Precision Hole Reaming Video

Summary

This video tutorial instructs viewers on achieving a precision-sized hole using a reamer. It explains that standard drills tend to enlarge the hole, so a reamer is necessary for exact sizing. The video demonstrates the process of pre-drilling a hole undersized by 1/64 inch and then using a reamer at half the drill's RPM and double the feed rate to refine the hole to the desired 0.375-inch size. It emphasizes the importance of maintaining adequate pressure and using cutting fluid for optimal results.

Takeaways

• ⚒️ Drills typically produce holes slightly larger than their size due to their sharpening angle and the blunt chisel point formed where the flutes meet.
• 🔩 To achieve an exact hole size, a reamer is used, which is sharpened differently from a drill and requires a pre-drilled hole that is undersized.
• 🛠️ Reamers are available in standard sizes, but custom sizes can be ordered to meet specific requirements for non-standard hole sizes.
• ⚙️ The RPM for a reamer should be half of what it would be for a drill, and the feed rate should be doubled to ensure a precise and clean cut.
• 🔧 Pre-drilling a hole 1/64 of an inch smaller than the desired finished size is recommended to allow the reamer to make fine adjustments without taking heavy cuts.
• 💧 Cutting fluid is used during the reaming process, especially for specific materials like aluminum or steel, to improve the cutting efficiency and tool life.
• 🔬 The reaming process requires maintaining adequate pressure to prevent the tool from running out of round, ensuring a precise and accurate hole size.
• 📏 The video demonstrates the use of a 3/8 inch reamer to produce a 0.375 inch hole, showcasing the precision achievable with the correct reaming technique.
• 🔧 Reamers are not designed to produce their own holes; they are meant to refine a pre-drilled hole to the exact desired size.
• 👁️‍🗨️ The importance of visual inspection and monitoring the reaming process is highlighted, as it helps in achieving the desired hole size and quality.

Q & A

What is the typical tool used to create a hole in a material?

A drill or drill bit is typically used to create a hole in a material.

Why does a drill bit tend to produce a hole slightly larger than its size?

A drill bit tends to produce a hole slightly larger than its size because the included angle of the drill bit is 118 degrees, and where each flute comes together, it forms a blunt chisel point, causing the drill to run a little out of round.

What is the purpose of using a reamer in hole production?

A reamer is used to produce a hole of an exact size, especially when there are requirements for a mating component to fit comfortably or for a press fit.

How is a reamer different from a drill bit in terms of sharpening?

A reamer is sharpened totally different from a drill bit. It cannot produce its own hole and requires a pre-drilled hole to be undersized before the reamer is used to finish the job and bring the hole to the desired size.

What is the standard procedure for using a reamer?

To use a reamer, one must pre-drill the hole undersized and then use the reamer to finish the job, bringing the hole to the desired size.

Why is it important to pre-drill the hole undersized for a reamer?

The hole should be pre-drilled 1/64 smaller than the finished size because reamers are not designed to take heavy cuts.

How does the RPM for a reamer differ from that of a drill bit?

The RPM for a reamer should be half of what it would be if the reamer were a drill bit.

What is the recommended feed rate when using a reamer?

The recommended feed rate when using a reamer is twice the feed rate of a drill bit.

What is the purpose of using cutting fluid when reaming?

Cutting fluid is used to reduce friction and heat, and to help in the cutting process, especially when reaming materials like aluminum or steel.

How can one ensure that the reamer produces an exact size hole?

To ensure an exact size hole, one should keep an adequate amount of pressure on the reamer to prevent it from running out of round, and maintain a consistent feed rate.

What size hole was produced in the example given in the script?

In the example, a 3/8 reamer was used to produce a hole with an exact size of 0.375 inches.

Outlines

00:00

🛠️ Precision Hole Production with a Reamer

This paragraph introduces the process of creating a precision-sized hole using a drill bit and a reamer. It explains that a drill bit, sharpened with a 118-degree included angle, tends to produce a hole slightly larger than its size due to its blunt chisel point. To achieve an exact hole size, a reamer is used after pre-drilling the hole undersized. Reamers are designed differently from drill bits and require a different approach to speed and feed rates. The recommended practice is to use half the speed of a drill and twice the feed rate for the reamer. The paragraph also mentions the use of cutting fluid suitable for the material being worked on, in this case, aluminum. The process is demonstrated with a 3/8 reamer to achieve a 0.375-inch hole size, emphasizing the importance of pre-drilling the hole 1/64 of an inch smaller than the desired finished size.

Keywords

💡Precision-sized hole

A precision-sized hole is a hole with a very accurate and specific diameter, often required in manufacturing and engineering to ensure proper fit and function of parts. In the video, the importance of producing a precision-sized hole is emphasized for mating components that need to fit snugly or for press-fit applications. The video aims to teach viewers how to achieve this level of accuracy using specific tools and techniques.

💡Drill bit

A drill bit is a cutting tool used to create holes by removing material. It is characterized by its sharp edges and a flute that helps in cutting and removing debris. The video mentions that a drill bit, due to its design, tends to produce a hole slightly larger than its diameter, which is why it's not always suitable for precision work.

💡Included angle

The included angle of a drill bit refers to the angle between the cutting edges of the bit. In the video, it is mentioned that the included angle of a drill bit is typically 118 degrees. This angle is important as it affects the cutting performance and the quality of the hole produced.

💡Flute

Flutes are the helical grooves on the periphery of a drill bit that help in cutting and removing the material being drilled. The video explains that where each flute meets, it forms a blunt chisel point, which is part of the drill bit's design that contributes to its cutting action.

💡Reamer

A reamer is a tool used to finish and resize existing holes with a desired level of precision. Unlike a drill bit, a reamer is not designed to create a new hole but to refine an already drilled one. The video highlights the use of a reamer for achieving an exact hole size, which is crucial for applications requiring a perfect fit.

💡Undersize

To drill an undersize hole means to drill a hole that is smaller than the final desired size. The video instructs viewers to pre-drill a hole that is 1/64 inch smaller than the finished size before using a reamer. This step is necessary because reamers are not meant to take heavy cuts but rather to refine the hole to the exact size.

💡RPM (Revolutions Per Minute)

RPM refers to the rotational speed of a tool, measured in rotations per minute. The video explains that the RPM for a reamer should be half of what it would be for a drill bit, as reamers require a slower speed to effectively size the hole without causing damage or inaccuracies.

💡Feed

Feed in the context of machining refers to the rate at which the cutting tool is advanced into the workpiece. The video advises using twice the feed rate for a reamer compared to a drill bit to ensure that the reamer cuts effectively and maintains the desired hole size.

💡Cutting fluid

Cutting fluid is a liquid used to cool and lubricate the tool and the workpiece during machining. The video mentions the use of cutting fluid designed for specific materials like aluminum or steel, highlighting its importance in reducing heat, friction, and wear during the reaming process.

💡Press fit

A press fit is a method of assembly where one component is forced into another by applying pressure, often used when a strong, fixed joint is required. The video discusses the need for precision-sized holes for press-fit applications, where the hole and the mating component must be of exact sizes to ensure a secure fit.

Highlights

The necessity of producing a precision-sized hole for mating components that need to fit comfortably or be press-fit.

Drills tend to produce holes slightly larger than their size due to their sharpening angle and blunt chisel point.

The use of a reamer to achieve an exact hole size after pre-drilling the hole undersized.

Reamers are not designed to produce their own hole and require a pre-drilled hole to work on.

Standard sizes of reamers are available, but special sizes can be ordered for specific needs.

The reaming process requires a different RPM calculation compared to drilling, using half the speed of a drill.

Feed rate during reaming should be double that of drilling to ensure a proper cut.

Maintaining adequate pressure on the reamer prevents the hole from running out of round.

The importance of using cutting fluid designed for specific materials like aluminum or steel.

Demonstration of reaming a hole with a 3/8 reamer to achieve an exact 0.375-inch hole size.

Pre-drilling the hole 1/64 inch smaller than the finished size to avoid heavy cuts with the reamer.

The reaming process is not intended for heavy cuts, which is why the speed and feed are adjusted.

The practical application of reaming in achieving precise hole sizes for engineering and manufacturing purposes.

The importance of using the correct RPM and feed rate for optimal reaming results.

The step-by-step process of reaming, from pre-drilling to applying cutting fluid and maintaining feed.

The role of reamers in ensuring a comfortable fit or press-fit for mating components.

The practical demonstration of reaming a hole to an exact 0.375-inch size using a 3/8 reamer.

Transcripts

in this video

we're going to take a look at how to

produce a precision

sized hole we have to realize that

when we produce the hole originally

we typically will be using some sort of

a drill or some people refer to it as a

drill bit

and the way this is sharpened remember

the included angle

is 118 degrees and where

each flute comes together it forms

rather

a blunt chisel point

and when the drill is drilling it has a

tendency to run a little bit out of

round so the drill will always produce a

hole

slightly larger than itself so

oftentimes

we need to produce a hole of an exact

size

there might be a mating component that's

going to need to slide in

very comfortably or maybe the mating

component has to be a press fit

regardless we do have requirements

that we have to fulfill in terms of

hitting an exact hole size

and one way to do that kind of a basic

way of doing that

is using a cutting tool called a reamer

the reamer is sharpened totally

different from a drill

it cannot produce its own hole we have

to pre-drill the hole

under size and let the reamer finish the

job

bringing the hole to that desired size

reamers again generally come to us

in standard size it is possible to order

special reamers

but there's another process that we'll

look at

to help us size holes that are not a

standard

size because the reamer is sharpened

different from a drill we do not use a

regular

rpm formula we would calculate

the rpm as if the reamer were a drill

and we take half of that rpm so we the

simple rule to remember for a reamer

is to take half the speed and

twice the feed so we want to keep an

adequate amount of pressure on that

reamer

so it doesn't have a tendency to run out

of round

so i've pre-drilled we're ready to go

but i think i'm going to adjust the

camera a little bit

so that you can see what's happening a

little better

so we're ready to go

i'm going to be running this i will make

an adjustment i'm in the high range

i need to bring that lever up and speed

a little bit

and i will use a little cutting fluid

again

this cutting fluid is used designed to

cut aluminum

we also have some to cut steel

just a little bit of fluid on there and

then

i'll take my coil handle you'll see that

i'm going to keep a nice

solid feed going through

and back out

and at that point i can be guaranteed

that i produced a an exact size hole

in this case i've chosen a 3 8 reamer

and 3 aces 0.375 so my hole would be

exactly

0.375 so we want to remember that

that a reamer can be used to produce an

exact size hole

we always want to drill the hole

pre-drill the hole

1 64 smaller than the finished size 1 64

of an

inch so the reamer is not designed to

take heavy cuts

and we use half the speed f the rpm

and twice the feed