The idea is simple, a stripped screw tends to lead to problems with the screwdriver “camming out”. To prevent this, pinch the screw and the screwdriver (or in this case, the screwdriver bit or “blade”) between the jaws of a vise. Keep the jaws just tight enough to prevent the screwdriver from camming out as it turns. As the screw starts to rotate, loosen the jaws slightly to allow for it to extract.

Here’s a quick video of the process in action.

In situations where it’s hard to grip the handle of the screwdriver (because it’s in a vise) I recommend using a screwdriver with a square or hex shank so you can get a wrench on it for leverage, or use a bit or blade like I show in the picture and video. Don’t try vise grips on a round shank screwdriver, you’ll just muck it up. Some screwdrivers have a round shank with hex portion (called a “hex bolster”) where the shank meets the handle. This little hex bolster is ideal for getting a little extra leverage when needed.

Screwdrivers with a hex bolster come in handy more often than you might think … if you remember to use it! I’ve started replacing all my cheap, damaged, or worn out screwdrivers with better ones that have a hex bolster near the handle. Here’s a nice set on Amazon by Klein (click image).

There are obviously other methods of removing a stripped screw. Two of which have already been mentioned in responses to this video on YouTube. For instance, one viewer suggested cutting a slit in the head of the stripped screw to use a flat blade screwdriver, while another viewer suggested using an impact wrench (or the impact setting on a cordless drill)  which I have used with great success also.

Lets see how many other ways we can think of to remove a stripped screw. If you have a method, please leave it via a comment on the forum (see link below).

And Happy New Year!

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Not ideal.

Luckily there are a few nifty storage solutions just waiting to be implemented. The first comes from Norman in Texas who was clever enough to make little dovetail brackets that he can secure to the wall. His first few brackets were milled, but now he’s casting them. Here’s what Norman’s brackets look like in use. The third one down from the top is an empty bracket:

But wait, there’s more!

After seeing Norman’s solution Alexander submitted a few of his own. Here’s a solution that Alex found on the web from DocsMachine.com.  Doc mounts his tool holders to the wall using a short rod (upper right highlighted in red – you can click the image to enlarge it). This seems to work well, but I think some J or Z channel would also work and might be sturdier and easier to mount.

And here’s Alexander’s personal solution, consisting of a piece of plastic angle bolted to his backsplash. I like the idea of plastic or aluminum angle instead of steel since there’s no chance of them damaging the dovetail on the tool holders.

If you’d like to read the original forum post or submit your own solution, please visit the forum post here:

QCTP Tool Storage Solutions

Anyway, adding a QCTP to the G0602 is very simple, as long as you  access to a milling machine to mill the plate that fits in the t-slot. Here’s a video of the process.

If you don’t have a milling machine you could figure out a way to hold the plate in your 4-way tool post and use an end mill held in the chuck (or better yet held in an end mill holder that fits the taper of your lathe spindle). But you’re best bet is to use a mill to modify the plate to fit your t-slot.

One final thing, your QCTP probably came with a plate to modify as mine did. But my plate was a bit short, so I fabricated my own out of a piece of scrap. Doing so requires you to also have a proper tap handy. That tap size may vary depending on who made your QCTP, but just keep that in mind if you decide to make your own plate rather than modify the one the tool post comes with. I purchased my tap for about $12 from a local supplier (no shipping). You could probably get one for about the same price from an online supplier + shipping. If it’s a size you think you’ll use a lot moving forward, go ahead and purchase a high-quality tap. But if not, go with a cheap tap. I haven’t used my tap since adding the QCTP over two years ago, so the cheapest tap they made was perfect!

As an alternative to buying a tap, you could also single point the internal threads on the plate, but that’s a whole ‘nother ball of wax, and somewhat outside of the scope of a beginner-level modification. But if someone does single point their plate, please post a comment with pictures &/or video of your modification.

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This is our first major video tutorial project with multiple camera views. We shot it in HD (1080p) with High Def cameras and then uploaded it to YouTube in HD (720p) which is as high a quality as YouTube will allow. But even at 720p the video is better than DVD quality.

Please leave your comments via the forum and let us know what you think. Our next videos will be on grinding your own HSS tooling (RH Tool, LH Tool, and Threading Tool), and then we plan to do a multi-cam video on single point threading.

However, your feedback is critical. We want to know your thoughts, good or bad. It would also be helpful to know if there are any other topics that you’d like to see made into videos.

Thanks!

Tyler and Barry

Video #1 of 2: Sharpening Twist Drills By Hand – Introduction

Video #2 of 2: Sharpening Twist Drills By Hand – Sharpening

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The Three Basic Types of  Hand Taps

A Tap is used for cutting an internal thread to create a female thread that a bolt can screw into. There are a wide range of taps available, and for beginners it can be quite overwhelming. This is a guide to give the new machinist an introduction to taps. I will also cover the tools for using the taps correctly to ensure you get a square thread – how often do you screw a bolt in to find it’s been tapped on an angle? Then I will explain the procedure for tapping a perfect thread.

Tapping begins with the drilling of a hole and then chamfering the top edge of the hole – this makes it easier to locate and start the tapping process. Ideally you want a chamfer that is slightly larger (+0.020″ or so) than the final internal diameter of the threads. If you discover that your chamfer isn’t large enough after tapping, you can always re-chamfer the hole.

There are 3 basic types of hand taps per thread size: (image source)

Taper Tap (also known as starter tap)
A taper tap is the first tap you want to use to start your thread. You will notice that the first 5-7 threads have been ground away resulting in a long taper which makes it easier to start your tap square, and it also makes the cutting action easy and gradual. In a way you could say a taper tap ‘paves the way’ for the plug tap to follow. If you are tapping a through-hole (a hole that passes all the way through your part) a taper tap is all you will need to complete your hole. However, if you’re tapping a blind hole (a hole that doesn’t pass all the way through your part) you’ll need to move on to a plug tap, and then to a bottoming tap if you intend to achieve fully formed threads all the way to the bottom of your hole.

Plug  Tap (sometimes referred to as second or intermediate tap in Australia and Britain)
The plug tap is the second tap you want to use to increase the thread depth inside your hole. This tap has a smaller taper with only 3-5 threads ground away which allows you to cut fully formed threads to within 3-5 threads of the bottom of the hole. If you’re tapping softer materials you can sometimes advance from a taper tap directly to a bottoming tap and skip the use of a plug tap. 

Bottoming Tap (sometimes referred to as a plug tap in Australia and Britain.)
The final tap is known as the bottoming tap. This tap has had only 1-2 threads ground away resulting in a very small taper at the tip of the tap. By finishing a blind hole with a bottoming tap you will achieve fully formed threads all the way to the bottom of your hole.

Different Tapping Tools used while Hand Tapping

If you want to use a tap you’re going to need a way to hold it. This is where tools known as Tap Handles or Tap Wrenches come in handy.  These tools are also sometimes referred to as a “T Bar” or ‘T Wrench”. It is fairly simple to work out how your tap fits into these tools.

Specialty Taps

The taps shown in the diagram above are known as Straight Flute Taps and are for general purpose and tapping by hand. There are also Power Driven taps that you can use with your machines (lathes, mills, CNCs).

The most common type of Power Driven tap is the Spiral Point tap – also commonly known as a Gun Tap (above). The cutting edges in these types of taps are angled ever so slightly so that the chip breaks away into the flute of the tap which prevents the tap ‘tightening’ – this is most commonly known as Crowding.

Above is the Spiral Flute Tap. It is designed primarily for the machine tapping of blind holes. The cutting action of the spiral flute curls the chips up out of the hole instead of them falling to the bottom and seizing your tap. These type of taps are most suitable for soft metals like aluminium and steel.

This is the Interrupted Thread Tap and you will notice it has large gaps between cutting teeth. This is to reduce friction which is ideal for threading tough materials such as Stainless Steel and Bronze. It also makes it easy for coolant to reach the cutting edges.

There are two types of taps in this photo, the top two are Fluteless Taps without oil grooves (also called “roll taps”) and the bottom tap you will see oil grooves – Fluteless Tap with oil grooves. The yellow coating is a protective layer called Titanium Nitride and this prevents the wearing of the tap. Fluteless taps are designed for soft materials such as Nylon. Taps with oil grooves give you the option of delivering lubricant to the cutting edges.

This is the Taper Pipe Straight Flute Tap. It is primarily designed for threading pipes and fittings. The tapered cutting edges create a tighter fit when fitted together. You wouldn’t want the pipes in your house to leak would you?

Please remember that Power Driven taps are recommended for the more experienced machinist – if they are not set up correctly as per manufactures instructions you could potentially harm yourself or damage your machine.

The correct way to tap an internal thread

There are two ways to tap a thread – by hand or by machine. If you do it by hand there is a strong possibility it won’t be square to the hole.  However if you do it by machine you will get it precisely square 99.99% of the time. Let me explain to you what I mean.

In this picture you will notice the correct setup for tapping a hole using the mill (the mill is used to align the tap, it is NOT turned on during the tapping procedure).

In this example I drilled the hole to the correct diameter needed for the thread and then applied a chamfer. I then used a pointer in the drill chuck – one that I ground on the Tool & Cutter grinder (see below for picture and description). You could also use a spring center. The pointer or spring center is used to keep the tap and tap wrench square and aligned with the hole in the part being tapped. Most taps and tap wrenches these days come with a centre hole in the top of them.

Next I applied tapping fluid to my taper/starter tap and placed the tap on the chamfered hole while applying a slight pressure using the quill (Note: pressure is not needed if you’re using a spring center, as the spring inside the center provides all the pressure you’ll need).

Next, I put my mill into neutral and from then on it was just a case of simply keeping a firm pressure on the quill lever with one hand, whilst rotating the tap wrench with the other in a clockwise direction (assuming you’re tapping a traditional right-handed thread). This process is not to hard – even for the uncoordinated! Once the taper tap has cut it’s first two or three threads you’ll start to feel some resistance. At that point you’ll need to reverse the direction of your rotation (turn the tap counterclockwise) to break away the chips that have formed. If you listen you’ll actually hear the chips break away. It usually takes a quarter to a half turn to break away the chips. Once you hear the chips break away, return to your original direction of rotation (turn clockwise) and continue the tapping procedure, pausing to break chips every quarter to half turn in hard materials and every half to two turns in softer materials. If you find your progress is slowing your hole may be filling with chips. Back the tap out entirely and blow the tap clean of chips. Also blow out any chips from within the hole that may be impeding your progress. Re-apply tapping fluid and return to tapping the hole.

Once you reach the bottom of the hole with your taper tap repeat the process with your plug and bottoming taps.

Now this is the correct way to tap a hole in a lathe. Notice it’s extremely similar, except this time you need to put your chuck into neutral or high gear and apply pressure on the tailstock handle (or use a spring center) – make sure you lock the tailstock in place otherwise you might find you can’t tap.

If you don’t own or have access to a lathe or mill you can still accurately tap a hole by hand using a tapping block or an engineers square. A tapping block typically has several holes drilled in it. Find the hole that is just large enough for your tap to pass through without binding.

Next, align the hole in the tapping block over the hole you’d like to tap, and hold the tapping block in place with one hand while rotating your tap with the other. By keeping firm pressure on the tapping block you’ll ensure that the tap stays square to the hole you’re trying to tap (image source).

Another method is to use a machinists square to check your tap angle every 90 degrees (every quarter turn). If the tap starts to stray from 90 degrees you can rectify it by gently guiding the tap in the next quarter turn to the proper orientation needed.

So there you have it, a simple guide on the types of taps available to you and the correct way to tap your holes. It shouldn’t be too hard even for a novice. Experience is the best teacher – so give it a go!

Pete Woods (AKA “MadRep”)
Machinist

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This table showing lathe cutting speeds in feet per minute. I use this table to calculate the speed of my lathe and my drills. Yes I am aware they are not as accurate when using them for drills, however they seem to work for me. The proper formula for calculating is as follows:

CS x 12 =   RPM

π x D

CS being ‘Cutting Speed’ which is locate in the table above and ‘D’ meaning diameter of stock

However you can shorten this down to make it easier, π (Pi) has a value of approximately 3.14 and divides into 12 just under 4 times.

So I use this shortened formula for working out my lathe speed.

CS x 4 =  RPM

D

Let say I have 3 inch ally stock and I’m using toolsteel to make the cut.  For roughing the formula would be as follows:

1000 x 4

3.000               =        1333.33 RPM

So 1300 RPM is the rough speed I should be cutting with 3 inch aluminium stock in a lathe.

Now lets say I now have 1.505″ stainless steel and I want to do my finishing cut with toolsteel. The math is as follows:

46 x 4

1.505                   =     122.25 RPM

Easy isn’t it? If your using metric and/or metres a minute for your cutting speed , you might want to convert the numbers above and create your own table.

Hope this helps,

‘MadRep’
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This question comes up occasionally on the forum and I’ve seen it addressed in books, but I’m not sure if I’ve ever seen a video of the process, so I decided to make one.

Setting up your lathe to take very fine cuts is a simple process. The quick version is this: By setting your compound at an angle of between 5° and 6° you’ll be able to use the dial on the compound as a very fine feed, advancing the tool in tenths for every thousandth you turn on the dial.

This is sometimes referred to as “Slewing the compound”. Although I’m not sure how technically accurate the term “to slew” is when talking about lathes. This could be slang for all I know and to make matters worse I’m not sure if it’s American slang or Brittish slang (as I have read dozens of books from both sides of the water), so be careful if you decide to break out the term in a shop full of machinists. You might get some funny looks.

I’ve seen this process described in multiple books, including the Machinist’s Bedside Reader by Guy Lautard, and in Lathework a Complete Course by Harold Hall. Both of which are excellent books. The first book by Lautard shows you the math behind the process I’ve outlined here and uses imperial (inch) measurements. The second book by Hall describes a slightly different method and is written for those who work in metric.

Anyway, if your compound is set at 5.75° and you advance the dial on your compound .001″, the tool bit advances toward the part .0001″ thus taking a very fine cut.

That’s as easy (or as complicated) as it gets. For most of you the image above will be enough of an explanation, but for those who require a little more reinforcement of the concept, here’s a “short” video of the process. I took 8 minutes to explain what should have taken 60 seconds. It seems I need to work on being succinct and not sounding deadpan. But hey, we all have our things to work on, right? Bueler … ?

Setting your compound to exactly 5.75° isn’t critical, somewhere between 5° and 6° will get you very close. You can also use this process for metric cuts.

Do you have a different method that you like to use? Please leave a comment on the forum. We’d like to hear it!

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Soft jaws have several advantages, especially when you need to hold a custom workpiece. For example, you can also make or buy a set of soft jaws and bore them out to the perfect size to hold the workpiece, and since you’ve bored them on lathe, the jaws will hold the part perfectly concentric to the spindle axis.

As you can see from above this can be especially helpful when you want to hold smaller parts made of soft metal.

But what about when you just want to hold a part without marring it? Are expensive/custom soft jaws necessary? NO!

Do you have a soda can lying around? If so you’re in business.

First, cut the can open (carefully) with scissors, and cut the aluminum into strips who’s width roughly match the size of you’re jaws. Make them long enough so that they can wrap around 3 sides of the jaw, and fold them around a piece of metal approximately the same width as your chuck jaws – my 6″ scale is perfect for this.

Next, slip them over the jaws. Folding them gives them a shape that allows them to grip the jaws – that way they stay in place – which is a lot easier than trying to slip pieces in around the part.

Finally, insert your part. You’ll be able to tighten the jaws a bit more than you would be able to normally, but the can is only about .004 thick, so you still need to be careful. Also, if the part spins replace the jaws – they wear through instantly.

I hope that helps! Obviously real shim stock (brass, aluminum, etc) would work as well, but aluminum cans are cheap – and you’ll be recycling at the same time!

Do you have a different method that you like? If so, please share it with our readers on the forum via the link below.

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Measuring a hole using plug gages:
(Accuracy to within .001)

This method is pretty straight forward. Every beginner should have a set of plug gages ranging from .011 – .500. An inexpensive import set (Type: Minus, Class: ZZ) from Enco would cost you around $120 new, and even less if you can find a set in good shape off of ebay. And with a set of .011 to .500 you can measure a hole up to .999 in diameter. How? By using the .500 plug gage and the .499 plug gage. Also, if you add a single 1.000 plug gage to your .011-.500 set, you can now measure from .011 to 1.500! A single 1.000 plug gage costs about $10. Plug gages are very versatile and useful for many other things as well, which is why every beginner should have a set.

Here you can see that I’m measuring the diameter of the cylinder bore on my flame sucker engine using two plug gages, the .500 plug gage and the .221 plug gage – giving a total diameter of .721″.

Some might argue that it is better to use a single .721 plug gage to measure this hole. They would be right in a way because using two gages can lead to an erroneous measurement if your hole is slightly out of round. However, if you remember to drill and then bore a hole to its final size you shouldn’t have an issue with the hole being out of round.

Another limitation of this method is the level of accuracy. Plug gages step up in size in .001 increments, so you’re accuracy is limited to within .001. Also, “minus” class ZZ plug gages are ground to within about .0002 undersized. So the .500 gage might actually measure anywhere from .4998 to .5000, so using two plug gages might introduce an error of up to .0004 if both gages were two tenths undersized. Keep that in mind.

Using a Brown & Sharpe Taper Bore Gage Set:
(Accuracy to within .0001)

B&S used to make a set of tapered bore gages that were similar to an adjustable parallel, but had a rounded edge so that they would fit snugly inside a hole. To my knowledge, nobody is making this type of measuring gage any longer, but you can still find them used on eBay for a reasonable price.

To use these gages you insert them into the hole and slide them past each other along the tapered edge until they grip the sides of the hole. Then you can measure across them using a micrometer. You can see that my micrometer reads .721, precisely the same measurement as the plug gages. However, since I’m using a micrometer that measures to within tenths, the accuracy of this method has the potential to be more accurate than using plug gages – which only measure to within .001 (not to mention the fact that minus class ZZ plug gages are undersized by up to two tenths).

I mention this method because you can occasionally find a set of these taper bore gages on eBay for $20-30, and they don’t take up a lot of space in your tool box. Also, don’t quote me on what these gages are actually called. I’ve seen them listed as “Tapered Bore Gages”, “Adjustable Taper Hole Gages”, and various other names. If anyone has an old B&S catalog, please look them up and let me know what their true name is. Thanks!

Using a Caliper Type Inside Micrometer:
(Accuracy ranges from .001 to .0001 depending on your micrometer)

I also happened to have a caliper type inside mic that I found for $20 on eBay so I thought I’d also show that method of measuring.

Again, this is a specialized micrometer and not as versatile as plug gages which have multiple uses beyond measure holes. This type of micrometer also suffers from a similar limitation when used with holes that aren’t perfectly round, which is probably why you’ll usually find them with graduations limited to an accuracy of .oo1.

Using a Starrett Taper Gage:
(Accuracy to within .001)

I don’t own a set of these taper gages, but they occassionally come up on eBay for a reasonable price. I’ve only seen ones made by Starrett, but I’m sure other companies make them as well.

One of their limitations include measuring a bore with a chamfer. If your hole has a chamfer or is slightly enlarged at the opening you won’t be able to get an accurage measurement. However these would be useful to quickly check the diameter of a hole while you’re boring it to size. Once you’re within .002 you can switch to a more accurate method of measuring to finish boring the hole.

Summary:

As I mentioned in the first paragraph, there are definitely better and more accurate methods of measuring the diameter of a hole. But as a hobby machinist it sometimes makes more sense to spend your money on versatile tools that are useful for multiple different things, rather than on specialized tools that are made for a taking a specific type of measurement. So if you’re new to the hobby, don’t run out and buy a $100+ dial bore gage right away, especially when you can spend that same amount of money on a set of .011-.500 plug gages. Unless you need accuracy to within tenths, the plug gages will prove a more worthwhile expenditure, and your plug gages will see much more use in your shop over the years than your dial bore gage ever will.

Do you have another interesting method for measuring hole diameters? Or perhaps you know the true name of the B&S taper bore gages. If so, please post it by visiting the forum topic linked to this post (via the link below). Thanks!

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I waited until Enco had a “free shipping” promotion to order the oil and a few other heavy items that were unrelated to the oil change. If you’re planning on getting a granite surface plate it might be a good time to order …

Next came the fun part, actually changing the oil. I had no idea how much oil the gearbox held, so I ordered a gallon of oil. Turns out I’ve got enough gearbox oil to last my little lathe a lifetime of use.

How much does the gearbox on a Grizzly G0602 hold you ask? About 9 ounces give or take. How many ounces in a gallon? 128. I can get 14 oil changes out of my gallon of DTE Heavy/Medium oil. If anyone has any suggestions for other uses for this oil please let me know. I’ve used it as a cutting fluid and it provides a reasonable finish on steel and aluminum. So maybe that’s how I’ll use it up. It’s too thick for the ways, and besides, I’ve got a gallon of way oil also!

On to the “Shop Tip” portion of this post. I remember reading somewhere (perhaps in one of my recent metalworking magazines) where someone had used soda cans to make a trough to guide the oil from the drain plug out past the chip tray during an oil change. It worked great!

You can see the 9 ounces of oil filling a disposable baking sheet. Later I poured the oil into a clean dry water bottle so I could transport it to a recycling center. Here’s how the color of the darker old oil (right) compared to the color of the lighter new oil (left).

The new oil is a bit lighter in color but otherwise seems identical in viscosity. I also didn’t see any evidence of shavings or metal debris in the drained oil – which suggests all my gears are meshing properly.

The drain plug wasn’t magnetic and I felt that adding a magnet would be a quick and easy improvement to the lathe. So I cleaned the oil from the plug thoroughly (using naptha and then rubbing alcohol) and secured a small magnet using 2-part epoxy. I roughed up the mating surfaces of the plug and the magnet using a file to give the epoxy something other than a smooth surface to adhere to. After 30 minutes the drain plug was ready to be reinstalled. The purpose of the magnet is to attract any (ferrous) metal shavings and pull them out of the circulating gearbox oil. Now, if your lathe uses aluminum (non-ferrous) gears this addition would be of limited benefit since non-ferrous metals aren’t attracted to magnets. I’m not sure if the G0602 has aluminum or steel gears, but I added the magnet just in case.

Next it was time to refill the gearbox with the new oil.  The fill hole is located on the side of the lathe so its hard to use a funnel. The solution was to use the same aluminum can trough to refill the gearbox.

I filled a clean 10 ounce container with about 9 ounces of oil and used it to fill the gearbox (this seemed like a better method than trying to pour 9 ounces directly from the gallon jug – I’m not good at eyeballing fluids). I knew 9 ounces came out, so I didn’t want to put any more than 9 ounces back in. Remember, since the oil is thick it takes a while for it to register correctly in the sight glass.

After adding the 9 ounces I let things settle for about 30 minutes and then I rechecked the sight glass. The oil registered just above the red “full” line.

All that was left to do was to replace the fill plug and I was done!

Note, there’s one additional tip that I came across. The drain and fill plugs are normal 3/8″ pipe thread. That means you can replace the fill plug with a 3/8″ street elbow to make it easier to fill using a regular funnel. Here’s a picture from Crevice Reamer showing this handy upgrade.

You can buy a 3/8″ street elbow from any hardware store. They are $2 at Home Depot.

If anyone has any other handy tips to share please leave a comment on the forum topic linked to this post (via the link below). And if anyone has any additional uses for the other 119 ounces of gearbox oil I’ve got left over please let me know!

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