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aboard_epsilon
08-18-2011, 09:22 AM
JUST THE0IRES AND GUESSES ..FEEL FREE TO POINT OUT MY ERRORS

Ive noticed that the wheels have a larger center hole than the arbor ..maybe 0.25 -0.5 mm larger, than the the hole in the stone its self ..this has been confirmed when i asked my engineer friend Alwyn ..he has also noticed .

this is mostly OK ..you put a diamond on the wheel and true it up ..and all is well ..I'm getting fantastic finishes ..no problem ..

Until you touch down a bit too harshly ..then ..i think it will move the wheel that amount on the arbor ..

necessitating you diamonding it again ..

now then ..on eBay ive seen aluminium foil tape ..do you guys think a rap of this around the arbor would help to eliminate the problems ..

here's a tip ..as well ..

very important..ive found ..especially on my j&s grinder.......is that you clean the wheelheads leadscrew....the grinding dust seems to be able to get in the back of the machine ..settle on the lead screw and turn into a paste ....which then gives false positive ..the weight of the wheelhead can settle into the paste in the nut half way across a grind ..and cause it to grind deeper ..that's my theory anyway ..

and this accumulation is no good at all for your lead screw ..as far as wear is concerned ..so if you use your grinder a lot ..clean the lead screw regularly ..and oil daily..or before every use ..so that any crud is flushed off it .

this also goes for all the other oiling points ..its more important to oil every time you use it..as you are flushing off the grinding dust ..so preventing wear

all the best.markj

PixMan
08-18-2011, 09:45 AM
Something is definitely not right.

The bore on the wheels shouldn't be that much larger than the wheel arbor. Surface grinder wheels should have a babbit bearing surface on the bore that's been machined to be just a "couple thousandsths" bigger than the shaft they slide onto. No matter, they should NOT be moving under even moderately heavy operation. Are you using the paper blotters on the wheels? Do you have the wrong-hand threads on the arbor?

I've never even see the elevation screw (I think this is what you mean) on my Kent surface grinder. OK, I saw it once when I pulled the sheel covers off to check condition and lubrication shortly after getting the machine, but there was nothing wrong. Is your machine missing a guard or cover from somewhere?

aboard_epsilon
08-18-2011, 10:11 AM
The wheel head ...no babbit..they moved on from that in about 1965 ..this has ball bearing wheel head ..

the wheels dont seem to have babbit in them ..Ive never seen a wheel with babbit in it

they seem to have some sort of darker ceramic clay/mortar or epoxy resin like material in them ..all of them do ..i have here about 20 grinding wheels all top makes by different companies...even meant for different grinders ..
Mrs Evan Williams may no better

far as i know ..no guards are missing ..despite the designers doing there best to keep the dust out ..it finds its way in ..would help if i had water cooling on it ..that's for another day .

http://www.lathes.co.uk/jonesandshipman/page4.html

all the best.markj

dalee100
08-18-2011, 10:15 AM
Hi,

That ain't right if he wheel is moving. You either have the wrong sized wheel, or the spindle arbor has been messed with. Even without blotters, it shouldn't move. The wheel should be a slip fit with little or no discernible movement when you mount it.

While grinder dust tends to get everywhere, particularly when dry grinding, it shouldn't require cleaning the screw every time. It is possible to over lubricate and thereby attracting unwanted grit. A thin film is all that's really required. And if you are having that much trouble, I'd seriously consider running the screw dry. You can't possibly be using the machine that hard or often. And in any case, the screw doesn't move often or much.

dalee

PixMan
08-18-2011, 10:45 AM
Perhaps it's not babbitt in the wheels, but there's that "substance" you describe in the bores of all 13 wheels I have. They all fit onto the array of wheel adapters I have quite snugly. I wasn't referring to the spindle construction at all.

One of the 8" wheels I have is a Norton 5SG46 seeded gel wheel which I've run very aggressively and nothing has moved.

I suggest you get some actual measurements of the spindle and the wheels to see which is faulty/worn/beatup.

tdmidget
08-18-2011, 10:55 AM
Yes the wheel can move. It will move just from starting the machine. No grinding wheels haven't had lead (never was Babbitt) in 50 years.
When you tighten the adapter flange, be sure that you have blotters on both sides. Tighten with one hand, you need to hold the wheel with the other anyway. Then put your spanner in and tap it once with a tool similar in size and weight to the spanner. That's all it needs. Start the machine and let it run at least 1 minute. Then dress and go to work.
You should not be contacting the workpiece hard enough to move the wheel.