Those of you who are beta testing our G-Wizard Editor, be sure to upgrade to the latest 0.437 release. I have fixed a crash/lock-up bug that could very commonly strike while editing code. Thanks to our user Don for finding a set of steps that would reproduce this problem every time. Once I had that set of steps, I was able to find the problem very quickly and fix it.
Click here for the G-Wizard Editor Install Page.…
Found a good little tip over on CNCZone. One fellow says he put a torque wrench on his Kurt vise and discovered the fixed jaw starts to move if you torque it more than 45 ft lbs. Obviously you’re also asking for trouble if you crank your vise down with a workpiece only sticking partially on one side of the jaws.
Supposedely the Kurt 3600 has a pull, not a push screw, and is beefier in the right spots. This reduces flex 80%.
If you’re concerned about these vise torque issues, I have written in the past about Measuring and Controlling the Clamping Force in a Vise. That’s what the gadget in the picture does.
One fellow mentions most programmers setting up the work zero at the top left of the workpiece up against the fixed jaw. An admin berates him for that, and a nasty spat ensues. I don’t know about “most” programmers doing it, but it’s certainly not the first time I’ve heard it and it is a pretty good idea for vise jobs. A little better idea I got from my friend Pete is to make work zero be the lower left corner of the fixed jaw…
I’ve been watching and corresponding with this fellow for a little while now, and he has just released two new videos:
Being able to lock the axis opens up some possibilities, like slotting keyways. I’ve been thinking about this possibility for a while, though not in conjunction with a 4th axis…
Love the two speed belt drive too!
I’ve been accumulating some parts to build a 4th axis along these lines.…
At the end of my first article, “10 Things Beginning CNC Milling Users Need to Succeed“, I promised a second installment. It’s taken a little longer than I had hoped (things always seem to), but with the help of our good friends at CNCZone, I now have 10 More Things to help the beginner succeed:
1. Get a copy of Machinery’s Handbook and compare it to the information in a tooling catalog
The folks on the ‘Zone were adamant about the importance of Machinery’s Handbook. I have one, in fact, I have 2 different editions of Machinery’s Handbook and one edition of another handbook, and I have a confession to make: I refer to them very seldom. I might not refer to them at all except for my work on the G-Wizard Machinist’s Calculator which includes a lot of information I cross check there. If I were stuck on a dessert island with no Internet collection, I would insist on a Machinery’s Handbook to help me in my machine tasks. But, as it stands, I’m a big believer in having Internet access in the shop because I find I use it constantly to look up all sorts of things. Therefore,…
CNCCookbook loves to get pitches for guest posts on this site. While we’ll always have a lot to say ourselves (hey quit chuckling out there in the audience!), we realize we’re not the only ones with something to contribute. We have a large and engaged audience of machinists from all walks who interested in what you might have to contribute. In fact, we’ve even created a special blog category for our Guest Posts. And, we’ve had some wonderful guest posters including Art Fenerty, the Father of Mach3, and Robert Grzesek, founder of Grzsoftware and creator of the excellent MeshCAM 3D CAM software. We’d like to give others the opportunity to showcase their content on the site as well.
Starting today, I am accepting pitches for guest posts. Since I know the way many bloggers think, I am going to set down a few guidelines that I ask you to adhere to. Failure to adhere to these will result in me rejecting your post. Also, I reserve the right to not publish a post if I do not think that the quality is up to par with the other articles on this site.
Your post MUST be around topics of…
I noticed we were getting a lot of traffic to the Mill Tips and Techniques page from people searching for how to Tram their Mill. So, I made a special page just about Tramming a Mill, added even more content to it, and put a few new things onto Mill Tips and Techniques since I took the tramming information off that page.
Got my spindle squeegee, Traminator, wrenches, and pry bar (helps to have a little leverage when tramming). All set for an exciting afternoon tramming the mill, woohoo!
Hopefully it helps people find what they’re looking for sooner.…
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These new G-Code Course chapters come fast and furious when I am working on the G-Wizard G-Code Editor/Simulator and the addition of a new feature prompts me to write about it.
This chapter is called “Tool Changes and Tool Offsets” and describes how to go about programming tool changes in g-code on lathes and mills, and it also talks a bit about Tool Geometry Offsets and Tool Wear Offsets.
This completes the Basic section of the Course, which is a major milestone. We have some chapters written for the Intermediate and Advanced sections, as well as reference materials like our G-Code Charts, but there is still quite a lot of work to be done before we can truly call the G-Code course finished. But, by all means, get started on it and we’ll keep adding new material as we go. Also, the course is set up to make it easy to follow along using the G-Wizard Editor. You can play with the g-code right in the comfort of your favorite armchair that way, or you can head into the shop and punch this stuff up on your machine.…
If you’re familiar with feeds and speeds, or if you’ve ever read through a tooling catalog, surface speed is a quantity used to define how fast the tool tip can move across the workpiece. It is handier than spindle rpm because it is independent of diameter. For a given rpm, surface speed changes at every distance from the center.
For example, suppose we’re running a lathe at 2000 rpm, and we want to face off a 2″ diameter workpiece. At the start, the tool is 1″ from the center of the workpiece. At 2,000 rpm the surface speed may be calculated as follows:
Surface Speed = RPM * Pi * Diameter
So, our surface speed is 2000 * 3.14 * 1, nearly 6300 inches per minute. Surface speed is traditionally expressed in either feet per minute or meters per minute, so we can divide by 12 inches to the foot and arrive at 523 SFM. However, when we get near the center, the surface speed falls off rapidly. At 1/8″ from the center, it is only 65 SFM–a lot slower!
Constant Surface Speed is a feature that allows us to specify spindle speed in terms of Surface Speed instead of…
I was casting about for something kind of fun to post about this Friday the 13th and serendipity struck. I went first to a classified for a CNC Router, which happened to be on a forum for submarine builders called “Sub Pirates”. It didn’t take me long to wonder what sort of place I had landed in and the rest, as they say, is history. I had no idea this hobby was so popular, but I quickly found several sites dedicated to pursuit of happiness building radio controlled submarines. Go figure!
Anyway, this does seem like the sort of thing where having access to machine tools and the know-how to use them might come in pretty handy.
For starters, here a classic “Untersee Boot” is stalking an aircraft carrier complete with torpedo shots:
How about a 1/32 scale model of the Nautilus from the movie? This one shows the innards and a demonstration of the pump driven ballast system:
The Nautilus model uses no dive planes–the fantasy sub’s planes are too small and too close to the center line to be effective. Instead, the propeller is gimballed for even greater maneuverability.
Fun stuff, check out the Sub Pirates forums for…
Continuing our Friday the 13th fun theme, I had also come across these nearly full scale tanks various folks are building some time ago. My favorite was this series from an Aussie. I must say, I’ve never met an Aussie who didn’t know how to have a good time, and this chap is no exception.
Here is part 1 on building a Sherman Tank replica:
He also has a site called ScaledTanks.com.
Man, I’m going to need a bigger workshop!…
There’s gotten to be quite a few of CNC Router folks using our G-Wizard Calculator so I wanted to do a release that addresses some of their special needs. I have just uploaded G-Wizard Calculator version 1.635, and it includes several nifty things.
First, it has direct support for downcut, compression, and straight flute router cutters. They can be selected from the geometry drop down menu:
Feeds and Speeds for Router Cutters…
Second, we’ve now added a Minimum RPM setting to the machine profiles so you can tell it the minimum speed your spindle will go. Many routers have a pretty darned high minimum rpm for their spindles, so this is an important feature. Here’s how it looks on a machine profile:
Setting up minimum spindle rpm…
So what happens if we need to go slower than the minimum spindle rpm? Well, a 1/2″ HSS endmill shouldn’t be run at 10K rpm in 6061 aluminum, and if you try it with a minimum rpm of 10,000, you’ll see this screen:
Minimum RPM error message and warnings…
As you can see, both the RPM and the Min RPM boxes are lit in orange to indicate a limit is being exceeded. Also…
This is a guest blog post by Art Fenerty, father of Mach3 and now the Gearotic Motion software. I asked Art to tell us in his own words what was really great about Gearotic Motion and that’s what he’s done. If it sounds interesting, please check out the various deals we’re offering on Gearotic Motion.
Hi, my name is Art Fenerty, and Bob (your host here) has asked me to introduce Gearotic Motion to you and will be offering it here from this site. Its Bob’s thought that an introduction may help explain what Gearotic is all about and give you an idea as to my background.
Some of you may have heard of me if you have used Mach3 CNC software as Im the original author of that package. Ive been involved in CNC software since myself and a friend built a strange looking CNC contraption in my basement about 10 years back. It blew up almost immediately, but after much tinkering we had a machine that could move a wood router around a table.
At that point we discovered that software for such a beast was near impossible to find. So I wrote what ended up being…
Happy Easter all!
I’m proud to announce this new project with Art, where we’ll be offering his unique Gearotic Motion Software here on CNCCookbook.
Even if you don’t know Art, you probably do know Mach3. Art was the original father of Mach3 and still works Brian on special projects. He’s one of the CNC world’s software geniuses as well as an amazingly helpful and nice guy, and we’re proud to be working with him.
Aside from Mach3, Gearotic Motion is one of Art’s other creations. Think of Gearotic Motion as a special purpose CAD/CAM system for designing, simulating, and producing g-code for making gears. It’s Gear Design Software, in other words. Not everyone needs to design gears, but Gearotic is so much fun that even if you aren’t going to get serious with gears, it’s worth checking it out.
I love these kinds of special purpose programs that lavish amazing amounts of power on a very specific area. If that area happens to be something you’re interested in, they just can’t be beat. Heck, our own G-Wizard Calculator is pretty much that where feeds and speeds are concerned.
Rather than spend to much time explaining Gearotic, let me suggest you…
While you can use endmills and twist drills that are typical of the non-router (routers are also called gantry mills, if you prefer) CNC world, there are a number of special cutters than can help out in a variety of situations and that’s what this article is all about. For more on regular milling cutters (most of which can also be used on a router except for larger tooling like Face Mills), check out our Total Guide to Milling Cutters.
Let’s do a quick survey with some tips:
Upcut vs Downcut
Upcut router bit – aka conventional endmill…
Depending on which way the spiral goes on a cutter, you get a cutter that either moves the chips up or down. Whichever way the chips are going, there is also force exerted on the workpiece in the same directions. So, an upcut will move the chips up and out of the cut, and it will tend to pull up on the workpiece. BTW, the conventional endmill world refers to the cutters as left handed or right handed. This is not quite the same thing because it refers to the actual spindle rotation. You can get left hand (counter-clockwise) rotation router bits,…