Apron repair work area


In the course of disassembling the carriage to determine the source of the handwheel wobble I was able to get a good look at the lathe apron details and internals and the power feed gear system, as well as the half-nut contro.

As I was totally new to the lathe, this was a rather daunting project. I set up my work area, and began for a long slow study of the situation.

Apron repair work area
Apron Details

All screws and parts organized


There is an exploded view diagram of the apron assembly that comes with the lathe. It is fairly useful to help understand where things fit and how they align. As the Brits might say: "A lot of bits 'n bobs". The compound assembly can be seen - I also took the opportunity to file and stone all the dovetails.
All screws and parts organized
Apron Details

The SC4 apron revealed


Here is an inverted view of the Sieg SC4 lathe apron. A protective cover has been removed, and the little curl of paper in the corner of the apron is the inspectors ticket.

The exposed spur gear engages the rack on the bed for fast traversing of the carriage. The control wheel assembly which operates this gear was damaged.

The SC4 apron revealed
Apron Details

View into the apron


Here is a shot looking down into the gears of the apron. They were dry when I opened it, so judicially added some whit lithium grease. You can also see more of the Chinese painting 'standards' at work here.

View into the apron
Apron Details

Apron End view & Lead screw control lever


In this end view of the apron, you can see the leadscrew power engagement lever. See those two vertically aligned holes? These are the set screws for the gibs which tension this lever. Interestingly, there is THIRD screw carefully hidden by the lever assembly! Not knowing this can make removal of the gibs rather difficult, to say the least.

Just one of the many fun features of these 'snowflake' (no two alike) 'kit' machines!

Apron End view & Lead screw control lever
Apron Details

Leadscrew control handle gibs


Leadscrew control lever gibs. The worm which rides on the lead screw can be seen setting to the right. This sets loose in the apron, and the leadscrew is pushed thru it and engaged with a key. Don't forget it when you reassemble!

Leadscrew control handle gibs
Apron Details