Slip joint nail nick

S

Steve Beckwith

Joined
May 29, 2004
Messages
393
I have just acquired, free of charge, a Jet model 16 mill/drill. I have no experience with a mill but I'll learn. Anyhoo, I have been making slip joints and using a Dremel to cut my nail nicks. This is an ok method but I believe a fly cutter would give a nicer looking end result. I would appreciate any feedback related to this. I see fly cutters online with HSS inserts that are quite cheap. Will these work? What speed should I use? What lube should i use? I have been using primarily 15N20 for my blades and springs. Thanks, Steve B
 
Wow... free mill. Thats very kind...

A cutoffdics with an angle on de cutting face works very nicely to... support the disc to prevent up and down wobble en redress the angle several times during cutting.

Its cheap, easy and gives you nail nicks like this one.
its not the only way. Just my way...
vizdYXc.jpg
 
Free mill is most excellent! I use a dovetail cutter for my nicks, and go slow rpm wise...real slow.
 
I've tried the fly cutter with pretty good success in the past, but lately I've just been using a 45 degree dovetail cutter that gives clean and consistent results.
 
What diameter dovetail cutter do you use? Is it a 45°? or 60°? Is the diameter large enough to make the nick by just moving inward? OR, do you move lengthwise also to make the nick?

I use a flycutter set to about 3" diameter and with a .040" deep cut it puts about 3/4" long nick just moving inward without any lengthwise movement.

One possible problem with 15N20 using a flycutter or dovetail is how hard is it? Most of the 15N20 I've got is in the 40 to 45 Rc range making it hard to cut. The grinding disk would work nicely for that.

Later
 
Ken H> said:
What diameter dovetail cutter do you use? Is it a 45°? or 60°? Is the diameter large enough to make the nick by just moving inward? OR, do you move lengthwise also to make the nick?
Click to expand...

I have these same questions. Although I'd probably lean to 60* cutter based on some info from a maker who tells me he uses a 2.75" 60* single angle cutter. I'd like to go that route as well but I just don't have the scratch for an arbor right now.
 
Joseph H, what kind of cut off disc are you using? That is a really crisp cut. Steve Culver, who wrote "Slip-joint Folder Design and Building ", said he uses a Dremel disc that he dresses the edge of but the only one I could find like he described are too soft and don't cut a crisp Nick. I have been using Dremel cutoff discs but they are only good for a thin slot. It works but...
Drew, with the dovetail cutter what lube do you use?
Ken H, will high speed steel that comes with the fly cutter work or do I need carbide? The steel I have came from JT. It is saw blade material and I had to anneal it but it machines easily pre heat treat. I realize stainless does make a better product and I have had JT heat treat some AEB-L but I like the instant gratification of the 15N20. I screw up a part on occasion and I can remake the part and move on fairly quickly.
Addition: I looked at dovetail cutters on Amazon. How do you hold a 3" blade? I ask this question because, again, I have absolutely no milling experience.
 
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I can try to give info on using a flycutter, but it won't come close to being as helpful as watching a decent video. You might try this one:

I've used HSS for the cutter, but they didn't last long at all, maybe one or two nicks at most. I wound up grinding a carbide tip to shape and using that.
 
You can use any cutoff disc. I use these.
Ayd7abq.jpg

The trick is to sand the top an bottom flat to 600 grit. Sand it completely flat till its solid and smooth. Adjust the the size and angle of the cutting face to your likings.

When cutting a nail nick, make sure to support the disc so it doesnt wobble up and down. It will move left to right a bit. This is my setup and the results are consistent. Its a bit, well... it is what it is. Little space and no room for a mill. But it works well.
6CZwVXJ.jpg

Start slow, go faster if you dare and finish slow. Redress the cuttingface during the grinding or at least before finishing slow. Make sure your blade stays in place.
Hope it is helpfull.
Grt
Joseph
 
That's an interesting setup - and it sure makes a NICE nail nick for you. I've got plenty of those cutoff disks around to use in a 4" grinder. You use sandpaper on backed with a block to do the shaping?
 
Ken H> said:
That's an interesting setup - and it sure makes a NICE nail nick for you. I've got plenty of those cutoff disks around to use in a 4" grinder. You use sandpaper on backed with a block to do the shaping?
Click to expand...
Thanks...
Most important to me is, I can break it all down and store it so my workspace is clean and empty. Stil thinking about making it of metal and in one piece.

I use cheap diamond stones. 120, 400 and 600 grit. I use them to flatten the top and bottom, as well as for the shaping for the edge.

Grt
Joseph
 
Signalprick said:
I have these same questions. Although I'd probably lean to 60* cutter based on some info from a maker who tells me he uses a 2.75" 60* single angle cutter. I'd like to go that route as well but I just don't have the scratch for an arbor right now.
Click to expand...
Ken H> said:
What diameter dovetail cutter do you use? Is it a 45°? or 60°? Is the diameter large enough to make the nick by just moving inward? OR, do you move lengthwise also to make the nick?

I use a flycutter set to about 3" diameter and with a .040" deep cut it puts about 3/4" long nick just moving inward without any lengthwise movement.

One possible problem with 15N20 using a flycutter or dovetail is how hard is it? Most of the 15N20 I've got is in the 40 to 45 Rc range making it hard to cut. The grinding disk would work nicely for that.

Later
Click to expand...

I started with a 60 degree cutter, but the nick seemed a little wide to me. I like the results much better with a 45 degree. The diameter is around 1-3/8" if I recall. I probably wouldn't want to go smaller than that, though a little wider wouldn't hurt.
Typically I just try to traverse in about 2/3 the blade thickness or so (Y axis). You can move left to right (X axis), but you will have a parallel line at the top of your nick, instead of the more traditional round/crescent, which I don't think looks quite as nice. With a 1-3/8" minimum diameter, the nick should be plenty wide after feeding straight in.

As for cutting harder steel, I typically use 1095 or 8670 that's annealed pretty soft, so I haven't had issues, but I'd definitely use a slow feed and speed with some good cutting fluid, or maybe see if I could find a carbide dovetail. It's be pricey, but the results are worth it, IMO. Maybe by a cheap one and see what you think, and if the 15N20 eats it up too quick, go with a carbide.
 
Good info all. Is thread cutting fluid ok for lubrication? I have some ideas regarding holding the blade while cutting the nick. I'll have to play with that.
 
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