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Show and Tell *PICS*

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Show and Tell *PICS*

#1

Show and Tell *PICS*

WoodburnBob

>Instead of watching the RNC in NYC on NBC with this Norris in my lap, I went down with it to the basement again. This is how I got it from Inchmartine for about $230 a year or two ago. It has a new, unsigned, thick parallel iron. I'd guess the metal has been worked on and the sole is extremely flat (suggesting a surface grinder). But the plane does NOT work at all well. Maddeningly worthless, it digs and chatters and stalls.


The diving and chattering usually mean the iron isn't bedded solid. This is confirmed on this plane by passing paper up from the mouth between the iron and bed on the right side (looking down the throat from above and behind). A familiar problem.

Peering down the throat from above and below I spotted a burr of metal on the right side where the sole plate and rosewood meet. I filed it down. No improvement.

Other clues to imperfect bedding were present: 1) the iron rocks on the bed before tightening down the screw, 2) on tightening the lever screw down the iron seems to flex and too much of a sponging turn is needed to finally seat things firm, 3) you can look closely at the abuttment of iron and bed along the side of the plane and see movement while tightening down the screw. The bed and iron are a bad fit. Which is it bed or iron?


Oh, by the way, here's the level cap. No, that's not my work. You might think someone thought to decorate the brass with post-modern art work. I think some person took a small round face hammer to the lever cap thinking this was the way to fix the problems I'm describing in this post. Presumably this is the reason for the price of this otherwise fine looking plane. I have my doubts about whether it's ever been actually used successfully.


So here is where I deviate a little from an earlier post on the bed-iron fix. I'm not going to yank the cap! Instead, I sqeezed out 1/4" of Titatium White Oil Paint (from the art store) and added 2 drops of 3 in 1 oil. I rolled it out (woodcut roller from art store) on the surface plane and pressed down the bed side of the iron. I was in Woodcraft last week and saw that they have surface plates from China for $28 touting 0.0001" flatness. That's about what shipping would be. No excuses now.


For my purposes here, this photo, I hope, shows you that unlike many, many irons, this one is flat...Actually flat enough to use as a reference flat down in that inaccessible plane throat.


So I've now scrapped and filed crud and gunk off the bed, cleaned the debris out and carefully inserted my iron/reference (seating it first at the sole/sole plate and then gently letting in drop to the bed. Trying not to rock the inked iron, I jiggle it just a little to deposit the white ink/paint. You can see why I used white instead of the usual bluing. The yellow arrow points at the problem underlying this poor crippple's malady.


The nice thing about using this process is that you can read the mirror image of the problem on the white surface of the iron/reference when you take it out. The only problem...or delicate part...is avoiding a rock of the iron on entry or exit of the mouth. It would be very easy to lay down false marks if either the iron or bed have convexity.


So now the only question is how to set things right without screwing it up worse. And that's always the hard part for me. Between the last photo and the next I spent a couple hours filing and spotting in endless iterations. I didn't really get anywhere until I used a #49 rasp. It's ticklish avoiding the steel bed plate.

This next photo is where I stopped filing and spotting.


I then inserted the blade, repeated the earlier checks (paper, feel of screw, inspect iron/bed margin) and put it to wood. All these indicated that I hadn't fixed much!

Highly frustrated, I ripped off a piece of adhesive sand paper and attached in to the bed surface of the iron. I used this as if it were a file or lap using light pressure and being careful not to "dub" the mouth or high shoulder of the infill. I did this 5 or 10 minutes and then reset the plane.


Here then is the nearly miraculous result. Note that I've left the sand paper on the blade. My thinking is that as it goes in and out it will continue to level (the truth is laziness). The problem is solved. I don't want to take the paper off and learn that it is unsolved yet.


I'm working on a big piece of rough cut walnut and now have a fire hazard on on the floor.


Another proud shot.


Putting the sandpaper in tightened the mouth, which I didn't really need.


I was hoping to show the figure in the wood after putting a little oil on it, but no luck here.


Hope you either learned something to avoid or enjoyed the show and tell

Bob

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#2

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David Miller from Iowa

>Another excellent tale... And I thought I knew how to tune a plane. - thanks Bob

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#3

Enjoyed it - pics were great ( NM)

Barry Va Beach

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#4

Jim in Burlington Ont.

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Jim in Burlington Ontario

>Another very interesting piece of the puzzle. Shame about the pounding it took.

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#5

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Jonathan Peck - N.Y.

>Thanks Bob, another great article. It's nice to see another old tool put back into service. I also use this technique to work on the beds of Bedrock style planes, only I use a Hock chipbreaker which is also a big slab of metal of almost the same width of the bed/mouth. I hadn't thought to use adhesive backed sandpaper. I'll have to try this - thanks

Regards

Jonathan

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#6

But we still don't know...

Rich Glisson (Durham, NC)

>...whether it is the sanding that you did or the mere presence of the sandpaper interposed between the iron and the bed that helped the performance. C'mon, PLEEEEEASE try it after peeling off the sandpaper!

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#7

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Frank Mutchler in Colorado Springs

>Anothe most Excellent Adventure from WBB ;>)!!

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#8

I love your tales...

Scott Burr in Ben Lomond CA

>Another fine redux. I too want to hear how it works after removeing the sandpaper. Thanks for sharing.

Scott, been wanting/looking for an un-hadled infill coffin smoother for sometime.

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#9

Yes, well okay then...

WoodburnBob

>It is simple enough to go down and peel off the sandpaper. I just did that. The three indicators of bad fit I mentioned are a little better (he consoles himself) but I can still perceptibly rock the iron. In use, the plane still dives as it did initially. Without the sandpaper I made it about 50% better, taking the plane from really bad to just bad and unuseable. In fact, it's not even now as good as when I just shimmed the rock out with 0.020 of brass strip. That was a little 20 sec shade-tree fix I tried before all the stuff I described. I just seems to me with all my cerebral cortex I ought to be able to generate a fix less temporary. Back to the drawing board...some day.

The problem I didn't mention, in order to keep things simple, is illustrated in these two photos you've already seen. Notice where the lever cap screw would clamp maximum pressure on the bed if the iron were in the plane here.


Now notice in the next photo that the area of the bed upon which that screw force would press did not touch the inked-up white blade/reference surface. That's right, the rounded over high part of the bed means there's in effect a fulcrum below the screw. If the effective lever arms of the screw cap (up and down from the hidden pivot rod) were equal, the blade should lift off the bed when screwing down the lever cap!!!!!

Again it's a simple fix with a shim. Shimming will fix both problems. All the other stuff was amateur problem solving and time wasted. I have had some fun though.

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#10

Ever thought of using bedding compound?

John K in Hastings, MN

>With the chips out of the wood and the other problems, I'd consider using rifle bedding epoxy. Put some release agent on the back of the blade, spread a small amount on the wood, and put the blade in and tighten it down. You won't be able to move anything, it will be a perfect fit.

John

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#11

You're an inspiration, Bob

Steve Elliott

>I hope it won't sound like I'm being sarcastic or ironic or anything, but I've got to tell you how refreshing it is to hear someone report how things actually came out instead of just telling about a successful project. This post of yours reminds me of so many of my projects that ended up not behaving the way I expected them to. Even if the problem ends up not being fixed yet, there's valuable learning going on.

Just this afternoon I have been testing the sharpness of plane blades, trying to get a method worked out that gives a statistically valid number that reflects the sharpness of an edge. I've made a lot of progress using a thread-cutting test I found on the web site of a grad student in physics who is interested in high-performance knives. After doing repeated tests to check the validity of my results, I went back to hone my CPM 3V blade on a Norton 8000x stone. Despite my extreme care in handling the blade, somehow several large chips appeared in the blade edge. I don't even want to think how they could have been put there. All my gumption has escaped for now.

I've still got several planes that need their beds trued up, and I'm hoping one of us will discover the way to do it.

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#12

Most Excellent...

Vic P

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#13

Re: You're an inspiration, Bob *LINK*

WoodburnBob

>Steve, you said "...using a thread-cutting test I found on the web site of a grad student in physics who is interested in high-performance knives." A year or two ago I was searching everywhere for some way to objectify sharpness. I followed a WWW link to a site that had a scientific looking report by some Japanese students who'd rigged up a model that as I remember included strings or threads. But I thinking now it was high school students. Is this what you found?

On the topic of novel approaches to bed truing, I bought a 7" Atlas metal shaper that I originally planned to use flattening smoother soles...a la Steven Thomas's 3 part series in Home Shop Machinist in the past couple of years (the one where he gives a step by step tutorial on building an infill from a St. James Bay casting). The only thing keeping me from experimenting with Atlas shaper and infill beds...other than common sense...is that I need to design and build a new ratchet mechanism for the shaper's automatic table advance. Someday maybe I'll be able to post a new comedy of errors on that fantasy technique.

Right now I'm obsessing about Brent Beach's theory of dulling.


Beach Theory of Dulling

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#14

The Epilogue

WoodburnBob

>Just for a little closure on this albatross, I want to announce that I thought about this some more and then did what I should have done in the first place.

1) If the plane iron is flat and it still rocks on the bed, the bed is not flat, no matter what the white markings on the bed seem to say...I overestimated the validity of "white spotting". Still, it should be possible by feel (rocking) to estimate where the mound on the bed is and remove it with a chisel.

So I went down and picked up a very thin 3/4" chisel and mallet. Going up through the mouth I chiselled off what I believed had to be the area of the mount. It wasn't pretty. I reinserted the blade. It no longer rocked. I tightened things up and put the plane to wood. It worked fine. No diving. Shavings of consistent thickness. No snagging. Problem solved.

2) The sandpaper on the flat plane iron was a very stupid idea. In the same way that a convex sole can't be flattened on a flat "lapping plate" by freehand rubbing (my religious belief), using the sandpaper/flat iron guaranteed that I would only further round the already convex bed.

Enough said.

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#15

Sharpness Testing

Steve Elliott

>It was Brent Beach who inspired me to get the microscope and start looking at quantifying edge retention. I just read his theory of dulling again, and I don't think it's quite right. A dull edge becomes rounded rather than developing a flat wear bevel. I tried to duplicate his imaging technique with my microscope and couldn't do it, which is what started me looking for another way to measure sharpness.


This is the site I found that uses a thread-cutting test to measure sharpness. You'll notice he uses a separate test for slicing. He gives his results in grams of cutting pressure, which is good scientific raw data, but I'm looking for a way to turn those numbers into a scale from 1 to 10. I made up a prototype table this morning that gives the idea of what I'm after. Here's the first very rough draft:




As you can see, I didn't even finish the descriptions for the lower numbers. I also have a draft formula for turning the gram force data of the thread-cutting tests into sharpness numbers. I plan on getting results such as 9.4 after planing 50 lineal feet of oak, 8.7 after 100 lineal feet, and so on. The key is to make the measurements standardized enough that the results of my planing tests today can be combined with ones I might do six months from now. My technique right now is to test an edge by cutting eleven loops of thread and taking the median value as the result. It�s pretty tedious, and I hope to get the variation down so that cutting fewer loops will still give an accurate result. The whole procedure still needs a lot of work.

If I haven't already bored you to death and you think you can stand more, email me and I'll give you a link to the prototype site I'm working on that describes my testing procedure and has pictures of the microscope. It's not ready for prime time at this point and it doesn't have any actual test data on it yet, but it does present my ideas on edge wear.

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#16

Re: Sharpness Testing

WoodburnBob

>Great information, Steve. Your link isn't what I'd found. Your's is the treatise. The thread cutting connected to a strain gauge is familiar though.

What you are working on is just what is needed: a standardize procedure that gives everyone the same reliable standard for measurement.

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#17

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Mark S. in Chalfont, PA

>Bob,

That was a great story. It was like reading a good whodunit. I had to read every word to get to the end and find out the resolution to the mystery. Besides, on the way I learned a thing or 10 about hand plane troubleshooting. You sure know how to keep an audience on the edge of their seat!!!

Mark

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#18

Re: The Epilogue

Bob Hackett

>Next time try dry brushing a very light coat of any metalic craft paint(I favor gold) on the back of the iron.It will show up against the dark wood and give you a more true sense of the high spot(s).On lighter color woods I use a soft pencil.

Mainely,Bob

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#19

Re: The Epilogue

Brent

>WBB

Interesting series.

One test you can do with a plane with a removable frog that you can't do with an infill, is look at the lever cap, cap iron, blade, frog assembly out of the plane. If you do, you will see that the blade arches when the lever is depressed. The blade only touches the frog just back of the bevel and near the top of the frog. So, a flat frog is only important to the extent that it allows this to happen. The arch is small, around 0.01", but detectable with shims. [My understanding of the importance of the cap iron, as the way the force from the lever cap is directed beyond the base of the bevel, forcing this arch, began with observing frogs out of planes. This arch is not an accident, it is essential to correct operation of the plane. The cap iron has no chip breaking effect.]

In an infill, when you put tension on the blade through the lever cap [assuming there is a cap iron and that the screw hits the blade near the top of the bed] the blade also arches. Testing for bed flatness then should be done with the blade under tension from the lever cap. You might do it by putting some carbon black on the iron, putting it in the plane very carefully, tensioning things, then tapping the blade forward a little. The bed should be uniformly coloured where the lower 1/2" of the blade meets the bed, and on the top 1/2" or so of the bed.

A long time ago on the earlier version of this forum I noted that you can change the mouth opening [and blade set] of many infills by turning the screw [increasing the tension, increasing the arch]. Does this happen on your plane?

Brent

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#20

Re: Sharpness Testing *LINK*

Brent

>Steve:

I have written another web page that discusses the shape of a worn blade (plane blade only, I don't think this applies to other edge tools, since planes scrape much more than most other tools).

I believe that the wear bevel on the lower side of the blade is very nearly flat, while the wear bevel on the upper side is more rounded.

I am still working on a test that determines the shapes. Since the surfaces being measured are very small, near the limits of the QX3 microscope, it is taking a little (ok, a lot) longer than I had hoped.

This web page shows current progress.


How Plane Irons Wear

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#21

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Don Thompson, Cutler Ridge, Florida

>Thanks for taking the time to compose and post this and your other infill article. I do not have an infill, but the articles have given me a better insite as to their makeup and operation.

👍 This page answered my questions

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