New DRO help

[fizzy]

Going to fit a DRO to my Colchester Triumph.
Is it ok to mix the scales? I would like to fit a 1um scale to the cross slide - would it be ok to fit a 5um to the bed? The 1um are a lot more expensive and I don't need that kind of accuracy on length.
It isn't just about accuracy though - apparently the 5um can be tricky to read on the cross slide due to measurements being in 0.0002 steps and some being approximated - well something like that anyway!

 

[Shox Dr]

Not a problem

 

[dan.taylor.1]

@fizzy what / where are you looking for one? It's on my to do list for the big bore triumph.

 

[fizzy]

@fizzy what / where are you looking for one? It's on my to do list for the big bore triumph.

I just bought a display off Ebay - they are all the same these days - there used to be a bit more variety.

2 Axis Digital Readout Display Lathe Machine Linear Scale CNC Milling Replace 824890549902 | eBay

Find many great new & used options and get the best deals for 2 Axis Digital Readout Display Lathe Machine Linear Scale CNC Milling Replace at the best online prices at eBay! Free delivery for many products.

www.ebay.co.uk

£55

The UK seller does the 5um scales but the 1um are direct from China. I will order one of each - then the fun of fitting starts! Plenty of good videos on Youtube - most seem to be for smaller Colchesters like the student but should be ok. Then when I have done this I have them to fit to a CVA and a Holbrook H20

 

[m_c]

I personally wouldn't bother with the 1um, as they're not anymore accurate as such.
They still use the same glass scale grating, and interpolate the extra pulses.

 

[Shox Dr]

I personally wouldn't bother with the 1um, as they're not anymore accurate as such.
They still use the same glass scale grating, and interpolate the extra pulses.

Repeatability is better. But not much

 

[fizzy]

Repeatability is better. But not much

That is what I am after really.
Considering far more expensive scales by people like Newall only claim 10um accuracy I doubt the Chinese ones are as good as they claim.

 

[Pete.]

You don't have to worry about the difference between 1um and 5um on a lathe. There's 25 of 'em in a thou.

 

[dan.taylor.1]

I just bought a display off Ebay - they are all the same these days - there used to be a bit more variety.

2 Axis Digital Readout Display Lathe Machine Linear Scale CNC Milling Replace 824890549902 | eBay

Find many great new & used options and get the best deals for 2 Axis Digital Readout Display Lathe Machine Linear Scale CNC Milling Replace at the best online prices at eBay! Free delivery for many products.

www.ebay.co.uk

£55

The UK seller does the 5um scales but the 1um are direct from China. I will order one of each - then the fun of fitting starts! Plenty of good videos on Youtube - most seem to be for smaller Colchesters like the student but should be ok. Then when I have done this I have them to fit to a CVA and a Holbrook H20

What scale length do you need? I can't remember what the travel is...!

 

[addjunkie]

What scale length do you need? I can't remember what the travel is...!

Thats why uk suppliers do kits for different machine. You can the buy from china once youve seen what in their kit

 

[minimutly]

What lengths encoders did you buy @fizzy ? Job pending for me - the plan, to buy one 3 way dro, with encoders for the lathe and millers - eventually.
There’s a decent looking Triumph on eBay atm. Dylan, the guy who helped me with the motorhome was going to buy a Warco - I suggested an imperial Roundhead would be a better buy. There’s a dusty one in Carmarthen, no bids at £275 last time I looked.

 

[fizzy]

What lengths encoders did you buy @fizzy ? Job pending for me - the plan, to buy one 3 way dro, with encoders for the lathe and millers - eventually.
There’s a decent looking Triumph on eBay atm. Dylan, the guy who helped me with the motorhome was going to buy a Warco - I suggested an imperial Roundhead would be a better buy. There’s a dusty one in Carmarthen, no bids at £275 last time I looked.

Done a bit of measuring - seems I need 48" travel for the bed and 9" travel for the cross slide. Most people only seem to do 1000mm ones although they do go longer.

 

[RichardM]

What about a magnetic read head and stick on tape?

1200mm scale here -

JCXG Long Linear Glass Measuring Scale 5 Micron Resolution | eBay UK

The 'A' and 'B' square wave output gives 5 micron resolution. Obviously installing these scales needs a little bit of care and skill. I install these scales across the UK. This will include travelling upto 100 miles from NG8 1PQ.

www.ebay.co.uk

 

[Pilgrim22]

I think you will need to make sure the DRO can handle different resolutions and input pulses for each axis.

 

[fizzy]

What about a magnetic read head and stick on tape?

1200mm scale here -

JCXG Long Linear Glass Measuring Scale 5 Micron Resolution | eBay UK

The 'A' and 'B' square wave output gives 5 micron resolution. Obviously installing these scales needs a little bit of care and skill. I install these scales across the UK. This will include travelling upto 100 miles from NG8 1PQ.

www.ebay.co.uk

I may have to use magnetic for my CVA on the cross slide - not a great deal of room.
I did find a 1200mm glass scale for about £140 - the 1m ones are only £70

 

[fizzy]

I think you will need to make sure the DRO can handle different resolutions and input pulses for each axis.

It does handle quite a large variety - not sure about magnetic will have to look into that!

 

[RichardM]

I may have to use magnetic for my CVA on the cross slide - not a great deal of room.
I did find a 1200mm glass scale for about £140 - the 1m ones are only £70

I think they go up on an exponential scale when they get longer than 600mm (no pun intended!).

 

[fizzy]

I think they go up on an exponential scale when they get longer than 600mm (no pun intended!).

A lot of it could be down to shipping costs - many carriers have a 1m length limit.

 

[minimutly]

What lengths encoders did you buy @fizzy ? Job pending for me - the plan, to buy one 3 way dro, with encoders for the lathe and millers - eventually.
There’s a decent looking Triumph on eBay atm. Dylan, the guy who helped me with the motorhome was going to buy a Warco - I suggested an imperial Roundhead would be a better buy. There’s a dusty one in Carmarthen, no bids at £275 last time I looked.

Well Dylan bought the Triumph Roundhead that was on eBay for £1400 - with dro and quickfit toolpost and a load of other bits - steadies and centres.
If it’s as good as the pics not a bad buy I would say. Will have to have a look.