Model Engine Maker
Supporting => Tooling & Machines => Topic started by: 10KPete on June 12, 2018, 01:41:10 AM
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Somewhere, more than one place I suspect, I have seen a finishing tool ground out of HSS that looks like it's just butted against the work piece. The end of the tool is sorta square-ish with an end relief angled to the right and an angle ground on the left side of the end so the tool edge 'tilts' to the right about 25*. It was called a shear tool for taking fine finishing cuts.
I was trying to get a good finish on a piece of 1 1/4 cold finished carbon steel that's something more than plain 1018. Pretty tough and wanting to tear even with a sharp HSS knife tool. Hmmm
I ground up a tool to look like the one I saw and honed it with a fine India stone.
Man, I gotta tell 'ya. That little gem leaves a finish like a grinder!! It shaves off a couple of thou so nicely...
Where has this tool been all my life???? Amazing!! Just amazing.
Pete
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Pictures? Drawing? ;D
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Pictures? Drawing? ;D
Both!
Video in use?!
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I don't know of the post you are asking about, but it reminding me of a tool used in a YouTube video about making fountain pens.
https://www.youtube.com/watch?v=SByOoh2XK6c
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OK, here are pics of the tool. Taken after making the part so another raw piece is shown.
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The part I was making is the bottom one. It takes an Irwin tap chuck (turned down to .750). This 'adaptor' slides on the same guide pin used for my die holder. These are, obviously, used for smaller sizes and are hand turned only. The die holder has a handle I can use for tough going.
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Nice little shaver! That diagonal part does the cutting, right? Like using a scraper almost.
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Yes, the angle on the end does the cutting. No scraping! It cuts at a high angle; a shearing action. It only works for light cuts and seems to work best cutting .005" DOC or less. Makes the neatest little shavings. I'll try to remember to take some pics next time I use it.
I like that... a little shaver...
:Lol:
Pete
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Oh yes, they're gorgeous little things :ThumbsUp: I was shown how to make and use them circa 1973 - ish . Yet I never seem to see any reference to them :headscratch:
If you get 'em right it's possible to get shavings off FCMS, brass & ally so fine they're like dust. :D
The action is similar to that of a Skew Chisel I used in my wood butchering days.
Maybe not the best example but this gives the idea @ about 2 mins. in.
www.youtube.com/watch?v=MOuznRWUGos
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Hi Pete
I have never come across this style of high shear shaver tool before. It looks like it could be a very useful addition to the tool rack. Can it cut/shave up to a step? Do you have a photo showing how the tool cuts and how the metal shavings come off?
I was fascinated by the fountain pen video. and the craftsmanship of old Mr Kato. He must have been crafting those beautiful fountain pens all of his working life. Some of those hand tools and techniques must date back to his apprenticeship. Love those wooden hand closing collet chucks and the direction reversing pedals under the bench. How about that rickety old home made chair?
Mr Kato seems so happy and proud of his traditional skills, and rightly so. It is good that these traditional skills still exist in the bustling, high tech environment which is modern Japan.
Mike
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Here you go mike, complete with swarf close ups
https://www.youtube.com/watch?v=_qZvUD48cZY
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Thanks Jason, The video shows off the vertical shear tool very well.
The cutting action is reminiscent of large end mill taking a 5 thou finishing cut, complete with angel hair swarf.
Mike :ThumbsUp: :ThumbsUp: :ThumbsUp:
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Here's my shear tool, made from an old 3/8" HSS tap.
Ian S C
(http://)
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That video from Mr. Pete shows off the tool better than anything I could have done. Thank you Jason!
Ian, that round cutter makes a lot more sense than a square one. I can be rotated in the holder to vary the edge angle to adjust for material conditions. I'm going to make one as I have a few (!) bits of broken HSS tools and I'm sure I can find a piece of square around here to drill a hole through! Excellent idea!
Anyone who hasn't tried a shear tool really should. It's a game changer for me...
Pete
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Definitely going to be giving this a try. Thanks for all the info. Pete and everyone!!
Bill
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You can use your diamond toolholder from Eccentric Engineering as a shear tool as well, just turn the toolbit 90°. See video below at around 4 minutes in.
https://www.youtube.com/watch?v=lHs0xVRwuzE
I use a shear tool on the shaping machine as well, it leaves a superb finish.
Phil
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That Diamond tool is really nice...
I went out to the shop and whipped up Ians' version with the round cutter. There was a lot less grinding to get the shape and I ground the face and end on the flat of the wheel so it would be easier to hone. I'm impressed. Thanks Ian!!