WTB CNC grinding equipment

Hello,
My employer is looking to buy:

1) a machine which could CNC grind complex splines, to finish the outer profile of rotors such as the one seen here:

This part is currently CNC milled and then polished as separate steps, but with grinding, we could save time and be more accurate (+/- 0.0005 or better would be great)

2) A machine to make crankshafts more efficiently
Currently, we use a lathe and an OD grinder, and have to make many fixtures to handle eccentric journals. A "crankshaft grinding machine" looks like it can grind on multiple axes in 1 setup (we only need 2 axes)

Maybe these two could be the same machine. We're open to new or used, and any advice about where to look/ what types of machines are out there/ etc is appreciated. Thank you.

Mark Winsor said:

1) a machine which could CNC grind complex splines, to finish the outer profile of rotors ... This part is currently CNC milled and then polished as separate steps, but with grinding, we could save time and be more accurate (+/- 0.0005 or better would be great)

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In the gear world, that's not what's called a spline. That's more a cad term for a curve, in gear splines you'd be thinking of something like fine-pitch teeth. That part might work well on an nc jig grinder ? Moore ! And not so expensive, because the market is limited ? There are gear grinders that could do it - maybe Hofler - but quite expensive if that's the only job you want to do on it.

Need budget.

btw, Gleason spent a couple million dollars developing a machine to grind Wankel rotors, somewhat similar to the piece you show. Unfortunately for Gleason the wankel never took off ....

2) A machine to make crankshafts more efficiently

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This is called - ta-daaa ! - a crank grinder. Common, but pretty sure an nc one is going to be expensive. Manual ones are not that bad but take some experience. Not magic, just practice.

You didn't give a budget (again) ... determining factor will be how much you want to spend. I mean, can afford to spend, none of us wants to spend a plug nickel

Give Parker Majestic a call, their CNC cylindrical grinder is capable grinding non round punches within tenths. Clever concept, seen it in action at IMTS

https://www.parkermajestic.com/

Studer grinders can do what you're looking for. They have grinders and software optimized for grinding curves/splines/polygons. United Grinding is the US distributor. UNITED GRINDING North America | Precision Grinding Machines

Well if we're gonna go off in search of big money, call Fives. Landis CNC cam grinder. Million and a half twenty years ago, no idea now. What you have to watch out for if you're going to grind that way tho is the reentrant curve in your photo. Need a smaller wheel than normal for that. Smaller than that curve, for sure.

Actually hate to say this, but saw a taiwan cnc cam grinder that would probably work for smaller production numbers. Looked pretty clean, but certainly no Landis.

I do not see the part to be ground or a print.
With no information you ask for a grinding machine.
Big end simply go to Untied with a whole range of machines and perhaps overkill.
This very easy if you have half a million dollars in the checkbook.
Different if you have sixty large.
Bob

There's a red arrow pointing right at the part to be ground, in the image I posted. Can't share prints without NDA, and I don't think they're needed for this discussion. I'm only looking for suggestions where to look. I want the cheapest machine that will do the job well. Thanks for the advice, I will check a few of these out.

I'm thinking it was Supertec in Taiwan that had a not-bad-looking cnc cam grinder that should do your rotor-thingy grinding. That'll be the least expensive choice for sure.

Although if you're not making very many, still think a jig grinder could work.

Not sure the inside rads involved but that looks like a small wheel needed which throws a lot of machines out the window.
Cams do not have this reverse inside cut so grinders for it use bigger wheels.
CNC Jig grinder yes but oh so slow.
Perhaps a CNC punch grinder?
Low cost? It is possible to grind such on a decent VMC.
One could rough mill and then finish grind all in one part clamping.
Bob

CarbideBob said:

Not sure the inside rads involved but that looks like a small wheel needed which throws a lot of machines out the window.
Cams do not have this reverse inside cut so grinders for it use bigger wheels.

Click to expand...

It's possible. Sportsters (for one) do, they are termed "re-entrant curves", Andrews has four of the Landises grinding those ... mil and a half apiece tho. A few of the manual cam grinders can as well, basically using a swingdown-type internal attachment for small wheels. In fact anyone grinding hi-po cams for roller followers probably can.

There's a good chance any of the companies whose cam grinders are an offshoot of their standard grinders can add a small-wheel attachment.