Using a Button Cutter to High Feed Ramp a Mold Core, then Plunge Finishing for Shortest Cycle Time

Summary

This video from Des Prés Tech Center explores different milling techniques for roughing and finishing core shapes in machining. It compares high feed ramping with a button cutter versus a high feed cutter, highlighting productivity and surface quality. The video also demonstrates three finishing methods: waterline profile milling with a bull nose cutter, the same with a ball nose cutter for faster cycle times, and plunge finishing with a bull nose for accessing tight corners and reduced tool pressure. The discussion covers the pros and cons of each method, providing insights for choosing the right tool and technique.

Takeaways

• 🛠️ The video discusses two machining approaches: roughing and finishing, using different types of cutters.
• ⏱️ Roughing with a button cutter is compared to high feed cutters, showing productivity and practical considerations.
• 🔩 Button cutters leave smaller scallops on sloped surfaces compared to high feed cutters, which is beneficial for semi-finishing and finishing.
• 💰 Economically, button cutters with double sides provide 12 usable indexes per insert, making them a strong option over high feed cutters.
• 📉 The roughing process with a button cutter took 8 minutes and 47 seconds, which is longer than high feed but results in a smoother surface.
• 🛠️ Three different finishing approaches are demonstrated: bull nose cutter with water line profile milling, ball nose cutter, and bull nose cutter with plunge finishing.
• ⏲️ Using a ball nose cutter significantly reduced the cycle time to 43 minutes and 30 seconds compared to the bull nose cutter.
• 🔍 The ball nose cutter provides a good finish but may require a secondary tool for smaller radii in corners.
• 🔩 The bull nose cutter in plunge finishing approach reduced cycle time by 75% compared to the profile milling approach.
• 🏁 The video concludes by summarizing the advantages of button cutters for roughing and bull nose cutters for finishing tapered walls over ball nose or barrel type cutters.

Q & A

What are the two main machining approaches discussed in the script?

The two main machining approaches discussed are roughing and finishing.

What type of cutter is suggested as an alternative to high feed cutters for roughing?

A button cutter is suggested as an alternative to high feed cutters for roughing.

How does the button cutter compare to a high feed cutter in terms of productivity?

The button cutter provides a smoother surface with smaller scallops and has more usable cutting edges, which can be more economical and efficient for certain applications.

What are the three different finishing approaches demonstrated in the script?

The three different finishing approaches demonstrated are using a bull nose cutter with a water line profile milling approach, using a ball nose cutter, and using a bull nose cutter with a plunge finishing approach.

Why might a bull nose cutter be preferred over a ball nose cutter for finishing?

A bull nose cutter allows for better access to tight corners and intersections, and it generates less tool pressure, which can result in fewer issues with tool deflection and the need for recutting.

What is the cycle time for roughing with a button cutter as mentioned in the script?

The cycle time for roughing with a button cutter is 8 minutes and 47 seconds.

What is the advantage of using a ball nose cutter over a bull nose cutter in terms of cycle time?

The ball nose cutter significantly reduces the cycle time compared to a bull nose cutter, as demonstrated by the 43 minutes and 30 seconds cycle time versus the longer time taken by the bull nose cutter.

What is the potential downside of using a ball nose cutter for finishing?

The potential downside of using a ball nose cutter is that it may not be able to access tight corners as effectively as a bull nose cutter, requiring a secondary tool to finish those areas.

How does the plunge finishing approach with a bull nose cutter compare to the water line profile milling approach in terms of cycle time?

The plunge finishing approach with a bull nose cutter is about four times faster than the water line profile milling approach, reducing the cycle time by 75%.

What are the economic considerations when choosing between a button cutter and a high feed cutter?

Economic considerations include the number of usable cutting edges, the depth of cut the tool can take, and the smoother surface left by the button cutter, which may require less finishing work.

Outlines

00:00

🛠️ Machining Techniques Comparison

The script introduces a comparison between two machining approaches: roughing using a button cutter versus a high feed cutter, and finishing using bull nose, ball nose, and plunge finishing techniques. The roughing process with a button cutter is highlighted for its productivity and practical advantages over a high feed cutter, such as smoother surfaces and more usable cutting edges. The finishing section discusses the steep taper core shape and the use of different cutters to achieve various cycle times and finishes. The bull nose cutter is used for water line profile milling, the ball nose cutter for its cycle time benefits, and the bull nose cutter again for plunge finishing, which offers less tool pressure and the ability to reach tight corners.

06:48

🔩 Detailed Finishing Process and Outcomes

This paragraph delves into the finishing process using a bull nose end mill, detailing the parameters like surface feed and feed rate. It emphasizes the excellent surface finish that requires minimal polishing and the associated risks of tool wear over extended cutting times. The comparison then shifts to using a ball nose cutter, which significantly reduces cycle time while maintaining a high-quality finish. However, it lacks the ability to reach tight corners, necessitating a secondary tool for those areas. The paragraph concludes with a plunge finishing approach using the bull nose cutter, which, despite being slightly slower than the ball nose, offers advantages in tool pressure management and accessibility to tight corners.

12:32

⏱️ Cycle Time and Tool Pressure Analysis

The final paragraph summarizes the comparative advantages of different finishing techniques. It points out that the plunge finishing approach with a bull nose cutter reduces cycle time by 75% compared to the profiling method and is four times faster than the initial bull nose profile finishing. The bull nose cutter's smaller corner radius allows for better access to tight corners and intersections, and its design results in less tool pressure and deflection, reducing the need for recutting. This is contrasted with the ball nose and barrel type cutters, which have larger radii, leading to more tool pressure and the potential for oversized cuts. The paragraph wraps up by reinforcing the benefits of using a bull nose cutter for finishing tapered walls due to its low tool pressure and ability to reach tight corners.

Keywords

💡Roughing

Roughing is the initial phase of machining where material is removed quickly to get close to the final shape of the part. In the video, roughing is discussed in the context of using a button cutter for high feed ramping, which is an alternative to traditional high feed cutters. The script mentions that roughing with a button cutter leaves smaller scallops on the surface, providing a smoother surface for subsequent finishing operations.

💡Finishing

Finishing refers to the final stages of machining where the part is refined to achieve the desired surface finish and dimensional accuracy. The video compares different finishing approaches, including using a bull nose cutter with a water line profile milling approach and a plunge finishing approach. The script highlights the importance of cycle times, surface finish, and tool pressure in the context of finishing.

💡Button Cutter

A button cutter is a type of milling tool with a round cutting edge, used for high feed ramping in roughing operations. The video script discusses the advantages of using a button cutter over a high feed cutter, such as the ability to take a good depth of cut, more usable cutting edges, and leaving smaller scallops on the surface, which can be more efficient and cost-effective.

💡High Feed Cutter

A high feed cutter is designed for high material removal rates during roughing operations. The video contrasts the use of a button cutter with that of a high feed cutter, noting that while high feed cutters can achieve faster cycle times, they may leave more scalloping on the part surfaces, requiring more finishing work.

💡Bull Nose Cutter

A bull nose cutter is a type of end mill with a rounded nose, used for finishing operations. The video script describes using a bull nose cutter for both water line profile milling and plunge finishing approaches. It discusses the cutter's ability to achieve a good surface finish and its advantages in terms of tool pressure and accessing tight corners.

💡Ball Nose Cutter

A ball nose cutter is an end mill with a hemispherical tip, which is used for finishing operations to achieve a smooth surface finish. The video compares the use of a ball nose cutter to a bull nose cutter, noting that while the ball nose cutter significantly reduces cycle time, it may not be suitable for workpieces that require tight corner radii due to its larger radius.

💡Water Line Profile Milling

Water line profile milling is a finishing technique where the tool follows the contour of the part, similar to how water would flow along the surface. The video describes using a bull nose cutter for this approach, which results in a good surface finish but with longer cycle times compared to other methods.

💡Plunge Finishing

Plunge finishing is a technique where the tool is plunged directly into the material to remove material in a vertical direction. The video contrasts plunge finishing with water line profile milling, showing that using a bull nose cutter in a plunge finishing approach can significantly reduce cycle times while maintaining access to tight corners.

💡Cycle Time

Cycle time refers to the total time taken to machine a part from start to finish. The video script emphasizes the importance of cycle time in evaluating the efficiency of different machining approaches, with shorter cycle times being more desirable for production environments.

💡Tool Pressure

Tool pressure is the force exerted by the cutting tool on the workpiece during machining. The video discusses how different tool types, such as ball nose and bull nose cutters, can affect tool pressure and deflection, with implications for part accuracy and the need for recutting to achieve the correct size.

💡Scalloping

Scalloping refers to the uneven surface finish that can occur when the tool's path leaves a series of small peaks and valleys on the machined surface. The video script mentions that using a button cutter can result in smaller scallops compared to a high feed cutter, leading to a smoother surface for finishing.

Highlights

Introduction of two application examples: roughing and finishing.

Comparison of high feed ramping using a button cutter versus a high feed cutter.

Practical reasons for considering a button tool over a high feed cutter.

Three different finishing approaches demonstrated: bull nosed cutter, ball nose tool, and plunge finishing.

Description of the core shape's steep taper and the finishing process.

Roughing with a double-sided button cutter took 8 minutes and 47 seconds.

Advantages of button cutter over high feed in terms of scalp size and number of usable edges.

Economic argument for using button cutters for high feed ramping.

Finishing operation with a bull nosed cutter, resulting in a beautiful finish.

Cycle time and surface feed rates for bull nosed cutter finishing.

Risk of edge breakdown with longer tool run times.

Comparison of cycle times between bull nosed and ball nose cutters.

Advantages of ball nose cutter in terms of cycle time and finish quality.

Limitations of ball nose cutters for smaller radius corners.

Plunge finishing approach with a bull nose cutter, reducing cycle time by 75%.

Advantages of bull nose cutters for accessing tight corners and reduced tool pressure.

Conclusion on the benefits of button cutters for roughing and bull nose cutters for finishing tapered walls.

Call to action for more information on applications from de pro.

Transcripts

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hey folks coming to you again from des

prés Tech Center in the Midwest

we've got a couple of application

examples for you today

one is roughing and the other is

finishing the roughing approach is going

to be high feed ramping but using a

button cutter instead of a high feed

cutter we'll show you how that compares

in terms of productivity and also maybe

some practical reasons you might want to

consider a button tool over a high feed

once we've roughed the part then we'll

finish using three different approaches

you can see we've got a pretty steep

taper core shape here and we're going to

finish this first with a bull nosed

cutter just like this one using the

typical water line profile milling

approach after that we'll put a ball

nose tool in same diameter same speeds

and feeds and the same tool path so that

you can compare cycle times with that

finally we'll use the same bull nose

cutter that we started with but instead

of the water line finishing approach

will use plunge finishing will compare

cycle times finishes and talk about some

different pros and cons between the bull

nose and the ball no style tool and in

fact this even applies towards the

barrel type cutters that are trending

right now as well so let's go

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so I roughing is complete we have a

total depth of about three and a quarter

inches top to bottom for our core

there's a fair amount of slope on this

shape as you can see our button cutter

double-sided button cutter took 8

minutes and 47 seconds to complete the

roughing routine keep in mind with a

button tool versus high feed the scalps

that are left on the sloped surfaces are

actually smaller with a button cutter so

you do get a little bit of a smoother

surface to work with for your semi

finishing and your finishing work after

the roughing is done we ran this at

about 230 inches per minute and got that

cycle time of a little over eight and a

half minutes had we used high feed we

probably would have been upwards of 300

inches a minute and probably finished

this and maybe six or seven minutes

however we would have had a little bit

more scalloping on the sides

additionally a high feed cutter might

have given you four usable edges or six

usable edges depending on what you're

using this button cutter with double

sides actually provides 12 usable

indexes per insert so economically

speaking you could make a very strong

argument for using this type of tool for

your high feed ramping versus an actual

high feed cutter so now that we've got

the part roughed out we'll move on to

the finishing operation with the bull

nosed cutter

so four hours and ten minutes later we

have our core walls and coroner's

finished the finish is beautiful

again this was with a three-quarter inch

bull nose end mill two fluted we ran 900

surface feed and 10,000 feet per tooth

so our feed rate was around 90 inches a

minute as we went around the profile we

did program a 1/10 scalloped height so

this surface finish will require very

little to no polishing time once it

comes off the machine so in that regard

it's very good you might say well so

what if it was 4 hours I'll just run it

overnight and that's true however the

longer that tool runs on the part the

more chance there is of a little bit of

edge breakdown on our insert so there's

some risk involved in possibly losing

size the longer we're in that type of a

cut so nice finish good outcome in terms

of appearance but for our cycle time is

longer than I think most shops would

want to see for a core of this size

which is about 6 and a quarter inches

long by 4 and a quarter inches wide at

the base and it's about three and a

quarter inches tall so let's try a ball

nose cutter next and see how that

compares in terms of surface finish and

cycle time

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okay so using a 3/4 inch ball nose our

cycle time is is reduced dramatically to

43 minutes and 30 seconds so the the

larger radius on our ball nose cutter

allowed us a larger step down between

passes still gives us an extremely good

finish possibly even a little bit better

then the profiling cuts did with the

bull nose tool and the smaller radius on

that one so big improvement in cycle

time nice finish the trade-off here is

we're going to lose our ability with

that large radius on the ball nose we

can't get down tight into a corner so if

the if the workpiece calls for a smaller

radius in the corner then you're forced

to follow up the ball nose with some

type of smaller diameter or smaller

corner radius finishing tool to take in

and blend that corner to the sloped

walls so the next thing we'll take a

look at is the the bull nose cutter same

one as before but in a plunge finishing

approach versus the profile finishing

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so 48 minutes later the bullnose cutter

has finished our core surfaces using the

plunge finishing approach that's about

half four minutes slower actually then

the ball nose cutter was but about four

times faster than this same style tool

was in using a profile mailing approach

so the plunge finishing approach

literally cut the cycle time by 75% two

distinct advantages that this cutter has

over the ball nose that was a few

minutes faster number one using this

small corner radius on a bull nose

cutter allows us to get down into tight

corners intersections between a floor

and a surface wall it definitely lets us

have more access to corners than what

the ball nose tool would obviously the

ball nose cutter would require some type

of secondary tool to get in and finish

that corner intersection the second

advantage is in regards to size and tool

pressure a ball nose cutter or for that

matter the new barrel type cutters both

of those type tools have a larger radius

and that means more contact more surface

area in contact with the work piece a

more surface area in contact means more

tool pressure and deflection and the

potential for having to actually recut

apart due to the fact that it comes in

oversized after the first finish pass

using a bull nose or backdraft style

tool like this the only tool pressure we

have is just on the slight corner radius

and small wiper area that does the bulk

of the work the insert then back tapers

away creating a very small amount of

tool pressure when you're cutting like

this and that generally means that we

take the part to size in one pass rather

than having to recut so to pretty

distinct advantages using this style

cutter for finishing tapered walls over

a ball nose or

over a barrel type cutter so that wraps

it up on the roughing side we showed you

how to do high feed profile ramping but

using a button cutter instead of high

feed some pretty good arguments for

using the button cutter strong robust

cutting edge it can take a good depth of

cut

you've got likely more usable cutting

edges versus high feed and you get

smaller scallops on that surface due to

the round cutting edge versus the high

feed cutting edge so that means your

semi finishing tool has a little bit

more even stock removal in store for it

so good arguments can be made for a

button cutter versus high feed on your

ramping you got to decide which works

better for your application on the

finishing side we showed you a typical

water line profile finishing using both

the bull nose and a ball nose cutter

obviously the ball nose cutter has a

huge advantage in terms of cycle time

but tool pressure is increased now

whether that's a ball nose or a barrel

type cutter definitely much more tool

pressure than using a bull know style

tool when we went to the bull nose

plunge finishing style cycle time was

very comparable to the ball nose and

we're generating a lot less tool

pressure versus a ball nose or a barrel

type cutter and we can get into these

tighter corners that we can't get into

with the ball nose so good good

advantages there in the plunge finishing

but using a bull nose low pressure tool

hopefully you found this helpful if

you'd like any more information about

this or other applications from de pro

call us at

you

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