Just completed a Easson 12B DRO install on my ERL-1340, I opted for the stock glass scales for the X and Z0 axis for cost reasons, but wanted to use the 3rd input on the Easson 12B DRO head. When I previously looked into the use of magnetic scales a few years ago with the Easson DRO's I was told that they may not be compatible (at least the those from DRO Pros). At the time I went with the EL700 on my mill with 4 axis magnetic scales. On my lathe, I did not need all the features of the EL700 and the Easson 12B is about 1/3rd the price. The stock glass scales are 1 micron slim line scale for the X axis and a 5 micron glass scale for the Z0 axis. The installs were pretty straight forward on the ERL-1340, I almost never use any of the stock brackets that come with these DRO's.
Cross slide was straight forward, I use some small spacer washers to set the standoff heights. Since the reader is directly mounted the holes needed to be spot on. I may at some point add some spacers to standoff the scale further from the cross slide to allow access to the cross slide lock, but so far I have not seen any creepage/movement of the cross slide when turning.
The Z0 axis is also a direct mount to the lathe bed, fortunately the surfaces are milled on the lathe bed so there are no surface irregularities. One downside of the Easson scales relative to other glass scales that I have installed, is the lack of jacking screws at the ends to adjust for height and tilt. Some kits provide a separate backing plate for the scale that has these adjustment screws. This kit did not come with those. I mounted an aluminum vertical mount to the cross slide using the coolant pipe holder holes and the coolant pipe can now be mounted to the vertical bracket. The reader head mounts to a L bracket which allows adjustment in the vertical and horizontal planes. A protective cover mounts over the scales. I spend more time trying to figure out how to do things, as opposed to making the parts. In this case it simplified the bracket installs for the scales/readers.
Next was the was the Z1 tailstock magnetic scale, I went with the SRA M-DRO EH-05 - 250mm/10" Reading Length Magnetic Linear Encoder (5 micron) which they said will work with the Easson DRO's so the ES-12B or ES-12C color displays. The magnetic reader and scale are very compact, a glass scale would be too bulky and awkward for mounting on the tailstock. I also wanted to mount the scale on the backside of the tailstock so it would not interfere with the QCTP. I have seen a few variations as to having a moving scale vs. have a moving reader head on a bracket. I choose to fix the reader head to the tailstock and have the scale move with the tailstock ram. I needed about 6" of scale travel so went with the longer scale, better longer than too short. The magnetic scale and stainless cover is easily trimmed to size with a tin snips.
The reader head mounts to a L bracket which straddles the the scale, the back of the bracket is milled with a channel and there is a separate backing plate behind the scale. This allows the scale to ride in a rectangular slot with no play. The scale as mounted was very rigid. I have checked the accuracy over the 5" of travel and it matches the mechanical dial perfectly, it repeats to around 0.0004" so worked out well. I do not know if SRA offers a 1 micron scale, I would have considered this for the cross slide if available. The only criticism I have of these magnetic scales is they are bare bones, so no end caps, covers, wipers, etc. just the magnetic tape, stainless strip cover and reader. The readers are very forgiving as to alignment, I origionally had a 1/4" gap between the reader head and the scale and it read with no errors. I subsequently adjusted the gap to have ~0.1" clearance.
www.sra-measurement.com
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The front plate for the scale mount is machined to fit over the ram and uses two 5 mm allen screws to hold it to the ram where it fits over it. The plate is 1/2" aluminum, the ram recess is 0.400" which allows MT3 holders to be fully retained w/o interference and eject properly. The scale mounts in a milled pocket and is secured with two 4 mm allen screws.
The DRO head unit is a straight forward install, but requires a backing plate to prevent the flex where it mounts to the electrical box. So far the ES-12B works very well, I much prefer the color display, the X axis changes from white to yellow when in the diameter mode. The readings are all very stable so no flickering between numbers, X0 reads to 0.0001" and Z axis read to 0.0002" increments. One interesting facet was that on the DRO menu all three displays are set to 5 micron, when I tried the 1 micron for the X axis it read out to 5 decimal places, 5 micron setting reads correctly and shows 4 decimal places. This is the newer Easson 12B display, the power supply is integrated into the unit and on the lathe setting the display shows Z0 and Z1 axis, apparently this was not the case with the previous version that had a separate power supply.
Cross slide was straight forward, I use some small spacer washers to set the standoff heights. Since the reader is directly mounted the holes needed to be spot on. I may at some point add some spacers to standoff the scale further from the cross slide to allow access to the cross slide lock, but so far I have not seen any creepage/movement of the cross slide when turning.
The Z0 axis is also a direct mount to the lathe bed, fortunately the surfaces are milled on the lathe bed so there are no surface irregularities. One downside of the Easson scales relative to other glass scales that I have installed, is the lack of jacking screws at the ends to adjust for height and tilt. Some kits provide a separate backing plate for the scale that has these adjustment screws. This kit did not come with those. I mounted an aluminum vertical mount to the cross slide using the coolant pipe holder holes and the coolant pipe can now be mounted to the vertical bracket. The reader head mounts to a L bracket which allows adjustment in the vertical and horizontal planes. A protective cover mounts over the scales. I spend more time trying to figure out how to do things, as opposed to making the parts. In this case it simplified the bracket installs for the scales/readers.
Next was the was the Z1 tailstock magnetic scale, I went with the SRA M-DRO EH-05 - 250mm/10" Reading Length Magnetic Linear Encoder (5 micron) which they said will work with the Easson DRO's so the ES-12B or ES-12C color displays. The magnetic reader and scale are very compact, a glass scale would be too bulky and awkward for mounting on the tailstock. I also wanted to mount the scale on the backside of the tailstock so it would not interfere with the QCTP. I have seen a few variations as to having a moving scale vs. have a moving reader head on a bracket. I choose to fix the reader head to the tailstock and have the scale move with the tailstock ram. I needed about 6" of scale travel so went with the longer scale, better longer than too short. The magnetic scale and stainless cover is easily trimmed to size with a tin snips.
The reader head mounts to a L bracket which straddles the the scale, the back of the bracket is milled with a channel and there is a separate backing plate behind the scale. This allows the scale to ride in a rectangular slot with no play. The scale as mounted was very rigid. I have checked the accuracy over the 5" of travel and it matches the mechanical dial perfectly, it repeats to around 0.0004" so worked out well. I do not know if SRA offers a 1 micron scale, I would have considered this for the cross slide if available. The only criticism I have of these magnetic scales is they are bare bones, so no end caps, covers, wipers, etc. just the magnetic tape, stainless strip cover and reader. The readers are very forgiving as to alignment, I origionally had a 1/4" gap between the reader head and the scale and it read with no errors. I subsequently adjusted the gap to have ~0.1" clearance.
M-DRO EH-05 - 250mm/ 10" Reading Length Magnetic Linear Encoder
M-DRO EH-05 linear magnetic encoder with 250mm (10inch) 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
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The front plate for the scale mount is machined to fit over the ram and uses two 5 mm allen screws to hold it to the ram where it fits over it. The plate is 1/2" aluminum, the ram recess is 0.400" which allows MT3 holders to be fully retained w/o interference and eject properly. The scale mounts in a milled pocket and is secured with two 4 mm allen screws.
The DRO head unit is a straight forward install, but requires a backing plate to prevent the flex where it mounts to the electrical box. So far the ES-12B works very well, I much prefer the color display, the X axis changes from white to yellow when in the diameter mode. The readings are all very stable so no flickering between numbers, X0 reads to 0.0001" and Z axis read to 0.0002" increments. One interesting facet was that on the DRO menu all three displays are set to 5 micron, when I tried the 1 micron for the X axis it read out to 5 decimal places, 5 micron setting reads correctly and shows 4 decimal places. This is the newer Easson 12B display, the power supply is integrated into the unit and on the lathe setting the display shows Z0 and Z1 axis, apparently this was not the case with the previous version that had a separate power supply.
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