Hi Jon, I watched your YouTube about this also. Your DRO installation looks great, Thank you for posting this. I am seriously thinking about using the same system on my 8520. I have a few questions.
1. What are your thoughts about the TouchDRO-bluetooth-to-tablet setup now that you've (presumably) had some time to use it?
2. Are you happy with the accuracy and consistency of the readout?
3. Any bugs or problems to report?
4. Does it ever lose the BT connection?
5. Are you fully satisfied with the Fire tablet for this application?
6. What length scales did you purchase for your X and Y? Did you cut them down to final length?
7. Did you maintain full travel of your table?
8. Anything else that you'd do differently if you did it again?
It looks like you installed everything so not to lose access to original locking handles or gib screws on the table and carriage, which is nice.
If I install this system I want to try to replace the USB cables from the reader heads with metal armored cable to make the installation more durable. Who knows, it might help with electro-magnetic shielding too.
Roger
1. I've used it much more on the lathe at this point. Love it. Now that the holidays (and a family funeral) are past, I hope to get back on the mill and finish up some things there. I highly recommend adding decoupling capacitors in the read heads. I still haven't gotten to it on the mill, and it's flickering in the least-significant digit. On the lathe it didn't work at all without them.
2. Accuracy-wise, the aluminum scales are good enough for what I'm doing, and had maybe 0.001" of hysteresis when I checked with a test indicator.
3. No actual bugs, but I wish the Preference Banks could be named and were "smart" enough to remember which Bluetooth connection to use.
4. The connection on the lathe started out finicky. It was particular about which wall wart I powered it from. Luckily, I've saved a big box of them over the years. Adding the decoupling capacitors in the heads also seemed to make it more stable in that respect. It's rock solid now, and only loses the connection when we lose power. I used an old transformer-based supply for the mill, and it seems happy other than that last-digit flicker which I expect to go away when I add the decoupling.
5. The Fire works great. It just requires some finagling to get the Google Store installed on it first. PITA in that respect.
6. I cut the 4" stainless scale that I installed on the quill and the 24" aluminum scale for the X axis. As I say above, you will need carbide if you want to drill stainless scales, but a cutoff wheel in your Dremel will hack through it. Try not to get them too hot, since the scale is just glued to the beam. I could have left the X scale longer and shifted the mounting blocks out flush with the ends of the table and it might have looked a little better. I had a reason for making it shorter, but I can't remember what it was now. Old age
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7. I have full travel on all four scales.
8. I keep wondering if I could have figured out a way to mount the X axis inside the table. I've seen it done with magnetic "tape" scales, where people have buried all of them inside the machine. You have to have a second mill to make the modifications, though. Other than that, it's made for a great setup.
-Jon