar to the Marcou and I'm still left wondering how much it improves the performance of the Marcou when it comes to use as a traditional bench planes. I believe the difference should be dramatic but I've never used the Marcou and only taken a couple passes with a Holty 98--I don't know for sure.There are documented BU planes from about 400 years ago. If you look at the history of hand planes you'll soon realize the early plane makers frequently demonstrated their knowledge of cutting geometry and necessary clearance angles. Other than the use of modern exotic materials, I don't see much that hasn't been tried before. None of this stuff is really new and that says a lot about why earlier plane makers weren't claiming some of the things you see claimed today.Tom, you can verify what I've said about clearance angles yourself. Hone a 50º bevel on your plane iron and try to take a relatively heavy roughing type of shaving. Let us know what you learn.