Worsening spindle runout over time is an indication of wear problems on your spindle. It’s always a good idea to keep a log of such things so you can track the trends. If runout gets bad enough, it may be time to rebuild your spindle.

Runout is a tolerance that stacks up. There is spindle runout, toolholder runout, perhaps collet runout in the toolholder, and so on.

Machining Calculators - Cutting Speed and Spindle Speed · Spindle speed equals cutting speed X 1000 divided by pi times tool diameter. Where: S = Spinde Speed ( ...

I was in the shop one day and managed to break 5 eighth inch endmills in a row before I finally decided to start checking runouts. I traced it to a brand new ER collet that was bad out of the box.

As a matter of fact, runout is usually the #1 factor affecting tool life for micromachining. I made a video that’s all about in my monthly “CNC Chef” series for Cutting Tool Engineering Magazine.

In this chart, runout is given as a percentage of chipload, which is the thickness of a single chip being sliced off by your cutter. This is how I like to think of runout–it increases chipload beyond what you intended. As you can see, tool life goes down dramatically when we get to TIR’s (Total Indicated Runout) beyond about 20% of your cutter’s targeted chipload. This also explains why runout is so hard on tiny cutters–they have small chiploads and can tolerate very little runout as a result.

There are a lot of rule of thumb and anecdotal answers floating around the web, but here’s a quick and easy to understand chart that explains how runout affects your tool life

Let’s work through a couple of examples. Let’s say we’ve got a 1/2″ endmill in a Side Lock (Weldon Shank) Toolholder. Further, let’s suppose the spindle has maybe 0.0003″ of runout, so it’s not real tight, and our toolholder adds another 0.0005″ since its set screws will tend to push the tool off center. That means we’ve got 0.0008″ of runout. So, if we want that to be less than 20% of chipload, the chipload must be greater than 0.0008/0.2 = 0.004. How realistic is that?

Now, when you insert the toolholder in your spindle, put the toolholder mark at 9 o’clock. It’s 180 degrees from the spindle’s 3 o’clock runout.

Now measure runout on a toolholder (perhaps using V-Blocks on a surface plate) and mark the maximum runout position with a Sharpie.

20231028 — ... windows. Harvey Customer Satisfaction. Customer Satisfaction. We pride ourselves on our ability to provide quality service to our customers.

It’s important to be aware that runout can kill tool life. But runout doesn’t have to be something you simply accept. There are ways to improve runout in order to improve your tool life.

If you think about it, the runout just makes the endmill act like it is a slightly larger diameter as it wobbles in the cut. If that effective diameter changes every toolchange, the CNC machinist will have a tough time maintaining tolerance. But if it is consistent, there is hope. You can use your wear offsets to just enter the effective diameter of the tool and cut accurately despite that runout.

Where it gets really crazy is small endmills.  Running the same kinds of numbers against a 1/8″ endmill suggests we run 0.0006″ of chipload.  Now we have over 100% TIR since 0.0008″ is larger than our allowable chipload. That endmill will definitely be broken very quickly in that scenario.

You might think spindle orientation is only about lining up the drive dogs with toolholder notches, but I recently learned differently. There are tapers that don’t have drive dogs and they still do spindle positioning during toolchanges for a very important reason.

Higher quality toolholders have less runout, or at least they should.  Sometimes toolholder type creates runout too. Set screw holders and Jacobs Chucks typically have more runout than ER collets, for example. It may not be much more, but it adds up as we’ve seen.

GD&T (Geometric Dimensioning and Tolerancing) is the science of defining and tolerancing allowable errors in manufacturing. Runout is so important to the design of rotating machinery that GD&T even has two kinds of runout:

They’re the two little “ears” that engage notches in the toolholder. Not every taper has them, but many do. Getting the drive dogs positioned to line up with the toolholder in the changer carousel before a toolchange can happen is called “spindle orientation” or sometimes “spindle positioning”.

Stock Check. Whole or partial ITT or competitor Part Number Preferred Region All America Europe Asia. Note: Data provided here are offered in good faith.

If we set up an aluminum cutting scenario in G-Wizard Calculator, it might look like this (the cut width and cut depth were optimized by CADCAM Wizard).

CNC Lathe Internal Threading Boring Bar Turning Tool Holder With 10pcs 16IR AG60 Carbide turning insert

Obviously if there’s a chip stuck in your spindle taper or in the toolholder, it can cock the assembly and create runout. Always clean and inspect your tooling and spindle taper to make sure this won’t be a problem.

Suppose you know the direction of maximum runout for your spindle (you can measure it!). Put a mark with a Sharpie and rotate the spindle so it is at 3 o’clock.

Spindle runout, or tool runout, as it can also be called, is the inaccuracies that cause a tool (in a mill) or workpiece (in a lathe) to spin off the ideal axis. It’s very bad for tool life, so it’s good to know more about it.

Retention Knobs are a consumable that sits atop the toolholder. The machine’s powered drawbar engages the retention knob to pull the tool holder up and seat it in the taper. But, if the knobs get worn or aren’t made to good tolerance to start with, they can be a source of added runout.

Drilling derrick ... FreeImages is a free pictures website, offering a diverse collection of high quality images, including photos, vectors, clipart, icons and ...

Now let’s try the same setup with a 3/8″ endmill. Changing endmill size won’t make our spindle have any less runout and it probably won’t affect the Side Lock holder much either so our max chipload must be greater than 0.004 again. G-Wizard suggests we need a chipload of 0.0028 in this case, which is less than our limit by a lot. Looking at the Tool Life chart above, 0.0008″ of runout against 0.0028 is 29* TIR. Not terrible, but we’re definitely going to reduce tool life to 80 odd percent of normal. We would definitely prefer an ER collet chuck at this endmill diameter.

Runout need not be perfectly parallel to the spindle axis. Perhaps the tool is also cocked at an angle. That means the longer the tool tip sticks out of the holder, the worse its runout will be at the tip. Always minimize tool stickout to create maximum rigidity and minimize runout.

When you maintain the same spindle position relationship to the toolholder, you ensure that whatever runout there is will at least be consistent–either consistently good or consistently bad. Consistency is the main thing, because if it is consistent, we can compensate for it.

The measurement shown will get you runout from all sources, but it’s important to understand that you may want to measure the individual component sources of spindle-tool runout to find the underlying causes.

As you can see, runout creates uneven chiploads, so some flutes get way too much and wear fast while others get too little. That’s not a happy situation for your endmills!

Big Kaiser ran tests with drills and reducing runout on carbide drills from 0.0006″ to 0.00008″ (tiny!) resulted in a 3x tool life improvement. Wow!

Runout can dramatically reduce tool life, but now you know how to measure it, and you have some tips on how to reduce it.

This video gives a good idea how to measure the runout and also does a good job showing the relative runout of 3 jaw drill chuck, ER collet chuck, and set screw type (Weldon shank) holders. You can surely see that while drill chucks may be fast and easy, they have a lot of runout. Set screw holders also have considerable runout compared to ER collet chucks which have little or none.

Find parking charges, opening hours, postcode and a parking map of Harvey Street 216 Cowbridge Rd E as well as other car parks, street parking, ...

This discussion will focus on improvements possible when machining the austenitic stainless steels, which are the most widely used stainless alloys.

This scenario wants a chipload of 0.004, so we are right at that limit.  We’d be better off with an ER collet chuck (less runout) to give a safety margin, but we’ll probably live to tell the tale.

For the working machinist, it is perhaps more important to define run out as simply a measurement of the spindle runout of a tool (or workpiece) installed in the CNC Machine’s spindle directly.

There’s even a fourth source that’s very hard to measure which is that the endmill may have been ground with its geometry slightly off-center.

Given that runout occurs when geometry is offset from the true axis of rotation, we can reducing runout by “clocking” runouts of the components so they cancel each other out.

Runout is the tendency to spin the tool around a center point that is not the tool’s center. It makes the tool wobble instead of spinning cleanly and increases chip loads.

All Solid Round Tools. The solid round tools' range covers all application types within the areas of solid carbide drilling, milling, HSS tapping, reaming, and ...

Dovetail definition: a tenon broader at its end than at its base; pin.. See examples of DOVETAIL used in a sentence.

Sep 2, 2015 — Does anyone know the diameter or drill bit size for a standard size shank for a keezer?

Dave Decaussin, one of the original founders of Fadal, recently remarked on a video I was watching that spindle orientation is also essential to maintaining tolerances while machining.

It’s a particular source of tool breakage for smaller cutters because runout is additive to chipload. In other words, if you have a toolholder with 0.003″ of runout, and your endmill is only rated for 0.004″ of chipload, then you can only program a cut with 0.001″ of chipload (0.004 – 0.003) or you’ll exceed the cutter’s chipload limits.

My micromachining video above talks about even higher quality systems that are needed for to reduce runouts to the tiny amounts that are tolerable when micromachining.

how to ER collet CNC Cookbook tool runout toolholder endmill spindle tool life dial test indicator spindle runout tool runout