problems with the Y axis

[toddschroeder76]

i'm in the process of doing some signs. the shortest carving was 40 inches long and the longest is 67 inches long. i got the first two signs done wihtout a problem, but during the craving of the third and final sign which was the longest of the 3 the carving jumped about a 1/2 inch to 3/4 half way through the sign. i thought it might be a belt issue but the belt and teeth on the gears were ok. i then checked the y truck motor and gears all of which were in good working order. i took off the back cover of the y truck motor to expose the sensor and there was some dust in there. so i cleaned it out put it all back together thinking i had hopefully solve my problem. started the carving again and about 45 min to an hour in it did it again but this time after it jumped it made what looks like about 2 passes and stoped with error 238 y axis stall coming up. just for the heck of it i cleaned the machine and ran it again on the same board. it stopped in the same spot. i am out of ideas of what this could be but it is starting to get expensive since the wood i'm using is cedar.

thanks for any help
todd

[aokweld101]

the first thing that I would do is turn off the machine and make sure that it moves freely without no hang ups.

[henry1]

go here and see the tip
http://www.carvewright.com/support-page/troubleshooting-guide/troubleshooting-the-carvewright/#random_axis_stalls

[bergerud]

If the "same spot" is a place where the carving went deeper, the problem could be as simple as a dull bit.

[toddschroeder76]

Everything moves freely and I just put a new bit in

[bergerud]

Could you post a picture of the carving where it "jumped".

[DickB]

I had a similar problem a while back. I thought the truck was moving freely when I pushed it by hand, but it turned out I had a stuck bearing. I believe that I actually had to loosen the two movable bearings away from the rails so that they could be spun freely. Two bearings were fine, one had some resistance, and one was nearly stuck. I ordered replacements, but tried cleaning and lubing them in the meantime, which worked. I never did install the replacements.

[toddschroeder76]

66075If you look close you will see that it jumps in the middle of the I and then again at the beginning of the N and at the end.

[bergerud]

These are places where extra y force was needed. Places where the bit had to plunge. The system gets tested at these places and sometimes stops with a y axis stall. The fact that yours kept going makes me think the y belt may have slipped.

[toddschroeder76]

That's what I thought to but couldn't find any thing wrong. Tension on the belt seemed good and the teeth on all the gears were there. Do u have any other ideas

[bergerud]

I would re-tighten the belt. Back off the locking screw and the re-tighten it. If the bit was new, the carriage rollers are free rolling, the y motor pack bearings are good, what else can it be? (You could also mark the belt and drive sprocket with a felt marker so you will know if it later slips.)

[toddschroeder76]

Good idea with the marker I will try it thanks for the input

[Digitalwoodshop]

That is some pretty hard to cut wood.... and you must be EXTRA Careful that it is Pressure Treated (I believe) and the Chemicals in the Pressure Treated are DEATH on Exposed Steel.... I have a Brad Point bit that I used to drill some Pressure Treated and forgot to clean it.. In a few days it was Badly Rusted....

Your Drill Rod Y and Z Rails will be the first to show the rust...

So back to the problem... I believe it is actualy the Y Gear box 2 little bearings... the 5 x 11 x 5 mm or 685ZZ bearings...

The two bearings take the most abuse of any part in the machine.... And Especially since you completed some SERIOUS cutting where the Y was doing a lot of work... I believe they have FAILED or are close to Failing and under the Stress of Cutting the belt pulls the big plastic gear AWAY from the Servo Motor Shaft. This is where the bit slips as the Servo is pulling or pushing but the big plastic gear leans AWAY to the point that the teeth slip between the servo shaft and big gear..... (How many times did he repeat that.... :))

This is evident in the FACT that you did not get a SERVO ERROR.... The Servo Motor was HAPPY.... The Pulses were "Right on the Money" so "No Problem"... but in fact.... The Big Plastic Gear sliped.... I have seen this many times.... and Sometimes the FIRST indication of a ERROR is when the Sign is done and the machine is returning the Y to HOME and all of a sudden it SMASHES into the Keyboard side "Before it Expected to"... and raises it's hand and tells you... Y STALL..... But ONLY because it was returning home and smashed into the wall... The Project is DONE... It may be OFF in Y.... but done...

A Critical piece of information anyone should post with a Y Stall is.... "How Many Cut Hours"... That tells me if it is likely the Y Gear Box is worn out... and the MORE hard Projects you push at the machine the Quicker the Y Bearings Fail.... I recommend changing the bearings at 250 Cut Hours... At the same time as you change the Carbon Brushes in the Cut Motor.... Most Y Gear Box failures that I had in 2007-2009 were in the range of 450 Cut Motor hours.... BUT.... It was a WORN THIN Shaft of the Big Plastic Gear that caught my Attention... And the 3 CLICKS when the Y was over at the Bit Plate.... The 3 Clicks was the Servo Motor Shaft trying to PUSH the Y over further and the Big Plastic Gear slipping 3 clicks...

LHR sells the little plastic gear with shaft if you find you have waited TOO long to replace the 2 bearings.... It took me WAY too long to put that simple fact together.... So NOW I stand on my "Tide" Soap Box and Shout Out the info to anyone who will listen......

The Y Bearings are CHEAP replace them OFTEN..... You can see by the Picture Dates... It IS a Issue.... Unless your PRO ACTIVE and change them OFTEN...

Good Luck,

AL

[toddschroeder76]

After reading Al's message I tore apart the cw for about the 5th time this week and sure enough the shaft on the y motor is worn down which explained the jumping. Ordered all new gears and bearings so hopefully this solves my problems and it's not the first chink in the armor

thanks again everybody

todd

[bergerud]

Al comes through yet again!

[Digitalwoodshop]

Yes BUT..... It was another user who posted the first pictures of the 2 bearings...... Up until that point I had 3 Worn out Gear Boxes that I swapped out with old Z Boxes from the A907 upgrade. I saw the worn shaft but thought the bearings were Babbit... I even recommended adding the back of the shaft to the "Oil Me" list.... I was Humbled.... The date can be seen on the picture with MY 2 bearings and you can find the related posts.... My Eureka Moment....

GOOD JOB !!!! finding the worn shaft and getting the parts on order.... :)

I will be away from my computer for 3 Days.....

Back Soon :)

AL

[badbert]

After reading Al's message I tore apart the cw for about the 5th time this week and sure enough the shaft on the y motor is worn down which explained the jumping. Ordered all new gears and bearings so hopefully this solves my problems and it's not the first chink in the armor

thanks again everybody

todd

The Bearings can't be ordered through LHR... http://www.avidrc.com/product/1/bearings/170/5x11x5-Metal-685ZZ-bearings.html You need four. two for the Z and two for the Y. I always order them by the dozen.

[ekimnamyr]

Thanks for the link badbert, ordered the bearings this am..

[aokweld101]

I must be doing something right I have 590 cut motor hours on one machine and 680 on my other machine and haven't changed anything and still going strong..... [don't want to jinx myself]

[DickB]

Not even brushes?

[bergerud]

You better check the y motor gear shaft for play. The shaft can get ruined if it is left too long. Catch it in time and you only need new bearings. Just try and wiggle the shaft around to test for slop.

[aokweld101]

You guys might be right I'll check all that tomorrow..... [in a snide voice]... And yes of coarse I've changed the brushes... geeze....Lmao

[Rob Mulgrew]

I just recently started having this problem but only when doing cutouts. The cut path shifts on every pass a little further. Do you guys think the "too much play in the plastic gear" would be causing my problem too? I have 320 hrs on my machine.
661566615766158

[CNC Carver]

May be a broken tooth in the plastic gear. Rolled sandpaper belt or rubber belt rubbing the board sensor brass roller. Also check side of board by brass roller for any imperfections. Or as Al would say add masking tape.

[Digitalwoodshop]

I'm back... It's all about the Brass Roller... 7 inch rule of wood possibly in this case... That cut path is shifting in the X axis... The board is loosing contact with the brass roller...

AL

[Digitalwoodshop]

I must be doing something right I have 590 cut motor hours on one machine and 680 on my other machine and haven't changed anything and still going strong..... [don't want to jinx myself]


Good Job !!!!

:) AL

[Rob Mulgrew]

The wood is select pine and perfectly square. I always select stay under rollers also. This is a new occurrence with every cutout for the past 5 signs. Is there anything I can do to check roller before having to replace?

[bergerud]

If you have sandpaper belts, check for belt roll under.
If you have rubber belts, check that the belt is not interfering with the brass roller.
Do you see the brass roller tracks on the board?
Check the head pressure.
Check out feed rollers too high.

[Rob Mulgrew]

Sandpaper belts are fine...Yes, you can see the tracks on the board and there are no areas that the board left contact with the roller...Head pressure is good...feed rollers don't actually touch the board, they sit a bit low but the board is only 24" long and not heavy.
I'm not sure where to go from here. I can carve fine but cannot cut anything out?
If you have sandpaper belts, check for belt roll under.
If you have rubber belts, check that the belt is not interfering with the brass roller.
Do you see the brass roller tracks on the board?
Check the head pressure.
Check out feed rollers too high.

[fwharris]

What version of software are you running?

[chief2007]

I just recently started having this problem but only when doing cutouts. The cut path shifts on every pass a little further. Do you guys think the "too much play in the plastic gear" would be causing my problem too? I have 320 hrs on my machine.
661566615766158

Check your y bearings - they should be changed around 250 hrs. If your bearings are going bad, the stress from a cutout can cause shifting/slippage and throw the cut off.

Happen to me once.

[Rob Mulgrew]

Version 1.187

What version of software are you running?

[Rob Mulgrew]

I changed them recently. I will recheck them tomorrow. That would be nice if that's all it was, they are easy to change and I bought a bunch of extras.
Check your y bearings - they should be changed around 250 hrs. If your bearings are going bad, the stress from a cutout can cause shifting/slippage and throw the cut off.

Happen to me once.

[DickB]

I would check the x encoder for dust. On a carve the board moves in increments in one direction and a misfire might not be noticable. Not so on a cutout.

[Rob Mulgrew]

Is the x encoder underneath the machine on the back of the motor? I'm not familiar with it.
I would check the x encoder for dust. On a carve the board moves in increments in one direction and a misfire might not be noticable. Not so on a cutout.

[bergerud]

Do you have dust collection? I would next look at the x gears. There may be a tooth missing. The belts and their bearings may be fouled up with dust. Roll the x gears by hand and see how hard the belts are to turn. Look for a sources of resistance to belt movement.

[DickB]

Is the x encoder underneath the machine on the back of the motor? I'm not familiar with it.It's part of the board tracking sensor: http://www.carvewright.com/assets/service/Service_instructions/CarveWright_service_replace_board_tracking_sensor. pdf

[bergerud]

I thought you were talking about the x motor encoder as well.

[DickB]

I thought you were talking about the x motor encoder as well.I guess I was letting my own experience influence here. I would check the board tracking encoder first, then the motor encoder.

[Digitalwoodshop]

If you will indulge me on a suggestion... or not....

Rolled under Sand Paper Belts are very hard to see.... One suggestion and it is something I do all the time.... I turn off the machine and using a pair of needle nose pliers I puncture a hole in the sand paper belt under the cut motor on the keyboard side where the steel outfeed roller gap is for the out feed tray. I then rip off a 3/8 to 1/2 inch strip with the needle nose pliers pushing the belt toward the center of the machine and rip it off.... This will uncover a hiding rolled under belt and lower the board at the brass roller slightly to make better contact with the brass roller... It usually looses contace 3.5 inches from the end of the physical board when the board is possibly being held by less pressure due to only being under one roller or even the back or one of the in feed or out feed tables are set TOO HIGH.

Humor me... I know you did select to stay under the rollers.... What do you have to loose but a 1/2 inch of belt... The machine will work fine with the missing piece.... I rip EVERY belt as it creeps toward the brass roller... I always have a gap... I believe the belt creep is caused by me cutting more narrow boards like 6 inch and less 12 inch boards. This causes the belt to wear or get broken in and slightly bigger making a tapered cone from the belt.....

Good luck... I don't believe the brass encoder is at fault.

It won't hurt my feelings if you decide that the belt is not rolled under and not the problem... and dissreguard my suggestion....

Have a GREAT DAY... This is more for others doing a search in the future...

AL Who?

[bergerud]

I guess I was letting my own experience influence here. I would check the board tracking encoder first, then the motor encoder.

I just meat that I misinterpreted what you were saying. I do not think I have ever heard of the x motor encoder being a problem. The tracking encoder, however, has been.

[Rob Mulgrew]

I checked and double checked the sandpaper belts and they are 100% fine. The tracking sensor never leaves the board. The big plastic X drive gear may be causing the problem but I am not sure. When turning it back and forth by hand it will slip one or two teeth but the there are no teeth missing and they are not worn down. Maybe I should get another whole x drive assembly or somehow adjust this one to sit tighter against the shaft coming from the motor? Any other recommendations before ordering another one? Thanks for the help everyone

[fwharris]

It just might be a slip in the X drive motor. There is a small amount of adjustment in the X motor to insure it is mating up good to the drive gear.

The attached picture shows the most common gear that strips out. Make sure you inspect yours for any wear.

[bergerud]

I checked and double checked the sandpaper belts and they are 100% fine. The tracking sensor never leaves the board. The big plastic X drive gear may be causing the problem but I am not sure. When turning it back and forth by hand it will slip one or two teeth but the there are no teeth missing and they are not worn down. Maybe I should get another whole x drive assembly or somehow adjust this one to sit tighter against the shaft coming from the motor? Any other recommendations before ordering another one? Thanks for the help everyone

Are you saying that the big, fine tooth gear is slipping on the small motor gear? Is the motor loose? There is not much there for adjustment. Maybe loosen all the relevant screws and retighten as you push the gears together.

[Digitalwoodshop]

Sounds like a broken off tooth is causing this.... A careful inspection of all gears is in order.... Or in your case a re check....

AL

[Rob Mulgrew]

Are you saying that the big, fine tooth gear is slipping on the small motor gear? Is the motor loose? Yes, the big fine tooth has a bit of a slip and no the motor is not loose. I took the x drive plate with the gears off for a closer inspection, there were no missing teeth and everything seemed fine but when I put it back in, it did the same thing. Would this small skip in this gear be the cause of this?
66222

[bergerud]

I would think it could certainly be the cause of your problems.

I cannot understand how it could be slipping. It does not seem possible on my machines. Is the bushing worn out? Is the gear plate a defective part? Just why are the gears not meshed close enough not to slip? You have to dig deeper and find out why.

[Digitalwoodshop]

Since the Gears checked out OK... Then we are back to the board loosing contact with the Brass Roller..... The Ripping of the Sand Paper Belt is in order... I know you are dissmissing this as a problem... BUT... from the years of use and if you look at the various dates on all the pictures I posted.... I have been down this road a few times... It was not until I ripped my first belt that looked GOOD... that I saw the Rolled Under part at the Brass Roller.... And know that "IF" the belt is in fact rolled under.... That at some time the rolled under belt will jam in the sand paper guide and cause the X Gears to SNAP... Yes, more than one Snapped Gear shown in the pictures were the result of a jammed rolled under belt.... I has been a very long time since I have seen a broken gear... Mostly since I now rip the belts... And know that the Rolled Under Belt is lifting the board UP by the thickness of the Paper folded over and that is why the cut is OFF JUST LIKE MY CLOCK PICTURE..... I have been their... and done that....

I will quit harping about this.... I will watch to hear the resut of finding the actual problem....

And to review.... Things to check...

Sand Paper Belt Rolled Under.

Little Rubber spacer UNDER the Brass Roller was sucked up by a vacuum.

Board Project designed with the BOARD only being held under ONE roller at ONE or BOTH ends of the project and failure to support the board and letting it tip UP a fraction of a inch and loose contact with the brass roller by 1/4 inch in X.... THREE OR FOUR Times.....

HIGH In or Out Feed table..

OK... OFF my Soap Box... I will check back in a dozen more posts of things to check by other users and see if it is fixed....

AL

[Rob Mulgrew]

Sorry it took so long but just wanted to give a quick update. There were a couple teeth on the shaft of the x motor that were worn and only when under pressure would slip. By loosening the motor screws & pushing the motor tight against the x gear, then retightening I have been able to keep on using my machine without anymore trouble but I did order a new x motor and x drive plate which I just got and will put on after this gives out again. Thanks for all the recommendations.

[bergerud]

Thanks for the update. Interesting problem. Glad you got it figured out.