I’m not getting straight edge.

Hey everyone. New member and a little late to this thread. But I’m currently working on my first few kamisori style razors. I don’t have many tools but I’m a tool sharpener and have access to a few good ones at work. Best tool I have for what I want is a tormek T8. I’ve been cutting out my blanks from 1075 with an angle grinder and cut off wheel, shaping them on a big bench grinder refining it with our little belt grinder, mark out a centre line on the edge then it’s to the tormek to profile it. I pretty much start in the centre of the blade on the omote side and i can give the omote a full hollow (very slight with the 10” grindstone) then I give the Ura an aggressive 1/2-3/4 hollow until i reach the centreline. Blah blah blah heat treat in my propane forge. Temper in a crappy oven. Touch up the omote and grind the Ura to zero (until I get a burr on the omote) here’s where I want some advice. I’m not getting straight edge. The centre always comes up first and the tip and heel are always a little thicker. When grinding it should I rock from heel to tip? Would that make it wavy and uneven? Thanks in advance and sorry for the rant!

You post was moved here Luke, to better help you get some answers.

Just a SWAG. There is a tendency in grinding on a wheel to move a blade back and forth. If the wheel is flat dressed, the effect is that the center of the blade spends more time on the stone than the ends. I found that out even with a 4" wide stone. Now when i use that grinder, I make passes across the whole length of the blade and off the tip end. Yup, a bit of a trick to keep the same pressure at the blade contact point. Can be done though.
Think of time on the stone at a given blade location if that helps understand the idea. Sorta like honing a 'frown" out of a blade. Do a search for frown here.

Good luck, I honor your dedication.
~Richard

In addition to the previous answers: when I am grinding a razor, I regularly put the razor on a flat surface and see if there are sections that need more metal removed. This makes it easier to get a good edge at the end.

could also be your presentation of the blade to the grinder. if you always present the same spot to the belt when you start, then it will get more grinding time than the rest of the blade.

also whatever spot you present to the grinder will almost always get a fraction of a second more time as the blade settles to the belt.

Thanks CaltonCutlery that makes heaps of sense thinking back to it! I think not dressing the stone flat often enough would have been a factor too! Next time I’ll do better!

Update. I’ll be working on a second razor tonight. I’ve put a smile in the blank hoping it’ll either work itself straight or be a slight smiling blade. Ive also convinced my boss who lets me take the Tormek home on weekends to work on my razors to buy a 4000 grit stone. Hopefully it’ll polish up the blade real nice and make it wicked sharp. Also our diamond abrasive supplier at work has .5 micron paste for stropping which I’ll get for my kangaroo strop

Nice looking fixed blades.

I think anyone who has spent time on the grinder has done this. When you are in contact with the wheel or belt, left to right or right to left, NEVER back and forth. If you go back and forth, the center spends more time on the wheel and gets more material removed.

I have recovered from that by making a "jig or round wooden block out of a 2x4" to the same diameter as your wheel and 2x the length of your cutting edge. Cover jig with sandpaper and continue your hollow by a pulling and pushing motion, parallel to your cutting edge. This will remove material at your high spots.

I agree with Scott, good advice.

IIRC, some dude named Charlie taught me that.

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Originally Posted by ScottGoodman

I think anyone who has spent time on the grinder has done this. When you are in contact with the wheel or belt, left to right or right to left, NEVER back and forth. If you go back and forth, the center spends more time on the wheel and gets more material removed.

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Unless you compensate by lingering at the heel and the toe, and keep an eye on the hollow to make sure that the line where the wheel loses contact with the hollow keeps running parallel to the spine. that way it will all work out in the end. Some crazy guy in Belgium does this :p

I agree with Scott btw, unidirectional is definitely the most reliable way to do this, and easiest to learn. It's what I would advise.
The only reason I keep doing it like I do is that I've always done it like that, and by now it is second nature like my edge down grinding.

Finally upgraded my equipment. Here’s some of the latest I’ve made. Attachment 299017Attachment 299018

Love this info thank you a bunch! I’ve gotta get on this forum more often and keep up to date with all the tips! Nothing but good things ahead thanks to all the help. Appreciated!

Quick few questions. One is spazola charlie Lewis? And two how does one grind a smiling blade ? In my mind if the belly is lower and I’m just pulling the blade across the contact wheel. It’ll reach the toe and heel before the belly ? Or am I over thinking things? Cheers Luke.

Yes, Spazola is the Great Charlie Lewis. When it comes to grinding smiling blades, look on YouTube for some of Charlie's video's.

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Originally Posted by LukeAugustini

Quick few questions. One is spazola charlie Lewis? And two how does one grind a smiling blade ? In my mind if the belly is lower and I’m just pulling the blade across the contact wheel. It’ll reach the toe and heel before the belly ? Or am I over thinking things? Cheers Luke.

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You don't keep the blade horizontal.
A smiling edge also needs a smiling spine.
This means that you only hold the blade horizontal when you are grinding the middle of the blade.
If you grind the part near the heel, the toe is higher than the heel.
If you grind near the toe, the heel is higher than the toe.

The curve of the blade matches the spine, like Bruno said.

The way that I think of it, as I rotate the blade on the wheel going back and forth, I try to keep the edge of the blade perpendicular to the wheel.

I have used the forum name of spazola since 2006 , it would feel weird to change it. I should have choose better years ago.

This is all beyond me sense ive never ground a razor but, ic you made a jiglike a triangle shape and the point was in the middle of the belt. Couldnt you rock and sweep the blade across the tip to keep a more uniform grind on a smiling edge with a smiling spine?

Now that i think about it, you guys mostlikely do it without jigs and freehanded. Sorry about my ignorance. I remember seeing Vics grinder and asking him how the hell is grinds. He told me "i just rest my elbow on this table here". Blew my mind.

Yes most of us freehand everything. Trying to come up with jigs for smiling grinds is probably more work than just learning to do it.

I’ve spent many hours watching your videos when I first wanted to make razors. But it was an extremely slow start and I’ve forgotten most of what I watched. Going back through them now. I do have yet another question. How much if any difference in thickness do you allow before heat treat?. I practice on scrap I have lying around to get my skills up and I’ve got about .2mm difference from the heel to toe. I don’t have the luxury of variable speed on my grinder at the moment and on final passes I just turn it off and use it as it slows down and repeat until I feel it’s done or I overhear and throw it out.

I find freehand difficult to maintain edge thickness exactly. I’ve usually got .2-.3mm different and I’m not happy with it. Any tips ?

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Originally Posted by spazola

I have used the forum name of spazola since 2006 , it would feel weird to change it. I should have choose better years ago.

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+1

I feel the same about mine.

We could have made worse choices!;)

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Originally Posted by LukeAugustini

I find freehand difficult to maintain edge thickness exactly. I’ve usually got .2-.3mm different and I’m not happy with it. Any tips ?

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When you are close to the finished edge, take it to the hones. That will quickly show you where you need to remove more metal.
Also use fresh belts that still cut right.
Sharp belts -> less heat.

Bruno. Notice that the OP is asking about thickness before heat treat .

I think that a .2mm difference before heat treat is not very significant as far as the heat treating is concerned, though I don't see why you can't correct this. You are going to need to get an even thickness after heat treat, why can't you do it before when it is easier.

Oh. I hadn't noticed.
I don't think the thickness before HT matters greatly. I never measure mine, and some of them have some thickness variance that I can see clear as day.
The difference shouldn't be extreme, but as long as it is more or less thicknes of a dime, give or take, it shouldn't matter at all.

It is possible to correct this. But at this stage I always opt for a 'good enough' approach.

I tend to leave mine a bit chunky before heat treat, maybe .030 to .050 of an inch thick, I do not measure before heat treat, I just eyeball it.

You will get better every blade you grind. I am still learning and trying new things, watch a lot of people and see what works for you and your brain.

Also since we're on this subject:
After HT, as you approach the final thickness, just put the razor on a flat surface as if you were going to hone it. If it wobbles, you can very easily see where you need to remove metal to make it sit flat.
And if you have a smiling blade, the same thing works: just roll the razor as if you are going to do a rolling X stroke on the hone. And if you notice a wobble in the roll that is not supposed to be there, just remove metal to correct. The important thing is to do this while you still have thickness to work with. If you grind all the way until the edge is near final thickness, and then you notice that the geometry doesn't work, there is no material to work with anymore.

Nice looking work so far. Must be really enjoyable turning an idea into something tangible like that.

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Originally Posted by spazola

The curve of the blade matches the spine, like Bruno said.

The way that I think of it, as I rotate the blade on the wheel going back and forth, I try to keep the edge of the blade perpendicular to the wheel.

I have used the forum name of spazola since 2006 , it would feel weird to change it. I should have choose better years ago.

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You could always put your name in your title or signature line if you wanted newer members to know who are. I recently found out from a newer member JP5 is a type of jet fuel!

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Originally Posted by JP5

I recently found out from a newer member JP5 is a type of jet fuel!

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:D I thought it probably had something to do with your work.

Maybe that is what you smell like when you come home at the end of the day.......:rofl2:

Not sure if I’m in the clear to add links or anything but the guy who bought the polished razor is an avid wet shaver and collector from the UK and he’s done a few write ups on it. Here’s his in depth look and opinion on my work. I’m blown away. https://wetshaverreview.com/2019/01/...tini-kamisori/

Congrats Luke, nice write up.