Maintaining a constant angle.
- This topic has 8 replies, 3 voices, and was last updated 08/20/2021 at 11:18 am by
.
-
Wicked Now.
There are many factors that may contribute to the relatively small (0.1-0.2°) angle change (increase). First consideration is your consistency. Every thing has to be the same and stay the same. Are you measuring the angles consistently? I assume you’re using a digital angle cube. Are you using a properly zeroed cubed? Only zeroed once at the onset of your sharpening session in the same zeroing position everytime. Are you positioning the cube the same way on the sharpening stone and leaning it against the knife edge in the same way, with the position and height placed consistently each every time you take a reading?
Is your WE sharpener staying still? Is it tight on it’s mount and base. Are the vise screws that hold the sides together tight? Is your table stable?
Are you holding your stones consistently all throughout the entire sharpening step. Just slight differences in hand-hold, finger positions and pressure may slightly effect the bevel angle. Easily enough to make the variances your seeing.
Are you using a quality cube with the resolution and accuracy far better than the error you’re finding? Many cubes are not. Repeatability and resolution in the cube’s readings are necessary.
Have you been verifying the knife is not shifting even just ever so slightly in the clamp? Have you verified you’re micro-angle settings on the guide rods are staying rigidly tight and not shifting with pressure over time.
All these factors combined can easily contribute to 0.1-0.2°. I suggest with that small a variance that you work on your consistency.
Check and make sure your angle is reset with the fine micro-angle adjustmenters done with each new grit change. With experience, attention to detail and improved consistency in your technique and stone work you’ll see improvements.
To monitor for those small variation requires a good quality angle cube and patience. It’s more time consuming to work at that level of consistency and an accurate cube take longer for it to settle or lock on the reading. It can be tedious and slow going. Especially when you double check each reading for consistency.
Weigh your needs. You won’t notice any difference in cutting performance if the bevels are 0.1-0.2° off what’s intended What is more important than the absolute angle is the keeness of the knife edge. That is how precisely the flat bevels can meet at the apex.
Marc
(MarcH's Rack-Its)2 users thanked author for this post.
I will add…a lighted, magnified, visual aide, (I prefer a USB Microscope) will allow you to inspect the consistency of your stone work, (that word again), to see exactly where the resulting scratch patterns are being laid down across the full height of your bevels. An application/reapplication of a sharpie marker across the bevels, also helps you to monitor the results of your stone work as you go through the grits. It’ll help you to determine if your favoring one part of the full bevel’s height or doing the entire bevel height evenly and consistently. It’ll also help you to you learn how finger positions and pressure on the stones effects where the bevel is worked so you can use this to your advantage. To essentially steer where you’re removing steel to best shape the bevels.
We are profiling, shaping, or setting the angles of our knife edge bevels relative to an imaginary vertical line, (0.00º) that transits down through the center of the vertically clamped knife, with our first coarsest grit stone. With each subsequent grit stones we are smoothing and refining these two flat planes, these edge bevels, on both sides of the knife. Where these two planes intersect, it forms a line at the apex. The more precisely, flat and consistent these planes are and they’re able to intersect, the finer the line is and the keener and sharper the knife edge will be.
Consistency from hours of practice and observation. I like to look at it as a study in cause and affect.
BTW: I too use that same DXL360S cube, the red model.
Marc
(MarcH's Rack-Its)1 user thanked author for this post.
I work with the USB scope on high power so I look at a very small portion of the bevel, maybe only a 1/4″ width section and usually the full height of the bevel. I prefer to view the bevel from the side, 90° to it. Others users prefer to look straight down onto the edge or apex from above it
I also work at a low resolution setting. Only 800 X 600. This low resolution allows the image to focus, lock in and show on the screen pretty quickly, clearly and detailed enough to clearly see the details I can wok with. I can scan down the edge watching the real-time video. This is compared to a higher resolution setting which requires that you hold the scope in position and steady, stable or motionless for much longer period of time before the image can lock in and show up on the monitor’s screen. I can’t view the image on the monitor in real-time while scanning down the bevels when set to higher resolutions.
I work with some part of the scope’s hood or lens shroud in physical contact with knife bevel. Maintaining this physical contact helps me to sharply focus the images by slightly tilting the scope shroud closer to, or further away from the knife bevel. With just these very slight differences in the lenses focal length I create with the minor rocking movements are how I focus the imagine sharply. I start by adjusting the focus ring so the image is sharp and clear. Then I wrapped tape around the focus ring to lock that focus down. Subsequently all focusing I can do with just minor tilting and positional changes how and where the shroud contacts the knife and it’s distance rocked off of it. After years of using it like this I can scan down the bevel and spot check my work quickly. I seldom need to remove the tape to refocus the ring.
I do snap and save images for each grit for comparison with past or future images if sharpening that same knife again.
Marc
(MarcH's Rack-Its)1 user thanked author for this post.
I turn my angle cube off to save batteries after I check the angles. Then I turn it back on and zero it in exactly the same place as before with each stones change.
1 user thanked author for this post.
All the angle cubes I have ever used stored the last or most recent zeroed-out value or reading, whether it’s on or powered off. It will hold that value until it’s zeroed out again. (Even after months without using it, I’ve placed my cube in my preferred zeroing position and taken a 0.00° reading, repeatedly). The proper way for using the angle cube is to set all your angles relative to the same zeroed-out meter value, start to finish, for that entire knife sharpening session. Then each stone/grit in your sharpening progression is measured relative to that same zeroed-out saved value, for consistency.
When the device is zeroed-out again and again between each grit, that relative-ness or basis for comparison, that gives the consistency we seek,, is lost. Each successive stone or grit is then being set relative to another new zeroed value and the angles are stand alone settings. With that basis for comparison lost the consistency and relative-ness across each grit in the full progression is then lost.
Even though the cube may be zeroed-out in the same (exact?) physical position each and every time it is still a new reading and a new zeroed-out value being saved. In the scheme of things if your technique is good and pretty consistent the difference this method will impart may or may not make a difference to your desired results. Many W.E. users set the guide rod angles just once with the very first grit and work with this setting, start to finish without any other adjustments. If your technique is good and you operate the W.E. sharpener well you should get a sharp knife.
I work with a highly accurate, precise and low resolution, (+/-0.01°), dual axis angle cube, along with upgraded micro-angle adjusters that allow me to take advantage of the ultrafine resolution settings this cube and my setup affords me. I will continue to use my single zeroed-out value method as my basis to set, reset, and micro-adjust my guide rod angles with each and every grit or medium I use in my sharpening progressions. For consistency.
Marc
(MarcH's Rack-Its)2 users thanked author for this post.
- You must be logged in to reply to this topic.