Snap ring groove cutter

[Brian Rupnow]

My Grandma was right!! Idle hands are the Devils workshop!!! This week, I've been pretty darned idle. To the point where I have started building those tools that you only need "Once in a blue moon!!" I occasionally have to put snap ring grooves in small shafts, ranging from 3/16" up to 3/8". Up until now, I have "made do" by clamping a hacksaw blade to my toolpost in the lathe. Yesterday afternoon, I designed one which will fit into my AXA toolholder, which is a lot more secure and a lot safer. Hacksaw blades seem to be just the right width for this. I know I could have ground down an HSS toolbit and accomplished the same thing, however I have a lifetime supply of hacksaw blades so thought I would do it this way. Note that on the drawing there are a couple of dimensions with ### or *** after them. They are to remind you to measure your own hacksaw blade to use in this rig. My hacksaw blades are .027" thick x 0.458" wide--yours might be different.

 

[Brian Rupnow]

These are the parts disassembled. The cut in the cover plate isn't supposed to be there. I was using up some stock that I had, and that little cut doesn't impair the way the tool works.

 

[Brian Rupnow]

And here we are, all assembled.

 

[Brian Rupnow]

And here is the tool in the lathe, and a couple of grooves cut into a piece of cold rolled steel.

 

[Brian Rupnow]

At first I tried the hacksaw blade with no top-rake, like I would normally use for aluminum, but it didn't want to "bite" into the cold rolled steel. Then I ground a 10 degree +/- top rake on the top of the hacksaw blade, and it started curling out chips like nobody's business. I wouldn't dare use this for a cut-off, but it certainly has no problems going in deep enough for a snap ring groove.---Brian

 

[SilverSanJuan]

That's great stuff, Brian! Thanks for sharing it. I'm gonna be doing a lot of "groovin'" on my locomotive project, so this'll come in handy.

Todd

 

[deverett]

Well published design, Brian.

Most hacksaw blades these days are bi-metallic, with the teeth being HSS and the rest of the blade being somewhat softer.

I use hacksaw blades in a holder similar to yours for parting off small items as well as grooving, but grind the tops of the teeth off so that the cutting edge is the same thickness as the rest of the blade, (removing the kerf?). Just the teeth, so that the HSS is still available for cutting. Using a stone in the Dremeloid, it is not too difficult to thin the lower part of the blade to create some clearance.

One broken blade lasts for more than a year!

Dave
The Emerald Isle

 

[Brian Rupnow]

Dave--My neighbour runs a small import/export company, and somehow??? ended up with a gross of hacksaw multi-packs. These blades are cheap junk, and after cutting one thing the teeth are dull. However the blades are harder than the devils horn and will snap like a candy cane. Its almost as if they were hardened but never annealed in their manufacturing process. As I said in an earlier post, I have a lifetime supply of the darn things. They aren't that great as hacksaw blades, but they make a great tool for making annular grooves. They seem to be as hard on the non toothed side as on the toothed side.---Brian

 

[gus]

Hi Brian,

Been thinking and wanting to DIY one of this. Thanks.

 

[aonemarine]

Adding to my to do list...

 

[deverett]

Here's my version, shoulda' posted pics last time:





Dave
The Emerald Isle

 

[Herbiev]

Great idea Brian. Thanks for sharing.

 

[tatt2s4don]

I have a sherline lathe with a cut off tool holder its great had to grind a bit on the side of the blade to the thickness of a snap ring it works good to get the depth use a pin that fit in a snap ring or E clip


Sent from my iPhone using Model Engines