Thread: An idea for a contact grinder.

Is there some sort of guide that follows the stiddie stick? (other than the drum sander itself)

Originally Posted by tintin

Is there some sort of guide that follows the stiddie stick? (other than the drum sander itself)

Here's a visual of how I'll use it. The guide is just the stick itself and the way it holds the blank.



Added for clarity:

All the stick is doing, really, is protecting the part of the blank that will become the spine and shoulder, so all I can grind on is the blade face.

You’re doing a rattler grind? I envisioned a hollow grind. Your template makes way more sense now.

Originally Posted by jfk742

You’re doing a rattler grind? I envisioned a hollow grind. Your template makes way more sense now.

Yup!

Based on the experiments I've done, this design is better suited to the tools I've got (IE, no contact grinder yet, which is ironic considering the thread title).

A fixture made of Corian counter top material would be sturdy and allow the use of hardware. Also, it can be machined with normal wood working equipment.

YMMV
~Richard
Local cabinet supply house could help locate sufficient atcha low cost.

Maybe a thin piece of metal across the wood guide to cut down on it changing from use? Rattler. Ok. I got it now. Otherwise it was going to be a REAL wedge!

That makes more sense now. Thanks for sharing the method.

Originally Posted by Gasman

Maybe a thin piece of metal across the wood guide to cut down on it changing from use? Rattler. Ok. I got it now. Otherwise it was going to be a REAL wedge!

Monday I’m gonna call some of the local countertop places and see if they’ve got any Corian cutoffs I can use, because that is a great idea!

I also may just make it on the mill out of a block of aluminum. Still pondering my options.

Just now I relalized I can just cut a piece off the block I cut the blades from to get the spine shape for fitting without doing anything fancy with cuting this gizmo out.

Things are slowed because I don’t have a dust collection system, and the weather hasn’t really been cooperative enough to roll the drill press outside and grind out there.

So, I’ve been doing some work on making punches for washers.



The method I settled on for these was to get the rough dimensions using the lathe tools, then doing all the rounded bits by using a file on the part while it’s spinning, then smoothing it all out with some sandpaper.

I settled on an unusual way of making a negative mold using a block of solder and some sheet metal.

Basically, I spin the cut die into the solder until it melts down to the right depth, then I stick a piece of galvanized steel under the die then sqush those together while it’s spinning until the solder gets hot enough to braze onto the galvanized metal which has been polished smooth by my cut die.

THEN I can stick the brass sheet between the two and get a really clean impression.

The next step is to make a proper, compact piece that has a punch that slides into it to knock out the center hole. I’ve made the second punch, but haven’t had a chance to make the part that holds the solder & sheet metal.

It sounds very complicated, but it’s really pretty simple and a surprisingly effective way of making a negative mold.

Also, heat treat. I should probably heat treat at least the punch die.

Originally Posted by Voidmonster

Here's a visual of how I'll use it. The guide is just the stick itself and the way it holds the blank.



Added for clarity:

All the stick is doing, really, is protecting the part of the blank that will become the spine and shoulder, so all I can grind on is the blade face.

Man I'm loving this thread!
Inventing/engineering/designing is something that I enjoy doing. Even if its been done, its interesting to note that many of the "lost" ways are realized again as the process takes the most logical and "human created" steps to completion..
Basically, the same reason completely unconnected people on opposite sides of the planet will invent the same things, and develop the same methods.
I was drawing out similar plans for a blade jig and so am excited to see this development in your project! Yours looks way better than mine, more professional.
Have you considered a track for the jig to slide on?
I like Richard's suggestion on jig material.
Also Jerry said something, let me see if I'm getting it right: attaching metal in spots of high friction? Perhaps stainless sheet, or bumpers?
Perhaps this would minimize variance over a number of blades, and instead of replacing the whole jig, a new sheet or bumper can be replaced..?
Various jigs and track assemblies can be made depending on what part of the blade needs to be ground, to hold the blade different and move it past the grinding wheel in just the right way.
Seems very repeatable.
Thanks for the updates, good stuff here!

Watching and learning. Although I may never join in, it is fun to learn things from the ground up. I really like the traditional look Zak!