Question Re: Sieg SX2.7 Mill

[blanik]

Greetings,

I bought a Sieg SX2.7 Mill about four months ago. So far, it has proven to be a very capable machine.

The only issue I have with the machine is with regard to the Z Axis Quill Fine Feed Knob. When the spindle is moved using the Quick Action Down Feed Handles (i.e. the handles you'd use for drilling), the movement of the Z Axis Quill is smooth and easy both up and down.

However, when the quill is moved using the Fine Feed Knob, the movement is stiff and jerky in the downwards direction. When the quill is moved up using the Fine Feed Knob, the movement is not as stiff. The stiffness and associated jerky action of the Fine Feed Knob makes it very difficult to use accurately.

In the following photograph, the Fine Feed Knob that I'm referring to is identified as the "Fine Feed For Milling" with the arrow pointing to the offending knob.

I suspect that the problem is caused by either; mis-assembly, an adjustment problem, or a lack of lubrication problem -- but that's just my best guess at the moment, as I have not yet tried disassembling the mechanism.

The exploded parts diagram for the machine is the only documentation I have that contains relevant information. But that diagram is very hard to read, as it is I think intended to be only a parts diagram, and not an assembly diagram. The method of disassembly of the Quill Fine Feed mechanism is not obvious so far.

I thought I'd seek guidance on the forum before I try to open up the mill and make a mess of things.

So a few questions for owners of SX2.3 and SX2.7 range of Mills, which all seem to have the same style of Quill Find Feed Mechanism .......

Can any other owners of the SX2.3 or SX2.7 range of Mills advise if they also have experienced this problem, and if so what they did to fix the problem?

Does anyone know how to fix this problem ?

Thanks,

Blanik

 

[doug gray]

On my Rong-Fu you need to tighten the knob in the centre of the "Quick Action Down Feed Handles " to use the fine feed.... Try it??


also see #19 on page five here http://www.axminster.co.uk/media/downloads/101598_manual.pdf

 

[blanik]

Thanks Doug. Yep, know about tightening the knob on the Quill Course Feed Handles....

I worked out how to fix this problem over the last few days. There is a thrust bearing directly behind the "Fine Feed for Milling" knob. The position of the Fine Feed Knob on it's shaft has to be adjusted to set the pre-load on the thrust bearing. Once the pre-load on the thrust bearing is set correctly, the thrust bearing absorbs the thrust from the worm gear, and the fine feed works correctly without binding.

Blanik