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elvio Junior Member
Joined: 04 Oct 2016 Posts: 6 Location: edinburgh, scotland
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Posted: Wed Oct 05, 2016 3:34 pm Post subject: mini planes |
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I have built three mini planes a la Krenov sandwich method. They are equipped with 1 German tool steel blade of 4 inches and the others with Dictum (herum)replacement mini- plane blades. I have so far, been unable to get shavings from any of the planes since they act as scrapers producing dust and small pieces of wood.
The attack angle of the blades are all 45* as recommended by the constructor in the "finely strung" url, the support for the blades having been filed flat and square. A metal cross piece keeps the hardwood blade retainer in place. I have tried the blades with cutting edge uppermost and reversed on the blade support with no improvement. Blades are firmly wedged and do not move .
All blades have been finished on US ultra fine stones then stropped with no improvement in performance. My Stanley block- plane blade angle is between 20*--30*and I wondered if this might be an attack angle which might be more useful. Any who have suffered this problem are very welcome to offer their solution. Thank you. |
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wm_crash Member
Joined: 24 Feb 2013 Posts: 140 Location: Wilmington, DE - USA
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Posted: Wed Oct 05, 2016 4:37 pm Post subject: |
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Hi,
Apologies if my suggestions here will sound insulting, but since planes don't work, everything is on the table.
- are you sure you installed blades bevel down?
- can your blades easily pop arm hairs? what grit have they been sharpened to before moving to the strop?
cheers,
wm_crash, the friendly hooligan |
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wm_crash Member
Joined: 24 Feb 2013 Posts: 140 Location: Wilmington, DE - USA
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Posted: Wed Oct 05, 2016 4:45 pm Post subject: |
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The more I think about it, the more I think you placed the blades bevel up like in a block plane. These planes with a 45 degree bed are not block planes, they are like mini bench planes. A 45 degree bed plus a 30 degree bevel give you a 75 degree attack angle. That's a scraper in most books, and with no hook, you're getting the results of a bad scraper.
Then again, I could be wrong
cheers,
wm_crash, the friendly hooligan |
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L P Reedy Super Member
Joined: 02 Apr 2009 Posts: 276 Location: Brevard, NC
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Posted: Wed Oct 05, 2016 6:21 pm Post subject: |
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wm, what you said makes sense, but he SAID he tried both ways. Without being there it is hard to tell anything, but if he really did try bevel-down the only thing I can think of is a poorly sharpened blade. It's possible that stropping could have ruined a good edge. |
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wm_crash Member
Joined: 24 Feb 2013 Posts: 140 Location: Wilmington, DE - USA
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Posted: Wed Oct 05, 2016 7:50 pm Post subject: |
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Just jotted down to read everything before jumping to conclusions.
cheers,
wm_crash, the friendly hooligan |
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Michael Darnton Moderator
Joined: 23 Mar 2007 Posts: 1286 Location: Chicago
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Dave Chandler Super Member
Joined: 31 Oct 2007 Posts: 691 Location: Mt Mitchell in North Carolina
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Posted: Thu Oct 06, 2016 10:06 pm Post subject: |
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From my experience (which is limited) the grind angle for a any plane should be about 5 degrees steeper than the "attach angle" of the blade so that the front edge can get a bite of the wood without the heel of the grind making it float on the wood. Any steeper, and it digs in too deeply, too shallow and it floats on the wood and can't get a bite. So you should be grinding at about 50 degrees.
The grind side down.
After grinding an edge, a stroke or two slightly steeper still (only a degree or so) will give you a nice cutting edge. You don't have to sharpen the entire grind area, you want to sharpen the edge itself. _________________ Dave in the Blue Ridge
Southern Violin Association
"Success is the ability to go from one failure to the next with no loss of enthusiasm" Winston Churchill
"I took the road less travelled, and now I don't know where I am." Marco Polo |
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elvio Junior Member
Joined: 04 Oct 2016 Posts: 6 Location: edinburgh, scotland
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Posted: Fri Oct 07, 2016 12:52 am Post subject: violin planes |
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My thanks to all who replied to my request. Mr. Darnton, your name is well known to me in my researches on violin making. The advice on stropping I find confusing but , since it comes from experts, I must accept it. Regarding my carving activities, I have always found it useful.
On reflection Mr. Crash,your opinions along with those of Mr. Chandler had given me sufficient food for thought which was put into effect earlier this evening with remarkably improved results. My reference to "angle of attack" is clearly not the accepted nomenclature in the violin world but is a relic of younger days when I steered aircraft around the skies for Her Majesty.
The blades were sharpened at the last stage of the exercise with American ultra fine grit which usually allows me to shave my arm hair but more assiduous application will be employed and will no doubt improve matters even further.
Once again , my sincere thanks to all. I can now approach plates carving in the certain knowledge that my thumb planes will do the job. |
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Dave Chandler Super Member
Joined: 31 Oct 2007 Posts: 691 Location: Mt Mitchell in North Carolina
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Posted: Fri Oct 07, 2016 8:55 am Post subject: |
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Now that I think about it, the grind should be 5 degrees less, you want the heel of the grind to be slightly higher than the leading edge. _________________ Dave in the Blue Ridge
Southern Violin Association
"Success is the ability to go from one failure to the next with no loss of enthusiasm" Winston Churchill
"I took the road less travelled, and now I don't know where I am." Marco Polo |
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Dave Chandler Super Member
Joined: 31 Oct 2007 Posts: 691 Location: Mt Mitchell in North Carolina
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Posted: Thu Oct 13, 2016 6:00 pm Post subject: |
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Here's some basic info to ponder:
You might be able to use this info when making your next plane, or at least some idea how the whetting angle should be. Not sure why these turned up rotated 90degrees, but you get the idea. _________________ Dave in the Blue Ridge
Southern Violin Association
"Success is the ability to go from one failure to the next with no loss of enthusiasm" Winston Churchill
"I took the road less travelled, and now I don't know where I am." Marco Polo |
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