# Inexpensive 3 axis DRO



## n3480h

Setting up a new HF mini mill/drill for a new HMS.  I took a chance and ordered three DigiMag remote readouts from Amazon for about $100.  Yesterday I mounted the X and Y axis units on the mill, and I am pretty pleased with the results of the install.  Still have to get the air spring conversion for the Z, so that DRO will have to wait a bit, but X and Y are working well.  Working on the display mount and chip guards today.

Anyone else here using these?  Any feedback after actually machining parts?

Tom


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## tripletap3

Lets see some photos. :thumbsup:


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## n3480h

The DROs come with most mounting brackets for the ends.  The scale is stainless, can be cut to length with a hacksaw, and comes with end mounting brackets.  I made simple .025" 2024 aluminum brackets to mount the sensors.  Mounting the Y was easy, but the X required a bit more thought.  For the X, I made another bracket with two small slots at the bottom edge and mounted the bracket to the sensor with supplied screws.  I loosened the two screws that hold the rubber 
	

		
			
		

		
	





	

		
			
		

		
	
chip guard to the back of the table, and slid the bracket slots in, then tightened the two screws.  Drilling and 8-32 tapping the cast parts on the mill was the hardest part, but it went well, with no broken taps (lots of taping oil).  I suspect these DROs will eat batteries, therefore I may fit them with inexpensive AC converter transformers which will stay powered up.

At the upper right of the second pic you can also see the start of an experimental 18V Black & Decker Z axis rapid transit and feed motor which will be mounted on the left end of the table.  It won't approach CNC, but it will be fun.

Tom


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## n3480h

You're welcome, Shawn.  I should point out that the install is not complete, as I still have to form up the full length chip guards to go above the X and Y axis scales.  I have some .040 PETG clear plastic that cold forms easily and should keep the scales relatively chip free and offer a little protection from "falling objects".hew:

Tom


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## rebush

Hopefully this is just a strange occurrence. A friend of mine bought a set of Igage's from Grizzly Tool. The problem he had was the display would just jump randomly to different readings when nothing had moved. Grizzly took them back and paid shipping and set him a new set, within a few days it was happening again. Grizzly took them back and refunded his money. He bought a set from DRO PROS and has had no problems and is happily milling away. Not trying to rain on anyones parade just letting you know about his problems. Roger


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## n3480h

Rebush, thanks for the input.  I wonder if machining steel might create a problem, as I believe these are magnetic scales.  We'll keep an eye on it.  

X axis chipguard is in place.




Tom


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## Hawkeye

I have these ones on two mills and a lathe, without guards. I haven't had any problems with chips. I haven't had the displays jump either, except as noted next ...

The only issue is with the Z-axis display on the ZX-25 mill. If I'm doing a brutal milling job and the vibration gets up there (Hey, it's not a Victoria, after all.), a loose connection in the display connector can get the numbers jumping.

The units with the shorter scales will shut off if there is no movement for a while, but the ones with the longer scales don't shut down. I usually come back into the shop and find that I left one or two on overnight.


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## n3480h

Thanks Mike, its good to know there may be hope for these working out ok. Ordering the gas spring conversion from LMS this week, and then I can mount the Z on the left side of the column.  In the meantime, I'll fabricate a mount for the 3 readouts and letter them X,Y,Z.  After seeing your comment about vibration, I'll figure out a way to mount them that does not involve actually attaching them to the mill.

Tom


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## Bill Gruby

I have these on my 9X20 and have had no problems when cutting steel or any other material. Just wipe them down at the end of playtime.

"Billy G"


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## darkzero

My Mitu scale came with insulating sheets, the instructions say they're used for insulating the head & mounting end brackets if mounted directly to metal on the machine if it displays weird. Some machines can cause interference because of the voltage. Maybe some of the issues mentioned here are related?


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## n3480h

Interesting tip, Darkzero.  If mine get fidgity, it would be easy to add isolation mounts and use nylon mounting screws.

Tom


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## darkzero

n3480h said:


> Interesting tip, Darkzero.  If mine get fidgity, it would be easy to add isolation mounts and use nylon mounting screws.
> 
> Tom



To add, in case someone wants to try it,  the purpose of the sheets are to insulate the scale & read head electrically from the machine.


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## n3480h

darkzero said:


> To add, in case someone wants to try it,  the purpose of the sheets are to insulate the scale & read head electrically from the machine.



Power on machine testing reveals no issues yet.  The displays track accurately, and return to center zero position very reliably.  Zero positions recall correctly when I shut everything off and then restart.  If a problem shows up in the future, I have some thin plastic material I can place under the end mounts and sensor mounts, and then secure the mounts with nylon screws in place of the steel screws.  That should provide electrical isolation.  The only other possible fault condition I can think of is the introduction of static electricity.  We'll see.

Tom


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## darkzero

n3480h said:


> Power on machine testing reveals no issues yet.  The displays track accurately, and return to center zero position very reliably.  Zero positions recall correctly when I shut everything off and then restart.  If a problem shows up in the future, I have some thin plastic material I can place under the end mounts and sensor mounts, and then secure the mounts with nylon screws in place of the steel screws.  That should provide electrical isolation.  The only other possible fault condition I can think of is the introduction of static electricity.  We'll see.
> 
> Tom



Good to hear. Nice setup & install BTW.

I'll install my quill DRO scale without he insulating sheets first. I'm thinking I won't run into an issue. This is the first time I am using a scale like this on a machine & I've never heard of issues related to this before. If I do have an issue & the insulation cures it I'll report back here.


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## Blackhawk

I bought my scales from grizzley, same as rebush friend and my y jumps .200 randomly.  There is a google fix for it but i forgot where.  

lanham


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## n3480h

After a move to the country and several other "life" events, I'm finally getting the shop set up in the new place.  Today I added the Z iGaging DRO and made the panel to hold the readouts.  I see I had Y in mm.  Oh ya, and I installed the airspring to replace the clunky torsion contraption.

Tom


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## brandonicus

Have you run into any problems with the X axis reader unit getting "pinched" against the center column when running the Y axis back all the way. I've seen that mentioned as a concern when mounting the X axis centered behind the table (which I think is the tidiest way of doing it). At the moment I'm intending to mount mine shifted about 3" to the left of center so that it misses the center column entirely. But if there ain't no need...


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## NightWing

Here's the way I did it:

http://www.hobby-machinist.com/showthread.php?t=24242


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## iron man

Blackhawk said:


> I bought my scales from grizzley, same as rebush friend and my y jumps .200 randomly. There is a google fix for it but i forgot where.
> 
> lanham



 I had one doing that I re-grounded the machine at a couple different locations and the problem went away. Ray


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## brandonicus

I see several installs that place the x reader in the center of the table, nobody has crushed theirs against the center column?


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## brandonicus

I have my y&z units installed and working nicely, btw. Just trying to determine optimal arrangement for the x.


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## drs23

brandonicus said:


> I see several installs that place the x reader in the center of the table, nobody has crushed theirs against the center column?



Yeah, ya lose a little there. Including the cover I lost just under an 1 1/2". I've not missed that travel yet. Not saying it can't happen some day, just that it hasn't yet and it's been there for several months now.


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## n3480h

You do lose a little, but so far it hasn't been a problem.  I guess the milling I've done so far is not large enough to cause an issue, but it may one day.  The largest piece I've done was decking VW case halves, and it still wasn't an issue. Fixturing had to be carefully considered to prevent the case from running into the column.  Could not have done this job accurately without a DRO.

Tom


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## brandonicus

Wow! I never would have thought these little mills could pull that off!


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## brandonicus

Ok, I have mounted the x axis behind the table, offset about 3.5" to the left. Even with this arrangement I lose about .5" of y travel since the aluminum bar contacts the webs on the center column mount - not too bad, considering that I may have never missed losing an inch or so more. I need to take it all back apart as the bracket I fabbed up to mount the reader in the offset position is slightly wrong. Anyway, I'll take some pics at that time.


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## brandonicus




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## brandonicus

For y and z I mounted the reader with the included brackets. They started out with a 90 degree bend, I flattened them (gently) with a hammer and presto! Perfect fit! Well, almost perfect. I had to file a flat into a couple of the washers I used for shims underneath the z reader's bracket, so that they wouldn't rub against the center column during travel - you can see in the second photo that it is fairly close. Seems to work just fine. Using a longer bracket would have eliminated this issue, but I didn't want to make another bracket and I had already drilled and tapped the hole in the head casting...


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## Matthew Gregory

Is there any reason these scales couldn't be mounted to the mill without drilling? I've got any number of serious adhesives that would be up to the task, and the benefit then is no holes drilled and I could remove them with a bit of carefully applied heat.
Loctite Speedbonder 324 comes to mind... I'd just need to make certain I have index points set up to keep the mounts from moving.

...or am I overthinking this? That would be like me. A lot.


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## brandonicus

Matthew Gregory said:


> Is there any reason these scales couldn't be mounted to the mill without drilling? I've got any number of serious adhesives that would be up to the task, and the benefit then is no holes drilled and I could remove them with a bit of carefully applied heat.
> Loctite Speedbonder 324 comes to mind... I'd just need to make certain I have index points set up to keep the mounts from moving.
> 
> ...or am I overthinking this? That would be like me. A lot.



I had to do a bit of fiddling with shims to get everything to line up acceptably, but if you were dealing with reasonably level surfaces, I dont see why it wouldnt work. Or perhaps there is a completely better way to approach this?


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## brandonicus

Here is the bracket I made to hold the x reader in its offset position:
	

		
			
		

		
	



This is the aluminum angle that the whole x assembly mounts to:
	

		
			
		

		
	



Here is where the bracket goes, held in place by the lower bellows screws. It has been cleaned up and given a coat of lacquer:
	

		
			
		

		
	



The mounting plate for the readouts:
	

		
			
		

		
	



Rear-view (actually from the front of the machine) of the bracket in place:
	

		
			
		

		
	



The last photo was taken before I removed and modified the bracket (thus the unused slot seen in the previous pics). I moved the reader's position about 3/4" toward the centerline of the table (toward the right in the photo) this allows full x travel without the reader crashing into the end of the track.


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## n3480h

Good job on the mounting, brandonicus!  You're going to enjoy having the DROs.  While they may not be as good as the high $ units, they have served me well, with no problems whatsoever.  It's good to know where Zero is, and to be able to return to it accurately.

While decking the VW case halves, I had a scary incident.  While most Type 1 VW cases are aluminum, these particular cases are a magnesium alloy.  Due to tool dulling and my reluctance to remove and sharpen the tool midway through machining, the light cut produced a "fuzzy" chip. Good thing I stopped several times and cleared the swarf away, because at one point it FLASHED.  As in rapid burning. It took less time than the blink of an eye for that light layer of fuzzy material to burn.  No damage was done, but I did have to go change my shorts, lol.  So, if you ever machine a magnesium alloy, don't make fuzzy chips.  This could have been a major disaster.  Lesson learned.

Tom


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## atunguyd

Brandonicus

Nice job! Now go look at Yuri's touch DRO andriod app. This involves building a simple electronic circuit that will interface your three igaging sensors to a Bluetooth connection that you connect to with your andriod smartphone or tablet. This is then able to display all your axis in one location, which means it now knows their interrelations and will give you full blown DRO features (circle pattern tool offset etc...).  You can even enter your RPM and it will display your SFM in real time.  It is also able to calibrate to your sensor and mounting system to cater for any cosine errors you may have. Has ability to remembers points etc... 

Since changing to it I find my igaging sensors seem way more accurate. 



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## brandonicus

atunguyd said:


> Brandonicus
> 
> Nice job! Now go look at Yuri's touch DRO andriod app. This involves building a simple electronic circuit that will interface your three igaging sensors to a Bluetooth connection...
> 
> ...Since changing to it I find my igaging sensors seem way more accurate.
> 
> 
> 
> Sent from my SM-P605 using Tapatalk



Now that sounds sweet - and i happen to have an android tablet collecting dust at my house! can you give any more info on where to find this?

B


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## brandonicus

Wait, I found it...

http://www.hobby-machinist.com/showthread.php?t=16051


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## atunguyd

That's the one... I got the components on the eBay for about $30 all up, but that's because I live in a 3rd world country so buying locally is pretty hard. 

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