My New Lathe; bigger/better

[Stevie]

overall view; you can see the massive headstock support; over 1 1/2" thick
The side of the bed are 3/4" the bottom plate is 1" 5 3/8" SHCS hold the sides to the bottom plate; 25mm SRV THK's on the 3/4" for Z and 1 W and 1 V plus the RSR15W guide the tailstock
20mm SR with W blocks for X

from the rear

Close up of the sideslide

close up of the ballscrew supports

As usuall my project is all made from offcuts which would have been scrapped one day; ebay provided the slides/ballscrews

The target is 0.0001 per step; the steppers will be conected by XL timing belts; with reductions of Z axis 3.75-1 plus 2-1; the X will be 3-1 plus 2-1
The Z ballscrew is 4mm pitch the X is 3mm pitch

A 4" 6 jaw will handle holding; FAG 45mmID 75mmOD taper rollers will support the spindle which as before will be 4140 prehard
2 toolposts as per my other design
The long sideslide is a result of experiance with the old design; max control of the tailstock is a must with what I drill

enjoy the photos

[mxtras]

Nice looking work - I like it. You have made one of these before? Have pics of it?

Keep us updated on the progress - I am interested to see the chuck, headstock and so-on.

Scott

[Stevie]

This is the other machine
http://www.cnczone.com/forums/showthread.php?t=8928

[Stevie]

A close up of the crossslide ballscrew; 2 nuts on a common carrier tocontrol backlash; the screw is 10mm ball pitch and 3mm actual pitch
with 200 steps + 2-1 reduction then 3-1 reduction afterthat; the advance per step will be 0.0001"

[timlkallam]

Nice job,Using the THK rails is the way to go.

[Mcgyver]

looking good. with all those linear bearing surfaces, I'm guessing they are not very swarf tolerant - what do you do, wipers? bellows, to be determined?

[JFettig]

Wow that is looking good, a few things:
It appears the x-axis travel is kind of low? not much there is there?

also, on the z-axis, you have a third rail on the side, what is the purpose of that one?

Watch out on the back tool post, I dont know how those SR rails work and all, but your going to have force pulling that upwards while using the back tool post.

Have you considered doing a slant bed? well basicly angling the lathe so the chips fall into a tray or something other than the ways. What about making a tool turret from those designs floating around?

Lookin good, Im hoping to soon be following your footsteps but instead, to make a mill.

Jon

[nervis1]

What are you going to use for a spindle?

I have been looking online and that is the one thing I can't figure out. Everything I can find that includes the headstock is over $5k.

[Stevie]

THere will be full covers; steel or brass shim 0.025 bent and telescoping
The SR is good in 2 directions; up and down; so parting off is not an issue; plus the things I part off are max 1/4" diameter and brass; max diameter of what I make is 5/8" and these are few and far apart; most are 3-0.5mm;please keep in mind what my machines are for is very specilized; they are not general use
The spindle will be like the other lathe; just bigger with more cooling; my lathe will run 45-60degrees C almost all the time

Fettig; my mill is 50% done also; I'm working on both at the same time; 21" 14" 9" 650ox/in steppers; the lathe has 300 oz/in steppers

[Stevie]

Originally Posted by JFettig also, on the z-axis, you have a third rail on the side, what is the purpose of that one? Jon

I drill 0.009" holes all the time (and other sizes)
I'm moving down to 0.005 holes soon and to control the accuracy of centering the drill every time; the 3rd rail is my solution; it increases the active length of the rail support and stops any up or sideways movement; as i gave $20 for 2 with 1 block on each it's a good return on my invesment

[CATCH22]

stevie looking good buddy,i know it will work great!

[Stevie]

Thanks Catch; hehehe; me and Catch work for the same boss (different plants)

New update

side view of the cross slide stepper reduction drive; the stepper 16T pully still needs boring out to 3/8" to fit the stepper motor

top view; common shaft for the 2 pulleys is below the crossslide ballscrew pulley

general view; that pilot diameter on the NEMA34 is so close it still has no screws; yet it's holding in just fine
Tomorrow i order 2 140XL37 belts