Sieg super C3

I've had my sieg super C3 for a couple of years now and the compound slide has never been great but never bothered to rely on it anyway as never had the need. However I'm now a little bored looking to tart the machine up a bit and sort out a couple of the little issues.

So the problem is when trying to rotate the handle the dial comes under some friction against the other dial ( the one screwed to the compound slide stating the increments of one figure as being 0.025mm) and doesn't rotate with the handle, meaning I can't know by how much I am moving the slide. Also I can not re-zero the micrometer dial due to this friction as it is grinding on the other dial!

This friction only seems to appear when rotating the handle clockwise and when roaring the handle anti clockwise the friction disappears.

Any help or ideas??

Many thanks

Hi Jack, I assume your C3 compound slide is similar design to that on my C6 which had a similar problem. When winding one way, the thrust on the leadscrew will push the handwheel away from the fixed dial, when winding the other way the thrust direction is reversed, drawing the handwheel into the fixed dial. I put a shim washer between the hand wheel and the boss on the shaft to provide sufficient clearance between the handwheel and fixed dial when the handwheel retaining nut was tightened. Might work for you too. Cheers.

Have you tried the Arceuro guide here?;
**LINK**

Especially section 172 which covers compound slide backlash.

I recently rplaced the compound lead screw which had worn noticeably.

Ok Geoff - just to clarify by "handwheel" are you referring to the actual handle used to crank the leadscrew or the micrometer dial? as I put a shim between the micrometer dial and the fixed dial to see if this made a difference which it did not and I am unable to put any shim between the handle and the micrometer gauge as there is already a spacer here so would not make any difference for me I'm afraid!

John - I have already been through the guide previously and turned the recess in the spacer to reduce backlash, which got rid of the backlash for me but not this problem (note that I still had this problem when the backlash was excessive before I turned the recess in the spacer)

I had also been suggested today to attempt aligning the leadsccrew by winding the slide to its full travel while having the fixed dial unclamped (loosening the two m4 screws holding this on) and re-aligning the fixed dial to ensure concentricity to the leadscrew and thread and this has not made a difference either I am afraid!

More about the problem to attempt to explain better; the micrometer dial does not roate with the handle when I am turning the handle moving the slide across its way, it does when reversing the handle and travelling away from the spindle but when turning it back to make the slide travel towards the spindle it tightens up against the fixed dial and does allow me to read off how much I am travelling on the micrometer dial, Also the micrometer dial is tightening up so much against the fixed dial it makes re-zeroing the dial a task.

Unlike my cross slide which has a very very smooth travel and has just .05 backlash and the micrometer dial can be re-zeroed with such ease!

Appreciate any help, many thanks.

Sounds like the construction is different from my C6 so sorry i can't be more help.

Hi Jack, I had the same problem on my sc2. If I tightened the gib the graduated dial would bind. If I slackened off the gib everything ran smoothly, but then everything was sloppy.

I sorted it out by fitting a couple of bearings so that the compound screw would always move smoothly. This entailed designing and making a complete replacement mechanism, including the compound screw. I re-used the original graduated dial.

I did this a fair while ago and it's been a massive improvement. The only downside is that the cross-slide handle can foul on the mechanism when the compound is set at an angle, but it can be got round and I wouldn't go back.

I've a couple of pictures of all the components and the assembled result.

Hope this helps.

Thanks anyway Geoff!

And that's a great work around Robert! I would like to go all out on this as you have but I have turned myself a tighter fitting diameter and pressed fitted this in the current dual and compressed the friction spring to put more pressure on the inside of the dual and this has worked for me, seems the problem was too little friction on the dial!