Let's Make Robots!

Drive Stepper (4th axis) off of PWM Spindle Control Ouput

Sorry 'bout this one, I am just sorta "thinking aloud" here, feel free to brainstorm with me, there is no real specific question here.

I want to use the 4th axis (horizontal rotary axis) as a lathe on my CNC. The X,Y,Z would operate normally, the only difference would be that they would be grinding away at a chunk of something spinning, as aposed to sheet-goods clamped down to the table.

Help with steering linkages (Not a robot)

Hey guys, I know this is not a robot but I could really use a second set of eyes on this one...

LMR/ HTML/ iFrame not playing nice

Hey guys, I am trying to embed a Google Docs (Google Drive) Presentation in a LMR post. I can paste the html into the HTML pop-up window, but after hitting "update" nothing happens and my html code is missing if I reopen the HTML editor.

I can get the iFrame to work via disabling rich-text, but again, it is nowhere to be found (also, again, the html code disappears) if I save or otherwise update the post.

I will post the code below, I am not sure how this post will handle it. 

Binary Number directly from Arduino I/O pins?

Hey guys, I know there has got to be a way to do this, but I can't seem to find it at the Arduino reference page and I don't seem to be using the correct google terms.

I have a 4-bit parallel output from a chip going to 4 digital input pins on an arduino. The chip I am using is putting out a nibble of 4 bits representing a number in binary form. I need the arduino to read the state of these 4 pins and give me a number. I have done this via Picaxe in the past, but I can't seem to find the same thing in Arduino.

Rocket Brand Studios 48 hour thing... Links now available

Hey guys, 

Rocket Brand Studios will be participating in Deconstruction 2013. (woo hoo!)

Starting Friday afternoon (2.22.13), I will start building...   ...something. 48 hours later I will be dead --or-- have something really cool built. --And it is all going to be live streamed!


You will be able to watch everything on the front page at

Rocket Brand Studios

Need Sumo built (as a gig)

Hey guys,

I have a customer in Italy that I have done a bunch of custom robots for. He recently has requested a sumo bot --a couple/few of them actually, coded and ready to go. Just like a toy from a toy store, but with wires showing. 

This is a real gig, and I will happily pass it on to whomever wants it and there will be a fair bit of change at the end. 

How-to for Thomas

First, lets state our goal:
We want a robot to drive to dark areas while avoiding stuff on the way using various sensors.

As with everything, we break it down into smaller pieces. We test each one individually, record any numbers we get (ADC readings and the like) and then start putting them together. While doing each of these tests individually, it helps us figure out how we are eventually going to put them together.

If someone told me to accomplish the goal above, I would do it just like this:

AC Motor Speed Control Triac PWM 0-cross

Hey guys, I am working on the CNC and putting together a speed control system. I went as far as buying a $20 "Router speed controller" which consists of a pot and a BTA41-600B triac basically. The control is terrible and "hiccups" at anything less than 1/2 speed or so.

Obviously, an Arduino would seem to fit in here. I did the googling and I think I am down to one sticky wicket.

Are you using anything from Rocket Brand Studios?

Hey guys, I am putting together some pics, videos etc of customer's projects using stuff from the shop.

If you have used anything from Rocket Brand Studios in one of your projects, I would be your very best friend if you would be so kind to drop me a link here.

No need to do anything else, I will take care of the cutting a pasting --Just the links would be super great.


Thanks guys.


The Passing of a Loved LMR Member.

Unknown to many LMR members, but here from the beginning, has been Bondo the Dog. The best damn shop dog I have ever had the pleasure of knowing and never further than my ankles as I recorded almost every video posted here at LMR.

Bondo passed today at 5:00 PM. Bondo was my protector, companion, best God Damn shop dog who ever lived, and my best friend. He will be dearly missed. He was my hero.