ballen
Diamond
- Joined
- Sep 25, 2011
- Location
- Garbsen, Germany
I've been fixing up a 1986 Jones & Shipman 540APR surface grinder. It's a nice machine. Now I'd like to add a digital read out (DRO) with glass scales to it. My question is, what's the best way to mount the scales onto the surface grinder?
[From the literature that came with the machine, I know that a factory-installed Heidenhain DRO was an option; it would be good to where those scales were installed.]
Here's what the machine looks like:
Not long ago, a friend gave me a defunct Heidenhain ND770 display, rescued from the trash, which I've repaired. This is a 3-axis display, really intended for a lathe, but will work fine here. I also got a set of LS803 scales the same way, which happen to be the correct length. These are working well, though they need new lip seals. But that's easy, I've done it before. The scales have a 40 micron grating, but together with the display will display to 1 micron resolution. The scales are about 18 x 30mm in cross section, the head adds about another 16mm to the long direction, making them 18 x 46 mm.
So regarding the three axes:
(1) The cross-feed direction is not difficult: the scale can be mounted to the right-hand side of the machine under the saddle, with the head fixed to the saddle. It might also be possible on the left side, but that's more exposed than the right.
(2) I'm less sure about the long (transverse) axis. The logical place to attach the scale would be to the back of the table, with the head fixed to the saddle. But since the saddle runs right up to the column, that would reduce the 150mm cross travel. I don't want that. Currently when the table is run as far back as possible, there is only about 12mm of space between the back of the table and the column. So unless I mill a slot in the back of the table (which I don't want to do) I would lose at least 6mm of travel in the cross direction (and probably more like 8mm). The other option would be to attach the scale to the front of the table. But that would get in the way of the adjustable trip dogs and the speed control lever. So neither option works well.
(3) For the vertical axis, there seem to be two options. One would be on the front of the column, facing the operator, on either the left or right side. The main disadvantage is that the scale is somewhat exposed to coolant and grinding dust. It's also far from the "ways", by which I mean the vertical steel bars and rollers which allow vertical movement. The other option (but I am not sure it is feasible) would be to mount the scale inside the column, in the space in between the body of the column and the moving internal frame that carries the motor and grinding spindle. It would be good to know if this is even possible: has someone out there done this or seen it?
Advice and photos would be greatly appreciated!
Cheers,
Bruce
[From the literature that came with the machine, I know that a factory-installed Heidenhain DRO was an option; it would be good to where those scales were installed.]
Here's what the machine looks like:
Not long ago, a friend gave me a defunct Heidenhain ND770 display, rescued from the trash, which I've repaired. This is a 3-axis display, really intended for a lathe, but will work fine here. I also got a set of LS803 scales the same way, which happen to be the correct length. These are working well, though they need new lip seals. But that's easy, I've done it before. The scales have a 40 micron grating, but together with the display will display to 1 micron resolution. The scales are about 18 x 30mm in cross section, the head adds about another 16mm to the long direction, making them 18 x 46 mm.
So regarding the three axes:
(1) The cross-feed direction is not difficult: the scale can be mounted to the right-hand side of the machine under the saddle, with the head fixed to the saddle. It might also be possible on the left side, but that's more exposed than the right.
(2) I'm less sure about the long (transverse) axis. The logical place to attach the scale would be to the back of the table, with the head fixed to the saddle. But since the saddle runs right up to the column, that would reduce the 150mm cross travel. I don't want that. Currently when the table is run as far back as possible, there is only about 12mm of space between the back of the table and the column. So unless I mill a slot in the back of the table (which I don't want to do) I would lose at least 6mm of travel in the cross direction (and probably more like 8mm). The other option would be to attach the scale to the front of the table. But that would get in the way of the adjustable trip dogs and the speed control lever. So neither option works well.
(3) For the vertical axis, there seem to be two options. One would be on the front of the column, facing the operator, on either the left or right side. The main disadvantage is that the scale is somewhat exposed to coolant and grinding dust. It's also far from the "ways", by which I mean the vertical steel bars and rollers which allow vertical movement. The other option (but I am not sure it is feasible) would be to mount the scale inside the column, in the space in between the body of the column and the moving internal frame that carries the motor and grinding spindle. It would be good to know if this is even possible: has someone out there done this or seen it?
Advice and photos would be greatly appreciated!
Cheers,
Bruce
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