Post by Kevan on Sept 6, 2020 19:41:03 GMT
I have thought a lot about adding a DRO to my Myford but have somewhat balked at the cost. I have been watching the EBay prices dropping and when I got an offer of one for £105 delivered I felt that it was worth a gamble.
The kit is supplied with 250mm and 1000mm scales a small bracket kit and the DRO console. It is typical Chinese and the instruction translation is laughably bad.
Much head scratching is involved in figuring out how best to mount things. I think I have read everything and watched a whole bunch of YouTube to inform my thinking. Cutting glass scales has been thought impossible however several youtubers have done it and I certainly could not live with a 1m scale strapped to my lathe so dremel
In hand I ‘edited’ the long scale to the length of the bed leaving a long run off at the cut end in case of problems. This was fixed to the taper turning holes via a length of steel angle I had to hand.
The instruction suggest that the scale needs to be dead parallel to the lathe bed. I spent an age with the clock on the cross slide running it up and down, adding jacking screws and adjusting until I concluded either there is a dip in the middle of the lathe bed or the scale ‘s extrusion is bent by several thou over its length.
Biggest challenge is the X axis mounting. Most Myford installations represent significant compromises that block T slots, limit access to the gib adjustment and carriage lock bolt. As my cheapie scales are of the larger cross section none of these options worked. I have seen DRO scales mounted out behind the lathe so I started trying to do this. I looked at attaching the scale to the cross slide but was unhappy with the potential for vibration and movement. I also gave up on the idea of fixing without drilling the lathe as none of the suitable fixings would bear onto machined surfaces.
In the end I used some substantial aluminium angle to bracket off the end of the cross slide for the X sensor and off the back face of the carriage for the X scale both fixed with a pair of M6 screws.
At first I tried to set up the full 250mm length of the scale but realised this just extends the cantilever and also meant sitting the lathe 100mm further off the wall so I cut the bit of scale left from editing the long scale and fitted the ends and reader from the 250mm scale. This clocked a lot better but still shows a few thou out along its length.
I made a sort of cleaver shaped plate that fixes to the cross slide bracket to pick up the X sensor and cut down one of the fixing kit angles to sit inside the Xscale bracket angle that holds the Y sensor. The x sensor bracket and mount on the same screws.
The x sensor and x scale need to be dead parallel. They were not too bad about 18 thou out between ends of travel, a little judicious bending brought them within 3 thou.
So I completed this today but not used in anger yet. Running them up and down looks like they are working right but have reveals really bad backlash on the lead screw. The next challenge is trying to understand the manual for operating all the functions on the read out however I doubt I will use much apart from setting values for cuts and quick calculations.
If anything interesting happens with the set up I’ll let you all know😃
The kit is supplied with 250mm and 1000mm scales a small bracket kit and the DRO console. It is typical Chinese and the instruction translation is laughably bad.
Much head scratching is involved in figuring out how best to mount things. I think I have read everything and watched a whole bunch of YouTube to inform my thinking. Cutting glass scales has been thought impossible however several youtubers have done it and I certainly could not live with a 1m scale strapped to my lathe so dremel
In hand I ‘edited’ the long scale to the length of the bed leaving a long run off at the cut end in case of problems. This was fixed to the taper turning holes via a length of steel angle I had to hand.
The instruction suggest that the scale needs to be dead parallel to the lathe bed. I spent an age with the clock on the cross slide running it up and down, adding jacking screws and adjusting until I concluded either there is a dip in the middle of the lathe bed or the scale ‘s extrusion is bent by several thou over its length.
Biggest challenge is the X axis mounting. Most Myford installations represent significant compromises that block T slots, limit access to the gib adjustment and carriage lock bolt. As my cheapie scales are of the larger cross section none of these options worked. I have seen DRO scales mounted out behind the lathe so I started trying to do this. I looked at attaching the scale to the cross slide but was unhappy with the potential for vibration and movement. I also gave up on the idea of fixing without drilling the lathe as none of the suitable fixings would bear onto machined surfaces.
In the end I used some substantial aluminium angle to bracket off the end of the cross slide for the X sensor and off the back face of the carriage for the X scale both fixed with a pair of M6 screws.
At first I tried to set up the full 250mm length of the scale but realised this just extends the cantilever and also meant sitting the lathe 100mm further off the wall so I cut the bit of scale left from editing the long scale and fitted the ends and reader from the 250mm scale. This clocked a lot better but still shows a few thou out along its length.
I made a sort of cleaver shaped plate that fixes to the cross slide bracket to pick up the X sensor and cut down one of the fixing kit angles to sit inside the Xscale bracket angle that holds the Y sensor. The x sensor bracket and mount on the same screws.
The x sensor and x scale need to be dead parallel. They were not too bad about 18 thou out between ends of travel, a little judicious bending brought them within 3 thou.
So I completed this today but not used in anger yet. Running them up and down looks like they are working right but have reveals really bad backlash on the lead screw. The next challenge is trying to understand the manual for operating all the functions on the read out however I doubt I will use much apart from setting values for cuts and quick calculations.
If anything interesting happens with the set up I’ll let you all know😃
