Bench top surface grinder build. Too much?

Justin Schmidt

Justin Schmidt

Joined
Feb 18, 2016
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So after reading the SGA build thread. It kinda got my wheels turning. Instead of building an attachment for the 2x72 why not just build a benchtop model?
My plan is to use the 2x42 2 wheel system and belts. Using a 4in ruber coated drive wheel as the grinding wheel. But utilize the tracking and tension of the 2x72
Roughly like this:
4lWd4mH.jpg

I wanna use an xy milling table like this: https://www.walmart.com/ip/Grizzly-...0125&wl11=online&wl12=158132534&wl13=&veh=sem
And mount an on /off magnetic chuck on it.
I wanna have the assembly mounted on table welded to a rack and pinion system like on a drill press for the z axis. Picture the milling table underneath this nonsense
JwmVQAP.jpg

But ill probably use a trailer jack that can support 1ton and its cheaper.

Is this too much when i can just do the attachment build?
 
Interesting idea - seems a bit complex, but I'm sure I don't yet follow exactly what you're talking about in design. I'll follow the thread so I understand as you build. Looking forward to your progress.
 
So the blade sits under the belt ? You want to use a drill press rack and pinion to move the blade closer after each pass ??
 
For a DIY Z axis, I would probably put a hard adjust on the grinder and a parallelogram table. I am thinking some sort of dovetail with a clamp for the grinder. It just needs to be adjustable between grindings. For the table I would use either a sliding dovetail or a parallelogram like you would see in a jointer. Because you are probably not worried about losing your X axis zero, either of these systems will give you precise Z axis control at the cost of X axis zero between adjustments. They are also both very stable and you won't lose parallel. Plus you could make either quite easily without a machine shop.
 
Sorry joel your speaking a different language lol im not sure exactly what you mean.
AR what makes you say that. I just forge so im mainly worried about keeping the riccasso flat and paralell and grind in a taper for the hidden tang
 
valknut said:
Sorry joel your speaking a different language lol im not sure exactly what you mean.
AR what makes you say that. I just forge so im mainly worried about keeping the riccasso flat and paralell and grind in a taper for the hidden tang
Click to expand...

I'm assuming that one handle rotation is around .100"? So you'll have to turn the handle 60x to move 6". If you go back and forth 10 times, that's 600 handle revs just for ONE side of the knife. For any real accuracy, you'll want the gibs relatively tight, and for the size of those handles, I'd say you'll be working on a power feed options after about 5 minutes on that thing. ;)

Even with a power feed, that's gonna be a pretty slow way to surface material though....
 
Great point. And probably proof im in way over my head lol.
Maybe the linear guide rail used in the SGA and mount a handle to the side to slide it by hand. But i would want more precise control of the z axis.
 
valknut said:
Great point. And probably proof im in way over my head lol.
Maybe the linear guide rail used in the SGA and mount a handle to the side to slide it by hand. But i would want more precise control of the z axis.
Click to expand...
You should watch Travis's video and then look at the SGA in the other thread...Precise control of the Z axis is done with the hand wheel you will see that is mounted to the mag chuck...looks like they are getting 0.001 or better accuracy. This is a good build project from what I have read and seen in the photos. Also much less expensive than ones that are available!!!
 
Busto said:
You should watch Travis's video and then look at the SGA in the other thread...Precise control of the Z axis is done with the hand wheel you will see that is mounted to the mag chuck...looks like they are getting 0.001 or better accuracy. This is a good build project from what I have read and seen in the photos. Also much less expensive than ones that are available!!!
Click to expand...

Yeah i was gollowing that thread when i got this idea. Im just gonna go with their idea lol itll be less than 300 to build that and gives me an excuse to get a 10in contact wheel
 
valknut said:
Sorry joel your speaking a different language lol im not sure exactly what you mean.
AR what makes you say that. I just forge so im mainly worried about keeping the riccasso flat and paralell and grind in a taper for the hidden tang
Click to expand...

Sorry, I meant htat you should consider a gross adjustment for the Z axis. Stable when locked but not designed to adress pass to pass Z axis adjustment. This would be designed to position the wheel-to-chuck distance within the Z axis adjustment range of your table. You would want this adjustment to be solid, but you dont care about adjustment precision in the thousands.

For precise Z axis adjustment between passes, I recommend one of two mechanisms. The parallelogram method would look similar (you may prefer to make from steel) to:
jointer10.jpg


The sliding dovetail would look like:
Aligning%20Tables.jpg


In both cases, I would use a screw to drive the mechanism.

Both of these techniques provide accurate (though the parallelogram method is more inherently precise) Z axis adjustment. They do lose X axis zero when they are adjusted in the Z axis, but this shouldn't be a concern in this case because you are trying to flatten a knife. A system like either of these would be inherently more accurate than you see on belt grinder attachments.

You can use a sliding rail for the X axis like most of the belt grinder attachments do, and you can eliminate Y axis adjustments if the widest blades you intend to grind are less than 2"
 
I don’t know what real surface grinders go for in your area but up here thy are quite pricy but I was able to snag one for $500. If I was you and it was going to cost $300 or so bucks to build one I would look around and see if you can just buy one. Might take some searching but if I can find s deal up here your most anyone else should be able to.
 
Thanks for the explanation joel. Yeah building one if these is just too far out of my expertise.
JT thats probably what ill end up doing. I have enough projects going on now. Including a PID controlled forge. Trying to figure that out is making my head spin
 
JTknives said:
I don’t know what real surface grinders go for in your area but up here thy are quite pricy but I was able to snag one for $500. If I was you and it was going to cost $300 or so bucks to build one I would look around and see if you can just buy one. Might take some searching but if I can find s deal up here your most anyone else should be able to.
Click to expand...

I found mine locally for just over $400 here in Northwest Indiana, which is less than you could build the attachments in the other thread, though I think those have their place too.
 
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