Stephen Thomas planes

Here, let me help.

woodburnbob


>Depends a little on what you are looking for.

Here's one of the several pictures from one of the threads at WC of the SMT loopie (or loopy).

Click on this to go to the thread from May 2005 from which the picture comes.

You may be looking for the 3 part series in which SMT details his construction of a smoother from a St. James Bay casting. Looks like SJB is still selling copies of the issues that contain his step by step discussion.

Go to SJB, click videos, and scroll to the last item.

So, Teacher, since I've done your work for you, how 'bout telling us someting about why you ask and what you're planning to do?

Re: Here, let me help.

Teacher


>Actually, I was just curious. I've read so much about these planes but have never seen one. Thanks for the links.

Re: Knapp Joint in Brass and Steel *PICS*

William Duffield, on the Cohansey


>The first two photos are of the third Thomas infill, under construction.

The second photo also shows two pieces of steel joined by the same method, to test the concept.

The last four photos are of the second Thomas infill, undergoing field trials. Cocobolo infill.

In the last two photos, the adjustable mouth block has been removed. Quilted Bigleaf Maple, Acer macrophyllum, was used for these tests.

Note the hand scraped sole in the last photo.

Re: Knapp Joint in Brass and Steel *PICS*

woodburnbob


>I must have missed this when you put it up. Those are excellent photos. Are they part of an online article? Or, do you own that now? What a lucky guy you are.

I've always want to ask two question.

How are the joints machined?

By what process are the mating surfaces (slides) of the moving sole pieces assured to remain exacting in the same plane as the sole? Is see the moving slide appears to perhaps be scraped, but the fixed slide looks like it still as the milling marks.

Re: Knapp Joint in Brass and Steel *PICS*

William Duffield, on the Cohansey


>Bob, they're not my planes, none of them. They're not even my pictures, but I've asked the galoots who took the photos if they might chime in.

As far as I know, there is no complete record of the construction of these planes online, or anywhere else.

As far as machinine Knapp joints, my understanding is that in the late 19th Century, they had production machines in the Victorial furniture factories which easily cut them out by the thousands, in flat pieces of wood destined to be drawer fronts and drawer sides, of course. Stephen explained briefly that it gets a lot more difficult when one of the pieces of metal has to be bent as it is being peined in place. The mill that cuts the pins into the plane bottom has to cut the bottom of the joint perpendicular to the pins, so you can't bend the side plate to final shape before joining it. The loops, IIRC, have to be cut a little off of perpendicular to the faces of the sides, each one at a different angle, so that each one will slide over the pin as the side is bent, and still be close enough that excessive peining is not needed to close the joint. I don't remember whether he started at the nose, or started at the mouth and worked in both directions, but he did note that it was a very tricky milling operation

I am not a machinist, but I also have puzzled over the problem of machining both surfaces of a movable mouth block flat and parallel, and parallel to the sliding surface of the plane sole, which also has to be parallel to the sole itself. The photosalso look to me like there was a lot more scraping on the mouth block than on its mating surface in the body pf the plane. I can only assume that Stephen did the scraping to the inside of the mouth block on "an as needed" basis for smooth operation. It seems that the final surface grinding and flattening of the sole would have been done with the mouth block in place, and the mouth set to a minimum opening. Since there is no lateral movement of the block and very little longitudinal movement, getting the mating surface exactly parallel to the sole is not critical. It becomes less critical with larger mouth opening settings. It definitely would not be as critical as scraping the bedways of a large milling machine with many inches of travel. The Home Shop Machinist articles might give you a clue, but didn't give any to me.