[Stevie]

Here is the newly installed Tailstock block; it's not qite all done; but is now useable for drilling; and if I can find the right bearing setup maybe pressed into service as a rotating center



Differant angle to show the locking device for the stock; that is a 10mm bolt through the outer section of 6061 T651 and tapped into the inner section and clamps to the rail by compression



Front view; the Rohm drill chuck (0-0.25") is mounted for now on a 0.500" dia mount; but as a #1 morse spindle will be fitted into the upper block the mount is temp; the spindle is ready to go into the Alum but the #1 morse has not arrived yet; nore has a #1 morse rotating center; the spindle will be threaded for in and out movement and another nice Knurled brass handwheel is to be made



In this shot you can see the gouge I've made to increase travel of the X axis; I gained almost 12mm



Similar gouge on the handwheel end; gain of 8mm



X axis almost to the limit; total travel is now up to 91.5mm; I could gain a bit more at the expense of strenght; but I feel it's not worth it



Top view of same



My new Z axis spindle; this is a 6" extended air powered diegrinder front shaft; I'll be modding this into a Z spindle for the Lathe; the tailstock is way bigger than it needs to be; this is for a gridge to be bolted across the headstock and tailstock; on this bridge will be mounted the compound slide once the new toolpost mount is made; the compound will carry the new spindle with it's drive motor 30,000rpm and will be driven up and down by another Compumotor stepper drive and step motor; the software I use to control this machine will have 2 copies in the computer; one will be the lathe control; the other will be a 4 axis mill setup; a new timing belt drive will be added to the main spindle in the headstock; with a common timing wheel on the spindle and 2 options for drive systems; one system will be a DC ver drive with about the same top speed as now; the other drive will be a Nema 34 stepper motor and drive (300oz/"+ hold)
With this system and by moving the Z axis off the bridge and mounting it to the cross slide (now Y axis as the mill) the spindle will become the 4th axis of the system (or a C axis) The Z axis of the lathe system will become the X axis of the mill
With this setup I can have
1/ lathe 2 axis
2/ Lathe 2 axis plus steppable spindle
3/ Mill with 3 axis (table is replacing the lathe toolpost; Z axis is on the bridge)
4/ Mill 4 axis Lathe spindle becomes C axis; Z axis moves from bridge to Y axis mount and is useable over the C axis in 3 directions
All in all a nice setup indeed once its all finished

[Stevie]

Well after a frustrating morning with dropped steps keeping me re-picking up my Zero's again (bloody crappy threaded rod; I have a ball screw coming)
I figured untill the new ball screw and the Compumotor 2 stack 23 size stepper comes i'll use one of the Japan Servo KP86SM2-002 that I got
Wow; some power heh I think that puppy would cut 1/2 hard 4140



Looking from the tailstock



looking from the headstock

Nice thing is it will be 3 mins to return to the original setup with the handwheel again; I just removed the drive belt and handwheel; tapped 2 holes that you would never see and added the new setup

[Stevie]

I've removed the compund slide; it's not needed on a CNC anyway; if I need to taper I just program the taper
I also lowered the tool post; I thought the chance to move to 3/8" sq tools was a good move
The max before was only 1/4" sq
The toolpost now has a nice P/Bronze bearing to rotate on too; before it was just a shoulder bolt; I still need to drill the indexing holes for the 90dgr points
Another thing I did was to make the mount block so I can rotate it on the 2 1/4" dowels and place the toolpost more to the tailstock; never know it may come in handy
The same mounting holes now drilled into the cross slide will mount the small mill table too; once the bridge is mounted the Z of the lathe will become the X of the mill setup Y will be the lathe X and the new bridge will carry the Z

[Ken_Shea]

Stevie,

LOL, (bloody crappy threaded rod; ) , I take it then that you are not happy with that

What do you have in mind for protecting the ball screw? maybe you could mill a rabbit all the way around and drop in a .125 or so fitted metal plate, possibly in two sections so it could be removed

EDIT:
Since you wont have the compound how does a CNC lathe deal with threading as I usually use the compound set at 29.5 and feed with that?

Ken

[Stevie]

I got a 3/8" dia .4 pitch ball screw from eBay last week (not here yet) with 2 ball tracks and 10" of travel (litte short but good enough)
Just need it to arrive and presto; fixed
However the 34 sized stepper has cured the main problem

It just sounds like an F16 on the run up ramp

[Stevie]

missed your edit

I always just plunge my threads at work; I rarely add side cuts; if you thread fast enough you generally dont need to move sideways

for a 1" dia thread I'd go 200rpm min usually faster if it's not blind

[Ken_Shea]

The compound feed was just how I was shown to thread, often wonderd why, speaking of which Why ?

Ken

[Stevie]

me too; but over the years I've developed many better ways; and way faster

[Stevie]

Well now I'm really blown away with the capacity of this tiny lathe; I've been machining my tailstock spindle; this is from a multi head tapping machine once; it's got to be at least 45RC; I'm using a 3/8" sq carbide at 1500rpm; at 100mm/min feed; with .5mm cut; this little bugger takes it with hardly any chatter or slowdown; no stepper slips since the 34 went on; I'm using the micro center I made; still in the drill chuck
The new spindle will shorten the distance the center is out; the #1 morse will be great for drilling and support; I was getting about 0.0025" taper over the 3.25" cut; but a simple addition to the gcode line made that go away in a hurry; not bad for a tough material like this; plus the slot for the drift is in there too creating an interupted cut at almost 5" out from the collets (the spindle is on a broken expanding reamer I've had kicking aroud for ever)
I feel with the right suppot by the tailstock; this little gem can do a lot of work; the travel steady is the next small project for it (after the tail is finished) I also roughed out the small 4"x6" miling table to replace the tool post and mount today

[Stevie]

Bored the Aluminum with a line bar using the 1/5" reamed hole as a guide
The reamed with 11/16" to match the spindle that is on the tailstock

[Stevie]

Here is the lathe making it's own morse taper mount for the Rohm Drill Chuck; the plain jane 1/2" mount is turned down to a #1 morse; still need to make the knock out tang at the small end

I also have to turn the threaded rod down to fit through the 5/16" hole in the spindle to push the morse taper out; the threaded rod (B7) will be turned at the back to fit 2 1/4x5/8x3/16 bearings and a handlwheel will be made just like the others from Bronze

Next project for it is the traveling 3 point steady rest; this will be full adjustable and with have 5 x 13 x 4mm bearings to contact the stock being turned; the cross slide is drilled to mount the steady ( I think ahead sometimes)

[Stevie]

Here is the new antibacklash nut assembly for my Z axis
The front nut (left side) is made from Ampco Bronze; the rear from Yellow brass; that spring is quite stronge and crushed about 1/8"
The principle is the spring will keep the forces at opp sides of the flanks of the leadscrew; hence no backlash; the 2 staked rods keep the nuts in line with each other (the brass nut floats in and out)
There are many way to do this; but as my space is very limited it what I had to do

[Stevie]

The new 240oz/in stepper for the Z axis; complete with US Digital encoder
As you can see the handwheel I stole for the tailstock
Temp on this only moves 4dgr above room @ 2Amps/phase 2000steps


The new 2 stack Compumotor stepper for the X axis; almost 80% more power; I was chking the temp rise with use and standby; hit 50dgr in the first config 1.5Amps/Phase; 40dgr(better) in the 2nd setting 1Amp/phase; still seems high but well within the specs (100C or 212F) again @2000 steps


The finished tailstock; complete with stolen handwheel (hehehe)
I need to remake another now for the Z axis

[Stevie]

The next update will be a big one
A New headstck and spindle is planned with taper roller bearings with setable pre-load (2X Fag320006X and 55x38x8 oilseals)
I got a 3" 3 jaw off eBay and I'll make a new more ridgid headstock to accomadate it
I'm still collecting the parts for the 3axis mill conversion; so that update will be coming too

[Ken_Shea]

The incredible Mr. Stevie !

I don't know how you do it but you are beginning to PI## me off

Once again you have outdone yourself, while I remain a jack of all trades and the master of none.

Nice, nice work Stevie.

Ken

[Stevie]

Thanks Ken

Well it has started to make it's self some money to pay for all the updates; as of now 36 barrels sold at $8.00US each; not bad; plus a few other things to make for cash too
Nice when it can pay it's own way

[Stevie]

Finally got a bit of time in the shop to start the head conversion
Here is the basic block bored for the Fag's and oil seals
It's bored exactly the same the other end; once the spindle is installed with a lock nut to preload the taper rollers the head stock will just rock; I'll add a couple of threaded holes in the side and bottom for an oil bath supply; the oil will not be in the head all the time; but I'll circulate it to cool it; I figure with the high rpm's it will be making this will be a good idea



Next will be finding time for the dual use spindle; I intend to make it accept ER25 collets without the 3 jaw; and the 3 jaw

Also note the new drive belt for the spindle; this round belt made all the differance to belt noise and vibrations

[cbcnc]

Hi Stevie,

Nice work. I'm impressed.
If you don't mind my backing things up a little, I have a couple of questions.
How did you drill your linear rods to bolt to the bed?
Second, How did you bore for and what kind of bearings did you use for your carriage?
Your new headstock looks great also.

Thanks,
Chris

[Stevie]

Hi Chris

Well the Thompson shafting is tough for sure; i used a carbide end mill at slow speed to punch the counterbore first; then drilled through with a 5mm carbide drill
I Held the bed in 2 V blocks to drill through rail to the bed; once i got 2 screw in I removed the c clamps; they really did not sit well; but worked long enough for the first 2 screw holes

The carriage bearing holes (I'm thinking you mean the crosslide shaft) were wire EDM'd at first with 8mm dia; but over the course of the project have changed a bit; I usually just stand it up in a good vice and dial it in with a 0.0001 finger dial (Mitatoyo) If however you mean the round guides; they were also Wire cut and the semi rough finish left by a 1 pass with the wire creates very small depressions for the oil to be trapped; these are no more than maybe 0.0001 deep

When I made the tail stock; I no longer had access to the wire (moved jobs) I made the matching holes for the bed way with a reamer and the DRO for correct centers; this works almost as well; but the holes are very smooth and do not slide as freely (sounds weird) I then roughed them up a bit and that seemed to free it up (now there is somewere for the oil) very high polish on bearing surfaces can cause oil to not stick
I was designing the new spindle last night (just 2D) and I can fit the ER25 Collets and the chuck in the same spindle; the front gets a bit complicated with the location diameter having to be used for both the chuck and the front section of a collet retainer

The old collet spindle (which I was never very happy with) I will use as a V/H dividing head; I'll add a set of gears to it and a stepper

[arvidb]

"New Head update"

What technique is used to make a hole like the one in the head block? Is it milled or turned, and with what tools?

Looks really cool!

Arvid