Project lathe

Posted by Unknown on 20th Dec 2011

I agree with Fraser that the metal gears are a definite bonus, and that there are benefits to taking the time to improve the stock accuracy. I did encounter some difficulties with functional aspects of the lathe which unfortunately were not quick fixes:

A few of the projects I used this lathe for required the full speed output (very small diameter parts). Running the motor at full speed resulted in significant arcing at the brushes, ultimately resulting in the consumption of one of the brushes, and annealing of the brush spring (which may have contributed to the arcing of the brushes). The brush holders were held in place with what appeared to be silicone adhesive and this had debonded (brush holders could spin in the motor housing). The arcing caused some damage to the commutator. After turning down the com on my other lathe, undercutting the mica, regluing the brush holders, and replacing the brushes, the motor now runs tolerably up to 50% of full speed. Reinstallation of the motor was very tedious: the mounts are difficult to adjust to achieve proper belt tension. The arcing becomes more pronounced above half speed, so in the interest of avoiding future problems, I don't run it above half speed.

The speed controller is, to me, unnecessarily complex, requiring a button push and a knob turn with a seemingly redundant 'off detent'. The button only seems to work after the knob has been brought past its off detent, and I believe is an unnecessary step (A kill stop button would make more sense).

The rated fuse for the speed controller will blow at what appears to me to be a low motor torque, and since the motor does not seem to have trouble with the higher torque at lower speed, the added cost of a more robust power transistor, in conjunction with thermal protection of the motor might enable more torque output at these low speeds.

The Stock gears for thread cutting include a wide variety of ratios for different threads. However, the lowest ratio provided, is still a bit coarse for smooth cuts while parallel turning. Grinding a radius on the cutter offers some improvement, but with the limited stiffness of a small lathe, this tends to result in chatter. Reducing speed and increasing feed brings you back to the issue of coarse parallel cuts that you were trying to avoid in the first place.

Changing the chuck/gear ratio is a tedious process, so one needs patience to use this lathe. I am in the process of modifying a small 4 jaw chuck, which Busy Bee sells for their rotary tables, for use on this lathe.

All in all I give this lathe an average review, since one must recognize that there are limits to a machine this small. Electrical issues aside, the mechanics of this lathe seem to be reasonably robust. For those who are considering buying this lathe, I will say:

The lathe is best suited for working softer materials: brass, copper, aluminum, in sizes up to 1". While it will turn steel and harder materials at larger diameters, great patience is required, since only light cuts are possible. Manually moving the hand wheels for parallel turning will yield better results than using the automatic feed. Make sure you get a shim kit with the lathe, along with the appropriate cutter stock.