Home Built Surface Grinder

[WC53]

Thanks One Armed, I have read the thread several times as wel as the other threads. Trying not to over analyze it while learning about magnetic chucks and the different ways the permanent chucks and their fields work. The thread and the work shared bu you and others has been very helpful

 

[Stromberg Knives]

Not sure why the steel being magnetic, would make it worse?? Seems it would make for a much stronger holding chuck. Although I may just try Aluminum again with more magnets closer together. Really though, the only downside I can see to steel is the weight and it would be more difficult to keep clean. (Because of the magnetism).

On the side, I find it odd that someone who hasn't built one is telling others what WOULD or WOULDN'T work well. (I'm not referring to you Stromberg)

Well, since my profession is in management, sourcing and procurement of IT services I tend to listen to individuals who are a lot more experienced in knifemaking and machining. Kuraki strikes me as a very experienced individual within these areas of expertise and his advice has yet to fail me to this point.

I just wanted to share the advice I received, nothing else.

Personally, even if a permanent magnetic chuck in steel would work just fine, I don't see any added benefit compared to one made in aluminium.

 

[WyldStyl3]

I finally finished mine up Saturday. I bolted it to the tooling arm at an angle though. Mainly so i can use it in the vertical position and not just horizontal, but also because it was just easier to bolt that sliding compound thing to the arm like that.

 

[Stromberg Knives]

I finally finished mine up Saturday. I bolted it to the tooling arm at an angle though. Mainly so i can use it in the vertical position and not just horizontal, but also because it was just easier to bolt that sliding compound thing to the arm like that.

Cool, let's see some pics!

 

[john april]

any good remedies for the steel dust caught between the spaces ? every time i flip the knife its a pain to clean it. i saw the wide scotch tape method mentioned earlier, but it is very hard to keep from tearing it. maybe fill in the slots with epoxy and resurface it, or how about a thin sheet of g10 on the face ? any other ideas ? thanks.

 

[KnuckleDownKnives]

any good remedies for the steel dust caught between the spaces ? every time i flip the knife its a pain to clean it. i saw the wide scotch tape method mentioned earlier, but it is very hard to keep from tearing it. maybe fill in the slots with epoxy and resurface it, or how about a thin sheet of g10 on the face ? any other ideas ? thanks.

I was thinking about this earlier. What about a cutting a piece of those usps tyvek type envelopes. It's very thin and very resistant to tearing. And pretty cheap too...

 

[Jesse Latham]

so i can use it in the vertical position

I did the same. What I found is the linear rail had too much play for vertical.
As I use my S G for ricasso finishing I tape the clean side before doing the second side.

 

[WC53]

Now someone figure out how to make a magnet that turns off

 

[Kevin McGovern]

Now someone figure out how to make a magnet that turns off

They did. But if you want one the size we need, it's going to cost a ton.

 

[KnuckleDownKnives]

I'll bet a dollar on a doughnut placing the tyvek over the mag chuck and placing the blade on it works pretty well.

 

[Kevin McGovern]

I'll bet a dollar on a doughnut placing the tyvek over the mag chuck and placing the blade on it works pretty well.

Probably does. I don't find wiping the dust off to be a problem.

 

[john april]

i will try that with the envelope, thank you. i guess i am worried even one speck of steel dust will change the angle of my tapered tangs.

 

[Stromberg Knives]

I just grab a towel and drag the dust downward (in line with the magnets), it’s simple and works fine. If I want a scratch free side I tape it.

 

[One Armed]

i will try that with the envelope, thank you. i guess i am worried even one speck of steel dust will change the angle of my tapered tangs.

Yeah, I think many of us have felt as you do. But when you really think about it, dealing with a .002" or less margin, specs of dust aren't going to amount to anything. Although I do understand your want of a PERECTLY CLEAN service. This said, the bulk of the shavings is easy enough to wipe off. Just something for the knifemaker to deal with.

 

[tmerkl]

For the contact wheel, the one I'm seeing is listed as 70 durometer...I contacted them about a harder wheel, but there's a minimum 5 piece order to go that route. Have you had any issues with the 70? Anywhere else to source a harder 3" wide contact wheel?

 

[Ken H>]

OK, just got back to this thread this morning after being out of town 3 or so days. I agree that wiping the chuck isn't very hard and cleans just fine. BUT - the SG leaves such a pretty finish I really hate to see the "pretty" side after it sits against the magnetic chuck while grinding the other side, so I put 2" wide scotch tape or tape the other side to protect it. I have resurfaced my chuck 2 or 3 times (doing some rework and changes) so the depth of the magnet bars is getting pretty small at places, and there is a couple of places the magnets are smooth with top of aluminum.

The SG has been one of my most useful projects for the grinder. Thanks One Armed for starting the thread and getting me all fired up.

 

[Toni Oostendorp]

For the contact wheel, the one I'm seeing is listed as 70 durometer...I contacted them about a harder wheel, but there's a minimum 5 piece order to go that route. Have you had any issues with the 70? Anywhere else to source a harder 3" wide contact wheel?

I have a wheel on order from Claryx metal works. Great people to deal with and very high quality. They offer a standard 10” wheel with 80 shore hardness. So I contacted them for a 5”x3” wheel with rhe same hardness. At this moment that wheel is being made custom for me, for a reasonable price.
Less then the standard wheel....

http://claryxmetalworks.com/product/290-contact-wheel/

 

[WC53]

In talking to a guy at Cmc magnets, for this usage, he believed aluminum is better as it will not redirect the field as steel does. He also said to make sure not to grind through the nickel coating as neo corrodes and not to heat above 170 as they start to lose magnetism and above 200 you can permanently reduce the strength.

Some of the magnet theory and workholding using electro permanent magnets is pretty interesting. Of course I only comprehend every third word, so no chance of building one.

Got my iron horse motor yesterday and my platen from OBM shows up tomorrow so I can mock things up for the grinder and then the sga. Going cheap on the build with what steel I have on hand, 2” heavy wall and 1/4 plate. Stitch welds and bolts.

 

[WyldStyl3]

Cool, let's see some pics!

Sorry, saw this the other day at work then forgot all about it.

This is before I milled the magnet channels.

Magnet channels milled and magnets epoxied in. I haven't put magnets in the 2 channels on each end yet as I don't really do anything that long, but they're there if I ever need to.

Now someone figure out how to make a magnet that turns off

I was thinking about getting one of those 2x2x6 switched magnets. They're like a really small version of the magnetic chucks on full size surface grinders. Like below. I was unsure about how to mount it though. I don't know if or where it could be drilled and tapped.

Oh also, I don't really like the ADV sliding table thing. As others have said it does have about .02 or so movement in it once everything is bolted together. I removed the washers that come on it and put more bolts in it to hopefully make it sturdier, but it still has too much slop in my opinion. I'm working on a replacement for it.

 

[Kevin McGovern]

Sorry, saw this the other day at work then forgot all about it.

This is before I milled the magnet channels.

Magnet channels milled and magnets epoxied in. I haven't put magnets in the 2 channels on each end yet as I don't really do anything that long, but they're there if I ever need to.

I was thinking about getting one of those 2x2x6 switched magnets. They're like a really small version of the magnetic chucks on full size surface grinders. Like below. I was unsure about how to mount it though. I don't know if or where it could be drilled and tapped.

Oh also, I don't really like the ADV sliding table thing. As others have said it does have about .02 or so movement in it once everything is bolted together. I removed the washers that come on it and put more bolts in it to hopefully make it sturdier, but it still has too much slop in my opinion. I'm working on a replacement for it.

I noticed when I took the table apart, that some of the holes that hold the sides together are slightly oversized. I think this is on purpose, as when I put it back together I was able to make the fir with the slide tighter simply by pressing them together as I tightened the screws. Mine is VERY tight now and has no slip. You may have to play with the tightness a bit to find the best fit that still allows movement.