H-M Supporter - Sustaining Member
H-M Platinum Supporter ($50)
- Jul 2, 2014
WOW! Just wow!
Not yet, but I am looking closely at 7" 1A1 diamond grinding wheels, 150 grit, and at the Norton combination stones. For those who do not use stones for cleaning up burs, it really works well and the original geometry and surface can be kept mostly intact when used correctly. Robin's methods kick that idea up by several more notches, and I will definitely be going there...Hey Bob, you have a surface grinder. Are you taking orders?
I am looking at the same stones Robin was using, Norton 61463685560. That was the 6 x 2 x 1".Which stones are you looking at?
I'm not sure how many hobby machinists even think about stoning precision surfaces. From the outset it seems like a bad idea ,and could be if you used "any stone". Once you understand that with the correct stone and technique you won't damage the precision surface. Robin did a good job of explaining that in his video.Very good video, but in all reality does the average hobby machinist need to get the stones that flat, I think its overkill. yor just removing burs
7" O.D., 150 grit, 1-1/4" bore, 1/2" wide, 1/8" thick resin bonded media, 100% concentration. I just ordered one of that description from Shars, p/n 505-2233. $81.00 plus freight from Shars, $91.00 and free shipping on eBay. I went with the eBay order, saved about five bucks. I also ordered the stones today, Norton 6 x 2 x 1" combination aluminum oxide, part number 05108568. $15.99 each.Did Robin mention in the video what diamond wheel he used on surface grinder? If he did I missed it.
OK, but isn’t it a simple lathe operation to make a bushing reducer. Or, am I missing something? My little Sanford has a 1/2” spindle. All my wheels have 1 1/4” holes. I just made some bushings. And the arbor flange and washer still catch the sides of the wheels. All is good now. Note; make sure you use a paper washer on each side of the wheel when mounting…Dave
1-1/4" with a 3" spindle taper per foot is a very common size for surface grinder wheel adapters (hubs). What kind of grinder are you contemplating using? This project requires an accurate grinder and flat and true chuck, a smooth running and tight spindle without runout, and a wheel with near zero runout (well dressed.) Not sure yet, but it might require coolant as well. If you do not have all that, you will not achieve what is needed to make quite flat stones with quite flat abrasive surfaces with a large surface area so they will work correctly. Make sure you understand what Robin is achieving in the video. It is incredibly cool, but not easy to achieve.
Ask Robin the answer to that as a comment to his video. He is so far ahead of me that I would not presume to know the answer. You can bet there is a well considered answer. Robin does not do things "just because." Robin is the most talented machinist I have seen yet, not that I am any kind of an expert. Seriously, ask him, and then report back with what he says...This may be a silly question. Robin rubs his stones back and forth. Would it not be better to rub them in a figure 8 motion? I was wondering if that would help keep them flat.
Thanks, Ken. I will be trying it, too. I do not have flood coolant on my surface grinder and I wonder how the diamond grit in the resin bond will do against the stones. I do have a mister setup I could use, or perhaps a plastic pump bottle like for various household cleaners. It might be good to find a pump bottle that can send a real stream, I will look around in my stuff for one. We want to flatten the grains, not tear them out. Heat could cause problems with the grit coming apart from the bond, or with damaging the resin bond on the wheel. Wisdom?Bob, I picked up a set of stones made by GWHOLE, made in China. I was quite impressed on how flat they are right out the box. Not sure about the quality of the stone. When I rub them together, they seem to wear down producing powdery superfine grit. I also have a set of Norton stones as Robin uses in his video coming sometime next week. When I get them, I'll see how flat they are coming out of the box. Then I'll set up and SG all four stones and report my results. Ken
Let's all keep in the loop on this. I have the diamond wheel and the stones, but it has been blazing hot here (108 F forecast today, 110 F tomorrow) and I have some other things I need to get done as well. I am quite interested if dry grinding will work for this. My plan at this point is to use my mister unit. I wonder if cutting oil or shortening might work?I loved the video and ordered an offshore diamond wheel and 2 - 4" X 1" stones to try out. I intend to dry grind the stones and see what happens. They say that I'll get them some time mid-to-late Jul. Fingers crossed!
Thanks, Dabbler. I am not in my comfort zone with these resin bond wheels. I have a 4" cup wheel with resin bond diamonds, 600 grit, and it works good dry, but I only use it at very slow RPM for sharpening carbide scraper blades. Robin was taking some eye opening plunge cuts in his video, and I don't think I am ready for any of that yet, don't want to destroy the wheel or throw a stone. Speaking of which, are there other work holding ideas beyond the feather board tools Robin was using? Is just blocking them in well with steel near the stone thickness good enough?My friend Bert only dry grinds with his diamond wheels. I know about toxicity of carbide, etc, but from the wheel longevity of the grinding wheel, his have lasted 30 years.
I plan to make a steel fixture for grinding my 4 X 1 stones, consisting of a channel that is wide enough for the stones plus 2 layers of notepad cardboard. There will be set screws along one side to put even force on the stone and a plate at the end for support. I'll pregrind the bottom so the stone will be held flat (or on 3 points as necessary). When I'm done the jig I'll post a photo or 2.Thanks, Dabbler. I am not in my comfort zone with these resin bond wheels. I have a 4" cup wheel with resin bond diamonds, 600 grit, and it works good dry, but I only use it at very slow RPM for sharpening carbide scraper blades. Robin was taking some eye opening plunge cuts in his video, and I don't think I am ready for any of that yet, don't want to destroy the wheel or throw a stone. Speaking of which, are there other work holding ideas beyond the feather board tools Robin was using? Is just blocking them in well with steel near the stone thickness good enough?