Metric Myford super 7

[john fletcher 1Participant @johnfletcher1]

Is the thread on a Myford Metric super 7 cross slide metric and if so, what is the size/details. Also what does each division represent in terms of metal removed. John

[john fletcher 1Participant @johnfletcher1]

[TomfileryParticipant @tomfilery]

John,

I would assume so (though we all know what assuming makes of us). You would have to check by measurement.

The cross slide dial shows reduction in DIAMETER, i.e. twice the depth of cut.

My dial is stamped in multiples of 5 (from 0 to 35), each 5 representing 0.5mm removed from the diameter, i.e. advancing the tool 0.25mm. So one complete revolution advances the tool 2mm, removing 4mm from the diameter.

I checked this with my DTI. Topslide is different with each 5 of the dial representing a move of 0.25mm.

Regards Tom

[SillyOldDufferModerator @sillyoldduffer]

Posted by john fletcher 1 on 15/06/2017 18:26:56:

Is the thread on a Myford Metric super 7 cross slide metric and if so, what is the size/details. Also what does each division represent in terms of metal removed. John

Good question! I'll stick my neck out and say that the average lathe owner couldn't answer the question without checking it physically.

On my metric lathe (not Myford), all I know is that the small divisions on the micrometer dial represent a reduction in diameter of 0.02mm. 0.02mm is just under a thou and this seems typical of the minimum graduation on most lathe micrometer dials. (I have now put on my tin hat in the expectation that an expert will be putting me right!)

Myford give different Part numbers for the metric cross-slide screw, dial and nut, which strongly implies they're using a metric thread.

The easiest way to find out is to measure it. Stick a rod in the chuck and measure it's diameter with a micrometer. Remove one dial turns worth of metal and remeasure the diameter. Now you know the number of graduations needed to remove a known amount of metal. It should be close to something metric.

Dave

[Neil LickfoldParticipant @neillickfold44316]

My Myord lathe 1 turn is 4mm on diameter, with each division being 0.05mm on diameter. Interestingly, the width of the marker and the width of the dial graduations, is such that on one side of the marker to the other makes for about 1/2 division, so is about 0.025mm on diameter.

The compound slide, 1 division is 0.05mm .

I made a 0.5mm pitch leadscrew and nut and then used the imperial 100 count dial. each division is 0.01mm on diameter. At times it is very useful as each division is equal to what is read on the micrometer.

The leadscrew is still 8tpi, and the hand wheel is rounded to 3.18mm per rev on the graduations even though it is actually 3.175mm /rev.

Neil

[John Stevenson 1Participant @johnstevenson1]

Just prior to the. Myford sale I went in to move a load of machines sold prior to the sale and also bought some tooling for myself.
Amongst this tooling was all the leadscrew taps for the whole range.

They did use some wierd sizes. I have 1/2 x 20 as expected but I also have 1/2 x 2mm pitch as well as 13 mm x 2mm pitch??

[Brian OldfordParticipant @brianoldford70365]

I'll stick my neck out by saying that I think Myford Metric ML7 & S7 machines use metric for the top-slide and cross-slide but the lead-screw remains 8TPI.

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