EMCO FB2 tram

[Y C LuiParticipant @yclui16187]

I recently found that my EMCO FB2 has the vertical slide tilted backward and head tilted forward slightly. May I know if how it can be fixed ? the machine does not allow any adjustment of the tilt along the Y direction but just X.

[Y C LuiParticipant @yclui16187]

[Ex contributorParticipant @mgnbuk]

I shimmed my Taiwanese FB2 clone to get the reading in the Y axis correct, with shims introduced between the main base casting & the column mounting casting – at the top edge in my case, but at the bottom edge in yours by your description of the lean direction.

This was a bit off a faff, as the adustment for the X axis (grub screws in the column casting that bear on the top clamping screws) get moved when the clamp bolts are slackened to introduce the shims. Long term, the face of the column mounting casting will get scraped to remove the shims, but it works fine as is. The reality is the scraping may well not happen !

I used a precision square to set the column perpendicular to the table top in X and Y first, then looked at the spindle tram. Obviously this can be adjusted in the X axis with the swivel on the head, but any error in the Y direction would be more involved – really you need to find which face of the swivel joint is in error & scrape it for a "proper" fix. I can't recall the numbers for mine, but it was close enough that I didn't bother to make any adjustments here. There is the possibility to introduce a (slight) error in the column squareness to reduce the tram error if the tram error is deemed to be excessive & scraping the swivel joint face is too difficult. I say "slight" as I value column squareness to the table as much as spindle tram – splitting the difference, if you like.

HTH,

Nigel B.

[Y C LuiParticipant @yclui16187]

Posted by mgnbuk on 28/10/2021 08:56:39:

I shimmed my Taiwanese FB2 clone to get the reading in the Y axis correct…..

Thanks, Nigel. May I know more about the shimming that you have done ? what material is the shim made of ? how big should it be ? will it affect the rigidity significantly ?

Regarding the magnitude of the tilt, I indicate a square on the table and found that there is a offset of 0.03 over a vertical distance of 100 mm. How much did you see in your FB2 ?

[Kiwi BlokeParticipant @kiwibloke62605]

Counsel of perfection perhaps, but the column should be set square to the axes of movement of the table, not its surface. You can't assume anything, when chasing perfect alignment. The table may top may not be parallel to its slideway surfaces, and the same goes for the saddle. Therefore, the column should be aligned to the main casting's slideway first, having checked the slideway surfaces for truth. Then move on to the saddle, and so on… Who said this would be quick or easy?

Having said that, it wouldn't necessarily be a bad thing to build in a little forward 'lean' of the column, so that its alignment is corrected by deflection from applied downwards forces when, say, drilling.. Of course, the 'correction' depends on the force applied, so it can only ever be a compromise. Which is one reason why one probably shouldn't worry too much about counsels of perfection…

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