[Konrad]

I'm running the CNC Mill and I sure love those coated carbide cutters.

A brand new 1/2", 4 fluted top Quality Kennametal, I can run 2days of milling, verses 2 hours of a sharpened one!

Well....been telling my Boss [He does tool grinding] to look into a coating set up!
But for a small Business, it's Impossible! very expensive proposition!

Is there a small setup out there, lets say, 50 - 100 endmill a week?

What do the small Grinding shops in general do??

Konrad

[HuFlungDung]

Personally, if I'm not running the cutter all that deep, only a relatively small amount of the flute near the end gets worn. So I figure why spoil all that flute that hasn't even tasted iron yet?

Regrinding the flute also erodes the rake angle created between the inside face of the flute relative to the land. The closer you get to the cutter axis, the less positive the flute becomes.

The gullet gets shallower and has more difficulty with expelling the chip in softer materials.

So, to preserve the coating and get an extra life or two out of the cutter, I simply cut it off at the wear depth with a narrow diamond wheel. Then, back off the ends of the teeth a little and then its back to the mill.

[Konrad]

Thanks HuFlungDung,

You are such a busy guy on this forum and a great Inspiration to others, special thanks!
Are you actually getting any machining done yourself, or you have good help?

I should have mentioned, 90% of the time we do the same thing, just re do the ends!
My front edges just don't stand up anymore!

Konrad

[HuFlungDung]

Konrad,

Yes I do get some machining done. Some of it is not too adventuresome, you know, rerunning old programs for the umpteenth time It is nice when something new comes along.

[Mouldmaker]

We also use Kennametal cutters and drills on our machining centre. When they are worn out, we send them back to Kennametal for resharpening and recoating at approximately 1/4 the price of a new tool.

[Konrad]

That sounds reasonable!

Something came in mind, lets say, you recoat a endmill 3 times, are you not getting too much coating
on the tool, where the coating never has touched the Iron?

What's the ideal max # of times, for recoating?

Are most Tool Grinding Shops not getting them recoated????
Toolgrinders, please talk!

Konrad

[sdigeso]

If all your doing is wearing the end of the tool, why don't you look at an inserted tool, wear the inserts only cost you about $12 and you can use them on both ends. I am looking in this at the shop I am in. We only use the end of a 3/4 rougher and then trash them. I will be testing insterted tools hopefully be the end of April.

Just my thoughts.

Scott

[Konrad]

Thanks for your reply Scott,

I'm using also 3/4" dia. 2 flute, inserted tool.

I'm not aware of any smaller cutters, like I have mentioned, 1/2", with inserts.
You just can't substitute a solid "Sharp" [4 flute] carbide tool, with anything else!
When you go this small, the cutting geometry is suffering, when inserts are used.

Konrad

[Mouldmaker]

Konrad,

When recoating a tool, the previous coating hat to be taken off and the cutter is then coated again.

Scott,

We use cutters with inserts when they are above 16mm (0.6 inch), but for a 1 mm (0.039 inch) (or even smaller) cutter you have to use solid carbide cutters.

[Jake]

Hello Konrad !!!

If your working with toolgrinding and wants satisfied customers
you must be able to regrind and recote a tool so that its as good as a new tool or even better.

this means regrinding a standard endmill includes , grinding of flute ( with compensation of the core diameter in relation of the stock removal on the OD) , grinding of the OD 1 & 2 nd clearance,
gashing the end , grinding of the end teeth .

all this operations with the same geometrics as the endmill had when it was new , to read all geometrics you need some kind of a measuring machine , there are vision systems , optical , and manual ones .

now when the tool is regrinded we can recote the tool , ofcourse with the same coating as the original one.

to answer your question about the possibility to recote the tools
there is to my knowledge no cheap coating systems that will pay off with the amount of endmills you wrote , its not very practical either since its realy a lot of steps to put a PVD layer on a tool.
(inspection , off coating , washing , recoating , mm )

why not send the tools to a company that does coating, normaly you will have the tools back in 48 hours.

sorry for writing a novel but since there were other questions i put in the hole package.

best regards // Jake

[Konrad]

Thanks Mouldmaker & Jake,

Yes Jake, it looks like we have to send them out, I have Kennametal to give me a quote.

Since, we just started to grind endmills on a Walter 5 axis CNC machine, there is not a problem anymore to grind the cutters as new, all we need now is the coating on carbide.

How is it with your Carbide Endmills, are they mostly worn on the very end, like from our Customers, or you have to sharpen everything? If you do, then the standard diameter is gone, and that's for some CNC Machinenist, like myself a problem, you have to redo the programs.

Can you recoat the tools yourself, or you have to send them out??
Oh...I just seen your posts on Walter CNC grinders, it looks like you sharpen the tools for the woodindustrie,
Are some of the tools also coated??
Here, I have not seen it yet.

Why your # of Posts still stands on # 5, after you have posted so many times??

Konrad

[CHAD]

QUOTE "How is it with your Carbide Endmills, are they mostly worn on the very end, like from our Customers, or you have to sharpen everything? If you do, then the standard diameter is gone, and that's for some CNC Machinenist, like myself a problem, you have to redo the programs."\

THAT SHOULD NOT BE A PROBLEM AT ALL IF YOU ARE USING CUTTER COMPENSATION, G41\G42 YOU USE THE OFFSET TO COMPENSATE FOR THE TOOL DIAMETER>>>>>>

[Jake]

Hello Konrad !!

No i mostly dont grind woodtools in the Walter machine becouse
of that we are more focused on supporting the metall industrie
although we grind lots of tct sawblades in our walter CNC5 loader
for the wood industrie.

regarding coating woodtools we have tried , but the edges gets
to unsharp , one thing that does work is to coat the tool and then grind either the flute or the od , this works in some applications where you have burn problems.

No we dont coat our tools by ourself becouse of the price of a coating unit , and that the coatings all the time expands and you would have to change your equipment quite often to supply your customers with the latest coatings.

best regards / Jake

[Konrad]

Just got some quotes back from Kennametal.

1/2" 4 flute carbide.

Quantity, doesn't matter, 10 or 100 pieces, same price ea.

They say, they wouldn't do the coating only, because they are not manuf. by them.
So they would only do the whole job, cut off ends, by my recommended length of 1/8" [redo ends only] & recoating for guess how much!.... please sit down!
$33.00 C.D.
Well....I buy them new for $43.00...
Not worth sending them out!....Buy new ones.

We do the sharpening for $14.00
I have to check with a Shop in Vancouver, or just a bit ouside Vancouver what does coating. Does anybody know??

Konrad

[Durkee]

I agree about the price from Kennametal. Doesn't sound like they want to help much, eh? I don't have time to run back thru the thread so I'll try to respond to what I can remeber.

We get $11 usd for a 1/2" four flute carbide, ground all over. Cuttoff if needed is included.

In general, what small grinding shops like myself do, is do the regrind then send them out to be coated. I happen to send mine to one of two places. Either Balzers or Gold Star coating.

As far as regrinds not lasting as long as new, my response is it all depends on the geometry along with the speeds and feeds you are using to grind, what type of coolant is in the grinder, and what shape you keep your wheel packs in just to name a few of the parameters.

I like to get to know the customer. Get them to tell me what it is they are going to try to get accomplished. If it's a tough job that requires special geometries, then I will give the tool a specific part # and save the program to use just for that customers job.

There are an infinite number of ways to grind the same tool. Every toolgrinder has his own ideas, but testing and experience is the key. Don't be fooled into thinking that coating is the cure all. It works great, but it is not necessarily cost effective to coat every tool. Coatings vary widely and are getting very application specific.

Hope I wasn't just babbling and that you could pull something of use from this post.

[Lawncutcraig]

The shop I work at has 2 Walter 5 axis machines that make several carbide em's for customers daily and they might send a dozen a week to be coated. Customers don't want to spend the extra $14.00 to have them coated, thats the cost of a 3/4 carbide EM for are shop. The dull em's with the coating are just cut off behind the dull and then we keyway them.

Craig

[Durkee]

I own a toolgrinding shop and we too use Walter CNC toolgrinders. I'm wondering what you mean keywaying an end mill. Sorry, but I have just never heard that term.

Keith

[Durkee]

Thanks Mouldmaker & Jake,

Yes Jake, it looks like we have to send them out, I have Kennametal to give me a quote.

Since, we just started to grind endmills on a Walter 5 axis CNC machine, there is not a problem anymore to grind the cutters as new, all we need now is the coating on carbide.

How is it with your Carbide Endmills, are they mostly worn on the very end, like from our Customers, or you have to sharpen everything? If you do, then the standard diameter is gone, and that's for some CNC Machinenist, like myself a problem, you have to redo the programs.

Can you recoat the tools yourself, or you have to send them out??
Oh...I just seen your posts on Walter CNC grinders, it looks like you sharpen the tools for the woodindustrie,
Are some of the tools also coated??
Here, I have not seen it yet.

Why your # of Posts still stands on # 5, after you have posted so many times??

Konrad

I have to agree with Chad on this one. There should be absolutely no problem with undersize tooling. Just comp it and away you go. Unless the customers specifically requests that we just cut off the end, we always grind the whole tool. Flute rake included. Most end mills are built to have a very strong edge in order to make it hold up to many different applications. Not always the best way to go. Different applications require different geometry. I try to know my customers well enough to know what they are going to use the tool for and adjust geometries accordingly. That's more than Kennametal can do for you. If it's for a specific job, then we name the program accordingly, adjust geometries for the application, and save the program for the next time. As far as coatings are concerned, we have several sources to use. Turn-around is normally less than a week and rush is possible. It's just not economically feasible to try to get set up for private coating. But we handle everything for the customer. They do not have to send the tooling out themselves. Anything we can do to make the machinists job easier.

Just my 2 cents

Keith

[Lawncutcraig]

Keyway is the trem used in are shop same as cut off and end only or radius. The Walters in are shop has the 400 control with 16hp motors there older machines with all updated software and motors. There considering getting a newer one at around $250.000 Everything we do is geared towards aircraft with quick turn around service. The shop has been in business for 35 years.

[Lawncutcraig]

Keith,
What kind of prices do you get for sharpening 3/4 carbide em's with a comp grind and a corner radius .125-.250 we charge $16.00 to $18.00 A 1" carbide em complete with a corner radius $21.00 Do you charge extra for cutting off 3/4 and 1" carbide em's? If we have to cut 3/4 and 1" em's off we charge an extra $2.00 If they don't need cut off and the corners are chipped we will just bump them back with a diamond cup wheel.

Craig