Advice/comments on DRO

Keith, I am a confessed numbskull- about these 'modern things'. I can, however, still tell my bank or building society managers how to close my credits with them. Probably, being a tite arsed git makes red change to black.But this isn't a lesson in cost accountancy.

Realising that it was now pssible to count to 20 without removing socks, I wrote to one of the number here with a question which only revolved around a princely 'fiver'.for his bunch of swag.Once the 'fiver' issue was solved, I would stumble on yet again!

To use a more refined remark to the one that comes instantly to mind, no service- no purchase.

Again to Chris, thank you for giving a service and not asking for even a 'Thank You'

Pass along the bus, please!

Norm

Norm, much of my youth was spent listening to my father who regularly gave the "pennies and pounds" talk. I'm sorry to say that I got bored and stopped listening before the message sunk in. Taken 40 years to learn what he was telling me when I was six.

Unfortunately I've experienced the "not worth the effort (cost per hour too great?) of speaking to someone who may only buy one" policy many times. A few years ago one could happily move on to one of the "other" suppliers; more difficult now that less and less find it worth while pandering to our "low dollar" market. Much easier to pile it high, sell it cheap to someone who doesn't expect too much. In their defence I see less and less people willing to pay extra for good service. Most want (no demand) old fashioned (good) service and modern rock bottom prices. Still with Gentlemen like Chris about I'm sure we will survive and prosper.

My issue this time is that I can't work out if it is this policy that applies or if they have sussed that a clear answer will expose what I don't want to hear.

I don't mind "passing along", it's the "mind the step when you get off" that I fear.

Keith

In article , Chris Edwards writes

Thanks Chris. Replied off-list.

David

In my book the DRO on a lathe is more a convenience than an accuracy thing. I wouldn't rely on it any more than the dials for final fine cuts. Great for working in the 'wrong' units for your machine, for displaying the actual (theoretically) diameter of a part, and for long axis measurement whih is where most lathes are deficient. Not as 'essential' as a DRO on a mill, though. Others opinions may vary, of course.

Cheers Tim

Dutton Dry-Dock Traditional & Modern canal craft repairs Vintage diesel engine service

A DRO can't replace calipers or micrometer screws. At least you need them once to set the actual diameter or length. Once set it is a very fast working, even to few 1/100 mm. But for a fit, you'll grab for the micrometer again.

If you have a selection of QC-tool holders and the DRO can handle them, you can work *well* better than 1/10mm without recalibrating the DRO.

Other thing being convenient is doing the math for saddle and top-slide movements or displaying the correct diameter and Z when the top slide is swiveled (thread cutting, turning cones).

Nick

Tim, thanks I totally agree with your comments and I confess to being guilty of trying to replace my increasingly poor eyesight and general lack of skill by buying an "easy ride". I should have learnt by now that there rarely is an easy way and if there is it always costs more than half a crown. I have just said to Norm off list that I can live with a thou or so on the long axis and as you rightly say, on my lathes the dials won't give me the last couple of tenths reliably anyway. I guess I will have to decide which of my current lathes is the one I'm going to stick with and get on and spend some money. Lets see, The Myford is really, really nice to use but the Boxford is almost mint and the Warco - well it has a lot more capacity. Perhaps one readout and three sets of scales? How about Chinese on the bed and better glass scales on the cross slide - now where is that piggy bank?

Regards

Keith

Chinese on the bed. Keith behave yourself!

I was struggling but know when I am ***********. Nope, forgotten.

I was merely trying with the x-y bit. Anything upright- forget!

Norm

In article , Chris Edwards writes

I would just like to give public thanks to Chris, for taking the trouble to send me some photos and answering my follow-up questions.

In summary, the BW wire-in-tube system certainly looks very neat, and should fit just about anywhere with little or no problem, but I do have some questions about the setting accuracy compared with the glass scale systems (which would be much harder to fit to a lathe without getting in the way.

I may go BW for the lathe, Machine-DRO for the mill.

Many thanks also to the others who were kind enough to reply here.

David

Sorry if I'm teaching granny to suck eggs, but do you know about angling the top slide and using that to shave the last bit off?

If the top slide is perpendicular to the axis, every thou' on the compound dial is two thou' off the diameter. If it is parallel to the axis, every thou' is zero off the diameter. For angles in between, it varies sinusoidally (i.e. 30 degreees to lathe axis gives one thou' on diameter for one thou' on dial).

...snip...

Well the big advantage of the BW Wire-In-Tube scales is they are supposed to be readily dismountable and so you can move them from lathe to lathe (AIUI you just need to unhook the wire and unclip the reader to dismount). So you could get a set of those and move them as the jobs required.

I'm seriously tempted by the BW myself because the topslide on my Boxford is such an akkard shape to fit a glass scale to. I'm pretty sure the BW would fit OK at the back with the wire out of the way below the topslide where the feedscrew runs. I haven't actually _checked_ that though.

Hmm...

Wasn't it Winston Churchill who said " Give us the tools and we'll finish the job"

Somebody much older said 'Chance would be a fine thing'

Another quip was " Everything comes to he who waits" but

For how long?

Norman Atkinson

The machine-DRO.co.uk kit looks really good. GOing off topic, can the glass scales be used to "close the loop" if you subsequently add CNC to the machine?

The articles I've seen leave the axes open loop and then attempt to tune out the backlash, which seems sub-optimal if you already have £400 invested in scales.

Steve

Hello David I have just won on e-bay an auction for the same units as Machine-Dro.co.u= k but the price is alot cheaper =C2=A3287.00 including a seletion of scale size all in= plus whatever the customs charge for it coming into the country will let you know what= it's like on reciept

No. That requires special controllers. And if you have them, you wouldn't have a DIY-CNC but a Fanuc, Haidenhain, ...

Nick

Machine-Dro.co.uk but the price is alot cheaper £287.00 including a seletion of scale size all in plus whatever the customs charge for it coming into the country will let you know what it's like on reciept

( But no UK backup ;) )

In article , Colin Wildgust writes

Thanks Colin. I hope you don't get too big a shock on the import duties when it arrives!

David

As far as I know, BW now only produce their DRO kits with a telescopic stainless-steel cover over the wire. See their web site at

for further information . The kit I bought for my Myford was their Model 334, which is currently listed at £332 + VAT. --

Chris Edwards (in deepest Dorset) "....there *must* be an easier way!"

PIC processor...

Mark Rand RTFM

I must say a big thank you to all who have contributed to this discussion as it has led me to one of those rare Eureka moments. No Norm nothing to do with my Freudian slip but a realisation that I have been chasing the wrong rabbit. I have looked at DROs as a means of "easy accuracy" when I should have been looking at "convienient use". Particulary as my definition of accuracy is working to something like

+/-.0002". I know I don't really need it that often but I want to be able to achieve it when I think it's necessary. So for that, forget the DRO and keep up the tried and tested techniques mentioned by Tim, John and Nick.

So all the systems mentioned now return to my "possible" category. I must say though that while I see the ease of installation offered by the BW wire system and the advantage of swapping between lathes I might find their claimed +/- .002" a bit hard to swallow. Can anyone comment on these systems in actual use, particularly when used on the cross slide and actually swapped between machines?

Best regards

Keith