Exploring Ramping and Interpolated Holes with G-Wizard’s New Mini-Calcs

I’ve just finished adding a new feature to the G-Wizard Calculator that I call “Mini-Calcs” for release 1.040. Mini-Calcs are little popup feeds and speeds calculators for special situations. We already had one popup for calculating ballnose cutter stepover to achieve a particular surface finish. I’ve just added two more–one is all about interpolated holes and the other is about ramping. Both are common CNC operations that may be used to get a cutter down into a pocket or in the case of interpolation, this is an effective way to use an endmill to create a hole of a particular size.… Read the rest

Thanks for the Survey Responses!

I’ve now gotten about 30 survey responses, which is enough to start looking for trends and doing research on some new articles of interest to the readership.
First, some observations about the overall tone and content of the responses:
I really appreciate the constructive view most have taken. With the Internet, and particularly when there is the opportunity to respond anonymously, sometimes you get a lot of hostile or very unconstructive feedback. Not here!
There is one major challenge, but it’s one I’ve known about for a long time–the readership is decidedly bi-modal.… Read the rest

Old Machines May Not Die, But They Need Some Creative Fixing Up

Many a small machine shop business or talented home hobby shop is started with an older CNC machine. I can’t blame a small shop, let alone a home shop, for not wanting to take on the payments associated with a brand new CNC machine. Once the shop that bought the machine new has fully depreciated it, they may choose to unload it in favor of something that’s newer and performs better. Recent economic stimulus has allowed machines to be immediately written off, at least the first few hundred thousand dollars, which potentially brings more new machines into shops and makes more old ones available to the next step down in the food chain.  … Read the rest

Interpolate or Twist Drill, Part Deaux – Making Holes, Not Pockets

In an earlier article, I wrote about the relative merits of twist drills and interpolating a hole with an endmill.   The focus of that article was on the initial hole needed to start pocketing.  This is classically done by helixing the endmill down to depth and then proceeding from there.  The question I wanted to explore was:
Although, profiles and pockets often begin with the need to get the endmill down to proper cutting depth. Given that you know how long a tool change takes on your CNC mill, how many such plunges do you think are required before you’d be better off to use a twist drill to do the initial plunge and then let the endmill interpolate off of that?… Read the rest

G-Wizard’s New Thermal Expansion Calculator

I was paging through new posts on Practical Machinist and came across a discussion of thermal expansion. Since it looked like something useful, and something I wanted to experiment with, I whipped up a Thermal Expansion Calculator for G-Wizard:

G-Wizard’s Thermal Expansion Calculator…
It’s pretty simple to use:
Select a material, and it will enter the Coefficient of Thermal Expansion for that material. Keep in mind the note at the bottom–it uses the average across many alloys. For more precision, look up the exact coefficient for your material and enter it.… Read the rest

Release 0.122 of G-Wizard Editor (Beta) is Available

There are quite a few new goodies in this release. The big news is the ability to download predefined CNC Controller (e.g. “Post” parameters) from the CNCCookbook servers. Hopefully this will simplify startup for new users:

You can choose from a list of pre-defined CNC Controller profiles to initialize G-Wizard Editor’s “Post”…
So far there are just Fanuc and Mach3 controls with variations to cover lathe, mill, and Inch or Metric units.
There’s also a new “Tortoise” and “Hare” feature inspired by the low and high speed range indicators on older Bridgeport milling machines:
Just click the buttons to speed up or slow down the g-code simulator’s playback speed…
More details are available on the G-Wizard Editor release notes page.… Read the rest

Progress on the Mill Enclosure

Got a little progress on the mill enclosure:

The sides are all bolted together…
The sides are bolted together. The design allows the side or front panels to be individually removed for additional access to the mill. We got all 4 sides made and the brackets set up so it could be bolted together. Next step is to apply West Marine epoxy for water proofing. After that we will paint and then start mounting windows, door, and various bulkhead fittings to get coolant and electrical into and out of the enclosure.… Read the rest

45 or 90 Degree Face Mill?

Of course if you can afford it, it’s great to have both 45 and 90 degree facemills, but what are the pros and cons for each?
Both Sandvik and Kennametal will suggest the 45 degree face mill is a better bet for general purpose face-milling. Incidentally, this is the sort of thing that’s a perfect topic for CNCCookbook’s Machinist’s Search. Try searching “45 degree face mill” using Machinist’s Search in one window and Google in the other window.
The arguments given by these two for choosing the 45 are:
- Cutting forces are better balanced so that axial and radial forces are about even.… Read the rest

Toolholding in Collets: How to Avoid Tool Pullout

Tormach has published a great report on variables that influence the holding power of R8 collets. You can view the pdf file here.
They basically did a series of tests while changing various things to see how that affected the amount of force needed to pull a tool out of an R8 collet. One of the most damaging things to the holding power is the protective oil that cutters come coated in. Cleaning that oil off and torquing the drawbar to 40 ft lbs resulted in an increase in holding power from 1300 lb to 3600lbs–big improvement!… Read the rest

Introducing CNCCookbook’s Machinist’s Search

Have you noticed there is more and more spam showing up every day in Google’s search results? When I’m researching topics for CNCCookbook, I wind up going through at least 10 and more often 20 pages of search results before I’m sure I’ve got all the good dope. Along the way to creating a thousand pages or so of content here, I noticed many of the same sites would crop up again and again in my search results. They were like old friends, because I knew they had reliable information.
So I gravitated to those search results.… Read the rest