Issues with carving, need a little help

[dover-sherborn]

Hello boys and girls,

I am having an issue and I am certain I have seen the fix on the forum but just cant seem to figure out what to search for to find the solution.

Basicly I am in the middle of carving the wooden gear clock project and on one of the files, the clock parts MPC, my carving is going sideways. I just put in a new Y axis motor and all the cut outs have been perfect, but the carving is stepping torward the keypad with each pass. I have run the file on my second machine and it ran perfect, so I know the card and MPC are fine.

Any Ideas?

thanks

Nick

[Kenm810]

Did you happen to check the tension screw for the "Y" belt,
mine was silpping a little after I serviced the "Y" motor and drive gears.

[dover-sherborn]

I have the tension screw all the way in and the top screw tight, I thought the same. Its odd because I cut out all the gears last night with no issues, now that Im carving its moving over with each pass, it actually made the clock face look like its melting, kinda neat but not the look im after. thanks for the thought

Nick

[Kenm810]

A little Salvador Dali-ish, but like you said fluid time is not what your looking for,
With the machine off slowly move the truck along the "Y" rail -- noting or observing
any drag or hic-ups as you make a few passes back and forth caused by chips or dust and lube build up.
I could hear mine lightly clicking as the belt slipped along the gears.

[dover-sherborn]

I took the Y motor out and took the belt off and cleaned it up, nothing out of the norm. the rails are clean and the belt is nopw good, still having the same issue, just slowly shifting the carve, but not the cutting. Anyone else have any thoughts

Thanks

Nick

[DocWheeler]

Nick,

Are you saying that after the carve has drifted that the cut-out happens in the right place?

Another question that I had, do you hear a "click" when the carve shifts?

In accordance with KenM's post about the machine screws holding the back "Y" belt tensioning pulley - did you tighten the top one last?

[Digitalwoodshop]

Just to recap....

Clicking is caused by 4 things... First is the two 5 x 11 x 5 mm bearings in the Y Gear Box are worn out and the big plastic gear is tilting away toward the center of the machine. They go bad about 450 cut motor hours... When worn too bad they grind the big gear shaft thin... Then you can buy just the shaft and gear from LHR.

The second is that the screw in the picture above holding the wire cover on the cut motor it tight before the smack has been removed by the spring screw.

Look for a frozen Y Rail Bearing by marking all the bearings with a marker. A frozen bearing will drag and slide in one direction but jam in the other direction causing the clicking.

This problem can also happen when the Y Encoder is DIRTY.... See my picture with the sawdust inside the Encoder...

AL

[DocWheeler]

Al,

The "click" that I was referring to was the "Y" belt jumping a cog, usually because of too much slack in the belt.
I was concerned that he might have positioned the "Y" belt idler using/tightening the top screw before tightening the back screw.

[dover-sherborn]

Not hearing any clicking. brand new Y motor, under twenty hours on it, didnt check the encoder, but the back is now clear on the motors and it looks clean ( nice new feature). The Y belt is not jumping, that is new also, but it does seem to have a little hold up during side to side motion with the machine off. It almost feels like it happenes with each rotation of the Y motor, the distance between sticky spots is to great for it to be the pulley.

back to the search, thanks for the ideas


Nick

[Digitalwoodshop]

Thought I posted this earlier today... But the Encoder Plug or Jack has solder joints and sometimes the plug is not seated all the way when soldered and then when the plug with wires is pushed in the jack, the solder joints snap on the underside of the circuit board at the hole and the lead. This causes missed pulses or stalls...

Can you swap the motor with another machine or swap the Z and Y Motor.... With the Y Motor going into the Z Spot with the Gear Box not having the hole on top.... Just for the test, manually tension the Z as you tighten it... Same as the top screw and spring would do...

We are trying to move the symptom to another Axis... This is called Half Splitting the Troubleshooting.... Or in Layman's Terms... A WAG.... Wild AL Guess....

I will throw this in just as a EVEN WILDER GUESS.... IF anyone from a Curious LHR Tech or the machine owner ever opens the Servo Motor and removes the Armature from the Permanent Magnet Stator then damage will result in the Ceramic Magnets loosing most of it's power.... In my Navy Servo Days we had a Magnetic Keeper metal device to keep the magnetic field as we serviced the servos. Newer Motors like this one are designed to be re magnetized after re assemble in a special jig. I posted this topic last year and gave all the Technical Links with Quotes from Techs saying that the Customer opened the Servo and made it useless..... So a Servo that has been opened MAY still work but at a very reduced force or power level....

AL

[unitedcases]

I had the clicking once, It was a dull bit. The bad thing about the 1/16th bit is that it is hard to clean out the flutes. I always use some oven cleaner after each carve however, that only works so much. I am a 100hr bit guy. Every hundred hours I install a new bit. Sounds funny and I know some of you guys can make them last forever, but I carve in nothing but red oak and deep. So for me that fixed the clicking. But I would also clean out the back of the encoder on the y motor. Also make sure you tighten the allen head on the y belt then tighten the top screw to anchor it down. Also every 250 hrs you should change out the y motor bushings, cut motor bushings, clean out both encoders and while you have it apart to do all that, really get down in the y rail and suck all that dust out. If that builds up too much then that will make your y belt drag. You would be surprised at how fast that fills up.

[earlyrider]

Check also the drag of the brass gear on the nylon gear. Its possible for the gears to be meshed so tight that when the belt is in place, the motor may tend to bog down; also, if the gears are meshed too loose, when the belt is under tension, the brass gear may slip. You said the Y motor was new, so the nylon gear shaft is probably fine.
ron

[dover-sherborn]

Thanks for the input, after taking off the Z truck, cleaning the rails, belt, bearings and changing the bit I got a carve to go ok. One strange issue was it gave a Y slip error when starting the carve. I hit ok and it ran perfect, and at the end while homing the truck came to far over and gave an axis stall error. Not a big deal as the carve was ok, but still need to do some more searching to see why the slip.

thanks for all the help, again you guys are all amazing.

Nick

[ktjwilliams]

Please check UR private message in box ....

[dover-sherborn]

4517745178ANy thoughts on what is causing this??? still cant find the issues

[AskBud]

4517745178ANy thoughts on what is causing this??? still cant find the issues
May we see the MPC?
Is your consern the rough places, or something else?
AskBud

[DickB]

I would think with that kind of drift it must be related to the encoder. Mine has a black opaque over - are you saying that your new motor has a clear cover, and you can see the encoder wheel through it? The one y slip error and y axis stall when homing that you reported are also clues pointing this way. It looks and sounds like the error is more prevalent when the y motion is longer and/or faster - is that the case?

[DickB]

May we see the MPC?
Is your consern the rough places, or something else?
AskBud

The mpc is from the Naked Clock project in the store - you can download and take a look if you like. The issue is that the larger circular item - the base - is supposed to be a circle. It looks like the truck is drifting off track as the carve progresses.

[dover-sherborn]

Thats correct, its the naked clock project so I can not post the MPC. The shape carved is not a circle as it should be. This is the first project since replacing the Y axis motor. The encoder case is now a clear plasic so we can see if any dust has gotten inside the case, and it looks clean. Could it be I have a bad Y axis motor??? does anyone know if LHR backs the motors, as Ive said I hacve about twenty hours on it, all of them have been trying to solve this issue.

thanks again

Nick

[DickB]

So it sounds like the problem started after you installed the new motor? I would suspect the motor, encoder, or related electrical connection. I wonder if the encoder wheel itself can be slipping? I think someone posted about swapping y and z motors for diagnostic purposes, to see if the problem would follow the motor. But I don't know for sure and don't know how involved this would be.

[dover-sherborn]

So here is the update and it does not look good for me..... I tried to run the project on two different memory cards, same issue, the carving slowly shifts torward the keyboard. I then took the new Y motor out and put it in my second machine, and ran the project twice, once off each card and it carved perfect. SO memory cards are fine, and so is the new Y motor. SO at this point my machine continues to carve sideways and its not the card, motor, belt, pulley, no slipping, what else could cause this???? also the machine hits the end of the track at homing and gets a stall when I hit stop, so the machine is lossing track of where it is I assume.

any help would be great guys, its the end of the school year and I have a few projects left to run for the kiddos

thanks so much
Nick

[Digitalwoodshop]

Swap the computer from machine to machine..... Yes, there could be a slight difference due to calibration.... But for the test, it will half split the problem.... wiring / power supply or Computer.... I would put the Good Computer in the Bad Machine...

AL

[dover-sherborn]

Al,

thanks for the fast response. I just ran a few more test and found that both centerline and cutting features work perfect. they go straight and look great. beofre I swap computers, which im assuming is timely do you think this proves not wiring and power supply issues? any idea what a computer cost ?

thanks
Nick

[unitedcases]

Computer is 300 with a 100 rebate if you send the bad one back in. 12 for shipping of course.

[dover-sherborn]

hmmmm thats a bit of coin.... thanks