Monday, April 21, 2014

Lathe restoration - final push

It has been about a month since the last update. I this time I have been able to get the lathe back into working condtion.

The first job was to repair the chowdered cross feed wheel.
I milled the top flat and drilled and tapped three M3 holes to attach a new pointer. The replacement cover/pointer was made from some 2mm aluminum I had laying around. I used a 45 degree router bit for the chamfer and to engrave the line. The Corners were hand filed to fit.
Before - Looks like somebody ran the compound over the dial at one point

Surface milled and drilled
Indicating in the new cover on my mini pallet
Cover installed on compound
 The next job was to install my Phase II BXA toolpost. I just needed to mill the T-nut to fit.
T-Nut after milling - will it fit??

Nice Snug fit :)

A BXA seems to be the perfect size for a Clausing 6300

Plenty of room left for up and down adjustment

 Next, I finally got my replacement worm gear. I still needed to make a bushing for one end. Since I didn't have a working lathe yet, I needed to "Turn" the bushing in the mill using my boring head. So I made a V-block soft jaw to hold on to the stock for this operation. I cut a slot in the back of a 2x2x6.5" aluminum block that was just wide enough to fit over the rear jaw in the vise.
V Block showing side walls to keep it from moving
 After that, I set up the block on a 45 degree angle and cut the V with a big endmill.
V Block installed in vise.
Now I could start "turning the bushing. After indicating the raw stock, I ran the boring head in reverse to get the OD sized correctly.
OD Turning on the Mill :)
Next, I drilled a 61/64" hole through the part to clear the Leadscrew. The final step was to bore the bushing 1/2" deep to hold the worm gear in place.
Drilling through bronze - only grabbed the drill twice :)

Final fit check - Pass :)
Now the apron can finaly be fully re-assembled.

Something was missing here....
Worm Gear Back In place

Bushing back where it belongs. :)
With the lathe looking like a lathe again, it was time to move everything into it's final place, level the machine and wire up the Variable Frequency drive.

Leveled out in its new home

New home - different angle

All wired up wit control panel prototype

VFD installation inside the base


Final motor mount setup

This will turn into a cover for the base to protect the electrical system.
 The current version of the control panel has a Pot for speed control, a 3-1/2 digit digital panel meter as a RPM display, the Start, Stop and Fwd/Rev switches as well as a lit switch that is used as a fault indicator and reset switch for the drive.
Closeup of Control panel
 The final test conists of turning down a ~1.75" aluminum bar to check the bed for twist. The fist pass showed about 0.01" of taper over 6" but I was able to get this down to .00015 in a couple of tries. I think I will let things settle for a bit and then test the alignment again.
Test bar - Currently showing .00015" taper in 6"