I was able to get my hands on a 3 axis DRO (digital read out) for the RF-45 clone mill. I have never had any experience with these units however I have only ever heard good things about DROs on mills. I currently have some milling jobs in the brainstorm and early design queue so I figured I would take the time now to get the mill in peak running state.
The DRO system I obtained is a Chinabuilt SINO SDS6-3V 3 axis unit. I was able to obtain the user manual for the system before I decided to buy and had spent time determining if I would be capable of using the system. The manual translation is a bit rough and it takes some mental work to decifier what is being explained however I figured once I could get my hands on the system and work with it I was going to achieve success. The manual contains no installation instructions as these systems are a universal fit and therefore it relies on the ingenuity of the installer to ensure it is going to fit.
So this blog posting is nothing more then a documentation of pictures showing my installation. I had attempted to find pictures and information on how others have done the install however I had no luck. I decided that with nothing to go on I was going to wing it and see what I could come up with. I was very pleased with the install and I am not sure I would have done it any differently. I am sure there are other ways of doing it, and perhaps better ways, however at this point I will plead ignorance. I decided I would post some pictures in hopes that it will help others who are planning to perform an install. Perhaps the information found here will either show others what to, or not to, do.
The basic concept is that there are 3 linear scales that need to be mounted to the mill. One scale for each axis X, Y, and Z. The criteria for the mounting is as follows; 1. The scales cannot affect the operation of the machine in any way. They cannot be mounted in such a way that it limits adjustment knobs or travel. They also cannot impede machine maintenance such as lubrication points of the ways or gearbox oil changes. 2. They need to be mounted rigidly as to maintain the accuracy of the readout. The biggest challenge was the Z axis. 3. The scales need to be as protected as possible from any oil, coolant, or metal contamination.
So off I went to start drilling and tapping holes into the mills castings. The DRO came with a few universal aluminum brackets; I was only able to use one for the Y axis. I ended up having to fabricate a total of three other adapters to get all the scales mounted.
I’ll let the pictures tell the story. It took me approximately 4 evenings to do the complete install and in the end I think it was 4 evenings well spent. I am happy with the rigidity of all the scales. The Z axis scale, the one that gets exposed to the worst vibrations, seems to be holding fairly accurate. Since the install I have spent a few hours educating myself with all the math functions. The DRO is more then just a readout as it can also help to perform accurate machining functions such as circle drilling, radiusing corners, center finding, drilling evenly space holes along an oblique line, plus a whole range of other functions. I was able to successfully get my way through many of the functions. Perhaps I’ll save my new found knowledge for another posting.
The Y axis needed a bracket made to connect the scale to the supplied aluminum adapter. Using a chunk of scrap channel I milled a bracket to attach to the Y table.
These are the three completed brackets that I built for both the X and Z axis. I left the quill clamp in the picture to show how the aluminum adapter fastens. The rigidity of the Z axis bracket was a concern however the use of 3/8" aluminum plate seemed to do the trick.
I was able to neatly bolt the X scale onto the back of the compound table. The scale is out of the way and protected.
A complete picture of the Y axis was difficult to take. This is the top view of the Y scale bracket mounted to the Y table on the right side of the mill.
Here you can see the mounting of the Y scale on the left side of the machine. The factory aluminum bracket goes up and connects to my fabricated steel bracket. Rigidity is not a problem with the Y scale.
The 3/8" aluminum plate bolted to the quill clamp was the right choice. It looks clean and is out of the way. The angle cut towards the left rear of the bracket allows me to still drain the gearbox oil.
The Z scale was tucked in behind the vertical feed controls. It's mounting still allows me to access the nut required to angle the machines head.
The final picture is of the plate I built in order to mount the control panel arm to a wall stud.