- Thread starter gordsgarage
- Start date
jugs
Dont wish to offend & annoy, but...
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Still on about the Lathe,does anyone have these fitted to their mini-lathe and are they worth the effort of buying?
http://www.mini-lathe.com/Mini_lathe/Reviews/Sieg_DRO/dro2.htm
Arc Euro trade knock em out for £84.
Cheers.
OK.......BUT
they only tell you where the screw is, not the tool, so its only a hi-tec dial, any slack in screw is unknown & unread.
IMHO
you'd be better off with something like THIS , it measures where the tool position is (I have one on an old mill that has 3/4 of a turn of slack (0.160") 
in the screw, but I can still do work to 0.0005").These units also do the maths (the lathe version will calculate tool ofsets, tapers & you can switch readings of DIA or RAD, in mm or ins) but the best feature is sizing - turn a dia, measure with a mic, enter size = you know the dia of all subsequent cuts
These are the ones I use
ps- For a lathe go for the 2 axis LATHE unit (the 2 axis mill unit looks same but has different maths).
I was thinking of sticking a DRO on my little myford too, but I'm confused how it measures the tool position.
What I mean is that the saddle obviously moves sideways, and then you have the cross slide that goes in and out, but the compound thing that sits on top of the cross slide can move "angled".
How do you fit the DRO readers so that it "understands" the compound slide?
What I mean is that the saddle obviously moves sideways, and then you have the cross slide that goes in and out, but the compound thing that sits on top of the cross slide can move "angled".
How do you fit the DRO readers so that it "understands" the compound slide?
GeorgiePorgie
pre-moderated
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Same way you would using the normal standard dial,you offer the tooling up to the job till it just touches the workpiece then zero the dials readout,is this what you're on about?
gavuk
artful-bodger
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The dro normally measures only the saddle and cross-slide not the compoundslide, at least the older ones i've used...
jugs
Dont wish to offend & annoy, but...
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You don't
. you don't move the compound, BUT you could remove it. 
The original primary purpose of a Lathe was for turning shafts & facing disc's (every thing else was achieved with attachments) & the tool-post was fitted directly to the cross-slide.
For screw-cutting you had to have a different lead-screw for each thread you wanted to cut.
To cut tapers you fitted a taper turning attachment (also called a compound slide) with its own smaller tool-post, cut the taper & removed the attachment.
Somewhere in the mist of time, some lazy bas$$d couldn't be as'd to shift it & by 1900 most lathe makers were supplying "with taper attachment fitted" I have some old machine catalogs pre 1880 & all show the compound as an extra.
In fact on a small lathe, unless you turn a lot of tapers or do alot of single point screw-cutting, its a good idea to remove the compound & fit a more substantial tool post. That removes a lot of the causes of chatter & will allow you to use larger tools, & parting off becomes a breeze
.It's a quick job to re-place when needed.
As gavuk & pete say,
It knows along & across + direction, every thing else is maths, (which it can do better than you or I
).quite a few company's do a complete kit for myford - circa £300.
rtbcomp
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Well I bought one and tested it on a fan. It does display the RPM and you can see it drop when you switch the fan off and it slows down. It also remembers the maximum, minimum and final speeds. You can also set it count the number of revolutions.
