# Accusize quill DRO for Bridgeport style mill



## petertha (Mar 26, 2019)

Just wondering if any of you have installed this quill DRO (or I suspect its offshore lookalikes). Are they battery gobblers like many offshore digital calipers?
https://www.ebay.ca/str/Canada-Quality-Machine-Shop?_trksid=p2047675.l2563 

Sadly my Mitutoyo has suddenly got crazy friction sticky recently after only a few months light use. I though I was having quill issues, it felt gritty. I removed it fully expecting a chip had migrated in there. No chip. Everything appear to be normal. Yes, its a real Mitutoyo not a copy, purchased from KBC. It was installed with TLC perfectly aligned. I slid the encoder bar out of the unit, examined the brass gib strip. There are 2 sets of opposing brass screws inside. One set rides on the encoder bar but you dont see them on outside of case. I noticed some light scratches on that side of the bar. The other set pushes on removable brass gib strip & they are painted red with loctite (factory adjusted). I didn't touch either, just gave the inside it a light blow of air & re-assembled. Same deal, gritty friction. Paid to much for this to have issues & this is coming from a Mitutoyo fan boy. So I will see what can be done through warranty.

Meanwhile looking at something cheaper to replace. Or who knows if I like it might stay with it. Its something I want & need but don't use often.


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## darkzero (Mar 26, 2019)

Accusize is China. I haven't heard of any China scales that don't like to eat batteries (compared to later Mitutoyos). Unfortunately there's not very many options for high quality scales like these. But it's just a simple battery change if it is a battery hog, I'm sure it'll do the job fine (unless you have a gripe about changing batteries). That is one thing I love about the Mitutoyos. I forget to turn mine off sometimes for days & the battery still lasts forever.

There must be more grit/dirt in there. The scale is hardended, it shouldn't scratch that easy (deep scratches). Whenever I clean mine I add a very small drop of instrument oil to the gib. Shouldn't need it but it makes mine much smoother. My Mitutoyo quill scale is going on 7 yrs now without any issues. All I've done to it is clean it every yr or so and last month I adjusted the set screws for the first time.

I'm sure you noticed as it probably wouldn't have gone back together but one end of the gib has a hole that should locate on one of the set screws that has a cone point. Try adjusting the set screws? Even though they have threadlock from the factory eventually they'll need adjusting. But normally the scale gets loose from wear over time instead of getting tight like in your case.


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## johnnyc14 (Mar 26, 2019)

I have one made by Accuremote. It does not eat batteries like my cheap Chinese digital calipers and has been working perfectly for 4 years now.










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## aliva (Mar 26, 2019)

I purchased a quill DRO from Accusize and have had the same battery for 2 years. Never had a problem with its operation or accuracy. I periodically check the movement with a Mitutoyo dial indicator. So Fit's preformed well.


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## petertha (Mar 26, 2019)

Well I confirmed the vendor will take the Mitutoyo back on warranty & they remit to service center, so back it goes. Outcome TBD. Unless a chip got in there which hung up on one of the brass sliders & then escaped without a trace I'm going to think something has come loose or out of alignment inside. Its within 0.001" alignment down the encoder axis, no adverse forces. the back plate bolts are only in by a thread so not interfering with anything. First time I had an issue with anything Mitutoyo. My calipers are silky smooth & super repeatable.

Shars what looks to me its close cousin for 90 USD.
https://www.shars.com/dro-quill-kit-for-z-axis-with-6-travel 
Thats 117 Kanuckistan dollars sans shipping vs 65 for Accusize. Only difference I can see is it comes with a frame whereas Accusize does not, just the end clamps. Weird. I figure my existing brackets will work, probably just need to make an adapter for the quill nut unless they were sneaky & match the Mitutoyo bolt pattern. May as well give it a shot while I'm waiting, it could be a while. Who knows, may end up with el-cheapo. For one thing I like the larger display. I don't use the quill DRO for precision, but when I want it I want it for consistent hole depthing or whatever.


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## petertha (Mar 26, 2019)

darkzero said:


> There must be more grit/dirt in there. The scale is hardended, it shouldn't scratch that easy (deep scratches).
> I'm sure you noticed as it probably wouldn't have gone back together but one end of the gib has a hole that should locate on one of the set screws that has a cone point. Try adjusting the set screws? Even though they have threadlock from the factory eventually they'll need adjusting. But normally the scale gets loose from wear over time instead of getting tight like in your case.



Ya something is not right, there were scores on the edge of of the scale & some around the corner. This was on the opposite side of 2 visible adjusting screws. But inside they look like 2 brass points or contact pads, maybe 1mm dia. But no frags came out over a white towel & the tracks inside look clean with Qtip swab. Unless is embedded somewhere.  Ive only been doing aluminum & mild steel lately but maybe a chip is a chip if it goes in the wrong way.

The display continues to work.

Yes I noticed the notch on the brass gib strip. If I put the scale in without it & just let it run on the brass friction pads points, it seems to run relatively smooth, but not silky smooth. The gib strip is not distorted or burnished or chip embedded. It seems to all go together with gib strip, then just has this severe binding.  I couldn't quite see how the plastic housing came off so I figured that was a good place to just leave it for the techs with the tools. Rather perplexing.


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## Dabbler (Mar 27, 2019)

I noticed that Shars has a 39$ version of the same thing, but without brackets.  Humm


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## petertha (Mar 27, 2019)

Ya but 39 USD is 51CDN and by the time you ship it to Kanuckistan, probably similar to Accusize.
Don’t buy it! I might have one to offer haha. 

Last night some more fiddling, I gave the scale the lightest touch of a ruby stone and the brass shim some gentle rubs on 1500 paper. The scales are hardened so nothing came off but I noticed there was a slight edge burr on the corner right where those score marks were, I could feel it with an Exacto blade running down. This improved the action.

Then onto re-assembly. I noticed if I tightened the back plate 5-40 screws into the DRO case I could make more or less friction. The screws never bottom out in the threaded holes but they somehow apply pressure to the case, I haven’t figured it out. But they were happy with maybe a couple threads of engagement almost just finger tight plus another 1/4 turn. I remembered this when I first got the unit, it is fussy that way. In fact I put a film of Kapton tape in there to give me kind of a thing gasket spacer. This time I just used a teeny amount of blue Loctite on the screws, got them into position & let them set. They will remove easy but hopefully this will preserve the setting.

Next issue. I mounted the scale in the C bracket the action was smooth in the middle, but again, depending on how much torque I put on the screws that secure the end clamps I could make more or less friction at the ends of the travel. I’m not gronking these teeny screws just slightly more or less torque. Here I have to mention I put my scale on the mill side (the back side) of the C bracket vs what might be the normal side (operator side) because I wanted more penetration of the round post into the quill nut hole. It didnt seem like an issue at the time. The scale & clamp & frame seem flat but obviously something is happening. So I did the same thing, used blue Loctite & tightened them just enough so it holds the scale but imparts no twist or bend or whatever is happening. Now it is silky smooth through the entire range. Re-mounted to the mill, re-calibrated vertical mounting runout with DTI. All seems well. Guess I’ll test & see.

I hate it when you ‘fix’ something but not entirely sure which of 5 things was the culprit or was it a combo type deal? I’ll post some pics when I have a moment.


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## petertha (Mar 27, 2019)

Here's some corresponding pictures.


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## petertha (Mar 28, 2019)

One thing I am now wondering, hinted at above. The C frame is basically stamped sheet metal. If the planes between the DRO scale & the mill mounting block are not real parallel (at an angle to one another) then that would inflict some bend into the scale as the clamps were secured. It seemed pretty flat & on the first install I ran an indicator up the front face & it looked good. I dunno, grasping at things now. Maybe it was just a stupid chip. But I think a future project is to make a more rigid frame assembly from milled parts.


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## Dabbler (Mar 28, 2019)

dunno about the need for rigidity - quill measurements are notoriously inaccurate anyway.  Getting to .002 is pretty good for drilling, even under power feed...

BTW have you used your power downfeed yet?  comments on it?


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## Winegrower (Mar 28, 2019)

I have this DRO on my Bridgeport clone.   It works fine, have not noticed any issue with batteries.   I have only these complaints:
1) it turns itself off in a fairly short time, just about when I want to read it again.  
2) when it turns off, it does not forget where it is.  That’s a good thing, except for...
3) pressing the power button restores the reading.  That’s a good thing too, except for...
4) the location of the zero key, at the bottom of the stack, is what I hit by reflex action.  It works, and zeros the reading.   That’s a bad thing.

Otherwise, it is good, and useful.   I had to make all new brackets, seems like what is included were designed by someone who had never actually seen a DRO or a mill.   My opinion.


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## petertha (Mar 28, 2019)

Dabbler, my personal view is the frame for any DRO should be stable & accurate so the scale orientation never sees any bending or twist or bow when its initially mounted. The stamped steel is 'ok' but I think i could improve it. Also needs to accurately aligned coincident to the motion of the reader head, which in turn is mounted to some other independent moving part of the mill. You'd be surprised to know how easy this is to say but can be harder to do LOL. Most regular DRO's can be quite picky about how many thou out along the length of the entire scale. It may actually function but misalignment can shorten life, at least that's what I was told. On a small 6" scale like this a couple thou is probably good. I'm actually wondering now if mine drifted because of the rather goofy, teeny screw engagements.

I think conventional quill scales & stop nuts are likely less inaccurate & repeatable over DRO. But the nice thing about DRO is its measuring pure displacement. They don't care about backlash or anything else, just displacement. So the guts of this quill DRO is not really different than a high quality digital vernier. I spot checked the quill readout to an inverted dial indicator & it agreed to the thou on (limited) 1" range. If you are saying not as accurate for milling purposes, I agree there. Lifting the knee is better. I like the quill DRO for depth drilling, spot facing, counterboring... that less critical but also important for consistency stuff. You can zero quicly and easily. Also good habit maybe is zero the quill when you zero the knee & it confirms if the quill lock has slipped. The accurate knee (raising the floor) is only relevant if the 'ceiling stays put' haha.

I played with the power down feed to ensure it worked & I was comfortable with the operations. But no, haven't had much call for it yet & been somewhat sidetracked stomping out all these little fires that seem to be flaring up. Hope that is behind me & I can get on with work. The machine itself is a joy to use.


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## johnnyc14 (Mar 28, 2019)

I made the bracket for mine from a piece of 2.5" square aluminum tube with 3/16" wall. Nice and square and very rigid.


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## Dabbler (Mar 28, 2019)

I agree with everything about alignment and such!  

Using the stop nuts can result in +/- .004 even in very large mills, but not too much of worry for counterbores, etc. I agree the quill DRO gives you way more accurate readings.  I've just not ever had much luck with the quill getting the accuracy I like, so I  almost always use the knee with a locked quill...  That isn't to say having a quill DRO is useless, cause it tells you what happened accurately!

I've got to test out my power down feed - as soon as I can get a proper plug for the motor!


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## Firstgear (May 6, 2019)

You mentioned the 5-40 screws, I recall reading on one of the forums that the screws are a known issue of being too long.....do some searches and you should find what others have run into.  I know that David Best customized his mounting as well as a few others.


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## petertha (May 6, 2019)

Yup I encountered that myself & was aware of the issue. I had some thin film tape to act as a shim. The initial setup was perfectly fine. My particular problem developed a month or so later when the screws must have come a bit loose. Its kind of finicky setup, just a smidgen of over or under tightening can affect the sliding performance. There aren't many threads engaged in the thin steel body plate to begin with so its not the best arrangement IMO. Why they didn't go with a much more common #4 (4-40) screw vs a #5 if they wanted to stay IMP is beyond me. Its not like you are ever going to gronk it down & will approach yield of the fasteners. Or 2-56 for that matter would give more thread engagement. It seems to be behaving now. The solution was just a toothpick tip of blue Loctite. Once the fasteners are in with just the right sliding tension, you want it to stay that way. Its still easily removable but at least wont drift out.


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## Firstgear (May 6, 2019)

I bought some 5-40 screws from McMaster, bag full.  If you need some LMK.


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## petertha (May 6, 2019)

Very generous offer thanks. I had some 5-40 spares that were just a bit long but I made a jig to accurately belt sand the end. I don't anticipate them falling out with the Loctite, but ya never know. Sometimes when I sweep under the bench I find the circlip of 2015, the set screw of 2012... 
Why is it you lose the part you don't have any more spares of? LOL


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## NCjeeper (May 9, 2019)

johnnyc14 said:


> I have one made by Accuremote. It does not eat batteries like my cheap Chinese digital calipers and has been working perfectly for 4 years now.
> 
> 
> 
> ...


I have the same one on my mill. It has been working fine for years now also. Not too much of a battery hog.


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