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I finally have gotten around to outfitting my Byrnes saw with a DRO as a previous member herein had shared. I employed a IGaging 35-712 P of a vintage around 2016. I glean it is an older model as it's accuracy is advertised as .004" vs todays .0015". I have spent a good deal of time learning how these devices work and empirically how they perform. I thought it would be a good "community" repository of knowledge to help others interested in digitizing non DRO machines.

 

There are relatively inexpensive units and of course there are more expensive ones as well. The IGaging company offers product at the lower end in two tiers; aluminum substrate versions and the more expensive stainless steel variety. The price differential is just about 2X between units. The Igaging units are not proprietary as other company's offer nearly look alike product. Also there is an emergence of Bluetooth connectivity and "apps" for some more intelligent display and interactive devices. One has to graduate to the more expensive tier to get at the data output.

 

Many people have used the units on midi mills and the like as they offer an X/Y/Z package. The saw of course only requires one for fence displacement.

 

Using the information located on Yuri's Toys web site one can get a decent understanding of the characteristics (and of course the vulnerabilities) of the devices.

 

Here in brief form is what I have learned so far applying the device to the saw:

 

1. The accuracy is pretty true to the advertised number i.e. .004

2. Repeatability is somewhat tenuous.

3. The unit functions better when the 6 foot cable is not coiled up. I suspect crosstalk.

4. It is recommended that the USB cable either be cut down or shielded for operation in "noisy' environments.

5. I find that the displacement function i.e. measuring from the saw blade to right or left is all I presently find useful.

6. The caveat is that it must be zeroed every time the fence is moved.

 

So with this beginning can we continue to create a repository of info for application of these devices and log them here? I think it would be of great value to many.

 

Joe

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Interesting topic and idea.  I'm assuming that you're just looking for repeatability of the fence setting?  

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I will be supplying photos soon. My only timidity is related to the actual device, not the mounting methodology. I am still evaluating the performance. I have no affiliation with the IGaging folk or anyone else that resells the product. I just want to be sure it is worth the trip. I hope you understand. I went through 3 iterations of the mounting and ended back where the original MSW member started with his mounting system. It is just a bit more refined I believe. However his approach is the right way to go.

 

In regard to the IGaging device I am thinking I will order a newer version and see if I find the utility and advertised performance works to my satisfaction. Of particular note in the product features it appears that they have slightly changed the functionality by what I can discern from the web site images.

 

Mark the repeatability is one area I am addressing. At first blush I am not too impressed with mine. It does not have an ABS(olute) function on my vintage. It has a Preset and INC(rement) function. The newer ones have the ABS function. Strangely "sometimes" my unit holds the measurement I dialed in when power is turned off and then on. It doesn't seem to hold the same (actual) displacement dimension when I move the fence however. These are the kind of performance anomalies I am addressing. 

Joe

 

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Thanks for sharing Joe, I will be interested in your final comments as I have been 'dabbling' with more 'manually controlled' methods of repeatability (all too complicated for my liking to date).

 

cheers

 

Pat

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Posted (edited)

I continue to evaluate the performance of the IGAging Linear Scale. For the past few days I have been observing some unexplainable deviations from what I expected in terms of repeatability of measurements. In trying to calibrate the fence settings I was using my wood shop brass gauging blocks (the square ones that are graduated from 1/8 to 1/2 inch). I was using the 1/2 inch one primarily and I was getting results that were way off (.010 deviation or more). I finally took a square to the brass bar and found it had a bow in the middle of the used face giving me the varying deviation. So I switched to the 3/8 bar and measured it at .3755" on my digital caliper (advertised accuracy .001"). In 10 consecutive measurements (blade set low, fence moved against blade and zeroed out on the DRO, fence moved past 0.0375 and then moved in against the brass bar) I got the following DRO readings:

  Test   Reading   Deviation H/L
Pwr On 1   0.384   0.0085   H
  2   0.378   0.0025   H
  3   0.374   0.0015   L
  4   0.379   0.0035   H
  5   0.375   0.0005    
  6   0.375   0.0005    
  7   0.374   0.0015   L
  8   0.375   0.0005    
  9   0.373   0.0025   L
  10   0.372   0.0035  

L

Edited by Thistle17
Correction of data

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With the exception of the first reading it appears to fall within the advertised accuracy (.004") but the repeatability ranges from -  .0035" to +.0035".

 

At this point I am thinking I will purchase the newer aluminum unit and retry the same experiment. Standby.

Joe

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In doing your tests, be aware that the blade may flex when you push against it during your measurements.  If you want to verify this, put a dial indicator on the back side of the blade.  Also, the fence will flex a little as well as it may not always register square each time.    When you're trying to work in the range of 0.001" you need to watch for these things even when using large metal working machines.  I do some work at 0.0001" and have to be hyper vigilant.

 

If you want to just test the accuracy of the IGaging system, I suggest zeroing on a block of wood clamped solidly to the table right next to the rail that the fence runs on.    I seriously doubt the iGaging system itself is not going to be repeatable within 0.001" as it's basically the same technology as your digital calipers.   The 0.004" accuracy is probably over the length of the travel.  

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Bruce you make a good observation. I will rerun the experiment using your suggestion to reduce/eliminate possible blade flex. Since yesterday I tried to order a new unit and they are out of stock so this may be an extended saga.

 

In the process of this experiment I have to admit that I may be taking this a bit far as I wonder just how much one needs .001 accuracy to make model ship parts?

Joe

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In the process of this experiment I have to admit that I may be taking this a bit far as I wonder just how much one needs .001 accuracy to make model ship parts. 

 

Only you can answer that.  One place I worked in engineering decades ago had a saying:  "How tight a tolerance do you want?  The standard here is measure with a laser laser interferometer, mark it with a piece of chalk, and cut it with an axe." The usually brought a laugh in any meeting with customers but the answer is as above... "how accurate do you want to be?".  And maybe should add:  "How accurate do you NEED to be?"

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Your right Mark, truly you are? I will have to keep that in mind as I progress.

 

Last eve I received an e-mail from Any Time Tools regarding a query I sent into them with the data above. They returned an answer I somewhat expected. My unit has been discontinued. They are recommending another unit but it seems to have the accuracy of mine. So I am back at them to get to the bottom of it all. The one on their site is out of stock but has a 4 X accuracy or so they say.

 

In retrospect I should have set up a "lab" experiment to evaluate the DRO unit prior to "tricking out" my saw. I had erroneously assumed that it had performance matching my digital calipers (a Harbor Freight Saturday Night Special) which demonstrates good accuracy and repeatability. One lives and learns!

 

Joe

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Posted (edited)

In the interim, as I await a response from Anytime Tools I am sharing my rendition of mounting the IGAGING Linear Scale to the Byrnes Saw. I had examined other ways of adapting the device to the saw and ultimately returned to a methodology of the earlier rendition posted on MSW by another member. It was sound to use the saw table top as the datum for mounting the device. It serves as an alignment measure for the height, parallelism and distancing references needed to enable easy alignment, mounting and "loading" of the inboard saw fence "carrier". I chose readily available materials, that were easily machined and light in weight. All mounting utilized is common #8-32 hardware. The other factor in choosing this methodology was "do no harm" to the Byrnes saw.

 

There are just a few modifications I would make to my current version:

1. Pad out the plexiglass mounts to "buy back" the 5/16" lost in fence excursion. This is related to the IGAGING electronic enclosure interference with the rail mount of the saw.

2. Instead of chamfered #8-32 mounting holes to attach the plexiglass supports to the aluminum saw mount I would make them countersunk loose fit clearance holes for easy alignment (parallelism) of the supports to the front and top of the saw table.

3. I had on hand 1/2 X 1 X 1/8 inch aluminum right angle. I would use 3/4 X 3/4 X 1/8 inch and eliminate the machining of the "port" bracket for interference of the belt shroud.

4. Depending on which unit anyone settles on the display mounting may need some consideration in that some units come with the swivel arm mount and some do not. Or maybe it is just a case of "as you like it".

5. If it is mounted as shown I would be very inclined to shorten the interconnect cable and shield it.

6. I had originally intended to use rare earth magnets to attach the "Z" bracket of the unit to the fence traveler but I have since noticed that there is a bit of play (in the "X" axis) using the knurled lock down nut as a securing method.

7. This is just an acknowledgement item. One can still get a 3/8" open end wrench in the belt shroud to hold the outboard height lock down but it would help if one that is a bit longer than the normal 3/8".

 

 

Picture1.dromnt.jpg

Picture1.dromnt2.jpg

Edited by Thistle17

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Posted (edited)

I happened to stumble upon, a new to me technology for DRO application. It is termed magnetic technology and in comparison is quite impressive in terms of performance with accuracy and repeatability beyond the performance of the capacitive type configurations. Here is a site for reference http://www.dropros.com/DRO_PROS_Digital_Readout_Magnetic_Scale.htm

 

That's the good news. The bad news is the cost for a 12 inch unit in the range of $400 to $500!

 

I still await a response from the Any Time Tools, so in the mean time I did rerun the test using the saw blade as a reference and again using the method suggested by Bruce in his post. For his suggestion I clamped the miter gauge to the table top and used its in board edge (the mitre bar) as a stationary reference. The other aspect of this test was that I ensured the 'Z' bracket "play" was canceled out since I now believe one must fasten it to the fence traveler as opposed to rare earth magnet attachment.

 

The results do show some deflection dissonance caused by the blade method but the results are relatively the same with no outliers.

I conclude, even with my older unit, that the accuracy and repeatability are worth the effort of adapting the unit to the saw.

 

Joe

 

 

IGAGING.Test.xlsx

Edited by Thistle17

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Posted (edited)

I have just heard back from the Any Time Tools people. The 12 inch unit on their web site is no longer available. They have directed me to the Amazon offering which has an advertised accuracy of .002 over 6 inches and .004 over 12 inches. I conclude from this that the referenced part performs as my older unit and is adequate for most operations one would need for ship modeling. To this point, with some outliers, my outdated unit is performing essentially as the newer ones.

The display functions seem adequate for normal saw operations. They communicate to me there is the capability to add a DC power source although the site depicts battery power. Mounting can be achieved through a separate attachment. Here are the references they have provided.

 

https://www.amazon.com/dp/B01G4FQJI6?ref=myi_title_dp

 

https://www.amazon.com/dp/B01CPLEW46?ref=myi_title_dp

 

https://www.amazon.com/dp/B00INL0BA2?ref=myi_title_dp

 

Joe

Edited by Thistle17
Information correction

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