Taig Mill from Ebay

I won an auction a little Taig mill on Ebay last Friday and it was delivered on Thursday. The packing left a little to be desired, but only because a UPS delivery requires that things be entirely encased in carbonite to protect them from the repeated drops and such that they inevitably encounter.

The mill didn't fair too badly, but the end of the x-axis lead screw was bent slightly and the nut on the end of it was a bit mangled. Everything seems to be alright, but I'm debating putting in a claim since it was insured.

Below is a picture of the mangled box that the mill came in and the end of the lead screw that was damaged. The lead screw does seem to drag a little on that end, so perhaps it will be worth calling UPS.













I did my best to clean the gibbs and ways and lead screws, and that made a big difference on the way that the mill table moves. Aside from the little bit of drag on the x axis where the lead screw was bent, the table moves pretty smoothly.

It looks as though this is on older version of the Taig mill, as the color is grey not blue and the gibbs use a different adjustment method than the ones that I have seen pictured elsewhere. I think that it will work just fine for me regardless. I do need to purchase a few items before I can do much with it. The vise that was included is pretty old and crappy. I will also need to buy some t-nuts and other means of holding work down.

The motor on the mill also doesn't appear to be the one currently sold with the mill. It has some problems spinning up with the belts in the highest speed position. It seems that the motor lacks the low speed torque to get the spindle going unless the belt is in the positions that give it a lower gear ratio. I'll see if I can come up with a remedy for that. The motor also came wired directly to a power cord, without a power switch in between. I intend to get a suitable switch for it eventually but for now I came up with a temporary solution. My garage only has a single outlet in it and it is not near where I want to use the mill. There is, however, a switch that goes to an outdoor outlet near where the mill is that I was able to easily tap into to add and outlet that I can switch on and off in the meantime.

I'm looking forward to getting this thing up and going. I have a few designs for LED bike lights that I intend to make with it. I'll post the designs when I get around to it.

Bike Light Build: Part Three - Milling around

I've never really used a milling machine before, aside from using it as a glorified drill press. I decided that the bike light project was worth giving it a try. I needed to mill a 1/8" thick piece of aluminum into a 7/8" square. It was a pretty unambitious job, but you need to learn to walk before you can run, right? I won't go into a ton of detail about how I did it and whatnot, since I am by no means approaching being an expert. I am, in fact, the opposite. I know just enough to not hurt myself. Not this time anyway.

I was actually surprised at how easily the aluminum cut on the Bridgeport. My few previous attempts at milling had pretty poor results as I was trying to cut steel with dull end mills and absolutely no clue what I was doing. I have since learned a bit more of the proper technique. I still struggle with knowing which direction the slides move when you turn the handles, but I assume that I have the capacity to learn that with more experience.

I will detail later what this piece will be used for. Right now I'm just going to bask in the glow of knowing that I turned handles on a Bridgeport and got more than a squealing noise, hot discolored chips, and a mangled piece of scrap from the endeavor.

Bike Light Build: Part Two

I got around to playing with the light and the bench power supply last night and it appears that the light shows little or no dimming until the voltage drops below 12V. This means that in mild/warm temperatures I could possibly use NiMh batteries two, without going to the added trouble of buying two 8.4V packs instead of the standard 7.2V packs. At least that is what I have gleaned from wikipedia's information on NiMH batteries. The only other concern is the amperage draw, but I think that the sub-C size cells found in RC battery packs can handle the 500mA draw of the light, and then some.

Today I started building the body of the light with 1" square aluminum tubing that I bought at the hardware store down the road. I started with a 2" long section, which I then notched out so that a 7/8" long section of square tube could be held inside the notch.

I did this by first using a hacksaw to slit down the sides of the tube adjacent to the inner wall, up to a line that I had scribed one inch down the tube.


Next I drilled holes in the tube along the side of the scribed line where I wanted to remove material.


I then used a pair of vice-grips to break off the material at the line of drilled holes.


The next step is to file the bottom and sides flat. Then a piece of square tube is cut to 7/8" and filed to fit into the notch.

I was going to use a piece of aluminum extrusion intended to be a shelf braket as heat sinks, but then I remembered that I had some PC heat sinks that I never used on the PC in our office. I proceeded to cut those to two inches long and added a chamfer on one top corner. The picture below shows the pieces placed together as I intend them to fit.


I also placed an order with Newegg.com for some Arctic Alumina adhesive(AAA). AAA is thermally conductive, commonly used to attach heat sinks to CPU's and such. It has a good reputation for being a tough adhesive too, so I will at the very least use it to adhere the LED and heat sinks to the body. I will probably use JB Weld for more structural joints.

Next up we will finish constructing the body...

Bike Light Build: Part One

Just a few quick note about my latest project. I'm hoping to actually document this one in a useful manner, so bear with me. I've done a little bit of research about DIY lights for mountain biking and finally decided to get around to making one. Fall is upon us and soon there will be little to no chance that we will see the sun for months on end. I will therefor need something to light my path while biking.

I had considered going the cheap route of using a halogen light, but the run time is abysmal compared to other options, such as LED and HID. HID is simply stupid expensive, so I decided to go with an LED. After reading a website all about such lights here, I decided to go with a Cree MC-E emitter from ledsupply.com. The MC-E is actually four emitters closely packed together under one lens and it comes pre-mounted on an aluminum plate to help dissipate heat. The emitters are wired in series which means the forward voltages must be added together, resulting in a Vf of 12.8-13.2. The current is shared by the emitters and I will supply that with a Luxdrive Buckpuck with which I can provide a regulated 500 mA. I chose the wired model, with the potentiometer to vary the current from 0-100%.

To test the Buckpuck and LED I soldered some speaker wires that I scrounged from a box of stereo stuff I had in the closet. I put some alligator clips on those to aid in testing as well. I wired the Buckpuck to my regulated power supply and set the PS to 14.4V which is the voltage that I can get from two 7.2V Ni-Cd battery packs that I bought for my remote control car, when they are wired in series. I then attached the clips on the LED to the Buckpuck outputs and turned on the PS. Voila! Blinding frigging light. Seriously, don't look directly at this thing. At 350 mA this LED throws approximately 430 Lumens and I was driving it at 500 mA which should give it a 30% increase in flux. That is truly bright. I didn't leave the light on for long as it was not attached to any heat sinks and even an LED will heat up when driven at 6.5 watts. I just wanted to verify that everything worked anyway.

Next step... check to see how low a voltage this thing can be driven at so that I can be sure that the battery packs I have will work even when low, or if I need something with more than a nominal 14.4V.