Cliff Stamp
BANNED
- Joined
- Oct 5, 1998
- Messages
- 17,562
Model 10 from R. W. Clark in Liquid Metal (LM1)
The Model 10 in Liquid Metal (LM1) has a dropped blade, the primary grind is full flat grind on 1/8" stock with a v-ground secondary edge bevel. The blade is 1.3" wide and 5.25" long. The knife weighs 160 g and has a handle heavy balance centred 2.5 cm back from the guard. The spine is ridged just ahead of the handle, as is the end of the tang for security. A shot from the side :
http://www.physics.mun.ca/~sstamp/images/model_10_lm1_side.jpg
and from the top showing the profile :
http://www.physics.mun.ca/~sstamp/images/model_10_lm1_top.jpg
Fit and finish :
The edge is uneven from side to side and along the length. The thickness and width vary from 0.021 to 0.027 and from 0.029 to 0.039", the tip is strongly asymmetric due to the variance in edge width. The angle is however fairly consistent at 19-21 degrees. Under magnification (10x), the edge is clean no burrs, a significant and steep secondary edge bevel is present. The handle slab fit to the tang is perfect, everything is flush. The slabs are bead blasted to produce a nice secure yet non abrasive coating. The spine is squarish and fairly sharp.
Initial sharpness and cutting ability :
The Model 10 was quite blunt NIB (unused from the maker). There is a spot about one cm long in the tip region which reflects light. The knife scored on average 353 (46) on the light thread throughout the edge, and 5.0 - 5.5 cm on the 1/4" poly. This is about 25% of an optimally sharpened blade at a high polish (CrO).
The Model 10 had no ability to shave, slicing newsprint was rough, tearing could be seen along the cut, no ability to push cut the paper. On some 3/8" manilla hemp, 80-90 lbs was required with a rocking push cut through the tip, 90-100 lbs near the choil, and 40 (1) lbs on two inch a slice. This cutting ability is several times worse than optimal due to the low sharpness.
Initial sharpening :
A smooth steel was used to check the edge for alignment. The thread cutting performance did not significantly improve, however the length required to slice the poly dropped to 3.7 (0.1) cm . Checking the blade on some meats and fats in the kitchen, a lot of slipping was observed. The knife still had no ability to push cut cardboard and would just mash it down, slices were very rough. Thus it seems the standard tests of sharpness work decently well on the LM1 alloy.
A test was made with a few passes on a 22 degree jig to gauge the angle of the micro-bevel, it was far steeper than 22 degrees. To remove it, a 1000 grit waterstone was used. The metal worked easily compared to a few other knives which also had to be sharpened (various 52100 blades with more narrow edge bevels). The polish was then raised with a 4000 grit waterstone and the edge then stropped on CrO, 10 passes per side on loaded leather. Total sharpening time was about twenty minutes.
With the new finish the knife could shave readily, with just a hint of bite left from the 1000 grit stone (freehand skills are a little sloppy). The thread cutting was now very high, 108 (13) grams. The edge was checked 12h later to confirm the sharpness was stable, it again tested well 119 (44) grams. Thus there is no trouble in getting this material very sharp.
Going back to the manilla hemp, the Model 10 showed a massive improvement and now only needed 24 (1) lbs on a rocking push cut through the tip and 37 (1) lbs through the choil. The slicing ability had also improved dramatically and only 15 (1) lbs were required on a two inch draw.
Kitchen :
The dropped blade profile is perfect for kitchen work on a cutting board, allowing full and deep cuts. With the sharpness high the knife had no problems on meats, fats and various fruits and vegetables. The combination of decently thin stock and efficient edge profile produce solid cutting ability which fared well with most kitchen knives. The only drawback to a truly optimised kitchen knife was seen on thick and binding vegetables. On a medium sized turnip the Model 10 took 16 (1) lbs on a push cut while the Japanese utility knife only took 7.0 (0.5) lbs. The lack of rounding on the spine of the Model 10 could also be felt with the heavier push cuts.
The Model 10 was also used to take apart a medium sized turkey for meals, stock and soup. The handle stayed secure even when covered in fat and grease and was comfortable throughout the cutting. The thin tip easily penetrated the skin and meats efficiently. The upsweep was a bit high however for some cutting such as removing the breasts, which was done with the tip, the Pronghorn has a more suitable tip profile for that type of cutting. For most small cutting around joints, a Blackjack Small proved to be more efficient, due to the shallow nature of the cuts. No bones were cut this time as it was just an examination of cutting ability and general handling characteristics.
Edge retention :
The edge retention was checked on slicing 3/8" manilla hemp (no backing board) and cutting used carpet using a few other knives as benchmarks . Only a couple of runs of each have been done, a few more need to be performed to ensure a decently stable performance estimate, however initially the edge retention on those materials does not seem to be that of a decent quality steel. The edge retention will also be checked on cardboard and possibly on wood chopping and other harder cutting.
Handle ergonomics and security :
The grip has four inches of functional width, the contouring is heavy and very specific. It fits my hand well both in a grip out on the tips of fingers with thumb on spine for precise work, as well as in a hammer grip. With the contouring reversed into the palm comfort is reduced, but do to the radiusing, it isn't problematic. However I had it checked with a few friends of different hand sizes (larger and smaller), and had complaints of the finger grooves being less than optimal which is expected on a highly specific contour.
Sheath :
The Kydex sheath (0.055") is made in a pancake style, all seams match well and the edges are smooth. The blade locks in securely, taking ~8 lbs to draw. There is however some rattle in the tip region.
Blade material specifics :
This is a cast alloy, not steel but a Liquid Metal. The hardness of this particular grade, LM1, is 50 HRC, the impact toughness is 6 ft.lbs, and the yield strength 290 kpsi. For reference CPM-10V at 63 HRC has a yield strength of 375 kpsi and an impact toughness of 16 ft.lbs.
The edge is readily filed, holding the handle in the left hand with the thumb and index finger pinching near tip, the blade flexed readily. Bracing the blade against the heel of the palm it was apparent the blade could be readily broken in hand. This seems to be in line with the materials properties.
Questions :
Does anyone have a working email for the maker. I sent an email on use through both his website email and the contact info through his profile on the forums, it just generated a form letter which is months out of date. Some specific issues I am curious about are :
1) Tip limits, is the knife intended to be able to be stabbed into soft targets (phone book), medium (most woods), hard (plastics), and very hard (bone). What is the functional upper end for the tip strength, removing thick bark, prying or digging in woods, separating thick joints ?
2) Edge durability, with the current geometry, should the edge be able to cut thick plastics, chop hard woods (small diameter), used with a baton for splitting, accidental hard contacts (such as thick staples). How about with a more efficient 15/22 degree dual profile, and better yet 10/15.
3) How wide is the elastic region of LM1. How far will this blade bend before it will break. Is the ductility significant, will it take a decent bend before breaking?
Ref :
This knife is also on loan from Gabe Newell.
-Cliff
The Model 10 in Liquid Metal (LM1) has a dropped blade, the primary grind is full flat grind on 1/8" stock with a v-ground secondary edge bevel. The blade is 1.3" wide and 5.25" long. The knife weighs 160 g and has a handle heavy balance centred 2.5 cm back from the guard. The spine is ridged just ahead of the handle, as is the end of the tang for security. A shot from the side :
http://www.physics.mun.ca/~sstamp/images/model_10_lm1_side.jpg
and from the top showing the profile :
http://www.physics.mun.ca/~sstamp/images/model_10_lm1_top.jpg
Fit and finish :
The edge is uneven from side to side and along the length. The thickness and width vary from 0.021 to 0.027 and from 0.029 to 0.039", the tip is strongly asymmetric due to the variance in edge width. The angle is however fairly consistent at 19-21 degrees. Under magnification (10x), the edge is clean no burrs, a significant and steep secondary edge bevel is present. The handle slab fit to the tang is perfect, everything is flush. The slabs are bead blasted to produce a nice secure yet non abrasive coating. The spine is squarish and fairly sharp.
Initial sharpness and cutting ability :
The Model 10 was quite blunt NIB (unused from the maker). There is a spot about one cm long in the tip region which reflects light. The knife scored on average 353 (46) on the light thread throughout the edge, and 5.0 - 5.5 cm on the 1/4" poly. This is about 25% of an optimally sharpened blade at a high polish (CrO).
The Model 10 had no ability to shave, slicing newsprint was rough, tearing could be seen along the cut, no ability to push cut the paper. On some 3/8" manilla hemp, 80-90 lbs was required with a rocking push cut through the tip, 90-100 lbs near the choil, and 40 (1) lbs on two inch a slice. This cutting ability is several times worse than optimal due to the low sharpness.
Initial sharpening :
A smooth steel was used to check the edge for alignment. The thread cutting performance did not significantly improve, however the length required to slice the poly dropped to 3.7 (0.1) cm . Checking the blade on some meats and fats in the kitchen, a lot of slipping was observed. The knife still had no ability to push cut cardboard and would just mash it down, slices were very rough. Thus it seems the standard tests of sharpness work decently well on the LM1 alloy.
A test was made with a few passes on a 22 degree jig to gauge the angle of the micro-bevel, it was far steeper than 22 degrees. To remove it, a 1000 grit waterstone was used. The metal worked easily compared to a few other knives which also had to be sharpened (various 52100 blades with more narrow edge bevels). The polish was then raised with a 4000 grit waterstone and the edge then stropped on CrO, 10 passes per side on loaded leather. Total sharpening time was about twenty minutes.
With the new finish the knife could shave readily, with just a hint of bite left from the 1000 grit stone (freehand skills are a little sloppy). The thread cutting was now very high, 108 (13) grams. The edge was checked 12h later to confirm the sharpness was stable, it again tested well 119 (44) grams. Thus there is no trouble in getting this material very sharp.
Going back to the manilla hemp, the Model 10 showed a massive improvement and now only needed 24 (1) lbs on a rocking push cut through the tip and 37 (1) lbs through the choil. The slicing ability had also improved dramatically and only 15 (1) lbs were required on a two inch draw.
Kitchen :
The dropped blade profile is perfect for kitchen work on a cutting board, allowing full and deep cuts. With the sharpness high the knife had no problems on meats, fats and various fruits and vegetables. The combination of decently thin stock and efficient edge profile produce solid cutting ability which fared well with most kitchen knives. The only drawback to a truly optimised kitchen knife was seen on thick and binding vegetables. On a medium sized turnip the Model 10 took 16 (1) lbs on a push cut while the Japanese utility knife only took 7.0 (0.5) lbs. The lack of rounding on the spine of the Model 10 could also be felt with the heavier push cuts.
The Model 10 was also used to take apart a medium sized turkey for meals, stock and soup. The handle stayed secure even when covered in fat and grease and was comfortable throughout the cutting. The thin tip easily penetrated the skin and meats efficiently. The upsweep was a bit high however for some cutting such as removing the breasts, which was done with the tip, the Pronghorn has a more suitable tip profile for that type of cutting. For most small cutting around joints, a Blackjack Small proved to be more efficient, due to the shallow nature of the cuts. No bones were cut this time as it was just an examination of cutting ability and general handling characteristics.
Edge retention :
The edge retention was checked on slicing 3/8" manilla hemp (no backing board) and cutting used carpet using a few other knives as benchmarks . Only a couple of runs of each have been done, a few more need to be performed to ensure a decently stable performance estimate, however initially the edge retention on those materials does not seem to be that of a decent quality steel. The edge retention will also be checked on cardboard and possibly on wood chopping and other harder cutting.
Handle ergonomics and security :
The grip has four inches of functional width, the contouring is heavy and very specific. It fits my hand well both in a grip out on the tips of fingers with thumb on spine for precise work, as well as in a hammer grip. With the contouring reversed into the palm comfort is reduced, but do to the radiusing, it isn't problematic. However I had it checked with a few friends of different hand sizes (larger and smaller), and had complaints of the finger grooves being less than optimal which is expected on a highly specific contour.
Sheath :
The Kydex sheath (0.055") is made in a pancake style, all seams match well and the edges are smooth. The blade locks in securely, taking ~8 lbs to draw. There is however some rattle in the tip region.
Blade material specifics :
This is a cast alloy, not steel but a Liquid Metal. The hardness of this particular grade, LM1, is 50 HRC, the impact toughness is 6 ft.lbs, and the yield strength 290 kpsi. For reference CPM-10V at 63 HRC has a yield strength of 375 kpsi and an impact toughness of 16 ft.lbs.
The edge is readily filed, holding the handle in the left hand with the thumb and index finger pinching near tip, the blade flexed readily. Bracing the blade against the heel of the palm it was apparent the blade could be readily broken in hand. This seems to be in line with the materials properties.
Questions :
Does anyone have a working email for the maker. I sent an email on use through both his website email and the contact info through his profile on the forums, it just generated a form letter which is months out of date. Some specific issues I am curious about are :
1) Tip limits, is the knife intended to be able to be stabbed into soft targets (phone book), medium (most woods), hard (plastics), and very hard (bone). What is the functional upper end for the tip strength, removing thick bark, prying or digging in woods, separating thick joints ?
2) Edge durability, with the current geometry, should the edge be able to cut thick plastics, chop hard woods (small diameter), used with a baton for splitting, accidental hard contacts (such as thick staples). How about with a more efficient 15/22 degree dual profile, and better yet 10/15.
3) How wide is the elastic region of LM1. How far will this blade bend before it will break. Is the ductility significant, will it take a decent bend before breaking?
Ref :
This knife is also on loan from Gabe Newell.
-Cliff
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