Post what you do for a cooling system if you have one for your grinding wheels...

REK Knives · Jul 21, 2012

I am interested in those of you out there who have a bench grinder settup that you sharpen knives on - but not paper wheels. I am speaking of true stone/bonded abrasive wheels that need to be cooled. How do you have it set up? If you can post pics, that would be much appreciated. The issue I run into is that I have 8" wheels, but the housing for my bench grinder are made for 6" wheels, so I can't really use that to catch the coolant as it flings off of the wheel...

ConBon · Jul 22, 2012

A dripper, which I am planning on making soon, sounds like a good plan to prolong the time I can grind between quenches. Hang a resevoir 6-12" above the wheel, and a wire from the hole down for the drops to follow down to within 1" or so of where metal meets wheel. Just a thought, but a pedal actuated dripper would be sweet; although I don't know how one could make it work fluidly (pun intended) but keep it compact.

REK Knives · Jul 23, 2012

sweet! please post pics when you get it done... I am no engineer so it would be quite a challenge to rig this thing up =)

Komitadjie · Jul 23, 2012

Head for your local home-improvement store, and back to the irrigation section. Pick up a couple of the fittings intended to take a quarter-inch tube up to a sprinker on a stake, grab some quarter-inch tube and a micro-valve for controlling drip lines. Lop the top half off of a two-litre bottle, punch the drip fitting into the side of the bottle bottom near the base (with a squirt of silicone if needed), pop a loop of wire through the top to hang it from, and drop a string either from the ceiling or from one of those plant-hanger hooks above the grinder to hold it. Tie your string to the nozzle of the valve, fill the reservour with water, and adjust the valve for the drip rate you want. Total project cost around five bucks, most likely.

Or get a grinder with a slower wheel speed.

Bill DeShivs · Jul 23, 2012

Most bench grinder wheels are not designed to be run wet! A bonded stone wheel spinning ar 3450 RPM, wet is a deadly explosion waiting to happen!
Water-cooled grinders use a slow moving (200-300 RPM) wheels.

REK Knives · Jul 23, 2012

Yeah but what if i dont run it like the tormek, lets say (ie. The lower half of the wheel submersed) but rather just do barely enough water or lubricant to just keep it slightly moist....i was planning on running my grinder at 1700 rpm since its variable speed too

Kom, how would you make sure the water that dripped onto the wheel wouldnt spray everywhere?

eKretz · Jul 24, 2012

Bill, that info is incorrect. Bonded wheels are used wet all the time in machine shops with surface grinders. The wheels used are functionally and effectively no different than the wheels used on bench grinders. A drip system as recommended by the member above is the only practical way to implement a cooling system on a bench grinder. There is no real good way to contain the spray from the wheel other than to contain as much of the wheel as possible in a wheel guard/shroud. Soaking the wheel is not recommended as it will cause an out of balance condition. (Major vibration for a short time). So, don't turn on the water until after the grinder is on and up to speed, and turn off the water and let the wheel continue to run for a minute or two to make sure most of the water is flung out of the wheel. This will ensure that your next startup of the grinder doesn't result in a walking/dancing grinder (if it isn't bolted down) or a possible catastrophic failure of the wheel (this will only happen if you have a damaged or majorly out of concentricity/balance wheel).

Komitadjie · Jul 24, 2012

There WOULD be spray, but I would try to drip in such a place that the bulk of the spray went straight downward along the front of the wheel. The spark shields should stop 95% of it from coming all the way back around. At that speed, it WILL be slightly messy, though. I don't really see a way to avoid that, given the massive centripetal acceleration there.

REK Knives · Jul 24, 2012

yeah you're right... but i removed all shielding and shrouds off of my grinder, lol... the reason primarily being that i got a 6" grinder but put the 8" paper wheels on them. my new grinding wheel will be at least 8" in diameter as well (looking at getting a custom CBN wheel made, i'll keep you guys posted). I'm not sure at this point if it will hurt it to run it dry, but i'm staying in touch with the abrasives company - should hear something back tomorrow about my wheel from them. i'll try to ask them when they contact me...

I was wondering if something like what this lady did in her video would work... i'm not thinking that it necessarily has to be water either, i could go w/ chainsaw oil like she did if it would work with CBN. We'll see =)

[video=youtube_share;bnvUraY7B78]http://youtu.be/bnvUraY7B78[/video]

ConBon · Jul 27, 2012

Dont think a pedal actuated dripper is necessary, just need to make a dripper that will drip at a slow and steady rate.