Cocobolo Smoother Build - #2

[David Weaver]

It was a while before I ever did, either. At least of the double iron planes. But the problem wasn't that they weren't available, it was that I didn't know what to look for. Hopefully if nobody else other than Steve, Kees and I want to build them after this, it'll at least clue people in what to look for when they're shopping old wooden planes, and then after that, how to make the wedge if a new wedge needs to be made.

I no longer have most of the planes that I had trouble with, but the issue could've been as simple as them just needing a new wedge. The only ones that I'd conclude are poorly made right away have been the ones that have a properly set up cap iron but that clog right in the middle of the plane without cutting at the corners.

[Matthew N. Masail]

No doubt you did a great service with this thread. I don't feel up to it yet, but one day.

[Shawn Pixley]

Hopefully if nobody else other than Steve, Kees and I want to build them after this, it'll at least clue people in what to look for when they're shopping old wooden planes, and then after that, how to make the wedge if a new wedge needs to be made.

David, I don't know that I want to build one right now as I have enough other projects, but I can see myself building one in the next couple of years. This has been very educational for me. I'll likely build a Krenov plane first and then a non-laminated plane.

[Kees Heiden]

Always interesting to theorize a bit about plane designs.
The krenov type is typically a power tool plane. Making these laminations precisely with handtools only is a bunch of extra work. The professional planemakers from the past could make 5 to 6 mortised planes a day (!) with handtools. At best they had some kind of mechanical saw or a planer to help preparing the stock.

When plane factories started to use more and more machines, they didn't used the laminated design either, but choose special mortising machines. Making the abutments means extra work, so the Germans who still make a lot of wooden planes today, invested a lot of energy into developing planes with pins. There are two obvious problems with the pins. In the first place, the pin hole in the sides of the plane wears out over time. They increased and strengthened this area with a much lager bearing ring. The second problem is the groove the pin wears in the wedge. This was solved with a swiveling piece in between wedge and pin, to increase the surface area. In the last pictures from this article you can see how they made it.
http://www.holzwerken.de/werkzeug/hobel.phtml

[Derek Cohen]

Hi Kees

I've made planes in a number of different configurations: solid body with abutments, laminated three-part with abutments, laminated two-part with abutments, and a variety of solid and laminated bodies without abutments. I would rather make a solid body plane than a laminated plane - less work overall.

The one advantage of the laminated construction is that all the parts may be cut on a table saw. This will be preferred by those who find chopping/paring waste to be too daunting or too physical. I cannot imaging Jim Krenov falling into the latter categories, and so he must have seen it as a method of efficiency. I have one of the planes he built, and it is a solid worker. Then again, there was nothing dainty about his planes ...



Those shavings came with the plane. Further, this plane is not suited to be used with a chip breaker, which came set 1/16" from the edge.

I see many "Krenov" planes on the forums built with steel pins for the wedge. I am certain that these planes do not last long. The essence of the Krenov design actually lies in the shape of the wooden pin, not the laminated construction. The pin is designed to rotate and lock flat against the wedge. It is also kept far away from the flow of shavings, not hindering their escape. Pins are OK as long as one side is filed flat and it is able to rotate (is not epoxied into position).

The other reason I think that Krenov designs are favoured by many is that some will find it daunting to fit a wedge into mortices. A pin is just so much easier (and, when correctly made, it does do as good a job). I have also gone so far as to replace the pins on a plane with cheeks/abutments: http://www.inthewoodshop.com/ShopMad...ToAKrenov.html

Another short-cut to abutments is to purchase the brass inserts used by Terry Gordon (HNT Gordon Planes). I used them but do not own any planes with them. They look easy enough to install, and they certainly work very well. A marvel of modern manufacturing ...

Terry build planes with both wooden and brass abutments.



Returning to your link, I found it interesting that the leading edge of the chipbreaker in the diagram was marked as 90 degrees on what looks like a 45 degree bed (just in case you missed this).



Regards from Perth

Derek

[Kees Heiden]

Yes, that's an interesting picture isn't it? I've lonked to it before. In the text the writer sais that the first goal of the capiron is to prevent the shavngs curling up in front of the plane, but instead straightens them out or even curls them backwards, so they aren't slipping in front of the plane. As a secundairy effect he describes the anti tear out function.

[David Weaver]

That plane has a short wear, just like my muji continental smoothers (which are probably a simplified copy of the euro designs, anyway, from the short wear to the lack of eyes).

I never liked the 80-90 degree cap iron setting, which we've discussed before. Maybe it has more merit for thicker shavings, I don't know. i don't like it for a smoother, though.

[george wilson]

With all due respect,I just cannot agree that the pin,especially if rotating in the hole,does as good a job as the traditional English style wedge. All that stress on the little pin in the hole just isn't going to last as long as the long bearing surfaces in English style planes. English style escapements have over 2" on each side of bearing surfaces against the wedge. And,those surfaces cannot start rotating and distorting the pin,and worrying out the hole.

A plus,though,is the relative ease with which loose pins can be owner replaced (though wear in the holes is another matter).

Remember the 16th. C. elaborately etched iron plane that used a cross pin? It was all iron,though,and strong due to the all metal construction. Probably little used,if any. We made a copy in sterling silver that was a gift to a large donor. I have posted it here before,but it's been some time. The original was a king's "gentleman's" plane,and is about 1/2 size.


Certainly the large rings and flat metal piece bearing against the wedge will help out a great deal to increase longevity,as Kees mentioned in later German construction. I still don't know if the advanced German style will last as long as the English type wedge construction. It is doubtful if any modern user would wear one out,in a hobby situation.

I don't know how durable those brass Gorton abutments are either. They'd better be pretty husky to not wear loose. That 1 relatively small diameter pin is going to at least loosen the hole in the wood,which it rides in,over time. Use of harder woods like rosewood for the plane's body will help. But,it's just inherently not as strong a design. It would be a lot more durable if the sides of the plane were metal. I have seen a few 19th. C. cast iron planes that obviously could be bought as bare body castings,and stuffed by the user. There is one such unused casting in a tool chest in the Williamsburg collection. And,I saw an identical plane completed by the owner,for sale somewhere. The little abutments,which were cast in,were very identical to the brass add on ones in the plane above. But,infinitely stronger,being cast integral with the plane's body.

The weakest spot in the English style wedge construction is just at the top of the body,where the wedge can start to split out the wood. I have minimized this splitting by slightly relieving the wood in the tapered mortise,so that the wedge bears more tightly against the BOTTOM of the mortise. The wood in the outer edges of the wedge over time,will compress slightly as it is hammered in repeatedly,making the wedge slightly tapered to fit the mortise. But the wedge wood will be stronger and more dense at the bottom of this mortise. It will still tend to distribute the load more tightly in the bottom,and away from the more delicate outside edge.(I hope this makes sense).

The advantage of the cross pin method is there is more room for the chips to emerge up out of the escapement.

I have made a few of the pin type planes,including that elaborate boxwood one I've posted here before(I can't remember WHY I made that plane pin type. I think I decided to add on the elaborate snail shell front knob later on). But,when I make that type,it is usually because I wanted the plane at once,and did not care to invest the extra time. I did not make pin type planes to last a real long time. One example of a pin type plane by me is a rounded bottom one I made for hollowing out cello size bowed instrument tops and backs.(Actually used for the fancy Viola da Gamba I posted here). I still have it,and can use it on arch top guitars,but its use is limited to those applications,not hard daily wear. Not that I subject my tools to that any more!! Too much hard daily wear on my skeleton already.

[Derek Cohen]

Hi George

I do agree that a pin is the weakest method (which is why I changed one pinned plane to a more traditional abutment style). A flattened round pin is a little less secure than a Krenov-style pin since the latter has more bearing area. The design, nevertheless, is weak - all depends on the ends that pivot in the cheeks, and I have seen some snap.

The brass abutments from Terry Gordon do a good job - there have not been any failures reported, that I know of. Further, the wood he uses for the body is like mild steel, and they are riveted through this. He has also changed his wedge from a "tap in" type to a "lever cap" type (he told me that this was in response to requests from the USA). No doubt these alter the dynamics.

Regards from Perth

Derek

[george wilson]

It helps Gordon's design that his brass parts appear to butt up against the front of the escapement.


I want some of that mild steel wood so I can stop paying for metal!!

I think we will be having Chris Vesper here in October. No doubt he will be wanting to make more knurls on my HLVH.

[Derek Cohen]

I expect to have Chris to stay in August. I will ensure he bring you some "mild steel"

Terry Gordon uses Gidgee as his basic wood. Here are comparisons with Macassar Ebony and Purpleheart:

Common Name(s): Gidgee Scientific Name: Acacia cambagei, A. pruinocarpa Distribution: Endemic to Australia Tree Size: 20-40 ft (6-12 m) tall, 1 ft (.3 m) trunk diameter Average Dried Weight: 72 lbs/ft3 (1,150 kg/m3) Specific Gravity (Basic, 12% MC): .93, 1.15 Janka Hardness:4,270 lbf (18,990 N) Modulus of Rupture: 18,850 lbf/in2 (130.0 MPa)* Elastic Modulus: 2,683,000 lbf/in2 (18.50 GPa)* Crushing Strength: 10,150 lbf/in2 (70.0 MPa)* *Conservative values based on strength group/bracket Shrinkage: Radial: 4.0%, Tangential: 5.1%, Volumetric: 9.2%, T/R Ratio: 1.3

Common Name(s): Macassar Ebony, Striped Ebony
Scientific Name: Diospyros celebica
Distribution: Southeast Asia
Tree Size: 50-65 ft (15-20m) tall, 1.5 ft (.4 m) trunk diameter
Average Dried Weight: 72 lbs/ft³ (1,150 kg/m³)
Specific Gravity (Basic, 12% MC): .89, 1.15
Janka Hardness: 3,220 lb_f (14,140 N)
Modulus of Rupture:No data available
Elastic Modulus: No data available
Crushing Strength: No data available
Shrinkage: No data available

Common Name(s): Purpleheart, Amaranth Scientific Name: Peltogyne spp. Distribution: Central and South America (from Mexico down to southern Brazil) Tree Size: 100-170 ft (30-50 m) tall, 3-5 ft (1-1.5 m) trunk diameter Average Dried Weight: 56 lbs/ft3 (905 kg/m3) Specific Gravity (Basic, 12% MC): .76, .90 Janka Hardness: 2,520 lbf (11,190 N) Modulus of Rupture: 22,000 lbf/in2 (151.7 MPa) Elastic Modulus: 2,937,000 lbf/in2 (20.26 GPa) Crushing Strength: 12,140 lbf/in2 (83.7 MPa) Shrinkage: Radial: 3.8%, Tangential: 6.4%, Volumetric: 10.6%, T/R Ratio: 1.7 Look at the Janka differences. Makes your eyes water Regards from Perth Derek Reference: http://www.wood-database.com/wood-identification/

[Steve Voigt]

Yes, that's an interesting picture isn't it? I've lonked to it before. In the text the writer sais that the first goal of the capiron is to prevent the shavngs curling up in front of the plane, but instead straightens them out or even curls them backwards, so they aren't slipping in front of the plane. As a secundairy effect he describes the anti tear out function.

It's also interesting that the stock is oriented pith side down, 180° from the usual.

[David Weaver]

I have no idea why they do that. The only thing I can actually ever remember reading in a planemaking book (I can only learn by making a few of something for some reason, and never remember and apply what I read) is that the bark side of beech is harder than the pith side, and thus should be on the outside of the plane.

For someone tuning a plane, I doubt it matters. None of us will probably wear a plane out on its first iron.

I had a very nicely made small double iron smoother that was 55 degrees, and I couldn't get it to feed right (probably because the wedge had shrunk, I don't know now - it's gone) and it was pith side down. Must've been shop made by someone, but one would've never known if the wood had been oriented the other way.

[george wilson]

I'm just kidding about wanting wood. Practically being driven out of the shop by it already,unless you have YEW,which I love!! I want to make a long bow.

[Steve Voigt]

I have no idea why they do that. The only thing I can actually ever remember reading in a planemaking book (I can only learn by making a few of something for some reason, and never remember and apply what I read) is that the bark side of beech is harder than the pith side, and thus should be on the outside of the plane.

Larry discusses it here. Short version: the hardness thing is a myth. The real reason is that the rings with the largest radius will be on the sole, so there will be the least amount of cupping there. I'd also add that if the bark side is down, the sole is more likely to become concave than convex, and I'd rather flatten a concave sole.