DRO’s and cold.

This topic has 10 replies, 10 voices, and was last updated 10 April 2013 at 19:52 by Sub Mandrel.

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10 April 2013 at 08:29 #116517
Rik Shaw
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@rikshaw
My new 9×20 lathe is in an uninsulated shed where the temperatures can drop to sub zero in the British weather. After a cold night I usually turn a fan heater on an hour or so before I want to start work.

Given these cold conditions am I going to find problems using DRO's if I decide to purchase and fit them?

Rik
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10 April 2013 at 08:29 #22570
Rik Shaw
Participant
@rikshaw
will they work?
10 April 2013 at 08:49 #116519
mick
Participant
@mick65121
Leaving the DRO on over night you should insure there's no problem and will stop any condensation, especially in a cold shed, but modern systems should be ok any way. A far cry from the days when god was a boy and anything electronic had to warm for half an hour or so.
10 April 2013 at 08:53 #116520
Anonymous
Rik,

My mill DRO works fine in an unheated garage; however it is a Newall with Microsyn sensors*. I suspect that condensation would be a bigger problem than cold temperatures per se. So optical or magnetic sensors should be ok, but capacitative ones probably not. The display may be affected depending on the design and PCB layout.

Regards,

Andrew

* Steel balls in a carbon fibre tube, so unaffected by condensation
10 April 2013 at 09:37 #116522
Brian Wood
Participant
@brianwood45127
Hello Rik,

Some years ago I worked at an agricultural engineers where we had a big DSG lathe with 2 axis Newall DRO and a big vertical milling machine with a 3 axis Heidenheim DRO [optical system]

In the winter months we had to thaw the coolant tanks with a red diesel fired space heater so it got damned cold in this totally unheated shed.

The elderly DROs both behaved faultlessly straight from cold, it was the lack of coolant that slowed the start of work. As Andrew says, the Newall system was often left on overnight, but more as an oversight, not a policy to keep it warm.

Regards Brian
10 April 2013 at 10:40 #116534
Clive Hartland
Participant
@clivehartland94829
I have had no problem with my Dro's on my mill. I have with the Vernier calipers though.

Simple background heating that will keep a small rise in Temperature will solve lots of problems in the workshop. There are heaters that are called, 'Black heaters' plug in and forget. Fitted with a simple thermostat they will come on when required and switch off when a suitable heat is reached.

Me, Im lucky, my garage has a radiator on the house central heating.

Clive
10 April 2013 at 12:43 #116546
Ian S C
Participant
@iansc
The cold will effect the battery out put, and LCD screens don't like it much either.

Brian, maybe the old DRO used Nixie Tubes for the read out, they'll operate to minus as much as you like (or don't like). Ian S C
10 April 2013 at 13:08 #116548
MICHAEL WILLIAMS
Participant
@michaelwilliams41215
The biggest problem with operating all types of metrology equipment at extremes of temperature is that they go out of calibration .

Most metrology equipment is calibrated at + 20 deg C and is usually ok in the range of + 15 to +25 deg C unless of particularly high accuracy .

At temperatures approaching 0 deg C I would expect significant errors with some types of DRO – though it depends very much on the construction of the scale with some types being almost unaffected and some totally screwed .

A particularly bad situation is where whole assembly of machine and DRO is very cold but being warmed up too quickly .

Michael Williams .

Edited By MICHAEL WILLIAMS on 10/04/2013 13:23:34
10 April 2013 at 13:33 #116552
Bazyle
Participant
@bazyle
If you have the money to spend on the DRO perhaps spending a bit of it on insulation would help prepare the environment. An insulated and draughtproof shed without floor insulation will pick up heat from the ground. My 8×6 store with 2in of foam stayed at about 6C in this cold snap with just the heat from the dehumidifier which has about a 1:10 duty cycle.
10 April 2013 at 19:37 #116577
Muzzer
Participant
@muzzer
Any semi-decent DRO system should be specified over a reasonably wide temperature range that ideally would cover the range of expected working temperatures. Here's what Mutitoyo have to say about it. They specify their accuracy over the whole range 0-45C.Beyond that you might suffer operator malfunction!

You'd have to look up the spec of the system you actually have but hopefully it covers a sensible range too.

**LINK**

Merry
10 April 2013 at 19:52 #116579
Sub Mandrel
Participant
@submandrel
The LCD displays of cheap capacative DROs will struggle at low temperatures. Also, the battrery drain will be annoyingly quick – months rather than a year or two. Not an issue if they are remotely powered.

Neil
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