Monday, January 2, 2012

PD400 - Quick Update

I bite the bullet and flipped the lathe over to access the gib plate from underneath. The weight of the lathe is rather unevenly distributed, making it hard to slide out of the chip tray's motor compartment. One thing to note when flipping over the lathe is the plastic cover of the motor. It has to be removed to prevent damage (thanks to the review done by Dan Kautz on his site

I'm a happy man! The carriage now slide smoothly on the ways whether the carriage handwheel or the leadscrew handwheel is used.

The gib plate for the carriage. The bolts and setscrews were very tight. I've to use a plier on the allen key to loosen them. They were retightened till snug.

The lathe on its side.

The movement is now very smooth. I'll be testing for play and adjust accordingly. The exercise of preparing the lathe for use is an invaluable experience.

I wanted to test cut a piece of steel rod measuring 8.35mm in diameter. This is the part that stumped me, who is too used to variable speed spindle of the Sherline. I need to learn how to read the table on the front of the machine. Anyone can help?

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Anonymous said...

Wong, the chart on your lathe is to find the surface speed of different size material at different spindle speeds.
the row on the top lists the spindle speeds in rpm. The left column is the diameter in mm. you say you want to turn 8.35 mm in steel. the chart on top lists stahl,(German for steel) as 2o-40 meters/ minute. Using the 10 mm, the chart shows 21 meter/minute at 660 rpm, and 44 meters/minute at 1400 rpm.
If you are starting with an 8.35 diameter the 660 setting may be on the slow side, if you are turning something larger to 8.35mm starting at 660 may be ok.


Wongster said...

I tested using 1400rpm with doc of 0.1mm, 0.2mm and 0.3mm using carbide insert and HSS tool. Power feed was employed at 0.14mm/rev and 0.07mm/rev. Best result for the small diameter is 1400rpm with 0.2mm depth at 0.07mm/rev.

I notice some taper in my cut, as much as 0.06mm for 100mm as the diameter gets smaller (started at 0.02mm). Likely flex in stock. The end was held in revolving centre.

I'm testing on a piece of 24mm+ dia steel in a while. Will post result.