I'm looking for advice on geometry for a shaper toolbit. The goal is to produce a relatively large surface with very nice finish and light cuts...cold rolled steel.
My experimentation has tried a relatively sharp corner of the toolbit under minimal crossfeed (1 ratchet tooth per stroke, about .005") which produces a nice "lined" finish under close inspection. Surface is smooth to the touch.
Just wondering about the possibility of doing better. It seems like a larger nose radius will blend the micro-"furrows" cut by the toolbit on individual strokes, but the one surface I tried came out with a "torn & smeared" look, even though I had just honed the toolbit with a stone.
I haven't messed around much with the cutting speeds yet, cutting at around 35 strokes per minute with about a 6" stroke. Maybe a little faster with a broad nose.
Shaper (& maybe planer) toolbit shape
Re: Shaper (& maybe planer) toolbit shape
Matt,
I'll do my best to describe a " broad face " finishing tool that is almost always used to finish surface plates.
1. The tool is used to take a small finish cut on the order of 0.005 to 0.010 deep and indexed across the surface at the effective cutting width of the bit minus enough to accomodate any variation in the index feed mechanism.
2. The tool geometry will vary with the material being cut. One thing that is a given is that the setup must be as rigid as possible. Liken this to using "0" rake form tools on a lathe. The end of a HSS blank of size to just fit the tool post ( in lieu of a tool holder ) should be set up and ground on a surface grinder so it has proper relief and is just about square to the length of the blank. If you are finishing steel, a side angle ( either L or R of 5 to 20 degrees ) should be added to the top of the tool along with a circular chip breaker so the shavings will ' roll out ' in a spiral fashion without marring the finish or building up in front of the tool and tool post.
3. One way the setup for the finish is to place a quality parallel across the rough cut surface. Sometimes it is good to give the surface a hit with a fine or medium single-cut file to eliminate any bumps that will interfer with the parallel. Set the tool bit to the top of the parallel. Use a piece of white paper to reflect light from behind and give it a good look. Then put the parallel away and use layout ink to blue up a patch near the starting edge of the job so you can witness the accruacy of the finish as you bring the tool onto the work ( do this very carefully with the machine moving ). If you are satisfied with the alignment, move off the work and set the finish depth and index, lock everything tightly, and proceed to finish the job.
Dave
I'll do my best to describe a " broad face " finishing tool that is almost always used to finish surface plates.
1. The tool is used to take a small finish cut on the order of 0.005 to 0.010 deep and indexed across the surface at the effective cutting width of the bit minus enough to accomodate any variation in the index feed mechanism.
2. The tool geometry will vary with the material being cut. One thing that is a given is that the setup must be as rigid as possible. Liken this to using "0" rake form tools on a lathe. The end of a HSS blank of size to just fit the tool post ( in lieu of a tool holder ) should be set up and ground on a surface grinder so it has proper relief and is just about square to the length of the blank. If you are finishing steel, a side angle ( either L or R of 5 to 20 degrees ) should be added to the top of the tool along with a circular chip breaker so the shavings will ' roll out ' in a spiral fashion without marring the finish or building up in front of the tool and tool post.
3. One way the setup for the finish is to place a quality parallel across the rough cut surface. Sometimes it is good to give the surface a hit with a fine or medium single-cut file to eliminate any bumps that will interfer with the parallel. Set the tool bit to the top of the parallel. Use a piece of white paper to reflect light from behind and give it a good look. Then put the parallel away and use layout ink to blue up a patch near the starting edge of the job so you can witness the accruacy of the finish as you bring the tool onto the work ( do this very carefully with the machine moving ). If you are satisfied with the alignment, move off the work and set the finish depth and index, lock everything tightly, and proceed to finish the job.
Dave
Re: Shaper (& maybe planer) toolbit shape
Matt From what little experience I have with my shaper (homebuilt Gingery) I found that the shape of the tool is more critical regarding use in a shaper than it is in a lathe or mill. From what I have been shown and read, it requires one shape for a Left to Right cut and another for Right to Left cut, one for roughing and one shape again for finish. I find that the less advancement on the table the better the finish I get, but if your already down to 1 tooth thats probably as slow as its gong to feed. The rake is important, as too much it rips and too little it sort of drags and pulls without shearing. Iget my best finishes from a low table feed rate, low to medium ram speed, and a sharp corner on a toolbit, when shaping steel. I get better results in aluminum and brasses using a higher rate of ram speed and a radiused cutter.There is a yahoo foum dedicated to shapers, with a lot of usefull information in the photo and files area, especially the one article thats there on use and setup of a shaper, about 9 or 10 pages in length it is pretty darn thourough in expaining the ins and outs of shapers and tooling etc.
http://groups.yahoo.com/group/Metal_Shapers/
http://groups.yahoo.com/group/Metal_Shapers/
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stephen_thomas
- Posts: 9
- Joined: Wed Jan 08, 2003 9:30 pm
Re: Shaper (& maybe planer) toolbit shape
Matt,
the first tool described by Dave is for cast iron, it won't work for on steel as far as a fair finish. His second tool is what you want for steel.
The finish tool for steel looks about like a mouldboard plow in shape. It is hard to describe, but I'll give it a go. Your edge on this is going to be from one rear corner to the diagonal opposite front corner. It can be even more severe (closer to parallel to the stroke) but we'll start here so we can probably both (hopefully) follow the reference points. You will also see ways to modify the tool to make it stronger, or to increase the utility before the whole tip needs ground off to start over. But for now:
Grind one corner off flat about 3/16" or 1/4" high (depth of cut), so the flat reaches from corner to diagonal corner. Now round the top , still corner to corner, about the radius of a 50¢ piece. as you round, put a very little bit of back relief. The working end of the tool will be part of a sphere, at this point with a flat face spanning diagonal corners. Now very carefully, on the edge of a small radius wheel (say 5" - 7" diameter, but really any wheel will work), form the flat face to a hollow chip pocket. Stop a little shy of the radius edge, and blend in with the end of a cone or pear stone. Hone the whole edge smooth.
I'm making is sound like a lot of work, but once you get the picture and do it a few times it is as fast as any bit.
Put this bit in your straight holder, and tilt it in the lantern until the sharp radius edge is cutting near center, or maybe a little more toward the front. Make everything tight, set your feed for very small increment, and don't try to cut more than about .005 deep. Remember, this is finish bit only. .002 is even better. Feed in the same direction as the back of the bit points. (oddly, this bit will cut either direction. but generally better as described. If you try it the other directionand it works smoother, so be it, enjoy!). Brush out a full coating of good lard oil or wahtever your favorite steel elixir is on the surface, put in the clutch and go.
This will cut wispy long curlicues like a unicorn horn, and if your machine is in good shape and tight, the surface will look almost like it came off a surface grinder.
You have to experiment with radii, and with the angle you tile the bit to the work. Also, as mentioned, a shear angle greater than the 45º described works even better. I mean like down as low as 20º in some cases.
This bit will cut a long time on fine work if you keep it honed. Also, as one area on the radius wears, you can tilt the tool holder in the lantern a little ot move into an unexposed area. The edge is delicate, though, and will break down on heavy cuts or on scale. This bit is for steel and works well on Al and bronze, too. Not much good in CI, the ci is abbrasive on the thin edge.
You can generally cut up around 60 sfpm (or faster) on steel, so double your strokes per minute and see if it doesn't go a little better. (as long as your clapper isn't bouncing if you don't have closer or lifter)
smt
the first tool described by Dave is for cast iron, it won't work for on steel as far as a fair finish. His second tool is what you want for steel.
The finish tool for steel looks about like a mouldboard plow in shape. It is hard to describe, but I'll give it a go. Your edge on this is going to be from one rear corner to the diagonal opposite front corner. It can be even more severe (closer to parallel to the stroke) but we'll start here so we can probably both (hopefully) follow the reference points. You will also see ways to modify the tool to make it stronger, or to increase the utility before the whole tip needs ground off to start over. But for now:
Grind one corner off flat about 3/16" or 1/4" high (depth of cut), so the flat reaches from corner to diagonal corner. Now round the top , still corner to corner, about the radius of a 50¢ piece. as you round, put a very little bit of back relief. The working end of the tool will be part of a sphere, at this point with a flat face spanning diagonal corners. Now very carefully, on the edge of a small radius wheel (say 5" - 7" diameter, but really any wheel will work), form the flat face to a hollow chip pocket. Stop a little shy of the radius edge, and blend in with the end of a cone or pear stone. Hone the whole edge smooth.
I'm making is sound like a lot of work, but once you get the picture and do it a few times it is as fast as any bit.
Put this bit in your straight holder, and tilt it in the lantern until the sharp radius edge is cutting near center, or maybe a little more toward the front. Make everything tight, set your feed for very small increment, and don't try to cut more than about .005 deep. Remember, this is finish bit only. .002 is even better. Feed in the same direction as the back of the bit points. (oddly, this bit will cut either direction. but generally better as described. If you try it the other directionand it works smoother, so be it, enjoy!). Brush out a full coating of good lard oil or wahtever your favorite steel elixir is on the surface, put in the clutch and go.
This will cut wispy long curlicues like a unicorn horn, and if your machine is in good shape and tight, the surface will look almost like it came off a surface grinder.
You have to experiment with radii, and with the angle you tile the bit to the work. Also, as mentioned, a shear angle greater than the 45º described works even better. I mean like down as low as 20º in some cases.
This bit will cut a long time on fine work if you keep it honed. Also, as one area on the radius wears, you can tilt the tool holder in the lantern a little ot move into an unexposed area. The edge is delicate, though, and will break down on heavy cuts or on scale. This bit is for steel and works well on Al and bronze, too. Not much good in CI, the ci is abbrasive on the thin edge.
You can generally cut up around 60 sfpm (or faster) on steel, so double your strokes per minute and see if it doesn't go a little better. (as long as your clapper isn't bouncing if you don't have closer or lifter)
smt
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Matt_Isserstedt
Yeah, the Moldboard!
I'm an old farmer wannabee with antique tractors and a thirst for Nebraska Tests so I've got the perfect moldboard picture in my head.
Toolbit? Naaah, it's a PLOW...steel or dirt, take your pick. [img]/ubb/images/graemlins/laugh.gif"%20alt="[/img]
Thanks for the info
-Matt
Toolbit? Naaah, it's a PLOW...steel or dirt, take your pick. [img]/ubb/images/graemlins/laugh.gif"%20alt="[/img]
Thanks for the info
-Matt
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gregvasale
- Posts: 166
- Joined: Sat Jan 04, 2003 10:32 am
- Location: webster, ma
Re: Yeah, the Moldboard!
Matt: got lots of pictures of shaper tools, but can't post any (no scanner). But one book I was looking in today after seeing your first post on the subject says to make sure the bit is as close to the vertical plane of the ram as possible, so as to NOT dig in. Remember all the lathe manuals and pictures that show how a lathe bit will dig in to the work if angled to steeply to the headstock? Well, this showed the shaper bit, quite like a lathe goosneck threading tool (springform) following the clapperbox instead of hanging out in front. Also, that Armstrong "indexable square toolholder" reversed looks like it could do the job nicely.
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stephen_thomas
- Posts: 9
- Joined: Wed Jan 08, 2003 9:30 pm
Re:"they're all plows"
Matt,
that's true! I remember the first time I ever saw a larger than benchsized working planer about 2O years ago. A late buddy of mine used to build pool tables. Periodically, he would take a trip up to the slate mines around Pen Argyl and get a couple-three sets of slate. He knew I wanted a tour, so one time he didn't call in until the day before, that way they would mostly have to make it while we were there, and we would use the time to nose all around the operation. In the rough end, after the chunks were brought up on the cable trolleys and sawn and split, then material for finish slabs was planed to thickness before honing or sanding (depending on product). There was a row of planers along one wall, looking left over from the 19th c., kind of lightweight and spindly, but maybe 3 to 4 fto wide and 6 to 8 long. The cutting tool looked like the edge of a rounded medieval war axe, but cutting on a skew. Tool about 6" wide, stepping over at least a few inches per pass. Looked for all the world like it was plowing a furrow and was kind of amazing to watch. smt
that's true! I remember the first time I ever saw a larger than benchsized working planer about 2O years ago. A late buddy of mine used to build pool tables. Periodically, he would take a trip up to the slate mines around Pen Argyl and get a couple-three sets of slate. He knew I wanted a tour, so one time he didn't call in until the day before, that way they would mostly have to make it while we were there, and we would use the time to nose all around the operation. In the rough end, after the chunks were brought up on the cable trolleys and sawn and split, then material for finish slabs was planed to thickness before honing or sanding (depending on product). There was a row of planers along one wall, looking left over from the 19th c., kind of lightweight and spindly, but maybe 3 to 4 fto wide and 6 to 8 long. The cutting tool looked like the edge of a rounded medieval war axe, but cutting on a skew. Tool about 6" wide, stepping over at least a few inches per pass. Looked for all the world like it was plowing a furrow and was kind of amazing to watch. smt
Re: Shaper (& maybe planer) toolbit shape
To make a smooth flat surface, grind a round nose tool with a 5 degree relief, mount as close to the tool post as possible remove .005 to .010 with the slowest feed and 40 - 50 strokes per min.....if the clapper has a bounce to it oil the sides with heavy oil...have fun.but keep track of your fingers.....Phil in mt
Re: Shaper (& maybe planer) toolbit shape
I can attest to the point of keeping track of ones fingers. I have been used to working mils and lathes and drill presses etc. All of these machines have one basic thing in common. The toll that does the cutting is basically situated in the same spot and never moves other than rotating, it about the only area one needs to be truely concerned with contacting (baring belts pulleys etc, or a slow moving table)
When I first started playing with my new shaper, it was a totally new experience having the tool that cuts going in and out instead of round and round. Lots more moving stuff to keep track of on a shaper. Anyway I disengaged my mind and managed to get three fingers caught in the ram. Fractured three finger tips, lost 2 of the three nails, which were ripped right out of the nail beds, and only held on by the skin at the ends, and torn ligaments on the finger tips as well. It was not the machines fault by any means, just my mind going blank and not thinking before I did what I did. That fast retract is quicker than you think [img]/ubb/images/graemlins/frown.gif"%20alt="[/img] Just now geting to use the hand again and its touchy and awkward not having nails.
When I first started playing with my new shaper, it was a totally new experience having the tool that cuts going in and out instead of round and round. Lots more moving stuff to keep track of on a shaper. Anyway I disengaged my mind and managed to get three fingers caught in the ram. Fractured three finger tips, lost 2 of the three nails, which were ripped right out of the nail beds, and only held on by the skin at the ends, and torn ligaments on the finger tips as well. It was not the machines fault by any means, just my mind going blank and not thinking before I did what I did. That fast retract is quicker than you think [img]/ubb/images/graemlins/frown.gif"%20alt="[/img] Just now geting to use the hand again and its touchy and awkward not having nails.
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J_Tiers
Re: Shaper (& maybe planer) toolbit shape
Stephen Thomas has it right. I have used the shaper to make prototype heatsinks, and gotten a surface well within the 32 micro-inch surface wanted.
A wide curve of the tool end, a small table feed, and a "chip curler" rake to the tool seem to be the keys, along with a shallow finish pass.
Even the old beat-up Atlas 7B will produce nice surfaces that way. The monster you have might differ, but at least you can use a tool you don't need a microscope to see.
A wide curve of the tool end, a small table feed, and a "chip curler" rake to the tool seem to be the keys, along with a shallow finish pass.
Even the old beat-up Atlas 7B will produce nice surfaces that way. The monster you have might differ, but at least you can use a tool you don't need a microscope to see.
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UnkaJesse
- Posts: 4090
- Joined: Sat Jan 04, 2003 10:29 pm
- Location: Tennessee, Obion County, Town of Troy
Re: Shaper (& maybe planer) toolbit shape
Roy, Sorry 'bout the finger tips! You need to do what everybody else in this country does when they even think they have been hurt by a gun, machine or person- - - get a smart lawyer and become an instant millionaire! Of course you may have hurt your case a bit by admitting that you were at fault and not the machine! Hope the fingers get well and you get used to the different feel of things.
Unka Jesse
Unka Jesse
"The same hammer that breaks the glass, forges the steel" Russian proverb