The spindle is now almost ready and the main frame for the lathe will be welded this week. Also i ordered a ballscrew for Z-axis, it is 31mm in diameter, got 5mm pitch and is 600mm long.

The frame is now welded and looks really good!
The welding was done by my former classmate, who is a talented welder. I asked him to do it as my welds aren't that good.

Z-axis ballscrew is here!

Diameter: 31mm
Pitch: 5mm
Lenght: 600mm
Cost: ~120€ including shipping and customs (85$ buy-it-now bargain)

The screw looks precicion ground and moves incredibly smoothly. Also i didn't notice any backslash on the ballnut.

The frame is now machined and brought to my workshop. It ended up weighting 98.9kg and to the size of 860x270x230mm.

I have been spending tens of (if not few hundreds) of hours designing the lathe by looking at internet catalogs, ebay, and most of all, drawing with solidworks to find out the best ways to accomplish the functions i need. The lathe is really simple compared to industrial lathes (i have seen few mazaks, a goodway and a nakamura-tome lathe insides.) and they are much more complex. It must have been incredible amount of research and designing gone in to those machines.

I got the timing belt pulleys and few belts (rest of the belts will be ordered later on). The pulleys are T5 pitch. These pulleys and belts cost 171€. The ones in the right go to the lathe and ones in the left go to my featherweight combat robot.

Looking good.

Today i machined the bores of the timing pulleys. One of them was too big, so i turned a brass insert 0.01mm oversize and pressed it in to the pulley. After doing that, i machined the bore. In the picture, the pulleys aren't attached to the shafts, they can spin on them freely. If anyone has good ideas about how to attach them to (plain) shafts, please tell it for me!

Some information about X (and Z)-axis power transmission:

Pulleys: 16T and 36T for 10mm wide T-5 belt.
Ratio: 2.25:1
Accuracy for one step of the motor (=Resolution accuracy of the machine): X-axis: 0.0089mm (0.018mm in diameter) and 0.011mm for Z-axis.

Quick calculation shows that, the rapid positioning speed of the machine will be around 1500mm/min. I would like it faster, but it shall do as this is economy machine after all.

Either put a roll pin right through or machine a keyway. Either way it wont be easy as everything is hardened.

I have been busy, but have fount some really nice parts for this project. A chip cover unit on a '04 mazak HMC broke, so i took it apart to retrieve one of the two covers, which was in good condition (the other was bent and really broken.) I also fount an old servo motor encoder from one of the drawers, and asked my boss if it was a spare part or just lying around there. He said it's been there for a long time and i can have it The only thing i see broken in it is the connector, which is cracked but still useable. These parts must have been several thousand euros when new, so i will have some really good quality parts on my lathe. If you know what signals these put out and how to get this work on mach as a spindle encoder, please don't hesitate to tell me. If it helps, this is made by mitsubishi, was in early 90's mazak multiplex lathe, the connector is 19-pin and has these markings on the pins:

L M A
K U N B
J T V P C
H S R D
G F E

As ever, your work continues to impress me.

Depending on what drives you are using you might find it easier to replace those encoders with new digital quadrature encoders from US Digital.

Some progress in designing. Will buy sawblades for my bandsaw today so i can begin making some parts. The bandsaw is now finished, it has a VFD and high-quality wormgear gearbox with 0.25kw motor. Might post some pics of it later on.

Progressing slowly but steadily. To be exact this is a no hurry project which i build whenever i feel like it. Gives more time to think details and possible problems. FYI, this thread is almost identical with this, http://www.cnczone.com/forums/showthread.php?t=27031

I have made aluminium mounts for Z-axis ballnut, and bearing block for ballscrew angular contact bearings. These took a long time because my milling machine is that small (BF20). Today i took lathe stand parts to work and began welding them, should be ready next week. Then i give it a coat of paint and put lathe on the stand. I also have been tinkering with ideas for C-axis and live tooling at toolchanger, so there could be multiple rotary tools. I will probably make mounting holes for the system before i assemble the lathe, so i can add it later on. I've been thinking of a motor which i orginally ordered for a combat robot, would be perfect size to fit the lathe crosslide and should give 0.38kw/4700rpm. If i go to live tooling, it will take away the possibility to mount a tailstock, as the live tooling motor would hit it while turning close at the center. Anyway, i'm not that interested in shafts, so i will probably end with live tooling, that would be realy unique for a hobby machine.

Progressing.
I got the torch/plasmacut (i don't know how they did them, but looks nice) pieces for headstock. I began by grinding off sharp burrs and then machining chamfers for welding. After welding i squared the sides of the first weldment and made 8x M5 threads for attaching cooling fins. I now have the whole headstock welded to the same aligment as seen in second picture. I will begin machining of it next week.. should be a lot of work and tight tolerances. This headstock including the spindle, bearings, cooling fins, dust/coolant shields etc will be my graduation work for vocational school

I have welded the lathe base together and painted it. Still needs another layer. I also bought 1.75kw servomotor from ebay.de for under 100€! this will power the turning spindle.

This time with lots of pictures as requested...















































Obviously, my slitting saw holder wasn't running true so it grabbed...





So i hacksawed it half, and cleaned with face mill.(nuts)





























I fount these tool holders from school, being thrown away. They are too big for my small manual lathe, and this cnc project already has a turret. So i will save them for later on if i buy bigger lathe, or if i don't, i could sell them



I have been thinking about getting this universal milling machine.. might get it for 500€ including shaper attachment!