I would like to have a discussion about bolster shapes for the classical slipjoint patterns.
If I eliminate the SAK shape, which seems dead on to be half circles connected tangentially with straight lines everything else gets a bit interesting.
Each base shape has both symmetric and asymmetric variants.
Symmetric -
Jack - Straight - Cigar - English - Pen - Scout - Fish (tail not toothpick) - Canoe - Sunfish- congress
Round or flattened either 180° for round or somewhere between 50°-100° for the flattened Not finding any that are completely flat. The canoe has the exception that they are cut into in order to make the canoe shape, unless they are shorter than that shape and then angled. And the fish, is just weird in that it has the fishtail on one end, and those integral tiny guards at the other (bowtie bolster).
Larger One End -
Swell - Coke bottle - Sleeveboard (barlow, utility, electricians) - Balloon - Teardrop
Asymmetric -
Same size both ends:
Serpentine - Sowbelly
Some times it is round, sometimes it is between 50°-100°. I have found at least one serpentine that is symmetric in that if I take the shape and flip it both horizontal and vertical it will overlay itself. However, most of the time it is more like the letter S in which one curve is more acute and the other is more obtuse. So, there seems to be a variant possible. And the sowbelly, seems to be even more accentuated in the deeper curve.
Different sized each end-
Serpentine - Dogleg - Swayback - Churchwindow - Saddle horn - GunStock - Toothpick/fish - Clasp - Sodbuster - Peanut - Copperhead - Eureka - Crown - Trapper - Slim trapper - Lady's Leg
Once the serpentine gets a larger end on one side than the other, it becomes a new beast. This is straighter on one end (the narrower) with a more pronounced curve on the opposite end creating a dogleg. However, the direction of where the blade goes relative to the lower curve determines if it is a swayback, vs dogleg. If the curve comes up toward the blade it is a dogleg if it goes away from it then it is the swayback. So dogleg seems to include saddle horn, trapper, slim trapper, peanut, fish/toothpick, and I would classify Lanny's Clip in here as well. The one shape of note that shares the swayback are some that use the hawkbill blade like pruning knives and some sailor rope knives, which I think utilize the deeper body created by the curve away from the blade to handle the extended tip of the hawk bill. The clasp/hunter/fish all share the more pointed lower bolster shape, although, sometimes I have see the clasp sharing a more wide on both ends not unlike the sodbuster. So far, I have only seen the sodbuster as shadow patterns (lacking bolsters) but I mention the shape as though it were there.
The copperhead and baby copperhead seem to start off as a canoe, then a larger round bolster at the other. The lady's leg, well what can you say, it's a lady's leg. It seems to share some similarity in the bolster shape with the toothpick though, sometimes it seems off-round where it extends for the calf, and flattens for the shin. As for the toe, shoe, caplifter... well I guess once the blade tip is covered you can do whatever you like. I have seen these called ballet knives, but they always seem to have the same shoe style, and I have yet to see one with a ballet heel
Of other note are the "candle-end". These seem to be mostly smaller knives, but basically, instead of round bolsters either end may come more to a point, perhaps like an unlit candle.
In some cases, such as some of the doglegs what one might expect to see as an extended semicircle is rounder on one side (bottom spring side) and flatter on the other (top blade side).
I am not sure if I have classified all of these correctly. Certainly some of these shapes may have been modified for utilitarian purposes to make certain types of blades fit, but for the most part I believe these were all aesthetic of ergonomic.
If anyone would care to suggest any I have missed and where they fit, or offer some more insight into the math of the shapes. I would appreciate it. Or, even if you know some background into why/how some of the shapes originated, or perhaps what utility some of the shapes might provide. I have to look at the tickler/toothpick/fish and think spanish navaja, or french lagiole but maybe I have been perusing too many pictures lately.
If I eliminate the SAK shape, which seems dead on to be half circles connected tangentially with straight lines everything else gets a bit interesting.
Each base shape has both symmetric and asymmetric variants.
Symmetric -
Jack - Straight - Cigar - English - Pen - Scout - Fish (tail not toothpick) - Canoe - Sunfish- congress
Round or flattened either 180° for round or somewhere between 50°-100° for the flattened Not finding any that are completely flat. The canoe has the exception that they are cut into in order to make the canoe shape, unless they are shorter than that shape and then angled. And the fish, is just weird in that it has the fishtail on one end, and those integral tiny guards at the other (bowtie bolster).
Larger One End -
Swell - Coke bottle - Sleeveboard (barlow, utility, electricians) - Balloon - Teardrop
Asymmetric -
Same size both ends:
Serpentine - Sowbelly
Some times it is round, sometimes it is between 50°-100°. I have found at least one serpentine that is symmetric in that if I take the shape and flip it both horizontal and vertical it will overlay itself. However, most of the time it is more like the letter S in which one curve is more acute and the other is more obtuse. So, there seems to be a variant possible. And the sowbelly, seems to be even more accentuated in the deeper curve.
Different sized each end-
Serpentine - Dogleg - Swayback - Churchwindow - Saddle horn - GunStock - Toothpick/fish - Clasp - Sodbuster - Peanut - Copperhead - Eureka - Crown - Trapper - Slim trapper - Lady's Leg
Once the serpentine gets a larger end on one side than the other, it becomes a new beast. This is straighter on one end (the narrower) with a more pronounced curve on the opposite end creating a dogleg. However, the direction of where the blade goes relative to the lower curve determines if it is a swayback, vs dogleg. If the curve comes up toward the blade it is a dogleg if it goes away from it then it is the swayback. So dogleg seems to include saddle horn, trapper, slim trapper, peanut, fish/toothpick, and I would classify Lanny's Clip in here as well. The one shape of note that shares the swayback are some that use the hawkbill blade like pruning knives and some sailor rope knives, which I think utilize the deeper body created by the curve away from the blade to handle the extended tip of the hawk bill. The clasp/hunter/fish all share the more pointed lower bolster shape, although, sometimes I have see the clasp sharing a more wide on both ends not unlike the sodbuster. So far, I have only seen the sodbuster as shadow patterns (lacking bolsters) but I mention the shape as though it were there.
The copperhead and baby copperhead seem to start off as a canoe, then a larger round bolster at the other. The lady's leg, well what can you say, it's a lady's leg. It seems to share some similarity in the bolster shape with the toothpick though, sometimes it seems off-round where it extends for the calf, and flattens for the shin. As for the toe, shoe, caplifter... well I guess once the blade tip is covered you can do whatever you like. I have seen these called ballet knives, but they always seem to have the same shoe style, and I have yet to see one with a ballet heel
Of other note are the "candle-end". These seem to be mostly smaller knives, but basically, instead of round bolsters either end may come more to a point, perhaps like an unlit candle.
In some cases, such as some of the doglegs what one might expect to see as an extended semicircle is rounder on one side (bottom spring side) and flatter on the other (top blade side).
I am not sure if I have classified all of these correctly. Certainly some of these shapes may have been modified for utilitarian purposes to make certain types of blades fit, but for the most part I believe these were all aesthetic of ergonomic.
If anyone would care to suggest any I have missed and where they fit, or offer some more insight into the math of the shapes. I would appreciate it. Or, even if you know some background into why/how some of the shapes originated, or perhaps what utility some of the shapes might provide. I have to look at the tickler/toothpick/fish and think spanish navaja, or french lagiole but maybe I have been perusing too many pictures lately.