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I've had a belt sander for some time, used if for restorations, decided to try to make a blade
01 tool, I made a rough cut out
https://i.imgur.com/WsLQxeO.jpg
Spine
https://i.imgur.com/PHAq9lN.jpg
Grind after 40 grit
https://i.imgur.com/wPVuOiP.jpg
https://i.imgur.com/ErSlcER.jpg
Not too bad
Jimps
https://i.imgur.com/jNoFShO.jpg
Got it to here
https://i.imgur.com/nlXlT4B.jpg
Heat treat in very crude set up, got the metal glowing to a cherry red and quenched in warm oil
https://i.imgur.com/2rUvhzw.jpg
https://i.imgur.com/CPWUStG.jpg
Tempered in oven and started regrinding
Got it descent then this happened
https://i.imgur.com/sVIJJIT.mp4
It was going well, I was checking the grind by honing on a DMT coarse plate, almost had it and just went too far.
I was using an 8" wheel, I think I need to try on a 10", the metal got thin
Overall great experience and will definitely try again
I think the heat treat was good, I tested after and a file glided over, I was also getting nice sparks with with the grinding
I did the post heat treat grind on a 320 belt
What happened? The last pic didn't show up Alfred. It had a great shape.
https://youtu.be/IWtgK4xtnIoQuote:
Originally Posted by Gasman
Oh that's a very thin grind!
Might be easier on the fit and finish at the end if you go with a higher grit when you start getting close to the grind you want.
Shame that happened after such a good start. I bet you get it next time around though.
Bob
Couldn't see the final picture, but if I understand correctly, one sanding wheel has been used to create the two faces of the mildly-hollowed razor. From what I have seen in my travels, a two-wheeled grinder is used with the blade being introduced in between the wheels to arrive at the finish. This is just my arm-chair or hands-off speculation, but perhaps having a wheel on both sides at once acts to support the increasingly fragile hollow as it approaches edge formation?
There are guys that can do fantastic thin, hollow grinds with one wheell. Have you considered the Texas meet? That is an amazing place to get hands on instruction from accomplished makers. There have been a few novices come out of there with some nice razors. It is commonly attended by Bruno, Scott, Charlie, And Victor. They are all happy to hElk everyone and then there are others there with great skills at other things also. I think it is worth considering.
It is not difficult to stuff the grind at the end like that, both with a new grind and a regrind. Even the pros stuff a razor here and there. Charlie has a video called making and scrapping a Lewis razor.
Oh and Bruno has a video on how he does his final grind.
I see. Thanks for the link. Too bad on the thin grind. I wouldnt know what wouls cause that issue being ive never tried this. But i think Rez has a great idea. Go to charlies. Learn what went wrong. Looking forward to your next try.
Dang that sucks, but if it makes you feel better it was a nice looking piece of wobbly metal
Did that on the first razor I made. It’s heart breaking, I sat at the grinder for a day and half then had to throw it in the trash. The next one went much better and took almost half the time. Concentrate on the heel and toe when grinding and the middle will work itself out. Definitely get to Texas meet if you can, the cost of the trip will easily save you the equivalent
in materials and tool set up, let alone the education from the generous and patient makers who attend the meet and so freely share their experience.
The spine looks awfully thin for the width of the blade, if you make another one from that same stock make sure you can get around a 3.7to1 ratio spine width to edge to spine wodth. Make sure to calculate in tape thickness if you’re going to plan on using tape to hone.
I suspect that when you were getting close to finished the edge was deflecting away from the wheel so you were taking metal away from the area behind the edge, kind of like what happens if you hone a full hollow with too much pressure.
I support the edge with my fingertips directly behind the edge when things are getting thin. I get close to finish with 60 grit, and very close with 80 grit, then just clean up with higher grits. The coarser grits cut cooler and you can make progress with less pressure.
An 8" wheel should have a plenty big enough radius to keep from hollowing out the center if there is no deflection at the size of razor that you were making. But yeah if you're happy with a heavier grind use a 10".
Good first try!
Will try that next time. Will use the 10” wheel and give myself a little more wiggle room.Quote:
Originally Posted by bluesman7
Any site ls that give an idea of wheel size/blade width and the hollow?
I’d like to repeat the math lessen I got from Victor on the chalk board at Charlie’s to answer that specific question, but I’m not that good of a student.
Not that I know of. I've worked the math on several sizes.Quote:
Originally Posted by Doc226
Vic is always trying to show me math to explain things. I just wish it would sink in.
Keep trying and i know you will get it Doc!
Well, you can do the math and use the wheel that the math points to, and then adjust to what you actually got. As your skill improves the wheels start acting more true to size. When you're sloppy with your grinding the wheels behave as if they are bigger. If you are getting deflection the wheels behave as if they're smaller. So there is a bit of art to it.Quote:
Originally Posted by Gasman
I would stick with the 8" wheel. I like the 4" wheel the best for most razor grinding.Quote:
Originally Posted by Doc226
There is a lot of great advice in this thread, I wish I could think of answer to why it happened. I have made the same error multiple times. I tend to pay so much attention to the edge and just assume it is thicker behind the edge. The area of the curve where the flat behind the edge transitions to the curve of the blade gets ground a lot during process, it is easy to make it too thin. Copying the way Bruno grinds the edge half of the blade improved my grinding a lot.
Another thing that I thought of; I mentioned doing most of the post HT grinding with relatively coarse grits because in another thread you said that you were using 320 grit. If your belt was getting dull it leads to using more pressure= more deflection.
I don't usually pay much attention to the math of selecting wheel diameter. Sometimes I just use what I got, which by the conventional wisdom is usually way too small. Like @bluesman7 said, the grind does not necessarily precisely reflect the wheel diameter. In a perfect world I would have two professional grade 72" x whatever grinders in twin configuration with lots and lots of contact wheels. The reality is a bit different and I have clamped my share of belt sanders upside down in the bench vise. A twin grinder is on my list of projects to do. Unfortunately it is a long list. When you are retired, you never get a day off.
Makes senseQuote:
Originally Posted by bluesman7
It was a fun project even though it ended in failureQuote:
Originally Posted by CrescentCityRazors
Single grinder is enough for me
The perfect world? Do I note a bit of "ting-ting" at 1:00-1:02?
https://www.youtube.com/watch?v=Kb8VvmyN9vk
Love the little twin grinding wheels! Cute! I think I know what I want for Christmas next year!Quote:
Originally Posted by Brontosaurus
Doc-I'm sure you are familiar with the story of how many different filaments Edison tried that ended in "failure" before he found the magic for his light bulb in tungsten (over 100 as I recall). As I don't grind or hammer steel, I admire guys who do, and have no doubt that you will nail it soon. I for one look forward to your 1st finished custom razor. Judging by your past work, I know it will be a beauty!
Wheel diameter has little to do with the hollow diameter because you typically don't grind with the entire hollow in contact.
Also about heating to cherry red: don't focus too much on the color itself. When you are heating, it will turn reddisd orange. At some point you'll see the brightness make a jump and it will be much brighter. That is when you know you are austenizing properly.
Looks like a 6/8” wedge is in the future for that blade, just saying, or it’s just on the learning pile