Super 7 half nut adjustment

[Bob LambParticipant @boblamb44747]

Can anybody please tell me the correct procedure for adjusting the half nuts on the leadscrew – how much play should there be when you move the saddle with the rack handwheel? – at the moment it seems to be about 25 thou. Should I be thinking about new half nuts?

Bob

[Bob LambParticipant @boblamb44747]

[KWILParticipant @kwil]

The procedure is to fully close the half nut, with the screw that passes through the lower half nut retracted. Wind in that screw until it touches the upper half nut and then, having released the half nuts, rotate the screw 1/5 -. 1/4 turns. This means that the half nuts do not bind upon th lead screw (ie some minor clearance). At this point there should be little or no carriage movement. If there is, worrn nuts, worn leadscrew or sloppy bearings at the right hand support bracket. I have used needle roller thrust bearings at this point to minimise movement.

OK?

[ianjParticipant @ians]

Bob.

I found this else where on the www.

Ian

Myford ML-7 Half Nut Adjustment.

When re-fitting the saddle to the apron you will need to adjust both the saddle to

apron fit and the lead screw half nut adjusting screw.

1. First unscrew the half nut adjusting screw right out.

2. Move the apron as far to the right as it can go and engage the clasp nuts – it

will be tight.

3. Undo the screws securing the apron to the saddle and these two parts will

self align.

4. Nip up the screws and then tighten the screws.

5. Move the apron to the mid point along the bed and engage the clasp nuts.

6. Hold the lever down with your left hand and screw in the adjusting screw

until it stops, then take your hand off the lever and screw it in a further ¼

turn.

Note: If you do not adjust this then you may get tracking marks when

taking fine cuts – these will be at 1/8 inch? The lead screw pitch?

[KWILParticipant @kwil]

Ian,

Title is Super 7, not ML7. Your reference to saddle/apron adjustment is only necessary if as you say they have been removed or there is misalignment such as the leadscrew deflection upon half nut engagement.

[Bob LambParticipant @boblamb44747]

Thanks for the answers – It's a bit late now but I will try tomorrow – Bob

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