March 29, 2015


A new innovation in silly electric vehicle battery technology:

More to come soon.

March 11, 2015

New Cross Slide

Since I only have one of the original taig cross slides, but want both a cross slide and compound on the mini lathe, I had to make a new cross slide from scratch.  Also, since the little ballscrews I'm using are right-handed, rather than left-handed like cross feed leadscrews normally are, the whole system has to be rethought a bit.  To get the correct motion, the handwheel that moves the cross slide will be fixed to the cross slide, rather than the carriage.  Basically the same way compounds are normally set up.

As with most projects, I started out with a nice brick of aluminum.  The original cross slide is on top for reference:

It's significantly bigger than the original for a couple reasons.  First, by mounting the handwheel on the cross slide, you lose travel distance towards the spindle, since the hand wheel would collide with the carriage.  Also, I just wanted a bit more travel than a stock Taig has.

Why isn't it steel, or better yet, cast iron?  Well, aluminum was good enough for Taig... I may try hard-anodizing it like the original to improve its wear resistance.  Also I don't have any cast iron bricks lying around.

I faced the brick to size, and cut a strip of brass to make a gib from.  The bar I cut from had some nasty internal stresses, so the piece warped like crazy when I slit it off.  I was able to machine it down to size and get rid of the warp, though:

Here's the squarely-milled jib and cross slide.  A few holes were drilled and tapped to fix the two together, and then I milled the dovetails:

Preparing to mill the dovetails:

Turned out pretty nicely.  Tapped holes along the side were added for adjusting the gib.

I lapped the surface the same way as last time to get it to slide smoothly:

Next episode, I'll be adding the ballscrew and hand wheel to the cross slide.

March 1, 2015

Taig Mini Lathe

Back over the summer, while exploring some dusty top shelves at MITERS, I found what appeared to be they ways, carriage, and cross slide from a tiny lathe.  No one seemed to recognize them (and they were covered in a healthy layer of dust), so I claimed the parts as my own.  The steel dovetail ways were a bit rusty, but everything seemed in good shape otherwise.

The design of this thing is unusual.  The tailstock is lever-actuated, the carriage is cast aluminum with machined surfaces, and the cross slide looks like an anodized aluminum extrusion.

While looking at shiny machined things on some corner of the internet, I found a photo of a workpiece in a small lathe, and I recognized the distinct carriage and way assembly.  Elsewhere on the site, the lathe was identified as a Taig machine.  Turns out there's a pretty large community of people who use (and heavily modify) these machines.  Here's an example of a blog dedicated Taig mill and lathe projects.  

All the parts for the lathe are readily purchasable, and they are actually really reasonably priced.  But that would be no fun, so I'm going to basically build everything from scratch.  My basic plans are:

  • Make it metric!  Why?  Because metric is great, and I also happen to have a pair of sweet 1mm pitch metric ball screws I'll be using on the cross slide and the compound.  I haven't yet figured out the carriage rack situation though.  
  • Make a headstock and spindle.
  • Make a chuck from scratch.  Depending on how adventurous I'm feeling I may make both an independent 4-jaw (definitely easier to make) or a 3-jaw scroll chuck.
  • Brushless motor drive.  I'm deciding between a SK3 and a fancy Moog inrunner I have lying around.  The Moog will be quieter and shinier, but is definitely less power dense.
  • Make a new cross slide, and turn the old one into a compound slide.
  • Add a leadscrew for the carriage, for at least one speed of auto feed.  I don't care about threading, but a slow auto feed speed for finishing passes would be nice.
  • Make a mini quick change toolpost.

To start out, I removed most of the rust with steel wool, and then lapped the ways with oil and fine polishing compound.

In the next episode, I'll make a new cross slide, and ball screw couple it to the carriage.