Fitting DRO scales on my Sieg SX3L Mill

[ruxu]

Already before I bought my Sieg mill I started to search for a small budget DRO solution originally for my Myford lathe. I stumbled on Yuriy Krushelnytskiy’s TouchDro Android app with a hardware solution using a Iteaduino BT Arduino based micro controller with Bluetooth connectivity, iGaging digital scales and an interface circuit between the scales and the micro controller. Familiar with Arduino this seemed the way to go for me.

Here are some pictures of digital scales used, the breadboard testing phase and the final electronics for the lathe. For the lathe the interface board is also fitted with a IR sensor input for reading of the spindle speed.



Because of other projects DRO is not yet fitted on the lathe but for the Sieg mill I made a second set of electronics and ordered three new iGaging scales with a length of 6”, 20” and 24” from Arceurotrade.

On the mill all three digital scales are fitted and protected from chips with 40 x 40 mm aluminium angle bars. A number of small aluminium brackets and spacers were needed to fit the reading head of the scales. For the X and Y axis the mill had already a number of M4 holes available. For the Z axis I had to drill two holes in the spindle head frame. The steel was surprisingly hard resulting in one broken M4 threading tap that I luckily got out after some trickery.



Ready made parts for the X, Y and Z axles.

The scale cables are protected with 10 mm black flexible cable sleeves. Attached are pictures of the final digital scale mountings. Running the scale cables to the enclosure containing the interface board with mini USB connectors revealed a surprise - the Z -axis scale cable was the only one fitted with a micro USB connector! I solved this problem by patching the scale cable with a piece of cable having the right mini USB connector in one end.



I made a quick mount for the 7 inch Android tablet that runs the TouchDro app by bending a scrap piece of stainless steel sheet to take a grip of the tablet edges. A swivel joint from my old Garmin navigator and a scrap aluminium pipe finalized the mount.



The Android tablet will also serve as a display for my Myford lathe DRO once I have time to fit the scales. The lathe is immediately at the right of the mill. Now when the mill is fitted with DRO it is much easier to make the mounting parts for the fitting of the DRO to the Myford lathe.