Home Built Surface Grinder

bmilleker said:
How are you not rolling edges?
I have, what I think, is a 90 duro wheel. I roll edges. Aside from the rolled edges, its accurate and precise. I need to find an aluminum contact wheel.....[/QUOTE]

Contact Mr. Reeder. I am sure he can easily make a 5" aluminum wheel with the required bearings. My guess is will run $100-125.
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bmilleker said:
How are you not rolling edges?

I have, what I think, is a 90 duro wheel. I roll edges. Aside from the rolled edges, its accurate and precise. I need to find an aluminum contact wheel.....
Click to expand...

How big of advances are you making? I've had the best results with very fine advances towards the wheel. If you're forcing the advance too hard I think the rounding will happen easier since the wheel will have to compress and ride up the ends of your work.
 
Well this is how it turned out. Is it the most elegant solution? NOpe.... But I was able to fit this new chuck onto the SGA with the materials I had on hand.

There are 2 negatives I can think of right now:
  1. It increased the weight of the SGA by about 5 lbs (this isn't a big deal in my opinion when using in the horizontal position)
  2. It shortened the over all usable chuck length vs the one I originally made. This could for sure be an issue on longer knives than I normally make.
As yall saw on my previous post, it performed pretty gosh darn well. So we'll see if it can keep it up in the months to come.







Cheers,
RBO
 
A very good video - it's up to your usual standards for sure. Thank you for taking the time to do the video.

I do like that chuck, but at $300+ I'll not be rushing out to order one just yet. I do like it :)
 
Ken H> said:
A very good video - it's up to your usual standards for sure. Thank you for taking the time to do the video.

I do like that chuck, but at $300+ I'll not be rushing out to order one just yet. I do like it :)
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For grinding already flat steel you don t need this .BUT if there is slightly bow in knife ..............shimming knife for grinding that bow on permanent magnet.......... i would like to see how someone do that :)
 
Yes, clever "kid". Would be interesting to combine this idea with the SGA's as built in this thread. Maybe wind up with a simplified form of a traditional surface grinder. Thinking of a dedicated machine (not an attachment for a 2x72) could be a direct mount stone as in this video or a contact wheel and grinding belt. But instead of the fiberglass and bolts table, an xyz table/rail and magnetic chuck. Or just an xy table/rail with a magnetic chuck, and a motor/wheel that moves up and down.
Saludos
 
My first home made SG was a heavy duty drawer slide with a 100 pound pull fishing magnet mounted on the slide part. I would screw one end to the bench behind the contact wheel just snug enough to hold it in place. I would slide a block of wood under the slide to raise the other end until the magnet and knife would just touch the wheel/belt. I would pull the slide in and out as I slowly moved the block back to cut deeper. It worked pretty good for what it was.
 
Natlek said:
For grinding already flat steel you don t need this .BUT if there is slightly bow in knife ..............shimming knife for grinding that bow on permanent magnet.......... i would like to see how someone do that :)
Click to expand...
. fit the shim on a granite surface plate before putting the blade on the chuck.
 
I think I might like the idea of filling the magnet slots with epoxy for a smooth finish. Should make it easier to wipe dust of chuck. That would be easy to do - I don't use the slots for wedges to prevent objects from sliding very often. I'll think about that some.
 
Alright, you guys got me. I'm jumping in!

So far I have ordered the cross slide, the rail, and the wheel.

The wheel I ordered custom from sunray. I ordered a smooth wheel, 6x2.5" with 75D hardness, which their rep, Devin Carswell (very nice guy, by the way. Answered all my questions and patiently explained the difference between A and D hardness for rubber), tells me is the hardest they have, and says 75D is about as hard as a bowling ball. It was roughly $145 after shipping, so more expensive than the Ali Express wheel, but I do feel good about supporting an American company, and I think it will be worth it in the end. I wanted the extra half inch so I can run wider belts, though I don't believe I can get Trizact belts wider than 2".

32mm Metal Cross Slide,Z008M Y/Z Metal Cross Block,Small Body and Great Performance,for Z-Axis and Y-Axis Machining - - Amazon.com

32mm Metal Cross Slide,Z008M Y/Z Metal Cross Block,Small Body and Great Performance,for Z-Axis and Y-Axis Machining - - Amazon.com
www.amazon.com

VXB Brand SGR20 2' feet Compact Linear Motion Guide Rail 2 Feet Long + SGB20UU-5 Bearing Block: Amazon.com: Industrial & Scientific

VXB Brand SGR20 2' feet Compact Linear Motion Guide Rail 2 Feet Long + SGB20UU-5 Bearing Block: Amazon.com: Industrial & Scientific
www.amazon.com
 
That's a nice slide setup for sure. I like the 5 bearing version - wish I had that. You'll find more uses for the SGA than you ever imagined, and a hard wheel is best for best finish.
 
Ken H> said:
That's a nice slide setup for sure. I like the 5 bearing version - wish I had that. You'll find more uses for the SGA than you ever imagined, and a hard wheel is best for best finish.
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I'm imagining tapered tangs, flattening bolsters & scales, and reducing my hand sanding work. Am I missing anything? šŸ˜
 
distal taper to blades, as you use the SGA you'll find more things to use it for. Also, I do like the 2.5" wide wheel. That gives a tad more room for the belt to move around on.
 
Ken H> said:
distal taper to blades, as you use the SGA you'll find more things to use it for. Also, I do like the 2.5" wide wheel. That gives a tad more room for the belt to move around on.
Click to expand...
Question for you, Ken. I saw an older post of yours where you first built a 2.5" chuck and then a 2" chuck. What was your reasoning for the smaller chuck? I'm wondering if I should go for 2 or 2.5.
 
If I wrote I first built a 2.5" chuck then I mis-wrote. My first was a 2" chuck using 2" wheel. Since many chef blades are 2" wide I wanted a bit wider so built a 2.5 chuck to replace the original 2" chuck. I also got a 3" wheel - I wanted a 2.5" wide wheel, but the 3" was available to order.
 
Ken H> said:
If I wrote I first built a 2.5" chuck then I mis-wrote. My first was a 2" chuck using 2" wheel. Since many chef blades are 2" wide I wanted a bit wider so built a 2.5 chuck to replace the original 2" chuck. I also got a 3" wheel - I wanted a 2.5" wide wheel, but the 3" was available to order.
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I might have misread it. So I would be happier with the wider chuck to go with the wider wheel like I planned, by the sound of it.
 
Got the cross slide and the rail from amazon this week. The cross slide was smaller than I expected, so rather than mounting the bearing block directly to it, I'm having to come up with an adapter plate to go between.

The rail is impressing me with its smoothness and overall quality. I didn't expect a 100 dollar part to be that smooth.

Does anyone happen to know the bolt size for the SGR20n bearing block? My calipers are reading about .200" or 5.03mm. I'm thinking maybe M5 bolts would work?

Edit: Never mind on the bolt size. I watched Red Beard's video again and it seems that the bolts are M6.
 
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