I Want a Barbot!

Much as I like to whip up cocktails when friends are over, I love the idea of building a Barbot. I figure a robot of some sort has to be a future CNCCookbook project, but until now, I hadn’t really settled on any particular kind of ‘bot. I think a cocktail-making robot would not only be a lot of fun to build, but would also be one I’d get some actual use out of. Here’s one example of a Barbot I found in a recent MAKEzine article:

Each flask contains a different liquor or cocktail ingredient…

This particular barbot was created by EMSL (Evil Mad Scientist Laboratories), and there is a whole write up on EMSL’s web site. Up to 6 ingredients may be dispensed. Each ingredient is metered by air pressure from the flask to the tilting graduated cylinder:

When the cylinder is full enough, the weight of the ingredient above the pivot causes it to swing down and add the contents to the drink…

This particular ‘bot, called Drink Making Unit 2.0 (1.0 was purpose built for making White Russians), was entered in the Barbot 2011 competition.… Read the rest

Revisions: G-Code Transformations with the G-Wizard G-Code Editor

G-Wizard Editor is CNCCookbook’s G-Code Editor and Simulator. GWE version 0.138 was just uploaded the other day. Since it’s unfinished and still in Beta test, GWE is free until the Beta ends. Go ahead and click the link and sign up so you can play with it.

For this post, I want to talk about a unique feature in GWE called “Revisions”. Think of a Revision as a sort of automated editor that makes a particular change to your g-code. Examples of Revisions include:

• Adding or deleting spaces and blank lines.
• Adding or removing block skip characters (/) over sections of g-code.
• Changing capitalization
• Removing comments from blocks and commenting out or uncommenting blocks.
• Eliminating control, garbage, and other non-printing characters.
• Expanding tabs to spaces
• Renumbering block sequence numbers (“N” numbers)
• etc.

There’s a long list of Revisions that will eventually be added to GWE. “What’s so special about Revisions?” you ask. After all, a number of g-code editors have these capabilities.

It’s true, if Revisions were simply going to be commands you could trigger manually, they wouldn’t be that unique.… Read the rest

RAMTIC: Fast Super-Precision Manufacturing on Cheap Machines

A friend and I were discussing the problems of a lack of temperature compensation when 3D profiling. He was talking about how he’d run a group of 4 parts and the first one might have a big 0.003 or 0.004″ step in it at after a toolchange because the machine wasn’t warmed up properly. I got to wondering about temperature comp and eventually discovered an article on MMSOnline about RAMTIC by using CNCCookbook’s Machinist’s Search. There are so many great ideas there that I had to write about it.

First, what is RAMTIC? It’s an acronym for “Renishaw’s Automated Milling Turning and Inspection Center.” This was a system they came up with back in the early 1990′s to allow them to build their super-precision probes very cost effectively on inexpensive machines. It involves a great many excellent ideas that I want to go through one by one. Its essence is portable carousels for palletized workpieces, cutting tools, and reference artifacts.

Let’s check out some of these ideas in more detail.

Reference Artifacts

I want to start with the Reference Artifacts because I found RAMTIC looking to see how to use in-process probing to compensate for temperature effects.… Read the rest

How To Choose a Stepover

This is a guest post by Robert Grzesek, founder of Grzsoftware and creator of the excellent MeshCAM 3D CAM software. This post originally appeared on the Grzsoftware Blog, and I will be incorporating Robert’s excellent article on stepover for 3D profiling into the Milling Feeds and Speeds Cookbook, but I wanted to post it to the CNCCookbook Blog to make sure everyone sees it. It’s a very clear explanation of how to choose a stepover and I particularly like his analysis of the “sweet spot” for stepover. Very useful knowledge to have!

One of the fundamental parameters of any CNC machining, and 3D machining in particular, is the stepover. It is not a stretch to say that it is the single most important parameter in determining the quality of the finished parts you will produce. A machinist can pick a value by feel, based on previous experience, or do the math and calculate the exact value that will give them the finish required. New users generally don’t have the experience and don’t know the math so it takes a while to get an intuitive understanding of of the stepover parameter.… Read the rest

Give Yourself a STOP-Doing List

If you’re organized at all, you make and use ToDo lists. I’ll bet most machinists and engineers are pretty organized in this respect. I know I’m an inveterate list maker, and have it down to a fine art. While I’ve tried using a lot of different software for the task, I have found Excel to be the most convenient. My ToDo lists consist of an Excel spreadsheet with a few simple columns:

• Description of the Task
• Priority
• Area: Helps me group tasks together
• Purpose: It helps me to know why the item is on the list.
• Note: There’s often some comment, web link, or extra information that I want in a separate column from the Description
• Due Date: If there is one. Most are blank.
• Completion Date

That’s it, but it’s enough. I can sort, re-prioritize, group things together, and stay on top of why I’m doing what I’m doing. I used these lists in that format to organize all of my activities. For example, there are lists that track what needs to be done next for G-Wizard, CNCCookbook marketing, article ideas, Honey-Do household items, and so on.… Read the rest