Herbie & Friends The New York City Machine & Prototyping shop!

Milling 1018 steel with my TAIG!

Sun, 5 Jul 2009 21:31:15 -0400

I’m starting to work on a set of parts for an R&D project of which many will be machined from 1018 and 4140 steel. With my new air compressor and coolant system, I have been able to mill steel with very satisfactory results with my TAIG! The attached part took a few hours to mill (did it over the course of a weekend) but a few of the cuts were continuous milling for over a hour.

The recipe for this part was:
- 1018 Steel
- 1/4” 4-flute Altrax carbide end mill
- 8 IPM
- 2750 RPM
- 0.025 to 0.028 DOC
- 85% stepover

The mill is trammed well and the results are silky smooth. The part itself gets hot, but the carbide bit stays cool.

Everything was done on my TAIG except the holes (including the 0.5” diameter, 4.5” long shaft hole) which were drilled on my drill press (easier and has higher low-rpm torque).

I’m Back!

Mon, 22 Jun 2009 20:26:31 -0400

Back from my honeymoon (and wedding) and am proud to report that Online Metals has featured my ring on their blog! Check it out at http://blog.onlinemetals.com/?p=924

More posts on the workshop to come soon as I get back into the swing of things

New Air Compressor & Coolant System!

Thu, 28 May 2009 23:08:57 -0400

I’m getting ready to start cutting steel (1018 and 4140) with my TAIG which is going to require system. I was deciding between the Fogbuster and the Trico MD1200. I went with the Trico because it had more recommendations on cnczone and online literature which supported its technology.

However, before I could use the Trico, I knew that I needed a bigger air compressor. My existing Sil-Aire (which is effectively silent!) is great, but it doesn’t put out nearly enough air - only 2.0CFM at a very low PSI. I need ~4.0CFM at 90 PSI to run both lines on the Trico MD-1200.

I had tried an Ingersoll Rand Model DD2T2, which is advertised as being “only” 79 Db, but after using it in my apartment for a few minutes, it was WAY too loud. I would guess it was somewhere between 85 and 90 Db. Simply way too loud for me.

So after googling around, I found www.castair.net, which makes air compressors which are said to be more quiet. Most importantly, the model which I purchased has a motor which runs at 1725 rpm (versus the Ingersoll which ran at 3450) and much more importantly, it is belt driven such that the fan is only running somewhere around 1100 rpm (which is really what makes it quieter). I just received it tonight and starting breaking it in, but I can say that it’s really not too bad having it running right next to you in a room. Might get to be a bit much after a few hours, but it’s still very quiet.

I’m still experimenting with where I’m going to place the unit in the room and haven’t starting experimenting with the Trico MD1200 much yet, but will be sure to post a video soon with the results!

Adjusting Y-axis backlash

Tue, 26 May 2009 21:46:48 -0400

I knew that I had a bit of backlash in my Y-axis being caused by a loose nut (versus the gibs). I had been ignoring it for a while but it finally caught up with me while trying to mill some circular pockets.

So the other night I sat down and disassembled the front of my enclosure in order to disassemble the y-axis servo mount in order to adjust the nut.

Nick Carter has great pictures on this process here. A few snapshots of my mill are below.

The backlash is demonstrably better post-adjustment (per dial-indicator measurements). I’m waiting for my new air compressor to arrive (stay tuned for more on that!) before I start cutting again

Wedding Ring is Done!

Tue, 19 May 2009 23:51:28 -0400

I can get married now!

I tried experimenting previously turning my own wedding ring. I started with aluminum, but the surface finish wasn’t ideal and, more importantly, I found out that Aluminum can be/is toxic to the human body!

I then made one out of 12L14 steel which looked great (had a nice, dark-but-shiny-aesthetic - but couldn’t actually wear it due to the rust caused by moisture from skin...

So the solution was stainless steel! I hadn’t worked much with stainless before, but I was told that 316 Stainless can be a good / better version to try. I knew that I had to worry about work-hardening, so I did three things to best prepare my custom-ground HSS tool for turning the radius:
1) I bought this cutting fluid which was designed for “exotic” metals and stainless steels. It has the consistency of toothpaste (well, a little more viscus) and worked great
2) I bought this 3/8” diameter ultra fine arkansas stone which I used to both perfect the radius of my HSS cutting tool and, more importantly, to put a sharp edge on it
3) I bought this stainless steel buffing kit, although I actually only used the compounds included (didn’t use the buffing wheels yet) by putting them on a rag and applying while the part was in the lathe

I bored out the ID to my finger size (0.755”) without any problem using an import Carbide boring bar. I then used my custom-ground HSS tool (see photo below) to start turning the radius. It started off cutting well but got progressively worse. However, I expected this. FYI I’m turning around 300rpm. So I cut as much as I thought I could, then re-sharpened my bit, tightened up my gibs a little, and then with fresh lubricant on the part, I really turned the crossfeed into the part. This caused some squealing, and definitely generated a lot of heat, but it worked! I was actually getting a nice chip, too. Anyways, once that was done, I polished it with the kit mentioned above, parted it off, deburred and am done!

FYI - these pictures make the ring look grainy. It’s not. It’s just the camera. As long as you are ~6” or more away from the ring, it looks incredibly smooth and shiny.

Strange happenings....

Mon, 18 May 2009 23:50:16 -0400

I just realized that my Apple blog software (iWeb) somehow deleted a few posts during the month of April. First time this has happened - and i’ll be sure to keep a close eye so that it doesn’t delete any more...

Milling Steel!

Sun, 17 May 2009 23:28:30 -0400

After having spent a few years cutting a decent amount of aluminum on Herbie, I decided to take the plunge into Steel. The catalyst was that I need to mill a few parts which will be heat treated for strength. The pieces are to be made out of 1018 steel and 4140 steel. 1018 is your “bread & butter” cold-rolled steel. 4140 is a very common, strong alloy.

So, rather than dive in too quickly, I decided to start by practicing on 12L14. The “L” in 12L14 stands for “leaded”. When small amounts (i.e. fractions of a percent”) of lead are added to steel, it becomes much easier to machine (a.k.a. free machining). The round-stock piece seen in the photograph was a piece of 12L14 which I face-milled. I used a 1/4” HSS 4-flute end mill at ~1000 RPM and 4 IPM on my TAIG with a 0.03 DOC. This works out to a chipload of 0.001” or 1-thou (Remember: IPM = Chipload * Flutes * RPM) Although it went well (in fact , it cut incredibly well and left a very smooth finish), this isn’t ideal cutting. Here’s why:

Although you need to cut steel with MUCH slower RPM’s than aluminum, I found that, based on experimenting, you’re better off at 2,000 - 2,500 RPM. Since you want to keep the chipload about the same, this means increasing the feed IPM to, say, 6 or 7 IPM. This means that you may have to keep your DOC relatively shallow if you’re using a small mill, like my TAIG.

Two other key points:
1) Don’t use HSS (high speed steel) tools when cutting steel. Instead, use carbide tools. Why? Because HSS simply dulls out too quickly. Carbide bits, although never quite as sharp as HSS (hence why HSS leaves a better surface finish on aluminum), is a much stronger material and lasts longer in steel.
2) You need to use coolant!!! Otherwise it can get too hot. Some folks may have luck using TiN coating tooling without cutting - feel free to experiment.

So although I’ve experimenting with 1018 steel (that’s the other piece I cut in the photo), I’m waiting to get my coolant rig set up before I start milling more steel.

In the meantime, I just received two carbide end mills which I am excited to try:
1) http://www.use-enco.com/CGI/INSRIT?PMAKA=SN322-6016
2) http://www.use-enco.com/CGI/INSRIT?PMAKA=SN322-6116

Stay tuned for more!

Custom Arduino’s (from scratch!)

Sun, 5 Apr 2009 17:15:27 -0400

I’ve been working on some very cool Arduino projects! The photo above shows one of my efforts to build an Arduino from scratch for a total cost of ~$7 (the ATMEL chip + a 16hz crystal, a few resistors, a few capacitors and a B3F button)! This is going to be very cool / useful for projects which I give away or permanently use an arduino; cheaper and custom = good! Anyways, once I’ve got a few more things figured out I’ll post the results

XY Table & Cam-Lock Vise for new Drill Press!

Wed, 1 Apr 2009 20:45:10 -0400

Check out the video walkthrough of my new drill press (separate blog entry) and accompanying XY Table & Wilton 6” Cam-lock vise. Product links are:
1) Drill Press: http://www.use-enco.com/CGI/INSRIT?PMAKA=308-0056 (As of today, on sale for $269)
2) XY Table: http://www.use-enco.com/CGI/INSRIT?PMAKA=201-2826 (As of today, on sale for $89.95)
3) Wilton 6” Vise from Amazon.com (eligible for free super-saver shipping) and currently priced at $221 versus Enco’s price of $293!!

Arduino: inputShield & Servos!

Mon, 23 Mar 2009 09:18:18 -0400

I am really loving how easy it is to do some really cool things with the Arduino platform! As you all know, one of my main goals is to marry my CNC metal working with electromechanic drivers and sensors. I have been playing with a really cool shield made by the guys over at Liquidware called the ‘inputShield’. It has a joystick (which also doubles as a button), two other buttons (A & B) and a vibration motor!

In this program (see the code below), I use the joystick’s lateral (versus vertical) movement to move amazing servo! It’s amazing to me how simple the code is. This video (embedded below) also shows two very cool/useful things:
1) Learning how to use the Arduino serial monitor to measure the sensitivity range of an input or sensor
2) Using the “map” function to correlate the sensor’s input range to the motors output range. For example, the joystick’s input range is from 5 to 1023. But the servo motor only moves from 0 to 180 degrees. So how do you tell the motor to move between 0 and 180 degrees based on inputs from the joystick which range from 5 to 1023? Easy with the map function. See the code & video below for more.

Thanks!

CODE

/* Code to rotate a 180 degree servo with a Liquidware inputShield
*/

#include <Servo.h>

Servo myServo;

int pos=0;
int joylateral=5;

void setup(){
Serial.begin(9600);
myServo.attach(9);
myServo.write(0);
}

void loop()
{
pos=analogRead(joylateral);
Serial.println(pos);
pos=map(pos,0,1025,0,180);
myServo.write(pos); // tell servo to go to position in variable 'pos'
delay(15); // waits 15ms for the servo to reach the position
}

Beginners Guide to Arduino & Shields

Sat, 21 Mar 2009 17:43:56 -0400

As a newcomer to the Arduino platform, I felt that the sheer amount of Arduino ‘flavors’ (i.e. different versions) as well as Shields can be a bit confusing. The video embedded below is my attempt to help demystify that. I cover what the basic Arduino is, show examples of different Arduino ‘flavors’ and various shields.

As I mention in the video, the biggest factors with regard to the base Arduino flavors are:
1) Physical size (do you want the standard size, which also accommodates shields, or something more compact)
2) Computer connection: Do you want full-size USB, Mini-USB, or “no” connection (removes the USB equipment from the board, saving space, but requires special cable)
3) Cost & Assembly: Some arduinos you can purchase as kits, requiring the user to assemble with a soldering iron (note: all of the kits that I have seen ONLY require through-hole soldering; no ‘smt’ or surface-mount parts, which is considerably more difficult to solder
4) Processor heft: are you OK with the standard Arduino, it’s memory size, speed and number of I/O or do you need more heft?

Shields, in my opinion, can be broken into two main categories:
1) Shields which provide different/more convenient arrangement of the Arduino pins to facilitate prototyping. These are usually called ‘Proto’ Shields are are made by MANY different folks with different features. Most are not assembled but only require basic soldering
2) Shields which add Arduino functionality, including additional motor contor, wireless, ethernet, etc.

Here are some links which I mention in the video:
1) Freeduino at NKC Electronics
2) Illuminato, Extender shield, InputShield & More at Liquidware
3) MakerShed (stock many different Arduino’s, including base model, Mini, Nano, Bare Bones, Boarduino, LilyPad, Motorshield, Seeduino, etc
4) Arduino on Wikipedia (offers information on various models as they are introduced and updated)
5) Makerbot - maker of the very cool ‘Danger Shield’ which offers multiple input sensors and is a great one-stop-shop to learning and experimenting with Arduino

UPDATE
Quick update/correction:
1) Arduino (the company) is actually based in Boston (i.e. USA), not Italy (although it has ties to Italy)
2) The Nano is made by Gravitech, not by Arduino.

New Drill Press!

Wed, 18 Mar 2009 00:03:38 -0400

Real estate space in my shop is precious! However, I was tired of taking the time to set up my CNC Mill, program, part, vice, etc simply to drill a hole (or many holes). Unless I need high precision or I’m drilling a hold pattern, it would be much more convenient to have a drill press. There are also other improvisational uses - such as drum sanding and deburring. Anyways, it is very difficult for me to receive “truck” shipments because I am not home during the workday to receive the shipment and even if I was, there is usually a $75 residential fee for a lift-gate truck.

So I commenced my search, looking for the best drill value possible - either one I could purchase locally or have shipped via UPS. The best deal proved to be the one you see below from Enco. The drill, link here, is a 1/2 horsepower, 13” swing with speeds from 250 - 3000 rpm and weighs about 110 pounds. It normally costs $325 but was on sale for $270 and I got free shipping (Enco almost always has a free shipping for web order promotion...)

I also knew that I wanted an XY table for the drill. They are very handy when you need accurate holes drilled; the XY table allows you to clamp your part down firmly and THEN use the XY table to align the part to the perfect position. You can even use a center-finder (like an edge-finder except with a pointed tip). I found an XY table from Enco on sale too! Normally $129, I purchased this one for $90, also with free shipping. It has 8” of travel in the X axis and 5” on the Y. NOTE: One thing I did not realize until unpacking the XY table is that the hand-dials are METRIC, not inch! I don’t envision this being a big problem (I can either convert metric to inches, if I use them at all) but it also might be a nice project to turn & mill some new imperial ones.

More videos on basic drill use/tricks to come.

I haven’t yet selected a drill vice, but I have one in mind. I’ll be sure to keep everyone posted.

Grinding HSS Lathe tool!

Tue, 10 Mar 2009 23:48:43 -0400

According to all of the ‘wise’ folks (i.e. people who have been doing this far longer than I - a real machinists grinds their own tools. I ground a 60 degree bit a few months back in order to do single-point threading, but otherwise had not had any need to grind a tool. Until now.

I’m getting married soon and have been looking forward to making my wedding ring. I started experimenting with different sizes & shapes and finally got the approximate dimensions down. But I needed to put a radius out the outside diameter of the ring. In order to do that, one option would have been to use a ball-turner device... but the much-easier option would be to use my bench grinder with aluminum oxide wheel to grind my own!

So tonight I sat down to give it a whirl. I used a 1/4” HSS blank - so even if I screwed it up I wasn’t out much. Much to my surprise, it was easier to, by hand, get the radius / concave shape I was looking for! I guessed at the adequate relief/clearance and then put it in my A2Z CNC QCTP and viola! It worked much better than I expected!

Check out the video walk-though below and, at the bottom, a photograph of the final product!

Open Source Hardware Bank Logo!

Tue, 10 Mar 2009 00:27:34 -0400

A group of folks that I’ve recently come to know have started up an ‘Open Source Hardware Bank.’ Check out their blog for more info - but the short version is that they are providing a funding vehicle for people who want to develop electrical hardware to do cool stuff! A lot of it is currently based around the Arduino, which is the platform that I have been working with.

They recently created a logo for their ‘Bank’ and so I thought it would be cool to mill them up a version out of aluminum. This is very similar to a post I did quite a few months ago (see here). I am using BobCAD/CAM V22 and BobART to import the logo (jpg), vectorize it, then create a profile CAM toolpath with no offset to mill it. I’m using a 4-flute, 90-degree (I misspoke in the video, calling it a 45-degree by accident) at 6,500 RPM and 7ipm. Check out the video below. Enjoy!

P.S. I got an ‘Official‘ shoutout from the guys over at the Bank on their blog post - http://antipastohw.blogspot.com/2009/03/nothing-is-official-until.html. Thanks!

Update - Here’s the link to their official webpage

Arduino! Open-Source micro controller!

Sun, 8 Mar 2009 23:18:53 -0400

I have been spending a considerable amount of time over the recent months experimenting and learning with an ‘Arduino’. For folks who haven’t heard of it, it’s an very popular and relatively-new open source hardware microcontroller. In laymans terms, it’s a cheap ($30) and easy (USB!) way to do really cool stuff - like control motors based on sensor inputs. There is a huge online arduino community - and while I intend on posting some snippets of my arduino adventures on NYCCNC, my blog will only begin to scratch the surface of the Arduino’s potential. For folks looking to learn more, check out the links at the bottom, youtube, or do a little google-hunting.

My interest in Arduino is twofold: 1) learn more about ‘EE’ stuff - resistors, capacitors, regulators, voltage, etc and 2) make cool stuff! The great thing about Arduino being open-source and cheap is that there is a PLETHORA of information online - whether it’s tutorials or examples.

I also think that as a CNC’er, knowing more about electronics is a requisite skillset. Especially servo’s!

The example below is very simple and very do-able for anyone, regardless of prior experience. As always, post a comment with any questions.

See below the video for links & the source code

Arduino Links:
1) www.arduino.cc
2) www.sparkfun.com
3) www.liquidware.com
4) http://blog.makezine.com

Project Source Code:
// Servo Button Program
#include <Servo.h>

Servo myservo; // create servo object to control a servo
// a maximum of eight servo objects can be created

int pos = 0; // variable to store the servo position
int inputPin = 2; // choose the input pin (for a pushbutton)
int val = 0; // variable for reading the pin status

void setup()
{
myservo.attach(9); // attaches the servo on pin 9 to the servo object
pinMode(inputPin, INPUT); // declare pushbutton as input
}

void loop()
{
val = digitalRead(inputPin); //reads value of input

val = digitalRead(inputPin); // read input value
if (val == HIGH) // check if the input is HIGH
{
for(pos = 0; pos < 180; pos += 1) // goes from 0 degrees to 180 degrees
{ // in steps of 1 degree
myservo.write(pos); // tell servo to go to position in variable 'pos'
delay(7); // waits 15ms for the servo to reach the position
}
myservo.write(180);
}
else { }
}