Try googling " Dressing grinding wheel ". I just did it and found lots of good information. A star wheel dresser will revive the wheel on your bench grinder. Even if the grinding wheel on your bench grinder is not a good wheel, you still need to get a dressing tool. You will need it with even the best grinding wheel. So why not get one now and try it out on your current wheel?
So much to learn, so little time. While you are learning machining, I am learning about Analog Devices DDS's. Have fun.
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Thats on the list too - but a flat diamond dresser like I learned to use at school. Funny, machining started as a sideline to homebrew electronics stuff - its taken on a life of its own!....the fly cutter is to machine some plastic I am making into spacers for 450R ladder line from a HF doublet antenna - the wife has now got her ham license and wants a station inside the house, so am putting one together for her....the metalworking skills are coming in useful, the new mast outside her craft room window is mostly built (with removable couplings turned from steel, with drain holes, and water barriers, and nicely turned pins to hold them together....got a bit carried away, but hey, I can now do it, so why not...all good practice) and reasonable welds to hold the tubing together - the spacers are to keep the ladder line clear of the pole.....so it doesnt whip against the pole and create disturbance in the cosmic flow of Domestic Harmony....
(Honey, I know its 3am, its pissing down with rain, but I can hear something banging around outside - will you go and have a look?)
Bought some 8mm steel rod today at the hardware, will practice on that to get geometry right - and even it will machine soft plastic of the kitchen cutting board variety. The "real" fly cutter can wait till I have a need for it on hard materials. (and learn to machine a bit better as well...)
Having fun, stuffing around, in between all the other stuff that gets in the way - ie, wife, kids, dog, house, job, etc etc....
Dan, I suspect the AD devices are like machining - wade through the stuff written by guys in long robes wearing pointy hats covered in stars, and it devolves down to what does the job you need it to do. And its a new language which doesn't help either - but sheer determination and doggedness will get there in the end. It doesn't matter you can go and BUY one - thats not the point...
And thanks everyone for the comments - some not necessarily making much sense now, but in time they will .....
Use a singlepoint diamond to reshape the stone. The star wheel dressers work best for cleaning the surface of cut and otherwise non-cutting grit particles (the cause of hot work, due to more friction than cutting).
Read some of the info available on the internet when you have some time. There are times to use a flat diamond dresser, times to use a single point diamond, but I suspect the best dresser for your bench grinder would be a star dresser. The star dresser will put a surface on your wheel that will cut better than the surface gotten from using a diamond dresser. Here are some words from Harold.
"The heating is a sign of nothing. It is impossible to grind without generating heat. What is important is how the wheel is dressed, and how long you grind before quenching. Star type dressers do the best job of preparing a wheel for grinding, but they are difficult to use if you expect a wheel that runs true. They waste a lot of the wheel as you keep trying to improve the wheel condition. Diamond dressing is a poor method for offhand grinding because diamonds leave a wheel surface too smooth, necessitating greater pressure on the item in order to get it to grind. The wheel, in a sense, behaves as a bearing surface. A diamond, however, will true up a wheel with no problems, and by wasting almost none of the wheel in the process. The best of all worlds is a wheel that has been diamond dressed to flatten it and get it running dead true, then slightly roughed up with a dressing stick, but not one of the solid boron carbide variety. They leave a wheel in worse condition than a diamond does. If a boron carbide stick is rounded at all, it tends to dull the grain of a wheel, making it abrade rather than cut. That leads to very poor grinding, and considerably more heating. The dressing stick in question is usually a 1" square block that is 6" long when new, and has the appearance of a very coarse stone, shiny black in color."
================== Commercially available face mills and carbide insert fly cutters [like the B-58] are reasonably enough optimized for commercial high volume use in rigid high power machines, where the cost of tooling is included in the job bid price, and stocking a variety of inserts in the tool crib is accepted practice. Many of these tools are designed with negative/negative rake.
In many [but not all] home/hobby shops, the mills are low power and lightly built. From a power point, positive rake tools are desirable, as are smaller size tools with 5/8 or 1/2-inch shanks [e.g. 1/2 inch is the max size #2 MT collet available, 5/8 inch is the max ER25 collet]
The "standard" fly cutter is designed for a single tool bit set with 0/0 radial/axial rake. Of course you can grind in rake/hook, but as you sharpen the tool you are also cutting it in two.
In general, home/hobby shop equipment does not have the power/speed and more importantly the rigidity to effectively use carbide tooling.
Creation of a fly cutter with built in axial/radial rake [possibly 2, one for aluminum (c. +15 degrees) and one for steel (c +7 degrees)] using inexpensive M2 late tool bits that most any home/hobby shop machinist can easily shape/sharpen on a belt/disk sander or inexpensive grinder makes perfect sense.
Fabrication of such a fly cutter is well within the capabilities of all but the newest machinists, and requires only a minimum of tooling, and inexpensive materials [1/2 or 5/8 inch stripper bolt for the shank and a 2 X 2 X 1_1/2 block of steel], while providing very useful practice in precision layout, shop math, set up and milling. If 4 tool bits are used it is easy to set the cutter up so that you have rougher and finisher tools, and can employ different grinds/geometries. Try to buy one of those!!! Negative radial [chips to outside] positive axial fly cutters are also easily created.
FWIW - the commercial insert face mills use negative radial [chips to the outside] positive axial rake because the volume of chips produced and the number of inserts tends to trap the chips "inside" the face mill. With only 2 or 4 tool bits and much lower chip generation because of limited power, a multi tool fly cutter on home shop equipment does not have this problem.
How many people would like plans for such a fly cutter?
Unka' George [George McDuffee] ============ Merchants have no country. The mere spot they stand on does not constitute so strong an attachment as that from which they draw their gains.
Thomas Jefferson (1743-1826), U.S. president. Letter, 17 March 1814.
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