CLEAR BOARD SENSOR message- I know you'll say "get a new one" but not an option

[eastcutty]

I bought my Rev A machine from Sears 6yrs ago and the Board sensor has never worked right. It was sold as 'new', but I should have been more suspicious when it was a few hundred bucks off list price- as months, then years, went by, I kept finding more and more 'tells' that indicated someone had had their paws inside it- (tool marks/scratches/gouges, cracked plastic sensor mounts, etc) whether customer, Sears 'repair' people, or both. Don't ask me why I didn't just take it back- money, logistics, and the suspicion that their so-called service professionals would just 'turn it back around' weighed heavily.
Most of the time I found ways to repair, compensate for, or otherwise work around glitches, mis-alignments, and busted parts, guides and such (always been pretty much able to fix anything) but a constant and frustrating problem with the board sensor gets me almost to the point of tearing my hair out. 90% of the time I want to run I have to be prepared for a battle to get it to finish, or often even start, the measurement phase. I've never gotten a higher reading than the mid-30s during the sensor check, but I'd eventually get by by 'fooling' it with taped-on white paper on the board. Nowadays, tho, I'm only getting mid-20 readings.
I expect you're thinking "blow it out" or "wipe the window" but I've gone as far as removing it for disassembly/cleaning (found cracked sensor mount when locating the screws the first time- part of one of the screw tabs was missing) to remove fine dust that had gotten inside. Since then, sensor inspections found no dust in/around the light sources or light pipe because I used scotch tape pieces to better seal the enclosure before re-intallation. I do notice that I get higher (to my max) readings when I tighten down on the roller crank but it's then too hard for the X-axis drive to push the wood thru- I've had more than my share of dealing with belt tearing and busted gears- see my other posts.
To add to the confusing aspect, it sometimes, if rarely, works fine right out of the gate- or will 'decide' to suddenly work after endless re-tries with no changes made.
So, a couple of questions now that you have the basic picture: Am I alone in this type of anguish? I use light vs dark masking which seems to work best out of everything I've tried- anyone got better ideas? I also notice occasional sudden short reversals in drive direction in the middle of length- or span-wise measurement sweeps once I finally DO get past the initial 'Check Board Sensor' battle so could all of this be circuit board related? Is there a Board Sensor sensitivity adjustment potentiometer not mentioned in the available online docs?
I haven't worked for a year and a half since my last job, have no income, and I'm waiting on the Feds to stop dragging their feet regarding my disability case, so you can see that I have NO funds available to swap out expensive sensors and boards until I stumble upon the 'cure'.
Any other DIY tinkerers out there with any insights/ideas?

Forgot to mention: 205 hrs motor run time, 21?? hrs ON time on clock.

[badbert]

Just to be sure... the optical board sensor below the z-truck. Only comes in effect during width measurement and the last 3.5" of board length. If you are getting a tracking error at any other time... it is the brass roller. Are you using masking tape, on the bottom of the board? As far as reversing direction during measurements. That is usually caused by the board binding. The board is tapered, or the the guide is too tight.

[henry1]

Are you USA or Canada just Curious

[badbert]

I believe he is from Roanoke, Va.

[Digitalwoodshop]

Well you have come to the right place.... WE are hear to help....

If you do a search using the " " with the phrase like "Board Sensor" I have posted many posts and pictures that will help... As for the Reversing of directions, sounds like a frozen Rail Bearing or if it was the X Axis or Sand Paper Belt it could be a loose board or a binding board... Masking Tape on the track of the Brass Roller will help too....

I am in the middle of a few things including cooking a Turkey.... Below is my Website Links. Send me a PM or email and a phone number and I can call you and walk you through a few things Friday or Saturday.

Also look up the "250 Hour Maintenance" and read that thread. I expect you will need to do a complete cleaning and lubrication like I posted. I am betting you are going to find some frozen Roller Bearings due to dust getting into them... You can cover the sand paper belts and use WD-40 to wash out the dust. Just remember that the Silicone in the WD-40 IF it gets on your Wood can cause Fish Eyes where the Finish won't stick..... When I worked at the Sony Picture Tube Plant they BANNED WD-40 as it gets in the AIR and then sticks to the GLASS of the Picture Tube preventing the proper stuff to stick to it.... Like on the inside of the Screen....

I am here to help.... Do some homework... WE will get you working... THE FSC Cable on your version can be the OLD 18 pin with thinner wires and CAN cause Board Detector Problems along with the Z Driving into the Board.... A newer 14 pin replaced it... BUT you must remember to look as you never want to put the new 14 pin into the 18 pin socket.... it will short out the computer... They sell a kit with the 14 pin cable and the 2 circuit boards on each end. BUT the 18 will WORK just fine until it FAILS... They don't make 18 pin cables anymore.

AL

[eastcutty]

Just to be sure... the optical board sensor below the z-truck. Only comes in effect during width measurement and the last 3.5" of board length. If you are getting a tracking error at any other time... it is the brass roller. Are you using masking tape, on the bottom of the board? As far as reversing direction during measurements. That is usually caused by the board binding. The board is tapered, or the the guide is too tight.

Roanoke, VA, USA. Some of you know me and are familiar.
Not 'tracking' issue, it's the board sensor under the z-truck, and the tracking edge of the board is crispy, flat and sharp. No tracking messages. Board ends are square, even, and level. Sensor behavior is always odd, often failing right after 'Load Board', ...or will span board, truck will 'stutter' at far side then keep going only to return and stop at the far edge then error there, ...or will PASS those, begin lengthwise run to fail at back end, ...or will run all the way back forward to fail at the carve outlet end.
At any fail point, hitting ENTER (like on 'check tracking') does not reset, so starting over completely (aarg!) is the only fix. Note that I have 10x ON time as CARVE time, so you can see how much time I spend fighting with it.

[eastcutty]

Well you have come to the right place.... WE are hear to help....

If you do a search using the " " with the phrase like "Board Sensor" I have posted many posts and pictures that will help... As for the Reversing of directions, sounds like a frozen Rail Bearing or if it was the X Axis or Sand Paper Belt it could be a loose board or a binding board... Masking Tape on the track of the Brass Roller will help too....

I am in the middle of a few things including cooking a Turkey.... Below is my Website Links. Send me a PM or email and a phone number and I can call you and walk you through a few things Friday or Saturday.

Also look up the "250 Hour Maintenance" and read that thread. I expect you will need to do a complete cleaning and lubrication like I posted. I am betting you are going to find some frozen Roller Bearings due to dust getting into them... You can cover the sand paper belts and use WD-40 to wash out the dust. Just remember that the Silicone in the WD-40 IF it gets on your Wood can cause Fish Eyes where the Finish won't stick..... When I worked at the Sony Picture Tube Plant they BANNED WD-40 as it gets in the AIR and then sticks to the GLASS of the Picture Tube preventing the proper stuff to stick to it.... Like on the inside of the Screen....

I am here to help.... Do some homework... WE will get you working... THE FSC Cable on your version can be the OLD 18 pin with thinner wires and CAN cause Board Detector Problems along with the Z Driving into the Board.... A newer 14 pin replaced it... BUT you must remember to look as you never want to put the new 14 pin into the 18 pin socket.... it will short out the computer... They sell a kit with the 14 pin cable and the 2 circuit boards on each end. BUT the 18 will WORK just fine until it FAILS... They don't make 18 pin cables anymore.

AL

Cooking a turkey here myself.
I don't doubt reversing is an artifact of a binding condition- as I mentioned, I get higher readout numbers the tighter down it's cranked, that's how I kept failing X-drive gears. All roller bearings are clear and free, BTW, I do regular maintenance. Compression rollers get 'lift and listen for switch to click' at each run with a 'feel and spin' to boot. Drive rollers are free from recent belt tweaking. I even spray down the upper surfaces of the belt platforms with silicone, and let them thoroughly dry before replacing belts to cut down on drag.
Buying kits to repair design flaws aren't something I can afford at present time, and the ONLY money I'm bringing into the house is from pieces I sell. I could do well if I could rely on operation, I have heard of customers seeking out my new offerings in the stores.

[Digitalwoodshop]

OK sounds like you are on track with cleaning and lubrication. A test of the Board Sensor is to place a sheet of white copy paper on the board and crank down on it. The perfect reading is 156. A 90 would be a dirty board sensor.... IF you get a 90 or less I recommend removing the board sensor being careful not to pull down on the wires as they can slide down the SHARP edge of the track and cover and then pinch and short... I had that happen twice.... second time I took it apart and replaced the cable.

So once you remove the cable I recommend cutting down the back side to remove that flap on the back...

A few things can happen.... The Green Circuit Board will fall off.... This is not likely as you are still getting readings..... BUT as per the pictures you can see in the early years I had it happen often.... The 2 LED's and Sensor would snap off due to the vibration of the QC when I used it way past worn and got BB marks in the Bits. The High Speed Vibration caused the LED's to snap off....

So I am going that the board will stay on the plastic holder.... Next Carefully remove the little plastic window from the Cut end... Clean it.... Blow the dust out of the sensor and insert the window and use tape to seal it all back up... Catch the edge of the Window.

THIS should give you a 156 reading....

As for the 18 to 14 pin.... It was a Improvement that was allowed after they took the Homing Sensor, Probe Data, and a RPM Sensor out of the Truck... Needing less wires... They switched to a 14 pin cable...They LAST LONGER.... And let more current get to the Z Motor...

A TEST of the Cable with the Board Sensor... When you have that 156 reading.... Reach back and slowly roll and move the FSC Cable.. IF the Numbers drop off.... You have a bad cable.... as the ends are touching then not....

Good Luck,

AL

[eastcutty]

Great info there, AL! Those readings are what it says in the Manual. HAPPY THANKSGIVING by the way!
Unfortunately, I've NEVER gotten a reading higher than 35 in all the times I've checked with copy paper, before or after disassembly/cleaning. I've even gone as far as adding paper to the entire length center and width measurement locations.
I have to ask: is the light emitted supposed to be in the visible spectrum? Or is it UV or IR? I've never seen it that I recall- and looked. Both lamps look to be intact and firmly placed, but I can't tell if they are working. I have the enclosure kept sealed with tape and I don't see dust in there when I remove check. The circuit board is not exactly 'solid', but fixed in place. The light pipe is clear, too. Now I mainly use a magnifying mirror (awesome tool to use!) to double-check the window from beneath, as removal for inspection is, from experience, meritless.
Note that it works great when it wants to, so there has to be proper function at some point. Additionally, I know the sensor 'sees' the edge/ends of the board because it stops/stutters there. (I know the compression rollers affect end reading location determination.)
I have not, however, taken the truck off the machine as you have pictured. (Starting to smell REALLY frickin' GOOD in here!) I guess I'll do that and remove the 4pin cable altogether and go at it with my multimeter. It's likely OK, because it doesn't flex at all, but the vibration you mentioned could have damaged it, I guess. The QC Chuck run-out vibration issue has been corrected on my machine- after 2 chucks and several BB'd bit holders, I modified mine to take the QC out entirely- and now I'm running a modified Dremel shaft/chuck assembly in a welded-together bit holder/chuck mount (the parts that threads onto the arbor in the truck) with excellent results..INCREDIBLE improvement in detail and has never yet made me wonder if it's robust enough!
I'll check the readings while rolling the truck Y-wise first to see about the 18pin cable. If the cable is at fault (sounds more likely as we go along) I might be able to bridge the issue. Done dicier things!

[badbert]

Wow Eastcutty! You have mastered this machine, basically on your own! Now that you have found this great resource, Things can only get better! The generosity and camaraderie here, is inspirational! With that said, I am sure you will straighten that board sensor out!

[Digitalwoodshop]

Turkey Done... Dishes Done.... Time to play on the computer....

Yes, sounds like you have a plan. but that 35 is the source of the problems.... It needs to be higher.... The LED's are IR like the TV Remote control. Some in the past have used a lamp above the machine shining into the clear cover while it is measuring... Might be a Temp fix.... Or Shine a LED Flashlight inside....

AL

[eastcutty]

Turkey Done... Dishes Done.... Time to play on the computer....

Yes, sounds like you have a plan. but that 35 is the source of the problems.... It needs to be higher.... The LED's are IR like the TV Remote control. Some in the past have used a lamp above the machine shining into the clear cover while it is measuring... Might be a Temp fix.... Or Shine a LED Flashlight inside....


AL

I thought about external light sources but it seems to me the only way to make it work and have the light stay out of the way of the cutting head is to mount it on the truck itself. I even have one of those flexi-goose-necky-LED-book-light-thingies (too technical?) to use, I can hit STOP and remove it once running, then resume. Never tried it, tho, I can usually (eventually) fool the frackin' thing into working. I did have one thought- I don't think there's a way to calibrate the sensor's light sensitivity....or am I wrong?
This is particularly troublesome to me because it's the only thing I haven't been either able to fix, modify or work around. It just works when it wants to.
I'll see what's up with the cabling scenario then get back to you with the results- unless it decides to run LOL!
Thanks for all your help.

[fwharris]

Not sure if this would even work BUT place a mirror on your board and crank the head down. Do the board sensor check option in the dark. Would you be able to see the reflection of the lights to see if both are working?

The lights are installed at an angle so that the light beams meet at a point on the board surface to get the best reading.

In case you have not looked.... http://store.carvewright.com/product.php?productid=16177&cat=254&page=1

[gwizpro]

I had a somewhat similar problem with 2 different machines, an A and a B machine. Drove me and the guys crazy for awhile. Turned out they were in such a position in the shop that they were not getting enough ambient light. Moved them both to a new location and never had the problems again. As an example when we turned off the external lighting, the machines sensors read low, but did read...... Just a thought..... Of course it could have been the machines liked the new scenery inside the shop and a different power source. I have found working with machines, over the years, it is as if they have a mind of their own.....

[eastcutty]

Not sure if this would even work BUT place a mirror on your board and crank the head down. Do the board sensor check option in the dark. Would you be able to see the reflection of the lights to see if both are working?

The lights are installed at an angle so that the light beams meet at a point on the board surface to get the best reading.

In case you have not looked.... http://store.carvewright.com/product.php?productid=16177&cat=254&page=1

That's a neat idea, Floyd- definitely gonna try it! I'l let ya know what happens here and I'll shoot ya a hello on FB. Thanks!
Al mentioned the lamps are in IR wavelength, so likely won't be seen by eye- but who's to say they're putting out what they should? No wavelength measurement capability here.
I'm also going to follow up on Gwizpro's (gee whiz pro?) idea, but expand it to include natural, fluorescent, incandescent, blacklight near-UV, and VIS-spectrum LED sources to see what/which/if any seem more effective. I'll run this experiment in Sensor Check mode to collect actual raw data via digital readout- empirical data collection to determine lambda-max wavelength for my machine's optics sounds like fun! ...Not to mention useful! I'll be sure to post what I find.

P.S. Just found out there's no source of fluorescent here, so no data on that will be coming, but that's at the 'cooler' end of the spectrum from IR anyway.

By the way, Floyd, I asked earlier in the thread about if calibration of sensor accurracy/sensitivity was possible... is there any Zero/Span calibration/adjustment of the sensor that you (or anyone else?) know(s) of? Maybe a factory repair rep who's reading? I'm capable of understanding any advice or instructions given... I have 13yrs experience in laboratory technology including operation, maintenance, overhaul, troubleshooting and repair of High Performance Liquid Chromatography (HPLC) systems, Gas Chromatographs (GCs), UltraViolet-Visual Spectrum (UV-VIS) Spectrometers, Diode Array Detectors (DAD) and more. All I'd need is a schematic. .........Anybody?............? I'm not about to take a chance on 'coastering' my circuit board(s) fumbling around without any guide to follow. Been there/done that before! NOT FUN.

[eastcutty]

i had a somewhat similar problem with 2 different machines, an a and a b machine. Drove me and the guys crazy for awhile. Turned out they were in such a position in the shop that they were not getting enough ambient light. Moved them both to a new location and never had the problems again. As an example when we turned off the external lighting, the machines sensors read low, but did read...... Just a thought..... Of course it could have been the machines liked the new scenery inside the shop and a different power source. I have found working with machines, over the years, it is as if they have a mind of their own.....

yes they do !!!!!

[fwharris]

By the way, Floyd, I asked earlier in the thread about if calibration of sensor accurracy/sensitivity was possible... is there any Zero/Span calibration/adjustment of the sensor

Not that I am aware of....

[TerryT]

If you have a sony movie or digital camera with "nightshot" you should be able to see the ir light just like a beam from a flashlight. You may have to cover the ir iluminator on the camera so it doesn't overpower the glow from the carvewright illuminators.

[Digitalwoodshop]

That is a good point.... Even a Digital Still Camera could see the IR if you put a mirror or even the bottom of a CD down on the board...

AL

[eastcutty]

If you have a sony movie or digital camera with "nightshot" you should be able to see the ir light just like a beam from a flashlight. You may have to cover the ir iluminator on the camera so it doesn't overpower the glow from the carvewright illuminators.

Wow, hadn't thought of that!

Following up: I tried the test I described earlier and even with incandescent (closest to IR I have) shining right up into it, saw no increase in reading of 32-33, so no data to share.
Trying to pursue the cabling inspection/test idea... Seems I can remove the lower guide rollers and lift the truck right off the track...HOLY COW those lower Y-axis roller screws are TIGHT! I lowered the rear/left compression roller to gain access to the rear of the roller bearing shaft to keep it from turning, but the flathead driver slot is SO shallow it's hard to keep the driver tip in. Note the driver end is straight, sharp and correct size.
I should be farther along than this today, but leftover-induced napping took over today's itinerary temporarily. You know how that goes.
LATER: TerryT- YOU DA MAN! My phone has a 'night' setting so I used it to try. The video showed faint bluish 'cat eye'-looking light, but could't tell if it was reflection or not, so I placed white paper underneath and tried again- and saw the lights and illuminated paper. SOooooo... both lights are ON, but if 'correct' I can't say.
I'm gonna try this: increase the internal diameter of the light pipe to more effectively harvest reflected light. I am, after all, sensing SOMEthing, even if less than I should. Maybe vibration didn't affect emitters, but jostled the collector somewhat.
I did forget to report in earlier posts that the 'pass your hand under sensor' test failed to produce any reading fluctuation from ZERO, for what it's worth.
I'll let ya know what happens.

[eastcutty]

Floyd mentioned:
"The lights are installed at an angle so that the light beams meet at a point on the board surface to get the best reading."

Maybe the intersected beam-to-board distance isn't right? Should there be any gasket/spacer between the sensor mount and the truck?
This wouldn't answer the 'hand-pass-failure' issue, and the reading stops climbing after a certain crank-down point.....but still......?

[DickB]

No special camera needed - digital cameras and phones with cameras see IR.

[eastcutty]

OK....Happy to update! I pulled the board sensor YET AGAIN and re-inspected it- no dust per se that I could see, none that I could blow out, but I still dusted the lamps and sensor with my softest paintbrush and realized the sensor looked less 'smoky'. What I never did notice, however, was that the sensor itself wasn't quite level in its slot- so I'm guessing the incoming light up the pipe was reflecting off of the angled surface rather than straight in thru the end. I just so happened to catch the light reflecting off it and sorta sensed rather than saw at first that it was just a hair off. All it took was a tweak with a fingernail to straighten it out. While I was at it, I thought about what might improve the lightpath so I 'polished' the groove to a shine with a toothpick and increased the aperture with a shallow taper to gather more light. (like a telescope with a bigger objective lens) Note the inlet and tube were not blocked/dirty to begin with. Sealed it all back up with tape, re-installed, seems to be doing OK now. Don't know if one or all 'tweaks' did the trick, but the collective effect is dramatic.

[badbert]

I knew you could do it! You seem resourceful!

[Digitalwoodshop]

Good Job !!!!

[eastcutty]

Spoke too soon- seemed to cooperate better at first, so I said "Yay!", but it's really just doing as best as it's ever done...NOT what it should.
Also, the Manual says "It is recommended that this sensor and mirror be cleaned after every project". Mirror? What mirror? Have I been missing something, a portion of the sensor, all along? Note that this is original RevA parts as I rec'd them from Sears.

[Ropdoc]

I am now having this issue. I am going to cut the clear cover the covers the LED. Any thoughts?

[dehrlich]

I had a problem with the sensor yesterday when it tried to measure the board, it actually spit the board out the back of the machine! Cleaned everything up and all that, still gave me fits. Figured maybe it was the walnut board so I put a strip of blue masking tape on top, changed stay under rollers to NO and it worked fine. Oh, I forgot I stood on one leg while patting my head and whisling dixie to make it work :D

[TerryT]

I had a problem with the sensor yesterday when it tried to measure the board, it actually spit the board out the back of the machine! Cleaned everything up and all that, still gave me fits. Figured maybe it was the walnut board so I put a strip of blue masking tape on top, changed stay under rollers to NO and it worked fine. Oh, I forgot I stood on one leg while patting my head and whisling dixie to make it work :D

I hate to say it but the "whistling dixie" was probably the most effective part! LOL just kidding. Probably what did it was cranking the head up and down. I think you will continue to have this problem. If you had used the keypad to check sensors when it spit the board out the back of the machine I think you would have seen one or both rollers STILL showing COMPRESSED. Most likely the front one. Both ends of the roller should be cleaned, not only the switch end but the non keypad end as well. If the front roller sticks and does not RELEASE the board sensor that you are working on WONT EVEN COME ON. Thus not sensing the end of the board and the board traveling all the way out of the machine.

Just my two cents.

[Digitalwoodshop]

If the board spits out then the roller that is on the other end of the machine that the board came out is the sticking switch. When the board is measuring and the roller is released it tells the computer that the board in 3.5 inches from the end and to turn on the board detector.... No roller released signal, the board keeps moving..... OR.... A bad FSC Cable as the BOARD SENSOR signal passes through the FSC Cable, OR a bad or dirty sensor.

AL

[eastcutty]

I am now having this issue. I am going to cut the clear cover the covers the LED. Any thoughts?

I wouldnt get rid of the clear cover.
Dust would build up fast, and the blowing/brushing/sweeping it clear all the time is gonna break something eventually- plus the lightpipe would get clogged.

[eastcutty]

Spoke too soon- seemed to cooperate better at first, so I said "Yay!", but it's really just doing as best as it's ever done...NOT what it should.
Also, the Manual says "It is recommended that this sensor and mirror be cleaned after every project". Mirror? What mirror? Have I been missing something, a portion of the sensor, all along? Note that this is original RevA parts as I rec'd them from Sears.

Still no answer on the Mirror question?
Anyway, now I'm not getting ANY readings during sensor check besides "0". I pulled off the Y truck to check for shorting pinched wires, and they were fine- no crimps etc and continuity checks OK on each lead from sensor board thru to other end of wires.
I'm running out of ideas besides replacing things I can't afford right now. Any other tests to try?

[jaroot]

There is no mirror that I'm aware of. I have had to replace the board sensor a couple of times. The last one I ended up taking the lens off and just blow it out after each carve.

I will eventually replace it.

[lynnfrwd]

I know people have been told to use a dental mirror to see the sensor.


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[eastcutty]

I know people have been told to use a dental mirror to see the sensor.


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The mirror was mentioned in the manual, as if a part of the sensor.

The lamps are both working, I can see them via my phone cam, but the sensor check says "0" during hand-pass test, cranked down head, with and without white masking paper overlay, etc.
I am considering a manual bypass with a PB-NC switch to 'tell' the machine where the board width and end points are- press the button/open the circuit to simulate the sensor reading the edge/end points. Exact dimensions aren't nearly as critical to me as getting running again- I can always trim around the piece to compensate. If I understand correctly, the Board Sensor is only in use during the measurement phase of set-up and not while carving, so manipulation of the switch will be brief.
Anybody have any experience along these lines?
Anybody have any schematics?