Hand Tools Archive

Subject:
Re: studying edge failure...somewhat obscure

David Weaver
https://www.fine-tools.com/hobele.html

That picture understates the spring a little bit due to the angle.

Mujingfang appears to have copied these in their chinese planes, all the way down to the tall windowpane front on the cap iron, but they solved feed issues by making the wear really really short - like 1/4 inch or so.

Some are sprung more than this.

I remove some metal from these when I find them, but the modern planes are usually open enough that it doesn't matter, and they work fine. There's just so much spring that it makes fine adjustment below a certain amount kind of difficult.

Then, there's LN cap irons on the opposite end where there's just almost no give. Ward's design is between that but with the long gradual primary bevel (more so than just the thickness difference between those two in the picture) gives you the ability to stop tearout without having a big wall of a cap iron further up from just the point of contact that's needed to hold the chip in place.

The two that I have in the picture aren't doubly different in force, but it's noticeable. I was cleaning up rough cut sticking this weekend with this try plane and with a fat little smoother I made when we first started figuring out how to make double iron planes.
https://i.imgur.com/ybiuuLT.jpg
https://imgur.com/gallery/KgTW24k

https://i.imgur.com/jr9O8ZI.jpg

(the kids love these shavings)

The cap iron in the smooth plane is (not sure) on top of an IH sorby iron. IH sorby irons are usually pretty good, but this one is a tad soft, so I let it do fat shaving work only, and it sails through wood - same shape of cap iron. 5-7 thosuandth for smoother shavings to get things cleaned up, then anything left is almost nothing in terms of tearout. The shavings out of the try plane were double that - 2 1/8th wide. Heavenly to work - everything is so stable and as soon as the shaving is continuous, you know you have a pretty good surface - not much to check.

I did one stick with the try plane in this picture (ward cap iron and ward iron) and one with my first try plane after making a jointer (which is actually a decent plane, and uses the other iron in the picture above). I learned based on that fatter cap iron that I can't just pick a wear iron and size when dealing with different irons, but rather have to guess at setting the wear up to work with the cap iron - as in steeper by 5 degrees or so. It pushes a chip right into the wear, so opening the mouth doesn't really solve it, the wear has to be steeper. I'm stuck on that whole thing - keeping the wear as tight as possible because it looks pretty on the older planes like this greenslade.

The aesthetics on that cocobolo smoother are suspicious, to say the least, but it's great at taking fat shavings off of cherry. 8 smoother shavings on one side of the board to go from sawn from the mill to finished (it's wide enough to do the narrow side of the sticking without using the try plane) and 9 on the other. The fat side was hand sawn (by me). I'd like to say it took fewer shavings than the mill edge, but I don't think it did!!

https://i.imgur.com/xqmm1m4.jpg

It looks pretty good off of the saw (that's the fat side, 2 1/8th), but it relieved itself a little away from straightness when sawn, bowing toward the sawn side.

TMI.

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