flattening planes

[tablesawtom]

I wanted to show the 608 being ground bit I forgot the camera. I just got finished grinding a 4 1/2 so I thought I would show the steps because They are the same. Usually one machines the largest surface first, and then the sides. but in this case it has already been machined. I clamped the largest surface to my angle plates. Yow can see that two angle plates were used. The 608 was done the same way it is just that the angle plated were spaced farther apart. Then the first side that was ground was placed on the magnetic table and the second side was ground parallel to the first. Then the plane is flipped and the first side reground, usually only about 1 to 1 1/2 thousands will clean up every thing. Because the bottoms of the planes may or may not be flat, the clamps can distort the plane a little bit. This is my way of making the sides as parallel as possible and exactly the same thickness. It also gets rid of any possibility of any twist from clamping to the angle plate.

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Next the plane is clamped in a precision vise and the bottom is ground. And trust me a precision vise is not just any ordinary vise vary accurate vise. When I did the 608 I used two vises, just like the two angle plates.

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I spent just under 4 hours grinding this plane. I also had about 40 minutes travel tine and I wouldn't have spent the time to use a machine that is designed to do one thing which is to remove metal and if I thought I could use sandpaper and a piece of glass to flatten it, or a scrapper, a skill I do not have, I would have done so at my home. I know every body thinks they can flatten a plane but iron doesn't sand like wood.

Tom

[MNice]

Very interesting. Thanks

[grwold]

Next the plane is clamped in a precision vise and the bottom is ground. And trust me a precision vise is not just any ordinary vise vary accurate vise.

Curious about that precision vise, and more, how you "true" the base before you flatten it. If the body's set under the grinder with the least bit of slope the plane's thickness will vary, front to back, once flattened. Does this matter, and if so, how do you (or that vice) account for this?

Thanks for sharing, Tom.

[tablesawtom]

Curious about that precision vise, and more, how you "true" the base before you flatten it.  If the body's set under the grinder with the least bit of slope the plane's thickness will vary, front to back, once flattened.  Does this matter, and if so, how do you (or that vice) account for this?

Thanks for sharing, Tom.

The side is ground with the bottom clamped to the angle plate. Then the other side is ground in the free state. so for any reason the body isn't perfectly flat the flex or twist can be removed. and to make sure every thing is fine the side that was first ground is then again ground in the free state. The piece is put in the vise and it is indicated in ( checked all over with an indicator and the two lowest spots on the bottom are set at exactly the same height from the table. Find the high spot as to where to start grinding and grind I like to take off .001 a pass until cleaned up.. I redress the wheel ( Sharpen my tools) and regrind the surface. Usually the surface has a .0005 to .0015 hollow and After picking up the surface with the wheel I finish grinding taking no more that .0004 at a pass until cleaned up. One can hear it go dead flat. then I take two spark out passes (two ore passes without lowering the wheel.

Most planes I have ground are high in the middle or crowned.  and they rock when hand lapping that is why I say you are wasting your time thinking you can do it because you know all about it. Me watching Dinner, Drive-ins and Dives doesn't make me a chief, or a restaurant owner.

I reread the the question to make sure I answered correctly. At the time the plane was made the bottom was probably flattened on a milling machine. then the milling machine marks were probably removed by hand on a belt sander. Not all production workers are created equal and one got what he got. In other words no bottoms are flat. That is why all the work getting the sides parallel and so the plane can not distort when clamped in the vise. Once in the vise or vises the condition of the bottom is a moot point.

Tom

[grwold]

The side is ground with the bottom clamped to the angle plate. Then the other side is ground in the free state. so for any reason the body isn't perfectly flat the flex or twist can be removed. and to make sure every thing is fine the side that was first ground is then again ground in the free state. The piece is put in the vise and it is indicated in ( checked all over with an indicator and the two lowest spots on the bottom are set at exactly the same height from the table. Find the high spot as to where to start grinding and grind I like to take off .001 a pass until cleaned up.. I redress the wheel ( Sharpen my tools) and regrind the surface. Usually the surface has a .0005 to .0015 hollow and After picking up the surface with the wheel I finish grinding taking no more that .0004 at a pass until cleaned up. One can hear it go dead flat. then I take two spark out passes (two ore passes without lowering the wheel.

Most planes I have ground are high in the middle or crowned.  and they rock when hand lapping that is why I say you are wasting your time thinking you can do it because you know all about it. Me watching Dinner, Drive-ins and Dives doesn't make me a chief, or a restaurant owner.

I reread the the question to make sure I answered correctly. At the time the plane was made the bottom was probably flattened on a milling machine. then the milling machine marks were probably removed by hand on a belt sander. Not all production workers are created equal and one got what he got. In other words no bottoms are flat. That is why all the work getting the sides parallel and so the plane can not distort when clamped in the vise. Once in the vise or vises the condition of the bottom is a moot point.

Tom

Good, clear explanation.  Indicating the body in for the sole flattening is the key answer to the question.  You put an impressive amount of effort into your clean-ups!

Thanks, Tom.