6" Baldor Carbide Grinder-Wheels?

[kroll]

Good morning guys,Bill that is an awesome setup you have. I wish I would have had that ideal,it would have save myself some $ for sure. I like the ideal of using tool post that is also a fantastic ideal. If possible could you talk little about your wheels, I like to find couple good wheels for my grinder guessing two different grits but which one's and I think wheel hardness? Any links would also help lot,I been looking over at Shars but like others there are so many choices out there.
Baddog- Thank you for your post,you are spot on describing me to a T. Well I do have a Rockwell 11" so this is what I need to tool up with this lathe in mined.Yesterday for the first time I turned the rpms up as high it would go and made a pass,I could hear the rpms change but not really that big up a cut. Anyway I don't feel comfortable at that rpm(not use to it I guess) so slowed it back down. What is fantastic is the way Harold wrote up his post on grinding made so much since and with help of your post I need to just learn more and make myself to start to use both carbide inserts and HSS. About month ago I wanted to grind a cutter for a 1/4 radius which i gave it try,but all it did was rub it and not cut it. I had watch Youtube on grinding radius but just didn't work so I gave up. But in your post a person who can grind to make just about any cutter and that's what I want to do. Guys I know that making these cutters its all about the skill but I need a starting point which for me its wheels either for my tool grinder or bench grinder. I just want to focus on HSS for now. So any suggestions for wheels, reading material,Youtubes,articles/post. Thanks guys for hanging with me on this

[BadDog]

but all it did was rub it and not cut it

With respect to the tool grind, that's almost certainly lack of clearance all the way up to the sharp edge. It could also be tool presentation above center line such that the edge isn't the first part to touch. And finally, too much lead angle can create excessive pressures pushing the tool away, though that's generally going to cause less depth of cut than indicated (rather than just "rubbing"), which can be amplified by lack of rigidity in the tool stack (saddle->compound->tool-post->tool-block->tool overhang). Combine more than one of these being any less than ideal, and you've lost all together.

You've also noticed the deficiency of the Rockwell 11" (and related/similar machines). They are a bit underpowered, and loss of mechanical advantage when cranking up the speed leaves you with very little torque to maintain speed in a cut, and working against mechanical advantage will slip the Reeves Drive belts if not in top condition. I had to make 6 steel cylinders on mine that were 5" diameter and 6" tall (IIRC). They were faced both ends with a hollow relief on one side (prevent rocking setting on concrete, pedestals for new big lathe) and flat with a 2" dia x 0.5" deep conical divot in the center of the other side, OD was just cleaned up and trued for cosmetics. That was a MISERABLE job even with the speed run down to get correct cutting sfpm and slow feed. Even with sharp positive HSS, only very light cuts could be taken without stalling the machine (and I had rebuilt the Reeves, motor stalled).

Higher speeds for larger diameters having less mechanical advantage are largely the domain of aluminum with fairly light cuts. And particularly on most common aluminum alloys, finish is much improved by higher speed cuts. You kinda have to work hard to run aluminum "too fast".

[Bill Shields]

Ask harold about wheels..not me

[kroll]

Guys I have receive some good information, I was told that I need to search for Type 50 Plate mounted wheels. Which google did that for me and several wheels did come up. But what about grit,what grit should I go with for either side? 60 grit for rough then 120 for finish? Which is what I found on net but just want this to be one time purchase so want to get it right. My plan is to just grid on bench grinder to rough size and shape then to carbide grinder. Also read like here to use the white aluminum oxide wheels and not the green wheels on carbide grinder.

[Bill Shields]

Wheel i use is 150 grit for finishing. I do roughing on a clunky old hand grinder that predates wwii.

[Bill Shields]

or maybe it is 120 - Harold is the person to ask about this. whatever I have, i purchased on his recommendation.

whatever grit it is...it is white alum oxide for HSS cutters

[Harold_V]

Actually, an 80 grit wheel is as fine as I'd recommend, assuming you're shaping cutting tools, and even that's too fine for roughing. If a person has more than one wheel as an option, a 46 for roughing and an 80 for finishing is more than adequate. Finer wheels cut hotter, and slower, but yield a better finish. That's not nearly as critical as it may seem, as (proper) honing of the tool after shaping will address the finish adequately. If you're limited to one wheel, choose an 60 grit wheel and keep it properly dressed and it will serve quite nicely.

If one prefers a much finer wheel, it would be best if it was softer than normally recommended. Fine wheels cut hotter even when they're sharp, so one's choice should be soft enough to slough off somewhat prematurely, so the wheel can continue to work as hoped. I don't really recommend extremely fine wheels unless form grinding is necessary.

There's a host of new wheels on the market since my years of grinding experience. Sadly, I'm unable to address them, as I have no experience with their use.

H

[kroll]

Fantastic thanks Harold,I will go with what you recommend,then watch few YouTube on honing that’s something I haven’t gave any thought