Plunge Cuts

DustinY

DustinY

Joined
Dec 29, 2016
Messages
754
I know i've seen Kyle Royer use like a horizontal plate attachment with a radius on it for plunge cuts, what do you guys recommend? Are there videos or good reference material for this? Also, I don't have a glass platen and have been wanting to install one on my flat platen.

Regards,

Dustin Young
 
I use a bevel guide, like what you’re describing. At first I used two little rectangles of stainless steel and just clamped them down evenly with a 1” C clamp from the hardware store! Then Bruce Bump was making a run in Stainless with Carbide inserts and I bought one. There around under the name of File Guide. EBay , knife supply stores etc. if you’re going to buy one, make sure they have two bolts to tighten evenly & that it’s made of Stainless you will be dunking the blade in your bucket . In case no ones mentioned it. I put simple green or dish soap to break the surface tension and thr grit will sink to the bottom.. stay safe & have Fun!
 
I made my own file guide with built in screws to tighten out of scraps left over from cutting out blanks. Did not even harden it (just throw it on the grinder to even up and flatten the ends. I was amazed at how well it worked. Treat it as disposable - grind and flatten until you cant any more. I have more scraps from my last profile run that will get turned into file guides.

there are several youtube videos on how to make them. Took me about half an hour...
 
DustinY said:
I know i've seen Kyle Royer use like a horizontal plate attachment with a radius on it for plunge cuts, what do you guys recommend? Are there videos or good reference material for this? Also, I don't have a glass platen and have been wanting to install one on my flat platen.

Regards,

Dustin Young
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I'm curious now, do you have a video how Kyle does it?
 
razor-edge-knives said:
I'm curious now, do you have a video how Kyle does it?
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Yes, I can probably find it. He runs his belt over a piece of radiused steel, places the blade length wise, and drives the knife up the steel into the radius steel to finish the bevels.


And yes, I am talking about what nick is showing here. I have a file guide with carbide tips but I’m looking for more on how to get perfect, consistent, radius plunge cuts every time.
 
Redmeadow Knives said:
If I understand correctly you're talking about dressing the plunge radius? Here's Nick Wheeler's version and a great video on the subject. A large piece of angle iron with the edge radiused works well also.
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This is good, and watched it last night, but people do this on the belt sander. Which addresses the issues of having a gouge sanded into the blade.
 
DustinY said:
This is good, and watched it last night, but people do this on the belt sander. Which addresses the issues of having a gouge sanded into the blade.
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Dustin, I don t know how you grind your bevels....free hand or with some jig . I use jig and here how i do that .I grind bevels slightly forward then where I want to be plunge .After I finish bevels on both side I work on plunge .That give me room for correction and to get nice curve and to make them symmetrical /nice radius on plunge and nice radius curve where plunge line meet upper grinding line , if I explain correctly ? I put jig with knife in line with edge of belt and mark where I want to be plunge line and start to grind BUT i move jig fast forward/to make that radius / I repeat that several time and that is that ......I can get almost 99% symmetrical plunge this way, need some practice of course but i found that this is most easy way for me .


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Just seen the video and wonder: why not tilt the grinder to horizontal and use a 1/4" small wheel with bubble jig? I will surely try both next week I am a firm believer that if you don't try you will never know, I'll let you know.
 
Alex T. said:
Just seen the video and wonder: why not tilt the grinder to horizontal and use a 1/4" small wheel with bubble jig? I will surely try both next week I am a firm believer that if you don't try you will never know, I'll let you know.
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Curious how you plan to set this up? hm
 
Tilt the grinder to horizontal, small wheel becomes vertical, use bubble jig to know the angle of your bevel, set it up, grind the plunge like a bevel.
 
Alex T. said:
Tilt the grinder to horizontal, small wheel becomes vertical, use bubble jig to know the angle of your bevel, set it up, grind the plunge like a bevel.
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1/4" might be small enough, I can't remember if this is the smallest wheel I have or if 1/2" is. Where did you find the 1/4"? I have a TW 90.
 
Oops, looking back I also have a 1/2". But you can buy a 1/4 on knifegrinderpart. If it is not small enough, I would just put a smaller steel rod directly in the small wheel holder, for such a small job it should do the trick. But looking at the radius on his platen, it looks to me like 3/8"- 1/2" ish.
 
DustinY said:

3:20 - 3:42 shows him doing it, and this is what I think makes SO much sense.

Input?
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Ahh yeah I see now. I actually have a similar platen that @Nathan the Machinist made, works really well too, but tbh I don't use it much because I'm grinding all sorts of knives vs. A dedicated design.

And you can get just as good of plunges just by grinding normally, just takes a little more finesse :)
 
Alex T. said:
Oops, looking back I also have a 1/2". But you can buy a 1/4 on knifegrinderpart. If it is not small enough, I would just put a smaller steel rod directly in the small wheel holder, for such a small job it should do the trick. But looking at the radius on his platen, it looks to me like 3/8"- 1/2" ish.
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It won't work... You will get divots /dimples from the small wheel - but feel free to try :)
 
In the past I've seen some Brazilian 'smiths make this same idea of an attachment for their integrals, but here is one attachment (idea) for using a small wheel to do plunges that Chris from Wilmont Grinders sells (it's pretty pricey though):



~Paul
My Youtube Channel
... (Some older vids of some of the older knives I made)
 
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And FWIW, I use Nicks method sometimes to even up the last little bit on the plunges; just get them close before doing so and it isn't too much trouble.

All methods with take practice to get to look good, whether it's the rounded platen end Kyle's using, getting them the way you want during grinding, Nick's method, or Chris's attachment in the video above. Just try one out a see what works best for you.


~Paul
My Youtube Channel
... (Some older vids of some of the older knives I made)
 
Below is also a technique I've also used and found can work well. It helps to use some scrap steel on the edge a j-flex belt to help soften the edge of the belts and kinda "preform" it around the corner. Just make sure the both edges of the platen both the same radius. But again. it takes practice to get right.



~Paul
My Youtube Channel
... (Some older vids of some of the older knives I made)
 
Guys stop, you are getting me way too much pumped up, I have to many things to try :D

I also tought about using a diamond file, if it even exists lol. Could it work on hardened steel?

Edit: diamond ROUND file, or maybe a stone dressed to the proper radius?
 
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