CNC honing machines: what’s out there?

Hey gents,

Silly question: what’s out there for CNC hones? My boss uses an old Sunnen, but we do so much of it on just about every hole on every part, I figure there has to be a better way. We work mostly with aluminum.

Are they just single axis cnc mills with through spindle oil? Do they use probing to check the parts and stone wear? I think I passed by one at IMTS, didn’t look like anything special. Other than that I’ve never seen one used nor know anyone that had one.

More of a curiosity than anything else. I doubt it’s worth the investment since not a lot of people do it, but I could be wrong.

There's companies that make plated abrasive sleeves that are mounted to adjustable mandrels for "in machine" honing/sizing.

Diamond Tool Manufacturing - Diamond and CBN Electroplated Tooling Manufacturer for example.

Would something like this work for you?

Milland said:

There's companies that make plated abrasive sleeves that are mounted to adjustable mandrels for "in machine" honing/sizing.

Diamond Tool Manufacturing - Diamond and CBN Electroplated Tooling Manufacturer for example.

Would something like this work for you?

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I’m going to give them a call at some point, haha. Any idea if you need to use a thicker oil?

thunderskunk said:

I’m going to give them a call at some point, haha. Any idea if you need to use a thicker oil?

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I imagine it's a function of abrasive, grain size, material to be removed, depth, etc. I would ask the applications engineer (not just the salesman) at whatever company you call.

I would bet for many applications just your regular (well maintained) coolant would work fine, but if you don't have filtration you may want to add it to the system.

Milland said:

I imagine it's a function of abrasive, grain size, material to be removed, depth, etc. I would ask the applications engineer (not just the salesman) at whatever company you call.

I would bet for many applications just your regular (well maintained) coolant would work fine, but if you don't have filtration you may want to add it to the system.

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So I got a hold of a sales guy at lapmaster (clerk said he didn’t know the number for the applications engineer, but the sales guy would. Suuuuuuuuure) and said exactly what you did. Needs a filtration system, but standard coolant works just fine. Just a matter of convincing the boss it’s worth more using spindle time than it is him leaning over the hone for half the week.

It might not be though. I don’t know his shop rate. He certainly has enough work, but probably needs another two machines to catch up enough where on machine honing or a separate CNC hone would pay for itself.

thunderskunk said:

It might not be though. I don’t know his shop rate. He certainly has enough work, but probably needs another two machines to catch up enough where on machine honing or a separate CNC hone would pay for itself.

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Good luck with whatever choice is made. If you do get a honing setup, let us know how it works for you, as well as an idea of the cost. It could help others along the way.

Sunnen makes newer semi-automatic and CNC hones, but they get very pricey for what they are (but what choice do we have sometimes). They have a unit I would suspect is similar in size to what your boss uses if it's like an older 1804-ish era machine. But that unit will run you up about 85K. Engis makes the one-size style hones similar to the DTM ones above if you want to go that route. The sunnen is an expanding mandrel and can be adjusted over a small range. Typically the Engis and DTM hones, once you go over, there's not much accuracy in coming back if you even could. They ride on a tapered mandrel and once you spread the steel that has the abrasive, it may not grab at a smaller size again without you trying to re-crimp it.

thunderskunk said:

Hey gents,

Silly question: what’s out there for CNC hones? My boss uses an old Sunnen, but we do so much of it on just about every hole on every part, I figure there has to be a better way. We work mostly with aluminum.

Are they just single axis cnc mills with through spindle oil? Do they use probing to check the parts and stone wear? I think I passed by one at IMTS, didn’t look like anything special. Other than that I’ve never seen one used nor know anyone that had one.

More of a curiosity than anything else. I doubt it’s worth the investment since not a lot of people do it, but I could be wrong.

Click to expand...

Did you try Google? Not trying (it comes naturally! ) to be a smart ass, but Google shows Sunnen, Rottler, Lapmaster.... Now of course I don't know anything about a cnc hone, but have used a good Sunnen before.

Just curious why you hone almost every hole in aluminum? Long length x diameter ratio? Surface finish, no good boring heads...? Do you do any 'standard' sizes where you could invest in roller burnishing tools?

Mike1974 said:

Did you try Google? Not trying (it comes naturally! ) to be a smart ass, but Google shows Sunnen, Rottler, Lapmaster.... Now of course I don't know anything about a cnc hone, but have used a good Sunnen before.

Just curious why you hone almost every hole in aluminum? Long length x diameter ratio? Surface finish, no good boring heads...? Do you do any 'standard' sizes where you could invest in roller burnishing tools?

Click to expand...

So I tried the mysterious google crystal ball, but it didn’t necessary have the answer for my search. Your questions are a case and point: why are we honing every hole? I’m not sure other companies have the same problem, thus it’s not really all that popular of a question for google. I was trying to get ballpark figures on what some sort of automatic honing setup would cost by looking for a used one. Either I’m not hitting the right buzz words or they’re not really out there.

I just talked to a company today who said the majority of their holes are held to such a tight tolerance in their mills, honing isn’t required. I guess the owner of my company just feels we can’t get that sort of precision from our machine and tooling setups. Or maybe that’s just the way it’s been done for so long he figures if it ain’t broken don’t fix it.

Call Sunnen and ask to have your sales rep contact you. The guy in your area is more than a salesman he also knows applications. The diamond plated tools have there place usually in high volume dedicated jobs. If you a job shop and do a hundred of this and fifty of that they aren't your answer. Sunnen has new machines that fill the gap for job shops talk to them.