# Engraver Power Hone - or carbide tool sharpening device



## Holescreek (Feb 8, 2018)

I gotta be honest, I couldn't figure out a better place to post this project.   I've been making all the tools I need to try to learn how to engrave metal.  I have everything done to the point that I may actually be able to put some deep scratches in steel soon.  The last item I finished is referred to as a "power hone" but is actually more like a 6" record player with a diamond blade on top.   The basic idea is that you use fixtures to hold carbide blanks at the proper angles to create graver bits.  After using it, I started seeing where it could be useful for carbide lathe tools too.

In a nutshell, I used a sewing machine motor I got off Ebay a long time ago for about $12. I looked at the motor speed and the size of the motor pulley and calculated the diameter of my platen pulley to give me a max RPM of 1000.  I have bearings above and below the platen pulley for the shaft to ride in.  all the materials were made from metal laying round the shop.  The 3 diamond discs also come from Ebay.  I got a 240 grit, 600, and 3000 for about $12 shipped from China.

The speed control is a $19 Harbor freight router speed control that I disassembled and remounted in the end plate of the unit.  The steel box is just 20 gauge sheet metal.

THe last photo is just a prop to show how the fixtures hold the carbide at the necessary angle. The fixture lets you grind 3 sides of the tip without removing the carbide tool.


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## mikey (Feb 8, 2018)

Very nice job, Holescreek! I bet that puts a nice edge on your gravers.


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## Rooster (Feb 9, 2018)

I like it very much.


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## Holescreek (Feb 9, 2018)

For those looking for motors, this is about the closest I could find to the one I used on Ebay today:



https://www.ebay.com/itm/1-Home-Sew...hash=item439d0e71f4:m:mm7RqAEV7Y5MZK2gLHuetNg


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## hman (Feb 12, 2018)

I like your grinder!  You can sometimes find an entire sewing machine at Goodwill or similar stores for as low as $25 - $2 less than the listed motor + shipping price in the ebay ad.  Garage sales are another source.  

Alternatively, if you can score a ceiling fan and extract the motor, you can mount the grinding wheel directly to it with a suitable arbor (quick lathe project).  Speeds range from about 100 to 400 RPM.


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## Holescreek (Feb 12, 2018)

I like that!  I might look at making one like that with a 1  1/4" adapter for diamond grinding wheels.


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## Janderso (Jan 19, 2020)

Holescreek,
Thank you for the motor source.
I may still go that direction.
What is the rpm?


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## middle.road (Jan 19, 2020)

Now I know what I can possibly do with those two ceiling fans I've been hoarding in the shed.  
Blades sagged and they were tossed.
There's also two old time sewing machines out there. . .

(just commented to Honey about this idea, and the reply was 'hmmmm...'. I don't think she's impressed with my idea.)


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## middle.road (Jan 19, 2020)

(hijacking the thread...) 
I've been chewing on this all day. Bought the discs months ago when I was going to make a scraper.
So if you're using a ceiling fan motor you get the (3) speeds, L,M,H - is there any loss of torque?


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## Holescreek (Jan 19, 2020)

Janderso said:


> Holescreek,
> Thank you for the motor source.
> I may still go that direction.
> What is the rpm?



The sewing machine motor looks like it's marked 7000 rpm in the photo. I used pulleys to reduce the rpm to 1000 max.


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## hman (Jan 20, 2020)

middle.road said:


> So if you're using a ceiling fan motor you get the (3) speeds, L,M,H - is there any loss of torque?


I just checked my homebrew grinder (shown in post #5) and a second similar one I'd made for my shop in Oregon.  Both are easy to stall by just grabbing the edges of the disk.  This is true for all speeds.  Not really an issue when grinding on a disk that small (~5" diameter), as I've mainly used the grinders for shaping glass. Might possibly be more of a problem when grinding tool bits.

Recall that a ceiling fan comes up to speed pretty slowly from a dead stop.  They aren't very powerful.


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## Bob Korves (Jan 20, 2020)

middle.road said:


> is there any loss of torque?


Torque is not a big issue with grinding scraper blades, a 20 watt motor is likely overkill, but if the grinder is going to be multi purpose, and especially if it is dialed down from the highest motor speed, or has an inefficient drive train, then a bigger motor will likely be needed.


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## middle.road (Jan 20, 2020)

Here's what I'm thinking. I've got a couple of these 'grinders' floating around and they have bearings and not bushings.
I've had a dream of doing up a SloMo™ for years.
I'm thinking that I can even make them up for 'wet' use since I can mount a motor well away from the wheels.
Only problem might be keeping the bearings dry.
I was considering using a treadmill motor for the one that would use stone wheels and now I'm wondering if I can get by with a ceiling fan motor for the diamond wheels and discs.
I have a set of discs similar to those above plus this 6" wheel.
I'm not even sure yet what speed it should run at.





	

		
			
		

		
	
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## hman (Jan 20, 2020)

My ceiling fan grinders are both wet grinders.  You can see from the second photo in my earlier post that there's a yellow tray (parts sorting tray from HF) below the wheel.  There's a cut down pill bottle glued on and extending upward about an inch above the tray,  A second pill bottle is attached to the spindle below the disk.  It's a bit larger than the other pill bottle and extends downward almost to the tray.  These two sleeves prevent water from dripping down into the motor bearings.

I've rigged up a small reservoir and drip tube that wets the disk.  There's a catch bucket below the spout of the tray.  If you need, I can take some more photos to show details of the arrangement.


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