Perfect timing. I just finished building a fixture to grind horizontal cutters using my surface grinder. So this video was very helpful since I am still learning all this.
I so often see cutters being ground this way. Beats me why. it's labour intensive, involves too many adjustments for different cutter types. So, you have a large collection of cutters to sharpen. (I know that at times, you'll need to sharpen a one-off for a specific job, but generally, we do jobs in batches, saving on set-up time...) Set the wheelhead spindle axis at the same height as the workhead axis (or the centre height of the centres if you're mounting plain mills, etc on arbors between centres) you need never adjust the wheelhead height again in either case. Do all your cutters mounted between centres, then all the wheelhead mounted ones (or vice versa) Primary and secondary clearances are achieved by adjusting the spring finger height. (the only adjustment you need to make during a sharpening run) Use a flared cup wheel for sharpening cutter peripheries. It's used with the wheelhead axis offset perhaps 5 degrees from the work's axis, so presents a more or less 'flat' surface to the tool. The use of the straight wheel's periphery results in a 'hollow' grind behind the cutting edge, weakening that cutting edge... The tooth that's being ground must be supported by the spring finger. Some cutters have staggered tooth spacing that screw up the idea of sharpening your way... So... cutter and wheel axes same height, set your spring finger at that same height, and from that point, drop the spring finger 8.8 thou per degree of clearance per inch of cutter diameter. (it's simple trig. Both sin and tan of one degree are, more or less 0.0175, half of which is 0.087, call it 8.8 thou per inch of cutter diameter., and you never need to remember another figure. For metric, just say you drop the spring finger 0.088 x the cutter diameter in millimetres x the number of degrees clearance you want.. No fuss... Using your method, with the spring finger supporting a tooth other than the one being sharpened, and fixed to the work table, how do you handle helical cutters of any flavour? Paired R & L handed? Staggered tooth? the spring finger must be fixed relative to the wheelhead for those, mustn't it? A spring finger fixed to the wheelhead can handle straight S&F cutters, helical of either hand (and grind pairs of any type on an arbor on one set) and staggered tooth, and chip saws, and slotting cutters of the same diameter on a single set, no raising and lowering of the wheelhead, just adjusting the spring finger height to achieve primary and secondary clearances as required. With some setups, I've used a forked spring finger succesfully, with one "prong" offering support as the cutter approaches the wheel, the other offering support on departure. Seems fiddly at first, becomes routine... And... grinding towards the tool body, rather than the cutting edge deals with the heat generated better... There's a wider path for it... Of course, it's now been 46 years since I ran Clarkson T&C grinders, 50 since I ran Cincinnatis...
Can you also sharpen the side teeth on your milling cutter with your setup? Also, thin (1/16", 3/32" etc. wide) side tooth slitting saws? Would be interested on any video showing this operation as well.
Grinding wheel cutting direction should b opposite... since cutter teeth is resting in opposite direction..if you increase cut size Cutter will rotate in opposite direction direction and accident may occure...
Hello from Bernie. The wheel doesn't reverse with this grinder. It is running in the right direction to form a sharp edge. The reverse rotation will leave a burr.
Perfect timing. I just finished building a fixture to grind horizontal cutters using my surface grinder. So this video was very helpful since I am still learning all this.
Hello from Aus. In a previous video I listed some good books with tool grinding info. BC
excellent!! very well narrated. Great explanation. Thanks for sharing.. More please :)
Nice one 👍
I so often see cutters being ground this way. Beats me why. it's labour intensive, involves too many adjustments for different cutter types.
So, you have a large collection of cutters to sharpen. (I know that at times, you'll need to sharpen a one-off for a specific job, but generally, we do jobs in batches, saving on set-up time...)
Set the wheelhead spindle axis at the same height as the workhead axis (or the centre height of the centres if you're mounting plain mills, etc on arbors between centres) you need never adjust the wheelhead height again in either case. Do all your cutters mounted between centres, then all the wheelhead mounted ones (or vice versa)
Primary and secondary clearances are achieved by adjusting the spring finger height. (the only adjustment you need to make during a sharpening run)
Use a flared cup wheel for sharpening cutter peripheries. It's used with the wheelhead axis offset perhaps 5 degrees from the work's axis, so presents a more or less 'flat' surface to the tool. The use of the straight wheel's periphery results in a 'hollow' grind behind the cutting edge, weakening that cutting edge...
The tooth that's being ground must be supported by the spring finger. Some cutters have staggered tooth spacing that screw up the idea of sharpening your way...
So... cutter and wheel axes same height, set your spring finger at that same height, and from that point, drop the spring finger 8.8 thou per degree of clearance per inch of cutter diameter. (it's simple trig. Both sin and tan of one degree are, more or less 0.0175, half of which is 0.087, call it 8.8 thou per inch of cutter diameter., and you never need to remember another figure. For metric, just say you drop the spring finger 0.088 x the cutter diameter in millimetres x the number of degrees clearance you want.. No fuss...
Using your method, with the spring finger supporting a tooth other than the one being sharpened, and fixed to the work table, how do you handle helical cutters of any flavour? Paired R & L handed? Staggered tooth? the spring finger must be fixed relative to the wheelhead for those, mustn't it? A spring finger fixed to the wheelhead can handle straight S&F cutters, helical of either hand (and grind pairs of any type on an arbor on one set) and staggered tooth, and chip saws, and slotting cutters of the same diameter on a single set, no raising and lowering of the wheelhead, just adjusting the spring finger height to achieve primary and secondary clearances as required.
With some setups, I've used a forked spring finger succesfully, with one "prong" offering support as the cutter approaches the wheel, the other offering support on departure. Seems fiddly at first, becomes routine... And... grinding towards the tool body, rather than the cutting edge deals with the heat generated better... There's a wider path for it...
Of course, it's now been 46 years since I ran Clarkson T&C grinders, 50 since I ran Cincinnatis...
Small and good tool and Cutter machine... i like it...
Nice one Bernie. That cutter was a bit how's your father. Doesn't take long to sharpen once set up.
Gzl
Can you also sharpen the side teeth on your milling cutter with your setup? Also, thin (1/16", 3/32" etc. wide) side tooth slitting saws? Would be interested on any video showing this operation as well.
👍🏻
Very nice work
Thank you Mr. Rusty. I have lost of other T & C videos up. BC
Sharpen it , I did those cutters for years
Do 6 degrees primary close enough
Milling bevel cutter side face pleZ
Grinding wheel cutting direction should b opposite... since cutter teeth is resting in opposite direction..if you increase cut size Cutter will rotate in opposite direction direction and accident may occure...
Hello from Bernie. The wheel doesn't reverse with this grinder. It is running in the right direction to form a sharp edge. The reverse rotation will leave a burr.
@@inmyshedwithbc. Thx for instant reply.... 😀