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Faro arm diy encoder repair thread

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Plastic
Joined
Dec 16, 2017
Hi guys, I have a faro platinum and I'm determined to repair this myself and share possible repair methods so far I have managed to get to the main joint or second axis encoder, we sort of, it's hard to determine how they joined the two halves it looks to be adhesive although I don't think it would be wise to separate them at this point for fear of throwing off a calibration of some kind?

so down to my theory of why they fail it can be down to three failure modes as far as I'm concerned.

1, the first one being contamination on the encoder glass

2, fracture of the encoder glass

3, actual sensor failure possibly due to emitter being burned out due to age or esd damage

Please see pictures below, I will try some social engineering tomorrow to determine how faro separate the encoder joints, although I don't think they will share as its a pretty good earner for them £2500 a pop. failing that I may machine some access to get to the sensor PCB without separating the arm joint and get some cleaning done, looking at there patents it looks like a reflective bassed encoder disk vs the more traditional through disk type, so microscope may be required for checking and cleaning...

if anyone has any info about these this would be most helpful, as they are becoming more attainable for individuals especially ones with the classic encoder faults.

124827803_2984437341844371_6508786843496436279_n.jpg

124031222_2444453012524942_5533083234442064313_n.jpg

Please ignore goblin foot :eek:
 
I have a faro quantum with a bad encoder I've spent the afternoon trying to open up. I've gotten about as far as you have with no luck beyond that. If you make any progress please share
 
so some slight updates turns out the joint is adhesively joined together, it's not temperature softening as well! so the only way in would be to machine a pocket to access the encoder of witch I have seemingly located the correct part number already its a choice of two, I will divulge later on just in case they frequent this site and to confirm it works :cool:.

before I cut anything I need to ascertain whether or not I can purchase the sensor without doing a bulk order, or even if they will sell me one, also, I have confirmed the other axis aside from the sprung main axis are addressed through rs485 due to there being an rs485 transceiver, specifically a MAX3486ECSA+T, further oscilloscope testing will be done on Monday morning it looks like the main sprung axis is raw encoder data specifically, quadrature output according to my encoder identification.

I have spoken to faro themselves, they have told me some things but I think they have told me things that are intended to throw me off the scent, being deliberately obscure, although the mear mention of my encoder findings seamed to be getting a slight reaction that maybe I'm on to something, I have posed the question that if they charge a reasonable rate I may consider halting my investigation, however, I doubt they will so like I said on Monday I'm going to probe the signals to see if the encoder is actually dead. it looks like there may be two encoders per axis and potentially if one doesn't agree with the other it won't home. I have also learned from faro that the generic stress waring is just that, it just means one of the axis may have erroneous data the coloured joint may be fine it's just a generic picture.

I will try to report back early next week.
 
Small update, encoder looked to be fine; the encoder is made up of two independent sensors and one common graduated disk.

Signals come through as sine then get converted to square then both converted streams go through a comparator, then the combined signals go through to the main DSP56F80 Motorola chip, few things that are beyond us are, if the encoders are fine why is it creating an error maybe misalignment?
Secondly, there doesn't appear to be the window trigger for setting the reference position I'm presuming this is due to design limitations of a limited range of motion but not sure yet, the PCB is a 6 layer jobby that may require a stint at an x-ray.

We are going to try and trick the signals going into the PCB during the week, but early indications are that our encoders are dead are false, they may just need to be re-learnt/referenced?

to be clear this is only applicable to the counterbalanced axis the others go through rs485/422 we may get onto that side in due course.
 
They must have got to him,
i am now in the process of doing the same with a legacy gage
the support i have got is "we no longer have the tools to repair these, we can send you a catalogue to upgrade" which i will not be doing
i have machined a pocket on the wrong side, no pinched wires, it is definatelly glued solid, i am at the stage of just breaking it open, hopefully someone has some insight.
 
Hello, I have an arm with a bad encoder on joint 4, am interested in pursuit of repair (either here at my plant or sending to someone with experience). I don't have any background with the devices so not much help regarding insight. I do have a lot of electrical/sensor background and might be able to help with troubleshooting.
 
Have you tried getting the encoder rebuilt?
I have no clue what type encoder it takes or anything about them, but I would call this guy and see what he says before trying to replace with something else:

Mark Troy
Oracle Encoder Service LLC
1712 A St
LaPorte, IN 46350
888-994-2001

And it would be swell if you doo - if you would please post his response here.


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Think Snow Eh!
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