rough removal of stock with 4 1/2 angle grinder?

[Knifemaker87]

hey everybody...
this is more of a consensus question than a guidance question... perhaps i am wondering if what i am doing is worth continuing.

when i cut out a blank i clean it up on my 6" wheel and then i used my 4 1/2" angle grinder to grind the blade... now i dont care if the blade gets overheated.. becasue i am just gonna normalize andx then heat treat it... but is that okay?
okay... but anyway... i take off a good bit of steel, my reasons being these:
1. i have a crappy grinder and belts are expensive... save as much work where i am grinding "blind" as possible
2. it keeps my blade symetrical (i litterally grind blind) so this keeps the initial angles straght as i can see what i am doing with the angle grinder)
3. it speeds up the process
4. it keeps my plunges symetrical and even.

do any of yall do this? i dont know if i am going to continue doing this now that i have a bader... but even though it is so much better.. i think i actually will.
here is a knife i just finished grinding with the angle grinder:

thanks for your insights!
~Chris

 

[ashtxsniper]

Wow you definitely have a steadier hand with an angle grinder than I do.

 

[Shawn fu]

Chris,I've seen your end results,and if you start with the 4 1/2" what does it really matter-it works for you,and your work is superb!As for me,I still use the 4 1/2(don't tell IG) or a bench grinder or the belt grinder or even a file-If your destination is the same-it doesn't matter what road you take.

 

[delbert ealy]

If you have a bader now, then learn to use it and you will be able to grind in bevels faster and cleaner than you can not with that angle grinder. I have a 4hp 8000rpm angle grinder that I run with 9" wheels and I just use it to grind scale. I use my bader to grind in bevels.
Del

 

[swede2207]

Knifemaker87..first of all that is a ridiculously straight grind with a belt grinder much less an angle grinder..So in essence..keep doing what youre doing brother your work is awesome. I grind my bevels in with my J&L to be honest using an angle grinder never occurred to me. I wouldnt change a thing..Later Luke

 

[richard j]

nothing wrong with what you are doing. i wish i was that steady with an angle grinder. if the end result is a good looking knife, what does it matter how you do it.

 

[grease-man]

Chris, you do outstanding work with what you have already. I agree with Del here. If you get used to the Bader, I think that it would be a great time saver for you. If it makes you feel any better about the cost of belts, I use the AO belts from Supergrit. I'll probably get clobbered for saying that, but it has worked for me so far in my limited experience. -Matt-

 

[heatride]

If you have a bader now, then learn to use it and you will be able to grind in bevels faster and cleaner than you can not with that angle grinder. I have a 4hp 8000rpm angle grinder that I run with 9" wheels and I just use it to grind scale. I use my bader to grind in bevels.
Del

Listen to this man .


Glenn Dykes
Louisiana

 

[silver_pilate]

I always use the 4 1/2" angle grinder to rough out my blanks. I've used the belt grinder and the bench grinder as well, but nothing hogs out a profile like an angle grinder. I've never tried doing bevels, but I'm impressed with what you've done! Anyway, if you get used to grinding on the belt, I think you'll have better overall control of your lines in time, but I've also seen your finished results, and you need to do whatever works for you.

The bottom line is the finished product. I don't care if you hand filed, bench ground, belt ground, angle ground, or licked your bevels onto the knife, if it's done with skill and by hand (or tounge ), I'll appreciate it. Do what you enjoy and what works well for you.

--nathan

 

[the possum]

I use a 6" angle grinder for big blades, because I don't have a decent belt grinder.

now i dont care if the blade gets overheated.. becasue i am just gonna normalize andx then heat treat it... but is that okay?

This is something that has concerned me for a long time, so I've sought advice from guys I trust. In my case, I'm doing only stock removal & having someone else do the heat treating. Since I'm not normalizing it myself, I am rather careful to prevent overheating & the associated stresses. I just make a few passes with the grinder & wipe it down with a wet rag to keep it cool, and flip the blade over & remove and equal amount of steel from the other side to keep things even as I go.

One metallurgist on another forum offered this advice:

Regardless of the piece, I would ALWAYS recommend a stress-relief cycle to reduce residual stresses from processing. This is typically a low temperature, about 700F, for several hours. I would do this after forging, after machining, after normalizing, and before heat treatment - especially after hard grinding.

I have recommended this on thin rotary blades used for cutting, large gears, and landing gear. It always helps.

 

[Knifemaker87]

sweet!
thats really helpful guys.
well i will work with what i have right now... but when the bader comes.. everything changes.
with that blade in the picture grinding the bevels my current grinder chokes up real bad. so.. going from 1/2hp to 2hp is going to be so nice.

and possum thanks for the tip on normalizing.. that is really helpful! i shall do 'er... i'll do 'er the first chanst i get!

thanks yall
~Chris

 

[knifemaniac]

I also use angle grinder 125mm wheel - 11000rpm for rough grinds. I also bought plastic disc for polishing with sandpaper from 40 grit up to 600. My first knife is made this way. You can even polish the blade after hardening like that, but sometimes the steel contaminates with abrasive because of the speed. It is damn hard job to clean contaminated surface. High speed is tricky, so aplly very light preasure after HT. Hope this helps.

 

[langchop]

I tried doing my first knife(s) today chris, using a 115mm angle grinder, although I cheated and made a rig that screws into the side of the angle grinder to keep the bevel angle while grinding (going to upload pics later tonight www.myspace.com/langs_space . That said, I still was not able to get my bevel lines as straight as yours. Great work. I bought a few fine sandpaper pads to finish off with but in the end the finish was pretty decent and I think i will be able to the polishing by hand as it is. I think its a very efficient way to make knives. ( cost of discs compared to belts) A belt would still be nice to finish off though.
A major factor for me is that I can see how the bevel is shaping while im grinding.

Lang

 

[deker]

In the knifemaking class that my blacksmith guild puts on we teach with angle grinders. It's a great way to get started inexpensively. That said, once you've decided to invest in a 2x72, and get comfortable with it, you'll be able to do those bevels a LOT faster I'd bet.

I will say this though. If you have an experienced maker near you, have them show you how to grind and watch you grind a blade or two and give you pointers. Once I had visited J. Neilson and he gave me the Neilson grinding overview I found it made me leaps and bounds better at grinding a nice flat bevel. I'm still nowhere near perfect, but I'm doing a bunch better than I was.

-d

 

[Knifemaker87]

there are a couple guys who make knivea roudn here.. i havent gotten a chance to meet with them but there are a couple. after i get my grinder i am gonna try and hook up with them.
thanks for all the insights guys!
~Chris

 

[SteelSlaver]

If I forge a knife or start with a heavy piece of stock I start out with a 4 1/2 grinder. I can knock off the scale, remove a high spot beside a hammer mark, refine the shape and have the blade on its way to being a fine knife in short order. I have spent many years as a pipefitter and have worn out thousands of disks. Butt welded pipe that is tig welded needs to be square with a knife edge and a good fitter should be able to fit up a 100 inches (diameter) a day so that is 314 inches of steel prepped to a knife edge a day along with setting it up and positioning it to weld. Needles to say the grinder is flying around the pipe. You can do some fine work with them is you want and your pictures prove it. The flapper wheels can smooth things up a bit and they can take a oversized handle block down to reality in short order to. I am getting spoiled by my KMG but, some 4 1/2 grinders will always have spots in my shop.

 

[Don Hanson III]

Git-R-Done!

My forged blades get the angle grinder treatment , before going to the belt gringer. Mainly to get the scale off but I do a bit of stock removal while at it.