View Full Version : Question re: Grizzly H6094 DRO

06-27-2009, 11:00 PM
Has anyone installed a Grizzly DRO on their machines? I have purchased the H6094 and installed it on my mill. It was quite a task requiring much creative thought and help from a friend. I was thoroughly warned by the tech at Grizzly, prior to purchasing this unit, that installation would be difficult thus I was more than somewhat prepared for the challenge I faced.

I do have a question regarding how the sensor is physically connected to the scale. Installation instructions are vague at best but it does mention that if a scale is installed backward, it will read negative rather than positive during travel (which really doesn’t bother me at this time). Their installation instructions provide a diagrammatic illustration of a milling table. They suggest that the display for the X axis indicate positive numbers if the table moves to the left or negative if moving to the right from zero. For the Y axis, the display should show positive number increase as the table progresses away from the operator.

It is mentioned that during installation, should the display read opposite than what is recommended, then it becomes merely a matter of turning around the sensor so it faces in the opposite direction.

When the blue plastic protective cover and spacer is removed during commissioning of the sensor, the sensor is somehow left physically attached to the bottom of the scale and I am very, very reluctant to attempt removal of this sensor *simply because the display reads opposite* of what the manual suggest.

As stated, I really don’t care at this point if the number is, for example, positive .005” or negative .005” just as long as I know my table has moved .005”. But should there someday be a need for everything to indicate as they suggest in the manual, then I would like to know how to make this “simple correction” without doing harm to my new DRO. Can you shed light on this matter?

A picture is enclosed.



Dave S.
06-28-2009, 12:15 AM
I installed a DRO on my mill not a grizzly. I do believe they mean to turn the scale end for end so the cable comes from the left verses the right. All my axis have the sencor fixed and the scale moving with X, Y and Z.


06-28-2009, 12:43 AM
Thanks Dave. I was wondering about that and what you have said makes sense.


06-28-2009, 08:41 AM
I installed a Grizzly DRO on my mill. It was not the same Model number as yours but a Grizzly product. Yes the installation was "practical engineering" to say the least. The hardest part was getting the sensors level and straignt over their entire lendth. Installing the Z-axis was the hardest becasue of the taper on the vertical column of my mill. As I said it was a lot of on the spot engineering but the end results were worth it. It makes using measurement on the mill very simple and easy to use.

I've use most of the built-in DRO functions and have found some idiosyncrasies in some of the different routines. For example, when using the LHOLE routine the total length of the line of holes MUST be entererd in millimeters even if you are in the inch mode! When using the R Function, you have be careful as to some times they are referring to the center of the tool and other times they are referring to the tool edge.

I set mine up to correspond to the mathematical X,Y,Z axis system so that positive X is to the right, positive Y is towards the operator and positive Z is up.

Quetico Bob
06-28-2009, 08:47 AM
Mine (have one on my lathe as well) are not grizzly but I think the installation would be similar. Took some photos this morning that may help.

You may find once you get through the operating manual that there is a direction function so you can change the count whether your working left to right or right to left. The older one on my lathe has a button specifically for this.

Cheers, Bob




06-29-2009, 03:38 AM
Hi Guys,

Thanks for your replies. I've gotten both X and Y axis installed and will complete the Z installation by next weekend.

I'm enclosing images of the machine and a closeup of the Y axis without protective covers to show setup. Protective covers will be installed. I'm quite proud of the outcome regarding the Y axis. The X axis took some thought but it wasn't as difficult as the Y axis.




06-29-2009, 08:22 AM

First of all, that installation is a job that you should feel very proud of.

I have the same mill and DRO. I am in the middle of installing the DRO. It is as you say a job that requires a lot of creative thinking - and hair-pulling.

The installation manual is - as is often the case - quite clear after you've worked it out for yourself!!

Further, the operation/user manual differs from the installation manual in places.

How the DRO's are installed as regards direction doesn't matter as it can be reversed in the set-up phase if required.

The "X" and "Y" directions are poorly explained in the operation manual (its written in "Chingalish"). It will make sense if you think of the tool axis moving over the static work as if it were a point or cursor in an "X"-"Y" graph.

Positive "X" moves right along the mill "X" table but to get that result, you have to move the "X" table to the left to get the correct relative movement.

The same applies to the "Y" direction where the positive "Y" direction is "up" or toward the back of the mill. But to get this relative movement, the table has to move to the "front" of the mill so that job/table moves correctly under the static mill spindle.

This take a bit of effort to get your head around but once it "clicks" - you've got it and it all falls into place.

If you recall from your math/physics days, if you were plotting an X-Y graph, zero was at the intersection of the "X" and "Y" planes, positive "X" was to the right of zero and positive "Y" was vertically above zero. In this case the point or cursor moved and all was well.

I suggest that you plot a rough X-Y graph, stick it on your mill table with the graph X and Y axis aligned to the mill X and Y axis respectively. Put a pointer in your mill spindle (collet or chuck - doesn't matter) and then use the mill X and Y feeds to trace the graph. It is counter-intuitive - but it works.

If you think about it, this is exactly how a CNC cutter follows a CAD drawing that was drawn with true X-Y co-ordinates.

I never use negative quantities in computing a graph or a CAD job as it brings in a difficult calculation if you are adding or subtracting a negative quantity. So I set my zero so that everything is in terms of positive X and Y quantities - and all is well. I set it as far left and low from the job as is reasonable. Its all too easy to mis-read a negative quantity if all you are concentrating on is the numerals/digits on the read-out screen.

I'd suggest not getting to concerned about the "holes on a circle" (aka setting holes on a PCD) for a while until the basics have been mastered. I intend to use my "Vertex" quick indexing rotary table (same as your 8") as I can set it up and get it drilled much faster and at least as well with a lot less tool-changes than I can with a DRO. Same goes for drilling holes along a slanted line. But, those features will a very handy "fall-back" ("Plan B") item or option if needed.