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cylindrical grinding versus honing

drcoelho

Stainless
Joined
Feb 19, 2017
Location
Los Altos
Assuming the work envelope matches, if one had a high quality cylindrical grinder such as a Studer S20 with both OD and ID setup, is this machine capable of doing most if not everything a honing machine can do?
 
Hi drcoelho:
The short answer is "no"

The reasons are many, but in essence, internal cylindrical grinding will be be a much better fit for some geometries than for others.
A simple example is a long skinny bore...simple to hone and impossible to cylindrical grind.
A counter example...a blind short bore; easily ground but very difficult to hone.

Another fundamental consideration; if you want to correct the location of an undersized bore you may grind it successfully but you cannot move it's location by honing.
Obversely, if you must preserve the location but only want to increase the diameter it's easy to hone but may be extraordinarily difficult to set up accurately for grinding.

So although both work in the same tolerance band, they are complementary processes with a zone of overlap.
A truly complete shop that works in this tolerance range has both.

Cheers
Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining
 
Marcus, very helpful feedback. I'm struggling with running out of space in my shop....curious what you think about the following product: PEMAMO SA | Machines et outils de rodage | Suisse Hand Honing Apparatus. Attractive to me because I could skip the dedicated honing machine and just attach this thing to my lathe or milling machine....what do you think?
 
Hi again drcoelho:
The thing I've always found with attachments over dedicated machines is that as soon as you intend to use it more than occasionally, it becomes a PITA to set up and to tear back down.
It seems to be always needed just when you have the machine it's going on set up for something else unless you are by nature a good project planner.

Having a dedicated machine is sooo nice, but only if you have the space for it; even rolling it out from under a bench and plugging it in will make you interrupt your workflow to some extent, but if you don't have the space then it's worth having something rather than nothing, and the unit you link to seems to be of high quality and will serve you well.

Having said that, I can typically bore within a thou without trying and I can bore within a few tenths with care and attention, so I've typically lapped accurate bores with simple cheap barrel laps rather than honing them, but it's a significantly more painful process than honing and it's a lot slower if you have substantial material to remove or many parts to process especially if you have to get them all the same.
Of course, now that I have a wire EDM I just wire cut them whenever possible, but that's beside the point here.

I think it's a nice unit...if you can spend the money and want to hone bores it'll serve you well; it just won't be as convenient as a Sunnen all set up and ready to go.
Plan for a good sized mess when you use it, and try to make some kind of convenient splash guarding you can install and tear down easily.

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining
 
Assuming the work envelope matches, if one had a high quality cylindrical grinder such as a Studer S20 with both OD and ID setup, is this machine capable of doing most if not everything a honing machine can do?
I love ID grinders. Not combo machines, dedicated internal grinders. You can put the hole exactly where you want it, size control is more positive, interruptions like keyways and splines are no problem, surface finish is more controllable, they are very hand-friendly to run, it's just really nice.

But if none of that matters for your parts, then it's not a good deal :(
 
A lot depends on what you are going to be grinding. I did a lot of grinding and honing of cold former dies before I retired. For most ID grinding I used a Bryant ID grinder that probably weighed in at around 5,000 pounds, maybe more. High speed spindle and I could grind a carbide ID of .380" dia. to within +- .0002 and leave a mirror finish after polishing. Also grind the radius at the bottom of the 3 inch deep hole. Pretty specialized grinding.

We also had a Parker Majestic ID grinder that I used for normal ID grinding. And a whole die room of grinders of various types.

I also had a Sunnen hone and that was pretty handy for cleaning up galled dies and prepping them for polishing. For most shops I think a combo ID/OD grinder would be OK. The ones that we had didn't have coolant so for things like die pins they probably wouldn't be very good even with a cold air gun.
 
The Studer S20 I'm considering will have coolant as well as automatic grind cycles, roundness claim for grinding operations (with live spindle) of 0.000012" (and optionally 0.000008"). Given my space contraints thinking maybe going with cylindrical grinder and using a combination of manual lapping and/or honing adapter attached to mill or lathe.
 
The Studer S20 I'm considering will have coolant as well as automatic grind cycles, roundness claim for grinding operations (with live spindle) of 0.000012" (and optionally 0.000008").
Sorry, but that's silly. A high-production grinder is not sensible for short-run or onesy-twosey use. It's just dumb.

Get a decent Landis 1R and save about fifty thousand dollars.

btw, those numbers are meaningless for you. You're never going to be doing work that requires that, and if you did you won't have tools to measure it.

People get way too carried away on specs.
 
Sorry, but that's silly. A high-production grinder is not sensible for short-run or onesy-twosey use. It's just dumb.

Get a decent Landis 1R and save about fifty thousand dollars.

btw, those numbers are meaningless for you. You're never going to be doing work that requires that, and if you did you won't have tools to measure it.

People get way too carried away on specs.

Hey, I'm just the messenger here....it just seemed to me that with that kind of accurancy, who needs honing....your feedback as usual is greatly valued :)
 
"That kind of accuracy" is only achieved when conditions are perfect. If you have a long diameter to length ratio that changes quickly. Your decision depends on how many parts are being processed. To set up honing or lapping take a very short amount of time and is slower stock removal therefore less scrap on 2-3 part runs.

Studer grinders are the best but ID grinding is tough to master. Say you have a .375 bore x 4 inches. Very difficult to grind. Very easy to hone and hold .0002" dimension. Very very easy to lap and hold .00005 dimension. When you crash a hone or lap the loss is $20-$200. Crash the grinder and WOW.

Many things to think about. Tolerance is not always king.
 
The Studer S20 I'm considering will have coolant as well as automatic grind cycles, roundness claim for grinding operations (with live spindle) of 0.000012" (and optionally 0.000008"). Given my space contraints thinking maybe going with cylindrical grinder and using a combination of manual lapping and/or honing adapter attached to mill or lathe.

Q:, [ is this machine capable of doing most if not everything a honing machine can do?] No.

Each has its place. One problem with grinding is that you must position the part for straight and wobble (radially and axially) and honing can often pick up the straight and wobble with little/less fixturing. With fixturing, grinding can correct straight and wobble when honing can not.

Both can do very good size.
 
Two things I see the hone doing better is a high depth/dia ration (trying grinding 10" 3/4" dia bore) and because it floats if you can lift it you can get a good result. Pick up a a tailstock is and honing bore is quiet doable - it'd be a lot harder to mount that on a revolving workhead for grinding.
 
It occurred to me that I have a little 9" southbend lathe sitting around, maybe I could use that for occasional lapping and honing, takes up less space than a full honing machine....dealing with honing oil would be a pain though....maybe just lapping....
 
The hone will be better than the grinder in holes where the length is 5 times or more the diameter. Hones are better suited for short runs. Initial cost will be lower with the hone.
 
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Hone is great and you can sometimes stack thin parts and do them all at once to get around the PITA of thin parts. You should have no trouble at all honing L/D ratios of 2:1 or more. At their very best, both hone and grinder can probably do equal tolerances, but I bet I can hit 20 millionths on the hone more easily then you'll do it on the grinder, assuming you can measure it.
 








 
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