Tag Archives: D250x550

New Optimum D250x550 Lathe

I finally got a lathe! I have been wanting to get one for so many years, but I got a milling machine first, also useful as a drill press. They didn’t have a DC Vario in stock. I wanted it because it had a pot + pwm driven 1.1kW universal motor on it (I was doubting its power though), later on I realized ac induction motors have a higher power factor (and no brushes!), and this 750W motor is really powerful. I can always get an even more powerful AC motor for real cheap, too. Although I’ve got some amateur workshop experience, I’m a noob when it comes to the lathe. I’ve read a bunch on it in the past, and watched many videos, but practice is something else. Here’s a video of my first cuts on 6013 aluminium and silver steel (1.2210), using 10mm brazed carbide tools. The tail stock still needs to be aligned (sideways done perfectly… now the height… but it’s 0.125 mm high?), the chuck is also 0.06 mm off. The video has the necessary explanations in the comments section. No, I can neither find, nor afford a true German, American, Japanese, or British lathe.

Lathe Bench

I need a lathe stand!

Here’s how I measured the chuck and the tailstock alignment, individually and in sync. They were at (negative) max at the same spot (I can’t guarantee that the regular indicator was right above the center, but the chuck’s runout last a bit longer, probably due to indicator sensitivity difference?), which tells me the chuck’s runout adds to the tailstock’s. When the chuck is lowest, the tailstock’s dead center is highest. So the chuck is 0.06 mm off, and the tailstock is actually 0.065 mm off. I need to go down to 0.01 mm!

before_the_test_both

Both indicators are reset when the DTI’s  (we call it a run out indicator in Turkish, the other one is just an indicator) body is pointing up.

Both indicators are at max.

Both indicators are at (negative) max. Zoom in for the mirror.

Induction Hardened

Even though this a German lathe made in China, this makes me feel better about it. Smaller models don’t have this.

I’ve been working on (and off) a mini table saw and an arcade console in the past couple of months, but mostly being lazy. I’ve also been lazy with the blog, but the projects are coming soon. I need to cleanup the workshop first. I also started stocking up some metal for future projects. Here are some 6013 aluminium, silver steel, and regular steel (the 2mm bunch. I thought ordered 1m and got 1kg. It was my mistake, the price was so good) rods and a package of brass,  7075 aluminium, and polyamide rods and bars from my friend Murat in İzmir.

Metal Stock

More on the way 😉 Find the cup holder…

Some parts I turned later on for a test. The 5.98 mm stainless steel rod slides smoothly, without much play in the aluminium part, drilled and reamed to 6.00 mm (not sure,  can’t measure correctly). The 6.00 mm shaft I made from silver steel is a tight fit for this hole.

Parts 2

A sliding fit.

parts 1

A tight fit.

I also got a sine vise last month. It’s my little treasure 🙂

Sine Vise

Finally I can cut angles. 0.005 mm tolerance in 100mm.

ind_cal_sin_vis

Sine vise, new digital caliper with ABS function, and a cheap DTI from China.

Update: As these two sources indicate, it’s ok for the tailstock to be 2-3 thousandths (damn imperial) high above the headstock’s center, which is 0.0508 – 0.0762 mm. They make them that way,  so it levels itself when its bottom wears off over time, or the weight of the workpiece pulls it down a bit. There’s also some discussion about indicator sagging due to weight.

http://www.chaski.org/homemachinist/viewtopic.php?f=42&t=92343

http://benchrest.com/showthread.php?73131-Tail-Stock-Too-High

Here are some pictures from the recent projects…

Full Plate Belts

A 90 mm x 6 mm breakthrough slot for the circular blade, and a 6 mm deep full t-slot (neck is 10 mm, t is 14 mm wide) for the protractor guide.

Wood Nut

Wood nuts used on 10 mm plywood for mounting the metal brackets to the arcade console.

And here’s the stand I designed for the lathe. Lathe model is taken from the 3D Warehouse and stretched to fit.

Lathe Stand

I don’t have enough sheet metal to cover the whole thing. So the list covers only what I got.