For lathe, M-DRO or DRO PROS?

[yota]

You could but the 1um cost more. On a lathe cross slide, one unit of motion on the slide means 2 units of difference in the size (radius verses diameter). So you need twice the resolution. Also, commonly length tolerances (carriage) are more forgiving than diameter tolerances, as the diameter gets involved in mating to bearing, interference vs slip fits, etc.

great explanation. even I understood it.

 

[mksj]

The primary cost of the Machine DRO packages is the magnetic scales, of which the head reader represents about 90% of the total cost. With their magnetic scales the magnetic tape is the same and it is the reader head that determines the resolution. The cost difference between 1uM and 5uM reader head is about $30, so not a significant cost factor for increased resolution for the cross slide. With a 5uM scale when doubled in diameter mode there is also increased calculation and rounding errors within the display unit. The other key factor is that the quality of the magnetic tape dictates the accuracy/variation over distance, which has been a significant issue with some of the less expensive magnetic DRO scales (i.e. they may be able to read 1uM but the accuracy or linearity of the scale is much worse). With the DRO packages the display is pretty much thrown in for the cost of the 2 or 3 magnetic scales. Just buying the scales and then getting say a TouchDRO will be quite a bit more, but if one were to use glass scales then it may be more cost effective, as well as in the milling functions where you would use more of its features.

As far as the 3rd axis scale if used, adding it to the tailstock I feel is a better option then the compound because it is much more frequently used. If placed on the tailstock you need a longer scale to account for mounting position of the reader head in addition to the reading length (see previous posted picture). Some magnetic scales like the Electronica the scale and head must be in the same read orientation (i.e. there are alignment marks on the read head and scale). Magnetic scales are more durable and less likely to become contaminated, but a scale cover is still recommeneded as ferrous chips between the reader and the magntic tape can cause read errors. Some reader heads (Elactronica Aokron) have wipers on either side of the read head.

If you need RPM (if using a VFD) the cost of an inexpensive meter is less than $20.

https://www.amazon.com/DIGITEN-Digital-Tachometer-Proximity-Switch/dp/B00VKAT8A2/ref=sr_1_2

X axis Cross slide M-DRO EH-01 - 450mm (18") Reading Length Magnetic Linear Encoder
https://www.machine-dro.co.uk/m-dro-eh-01-450mm-18-reading-length-magnetic-linear-encoder

Z1 Tailstock M-DRO EH-05 - 450mm (18") Reading Length Magnetic Linear Encoder

M-DRO EH-05 - 450mm (18") Reading Length Magnetic Linear Encoder

M-DRO EH-05 linear magnetic encoder with 450mm (18inch) reading length. A compact encoder profile suitable for a wide range of machine tool, XY tables, jigs and metrology applications. The encoder beam can be cut to length to suit install

www.machine-dro.co.uk

Z0 axis (bed) M-DRO EH-05 - 1450mm (58") Reading Length Magnetic Linear Encoder

M-DRO EH-05 - 1450mm (58") Reading Length Magnetic Linear Encoder

M-DRO EH-05 linear magnetic encoder with 1450mm (58inch) reading length. A compact encoder profile suitable for a wide range of machine tool, XY tables, jigs and metrology applications. The encoder beam can be cut to length to suit install

www.machine-dro.co.uk

Easson ES-12B LCD digital readout package including 3 linear magnetic encoders example of system cost, would need to specify changes to scalesused.

Easson ES-12B LCD digital readout package including 3 linear magnetic encoders

3 Axis Easson ES-12B LCD graphic digital readout package with three magnetic encoders. The encoders offer a very compact profile size and can be cut to length to custom fit the machine being installed. The package is suitable for mills up to Bridgeport 42" sized machines or 30" between centre...

www.machine-dro.co.uk

 

[wrmiller]

I did a search of the site, but no discussions I could find that was less than 2 or 3 years old. looking at 2 axis systems. been doing a lot of reading, been on both of their websites, seem very similar to me as far as tech goes. for M-DRO, was looking at the SRA Shops website, not the British one. M-DRO is about half the price. and I like the metal case on the M-DRO display console for some reason. MDRO supplies full length covers and as far as I can tell DRO PROS does not. looks like DRO PROS has a better warranty, on paper anyway. any input would be appreciated.

Sounds like you have already made up your mind.

My story: I've been using one or more DRO Pros dro for over 10 years now. Started with a 3-axis glass scale on my LMS mill that was moved to my PM25. When I got my bigger machines I installed a EL700 3-axis w/mag scales on my 935, and a EL400 two-axis (mag scales) on my 1340GT. I even had the touch probe on the EL700. Took a bit of fidgeting to get it set up, but it worked perfectly after that. The EL700 has programs that use the digital touch probe and I found them pretty easy and helpful to use.

Never had any problems with any of them.

My larger machines are gone, along with their DROs, but I have the PM25 with the old 3-axis (glass scale) still running perfectly on it. Can't say anything bad about them other than they cost a bit more. YMMV and all that...

 

[yota]

The primary cost of the Machine DRO packages is the magnetic scales, of which the head reader represents about 90% of the total cost. With their magnetic scales the magnetic tape is the same and it is the reader head that determines the resolution. The cost difference between 1uM and 5uM reader head is about $30, so not a significant cost factor for increased resolution for the cross slide. With a 5uM scale when doubled in diameter mode there is also increased calculation and rounding errors within the display unit. The other key factor is that the quality of the magnetic tape dictates the accuracy/variation over distance, which has been a significant issue with some of the less expensive magnetic DRO scales (i.e. they may be able to read 1uM but the accuracy or linearity of the scale is much worse). With the DRO packages the display is pretty much thrown in for the cost of the 2 or 3 magnetic scales. Just buying the scales and then getting say a TouchDRO will be quite a bit more, but if one were to use glass scales then it may be more cost effective, as well as in the milling functions where you would use more of its features.

As far as the 3rd axis scale if used, adding it to the tailstock I feel is a better option then the compound because it is much more frequently used. If placed on the tailstock you need a longer scale to account for mounting position of the reader head in addition to the reading length (see previous posted picture). Some magnetic scales like the Electronica the scale and head must be in the same read orientation (i.e. there are alignment marks on the read head and scale). Magnetic scales are more durable and less likely to become contaminated, but a scale cover is still recommeneded as ferrous chips between the reader and the magntic tape can cause read errors. Some reader heads (Elactronica Aokron) have wipers on either side of the read head.

If you need RPM (if using a VFD) the cost of an inexpensive meter is less than $20.

https://www.amazon.com/DIGITEN-Digital-Tachometer-Proximity-Switch/dp/B00VKAT8A2/ref=sr_1_2

X axis Cross slide M-DRO EH-01 - 450mm (18") Reading Length Magnetic Linear Encoder
https://www.machine-dro.co.uk/m-dro-eh-01-450mm-18-reading-length-magnetic-linear-encoder

Z1 Tailstock M-DRO EH-05 - 450mm (18") Reading Length Magnetic Linear Encoder

M-DRO EH-05 - 450mm (18") Reading Length Magnetic Linear Encoder

M-DRO EH-05 linear magnetic encoder with 450mm (18inch) reading length. A compact encoder profile suitable for a wide range of machine tool, XY tables, jigs and metrology applications. The encoder beam can be cut to length to suit install

www.machine-dro.co.uk

Z0 axis (bed) M-DRO EH-05 - 1450mm (58") Reading Length Magnetic Linear Encoder

M-DRO EH-05 - 1450mm (58") Reading Length Magnetic Linear Encoder

M-DRO EH-05 linear magnetic encoder with 1450mm (58inch) reading length. A compact encoder profile suitable for a wide range of machine tool, XY tables, jigs and metrology applications. The encoder beam can be cut to length to suit install

www.machine-dro.co.uk

Easson ES-12B LCD digital readout package including 3 linear magnetic encoders example of system cost, would need to specify changes to scalesused.

Easson ES-12B LCD digital readout package including 3 linear magnetic encoders

3 Axis Easson ES-12B LCD graphic digital readout package with three magnetic encoders. The encoders offer a very compact profile size and can be cut to length to custom fit the machine being installed. The package is suitable for mills up to Bridgeport 42" sized machines or 30" between centre...

www.machine-dro.co.uk

I filled out their form which includes my X and Z travel requirements and specified the ES12B and an upgrade to the 1UM cross slide encoder. not sure how long it will take to receive a quote. they can't charge me that stupid VAT can they? maybe that ended in England with the Brexit.

 

[yota]

Sounds like you have already made up your mind.

My story: I've been using one or more DRO Pros dro for over 10 years now. Started with a 3-axis glass scale on my LMS mill that was moved to my PM25. When I got my bigger machines I installed a EL700 3-axis w/mag scales on my 935, and a EL400 two-axis (mag scales) on my 1340GT. I even had the touch probe on the EL700. Took a bit of fidgeting to get it set up, but it worked perfectly after that. The EL700 has programs that use the digital touch probe and I found them pretty easy and helpful to use.

Never had any problems with any of them.

My larger machines are gone, along with their DROs, but I have the PM25 with the old 3-axis (glass scale) still running perfectly on it. Can't say anything bad about them other than they cost a bit more. YMMV and all that...

my mind isn't made up yet. but if the price is close, I will likely go with DRO Pros for the warranty and in country support. thanks for your input. good to know you've had over 10 years of service from their machine. I'm actually thinking about doing my PM 932M -PDF now also.

 

[yota]

The primary cost of the Machine DRO packages is the magnetic scales, of which the head reader represents about 90% of the total cost. With their magnetic scales the magnetic tape is the same and it is the reader head that determines the resolution. The cost difference between 1uM and 5uM reader head is about $30, so not a significant cost factor for increased resolution for the cross slide. With a 5uM scale when doubled in diameter mode there is also increased calculation and rounding errors within the display unit. The other key factor is that the quality of the magnetic tape dictates the accuracy/variation over distance, which has been a significant issue with some of the less expensive magnetic DRO scales (i.e. they may be able to read 1uM but the accuracy or linearity of the scale is much worse). With the DRO packages the display is pretty much thrown in for the cost of the 2 or 3 magnetic scales. Just buying the scales and then getting say a TouchDRO will be quite a bit more, but if one were to use glass scales then it may be more cost effective, as well as in the milling functions where you would use more of its features.

As far as the 3rd axis scale if used, adding it to the tailstock I feel is a better option then the compound because it is much more frequently used. If placed on the tailstock you need a longer scale to account for mounting position of the reader head in addition to the reading length (see previous posted picture). Some magnetic scales like the Electronica the scale and head must be in the same read orientation (i.e. there are alignment marks on the read head and scale). Magnetic scales are more durable and less likely to become contaminated, but a scale cover is still recommeneded as ferrous chips between the reader and the magntic tape can cause read errors. Some reader heads (Elactronica Aokron) have wipers on either side of the read head.

If you need RPM (if using a VFD) the cost of an inexpensive meter is less than $20.

https://www.amazon.com/DIGITEN-Digital-Tachometer-Proximity-Switch/dp/B00VKAT8A2/ref=sr_1_2

X axis Cross slide M-DRO EH-01 - 450mm (18") Reading Length Magnetic Linear Encoder
https://www.machine-dro.co.uk/m-dro-eh-01-450mm-18-reading-length-magnetic-linear-encoder

Z1 Tailstock M-DRO EH-05 - 450mm (18") Reading Length Magnetic Linear Encoder

M-DRO EH-05 - 450mm (18") Reading Length Magnetic Linear Encoder

M-DRO EH-05 linear magnetic encoder with 450mm (18inch) reading length. A compact encoder profile suitable for a wide range of machine tool, XY tables, jigs and metrology applications. The encoder beam can be cut to length to suit install

www.machine-dro.co.uk

Z0 axis (bed) M-DRO EH-05 - 1450mm (58") Reading Length Magnetic Linear Encoder

M-DRO EH-05 - 1450mm (58") Reading Length Magnetic Linear Encoder

M-DRO EH-05 linear magnetic encoder with 1450mm (58inch) reading length. A compact encoder profile suitable for a wide range of machine tool, XY tables, jigs and metrology applications. The encoder beam can be cut to length to suit install

www.machine-dro.co.uk

Easson ES-12B LCD digital readout package including 3 linear magnetic encoders example of system cost, would need to specify changes to scalesused.

Easson ES-12B LCD digital readout package including 3 linear magnetic encoders

3 Axis Easson ES-12B LCD graphic digital readout package with three magnetic encoders. The encoders offer a very compact profile size and can be cut to length to custom fit the machine being installed. The package is suitable for mills up to Bridgeport 42" sized machines or 30" between centre...

www.machine-dro.co.uk

BTW, thanks for looking all that stuff up.

 

[yota]

sent payment today to M-DRO UK. went with the Easson 12B and magnetic scales. for the cross slide I went with 1 UM, 300mm low profile AP-25 extruded support and cover, for the 1600mm scale went with 5 UM and the big AP-30 extrusion for rigidity over the long distance.

appreciate the input from everyone on this thread. thanks!

 

[SouthernChap]

they can't charge me that stupid VAT can they?

A company can charge what it wants for a product but if they are claiming part of the charge is "VAT" they better show that, since you're in the US, they only charged you what the sales tax is, in your state, and that they passed that part of the cost of the product along to your State treasury!

AFAIK, VAT is payable to the buyer's country (or Sales Tax to the buyer's State in the US). So no, you shouldn't be charged VAT (M-DRO have been around long enough, so they should know what they're doing as far as that sort of thing goes).

You might be charged a sales tax by your State or import levies by your federal government (or you might not, I don't know the import rules for the US or the sales tax rules for your State) when your kit arrives, but that's nothing to do with M-DRO.

 

[yota]

they did not charge me VAT, I was just speculating on my previous post. they did say there may be an import fee on my end.

 

[ChazzC]

they did not charge me VAT, I was just speculating on my previous post. they did say there may be an import fee on my end.

I gave up years ago trying to dig through the "Harmonized Tariffs" lists to see if I would have to pay duty on anything I buy from outside the U.S. So far, nothing from Canada, the UK, Germany, China or Australia has resulted in duty (and it the case of Australia the value of the goods was over $US750).