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Considering almost every knife handed to me by customers are at the tail end of trying almost every other gadget and sharpening service prior, there's never any sharpening angle to duplicate.

Kitchen knives: 15 DPS
Cleavers: 17 DPS
Fancy Japanese knives: 12-15 DPS
General use and fabric scissors: 60 DPS

I typically measure the behind edge thickness (knives only) and aim for a secondary bevel height between 1-2mm.

So far this framework seems to balance a smooth flow from the secondary to primary bevels, as well as edge retention for at least a few months for average 55-58 HRC steel.

For context, I sharpen knives and scissors commercially, been doing it for about... 1.5 years, and now on my second SG-250 (already down to 230mm/9" 😭)

I've used my SG-250 to reprofile many cheap-ass soft steel knives, many exotic Japanese steels, all the way up to ZDP-189.

I used to grade my SG-250 coarse quite frequently for it to cut a lot faster? Then I realised very quickly that it doesn't wear down evenly, and any slight change in the diameter (like grading again) would start to create another facet on the bevel (usually at heights 3mm or wider)

I used to think my stone was always glazed, and wasn't operating efficiently. Then I realised that when grinding any secondary bevel height more than 3mm, the progress slows to a crawl (possibly because all downward pressure is now more evenly distributed over a wider area)


In summation, before you start discarding serviceable items, why not try grinding a narrower angle (12-15 DPS) on your harder steel knives to get a better feel of how the SG-250 cuts? I learnt the hard way that the lack of significant tactile feedback during grinding doesn't mean the grindstone wasn't working 🤦🏻�♂️

Once I raise a burr on my last grindstone used, I make a few light alternating passes on both sides of the blade to weaken the burr.

I use the composite wheel on most knives, and I strop at sharpening angle the majority of the time. I start with the burr side up, make about 10 passes, before flipping the knife to burr side down, and another 10 passes.

I put in about 20 passes each side before I start alternating passes for about 10 passes each side.

Finally, I'd raise the stropping angle by about 1 degree, do about 10 alternating passes on each side, and later clean up the edge with 99% IPA before doing any sort of inspection/testing.

I notice the composite wheel tends to leave a bit of material on the cutting edge, so sometimes the roughness I feel isn't the burr, but just rubber and aluminium oxide still stuck on.

A bit too late to comment, but as you pass the blade across the grindstone, you don't really have to reach the tip (and pivot) all the time.

Sometimes I intentionally leave out a rounded tip during sharpening, and reduce the rest of the blade so the bevel matches the tip, and then I start sharpening the full length of the blade.

This is one way I've been avoiding rounding already rounded tips, while maintaining an even bevel height.

I did a search on the forum but didn't find any answers so I decided to ask here, I have honestly tried to hone free hand and not with any success, it gets frustrating to sharpen a knife with a great edge and then mess it up on the honing side. I have watched lots of videos bit I still seem to take the sharpness out of the knife but when I hone with the USB and KS-123, my results are perfect and I couldn't be happier. Obviously, I have to keep taking my wheel off to hone most of the knives so I was wondering if anyone has bought and tried a 10 inch honing wheel and the results. I have watched some videos from different YouTubers and I am impressed watching them move from sharpening to honing without removing any wheels.

Thanks

Pondering more... I think a good place to start is the perception of your Tormek T8.

I see it as a slow moving machine with capabilities for extreme precision and scalability.

Whenever I have to strop, I just remove the grindstone and slot it into the rack just below my T8, and reattach the water trough. (I'm just using an Ikea Bror workbench and Slipakniven rack at my workshop)

It's become part of my routine workflow and I don't really feel any significant time loss when moving the grindstone and leather wheel about.

Maybe a bit of (re)organisation to put your wheels within easy reach, so you're just removing and slotting would make your issue seem less troublesome.

At the end of it all, the final product you create would make a little swapping out here and there seem insignificant, and just "part of the game".

What a great idea, I cant believe I didn't think of that. Cheers.

To add a bit of context...

For scissor sharpening on my SG-250, I would round off the outer edge of the grindstone, and "index" the innermost part of the scissor blade to that rounded corner, creating a softer/rounder starting point, before sliding across the rest of the blade.

Hence the reason why I keep sharpening only in one direction, is because I don't want the grindstone to keep accidentally hitting the "heel" of the blade, pushing it further and further back, making it look terrible for my customers.

Based on the digital microscope that I use, I'd recommend going for something where the focus/zoom buttons are not on the camera itself. Some models have a wireless remote control, and some have the remote wired.

Bottomline, if you magnify high enough, tiny movements like tapping the buttons on the camera unit creates a heck of a lot of wobble.

Built it lighting on flexible arms are a bonus too. I made a ramp (aka knife holder) using MDF squares glued onto door stoppers, with magnets attached, just to make the knife secondary bevel parallel to the lens, making focus a lot better (at higher magnifications)

I think something to consider when sharpening things designed to spin, is the balance of it.

I've never sharpened lawnmower blades before, but I have sharpened a giant 35cm deli meat slicer blade. I was very mindful to keep the sharpening as even as possible around the entire circumference, and waiting on any complaints/feedback from the customer.

From my personal experience with my Tormek T8... I see the matter in terms of matching the abrasive to the steel type.

For cheap and soft steels with low carbide content, I use the SG-250 for speed.

For harder steels alloyed with more carbides, I still use the SG-250 for reprofiling (because at this stage I'm not bothered with carbide tear/fall out), but all follow up sharpening is done with diamond grindstones (DF-250, DE-250) because I want to cut through both the supporting ferrite matrix and carbides together. Takes a longer time, but often a "Do it good, do it once" type of situation.

Long story short, seeing the dimension of grit size only, may leave you missing out on a bigger part of the workflow.

Hope that made sense.

I stripped my KS-123 down, cleaned it thoroughly, and just applied a wee bit of PTFE grease on the pivot area. So far after a few months of daily use, it's been pretty smooth.

I typically sharpen scissors left to right only, and this often directs the drips back into the trough.

I think a good place to start is to be very clear on the standard(s) that you're aiming for, and the general trend in knives you receive.

About 99% of customer knives I receive are the end product of numerous botched sharpening attempts, and hatchet jobs by other sharpening businesses.

I just reprofile all knives I get with the SG-250, sharpen with the DF-250, then strop. BESS testing is only for my top tier service (for high end knives and/or professional chefs), and for this service I go through all diamond grindstones, the SJ-250, and strop.

But my motivation may be different from yours, because my business is still relatively new, and I'm more focused on social media outreach and generating customer to customer chatter.

But yeah, I'd recommend establishing what "good enough" is, to be very clear about it, then the workflow will pretty much create itself.

I'm waiting for my 1x30 belt sander to supplement my bench polisher.

I plan to use it for deep scratch removal, before blending everything together with my bench polisher and radial bristle discs/muslin wheels. (I do it because I have an optional component of knife polishing, in addition to my sharpening package)

In future, I plan to use the belt sander to do heavy reprofiling/material removal and polishing, but still use my Tormek T8 for sharpening. My business selling point is precision edges, and not speed + quantity at low-low prices.

It's really your call on how you plan to position your sharpening business. What I can say, is if you position yourself similarly to the majority businesses in your area, then you run a tough race where you've started very late, and everyone races to the bottom. But if you position yourself differently (like how I provide precision sharpening, repairs and refurbishing) then you may very well end up running a race where there's much fewer people. If you're trusted by people as a good sharpener, then nobody will care about price.

I've been using the T8 for a bit over a year now, and I have all 3 diamond grindstones, SG-250, SJ-250, MB-102, a third party front vertical base, both knife jigs, a scissor jig, the standard and extended support bar, small knife jig, the platform, and axe jig.

No regrets at all as I've used almost all the items in my sharpening business, less the axe jig. The equipment really is a sound investment that does have the longevity and precision.

I have a 1x30 belt sander on the way to be used mostly to supplement my bench polisher, and maybe some large scale reprofiling.

But long story short, the biggest hurdle to overcome would probably be the business aspect. How you create your pricing and standards framework, and how you do your own quality management.

Customers would never cease to "amaze" you. Just today, a customer claimed a knife sharpened by me had poor edge retention, and wanted me to do a resharpening for free.

I checked my records and I sharpened his knife FIVE MONTHS AGO

I think a good place to start, would be how the diamonds are attached to the steel hub.

If I'm not wrong, the diamonds are suspended in a solution that has a metal dissolved in it, then the steel hub and solution are electrified, drawing the dissolved metal out of the solution and onto the hub. The diamonds that are suspended in this constantly agitated solution get caught up in this electroplating process, and are "glued" onto the hub.

Long story short, diamond dust is glued to steel using another metal (nickel)

If the scissor blade manages to scrape off some of that metal, then your diamond grindstone is pretty much BER (Beyond Economical Repair)

The SG-250 is much more forgiving as any gouges/dents can be graded down to flat again. It's also great for practice and doing any experimentation on.

$300 may feel like a lot to add to your toolkit, but it's good to consider what you risk by saving that $300.

I don't have thousands of knives sharpened on the T8 under my belt, but I can confidently say that almost 99% of my customer knives needed reprofiling and repairs. (they are animals)

And once your business picks up, you won't regret having a 220 grit grindstone to power through more knives quickly.

Also, I sharpen scissors entirely on the SG-250. I use it at 220 grit to reprofile/repair, then use it at 1000 grit to smoothen the peaks the 220 grit creates, leaving a somewhat micro serrated edge. (I sharpen scissors mostly for tailors, so they need that consistent "bite" when sewing)