Inexpensive graver hogger, Mark II by Rod Cameron

rod

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I was chatting with our colleague, Katherine Plumer, about quickly hogging down graver blanks, ready for the hand sharpening with her existing set of Lindsay diamond stroppers. The basic idea can be applied if instead you own a universal-angle graver-fixture.

Pay no attention to this post, if you have money-making commissions on your bench, since you can lift your phone and have an excellent high/low rpm unit already on offer. Pay no attention also, if you have one of Carl B's nice drilling machine adaptations.

If you are cash strapped, have time to spare, and looking for an inexpensive solution, or if you just plain enjoy making up your own stuff, then take a look:

This is my mark II cheap hogger design, and it can take a blank down to shape in three minutes, and save elbow grease, so the last hand, or slow rpm shaping is more enjoyable.

I threw it together from left-overs in my shop which had been gathering dust in a corner.

You will find the small bench grinder online ... Google " images "... mini bench grinder .. Amazon.com has various prices. It is variable speed, up to 10,000 rpm, but we only need about 2000 rpm. With a flex drive included, mine cost $45 a few years back. Note, I have discarded the flex drive and put two handy stones on one side for roughing and finishing HHS. On the other end, I mounted a wood disc which nicely fits a 2 inch diameter rough diamond drum. This diamond hogging drum cost me $3 in a surplus toolstore. It is hollow, and light weight.

Tip: mount the wood disc onto the shaft while still slightly big, and hand turn it down to fit the inside of the thin diamond drum, that way it will be spinning very true, and next to no vibration.

Search around for one of these diamond drums, if not, use a $17 diamond drill sharpener diamond wheel:

Google...drill sharpener wheel replacement.

Yes, ideally you would make the unit to use flat disc laps, but this approach converts a bench grinder and leaves it to do other grinding chores.

My Mark I used a rather heavy and large diamond wheel, but Mark II is quite light, and so hardly any vibration. To a small graver, coming down on the top of a curved wheel circumference feels more or less like it is on a flat surface, and after all, we are only hogging off surplus material, before precise hand stropping on the flat diamond laps. Remember, the landscape where I stand feels pretty flat, but it ain't, its a round planet!

The pictures below tell the story. The little brass constraining rods will keep the graver on the top of the curve, but if you are used to tools you don't really need them. Leonardo from Barcelona suggested the constraint.

Tip: This small grinder has a push on/off, and turn the knob for speed control. It will tend to increase speed without a load, so I like to have one hand on the speed control and the other bearing down on the graver/template then I can dial the speed/load easily.

Tip: Have some super magnet discs anywhere near your graver sharpening setup... see a cluster of them under the diamond drum in the photos, and just watch them grab steel filings out of the air rather than you breathing them in.

Want an idea for a Mark III hogger? If you already own one of those small inexpensive bench belt/disc sanders, put your rough flat disc diamond lap on where the disc sanding plate is, turn the lightweight unit 90 degrees on its side with the disc now horizontal and do something similar.

Okay, okay .... I will stop here!

Now back to flutes.

Rod
 

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