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unitedcases
09-18-2014, 05:35 PM
So machine #2 has decided to give me fits. I went to carve a litho pane and I got a good long you click when it made its first pass. I realized I was about 7 hours over on my pm. I do them every 150. So I did a pm and changed to a new bit like I do with every pm. Changed y bearings and brushes too and lubed as usual. The next day started another carve and got the click again. Found teeth missing from the y belt so changed that out and restarted. Carves for about an hour then the depth goes nuts. The z axis. So took the encoder cap off and found no dust however found that the wheel was easily moved back and forth on the shaft. I have seen this before. So I epoxied it. Let it dry overnight. Today, go to do another carve. It goes thru the motions. When it gets to the bit check it hits the flag twice and instead of coming up it stops and says it has a z belt slip. I have it apart again and checked the belt and the cogs for the motor and the bottom that the z belt hooks to and can't find anything wrong with it. Guys and gals, I thought I had seen it all. I am stumped.

gashawk
09-18-2014, 06:15 PM
I have tore the z belt letting slack in the z travel.

unitedcases
09-18-2014, 06:31 PM
I have tore the z belt letting slack in the z travel.
Z belt is good.

fwharris
09-18-2014, 07:02 PM
A first as far as I know! I would check the Z motor bearings, how the Z motor mounts in the gear box, Z gear and bottom gear and Z motor mount tension.

Digitalwoodshop
09-18-2014, 07:20 PM
In Navy Repair Lingo.... "Go where sailors have been" Any chance the epoxy fix is hitting the dust cap on the encoder?

I did get the Z Belt Slip for the first time ever and it was a stray piece of plastic stuck to the Roller Rail Bearing in MY case... Never happened again... I am cutting a lot of plastic...

bergerud
09-18-2014, 08:06 PM
I assume you formatted and reflashed the card.

If the encoder disc was loose, was the plastic cracked?

unitedcases
09-18-2014, 08:08 PM
Everything looks good. I wonder if the encoder part is bad? There really isn't a lot to look at but I really don't want to change a bunch of parts. I would like to know what actually fixes it.

unitedcases
09-19-2014, 10:28 AM
Wanted to see if anyone else is thinking the same way I am. Is it possible the shaft has come loose inside the motor? So maybe the best thing to do is change the motor itself and see what happens. With the erratic behavior that seems logical. But if that doesn't work then what? Just thinking out loud.

fwharris
09-19-2014, 10:32 AM
Since you stated that you had to re glue the disc I would do a swap out of the motor.

unitedcases
09-19-2014, 12:27 PM
That's what I needed Floyd. A +1 to what I was thinking. I think I will. Thank goodness for spare parts. And backup machines.

Digitalwoodshop
09-19-2014, 12:34 PM
I would replace the FFC Cable too first.... I did have a bad Z Servo Motor years ago, it did this ticking noise... swapped it out and all OK... Put it back just to see if it was a loose wire and back to ticking... Put a good one in. So don't discount a bad servo motor... I have yet to open one because doing so will kill the magnetic field... I am thinking it has brushes.... I didn't re read back all the posts so you may have already changed the FFC.

And I had a strange Z problem the other day.. It would not let me enter the manual board thickness .75 It would let me enter .60.... Then I saw it... The FLEX was hitting the cover slot messing up one of the touch readings... Has not happened again since I adjusted the cover. It got moved when I pushed the sliding plate over for a wide sled.

unitedcases
09-19-2014, 12:53 PM
A good thought AL. The ffc cable can definitely be the root of a lot of problems. To be honest I just hate replacing them. I take pretty good care to stay away from them whenever I have to get in. I think since I have the motor already out going to change it first then do a trial run. Then the ffc cable next. Just because I hate changing them. I'm always worried I'm going to mess them up but you could be dead on right. As usual...

Digitalwoodshop
09-19-2014, 01:06 PM
I make a mark on the old cable near the Z. Then remove and lay the new cable on top and make the folds and mark same spot. Then install it. I too hate doing them....

Might be the problem. I get lucky some times and others just plain wrong... :)

unitedcases
09-19-2014, 01:25 PM
I make a mark on the old cable near the Z. Then remove and lay the new cable on top and make the folds and mark same spot. Then install it. I too hate doing them....

Might be the problem. I get lucky some times and others just plain wrong... :)
I have a spare bad one I've kept in its harness. I use it as a guide.

Digitalwoodshop
09-19-2014, 01:51 PM
I have a spare bad one I've kept in its harness. I use it as a guide.

That is a great idea.... I dropped the plastic FFC Cable guide from the Z Motor end one time and was in a rush to get back to carving... Well, without that FFC cable guide to support the cable it drooped and snagged on the Y Motor cooling fins and ripped the cable out under power... Burned up a Z Motor.... I never left it off again..

AL

gashawk
09-19-2014, 02:49 PM
[/QUOTE][/QUOTE]

If you take FFC guide off and put the screw back in, It can rub the z truck. It impedes the travel of the z truck. On mine all I did was tear the ring washer on the guide, slowing the z truck.

unitedcases
09-20-2014, 06:37 AM
So, last night I spent a good bit of time rolling the backup into its place so I could fix this machine without having to rush. This morning, mind you I haven't even had my coffee yet. I find this. Appears to be a loose pin. Will put back together and do a test run.

http://tapatalk.imageshack.com/v2/14/09/20/f893dda475a4318956ada35a21ad3f56.jpg

unitedcases
09-20-2014, 08:18 AM
Ha! Silly me. I decided to forego the test run and just have at it. Confidence at its best. Back to a Y click. Fresh bearings and all. Just pm'ed it. Back to confused. I think I may change the bit just for curiositys sake.

unitedcases
09-20-2014, 09:59 AM
So here we go. I have no idea what fixed it but...I changed the bit and noticed the Y was a bit stiffer than I like it. Moving it back and forth I was actually able to lock it up. The non keypad side was fine but the motor side looked like I may have set the motor assy too low. In other words I think the outer shaft of the gear was rubbing the bottom of the U channel on the frame. Had to be. So anyway it's carving. So far so good.

Digitalwoodshop
09-20-2014, 11:01 AM
So here we go. I have no idea what fixed it but...I changed the bit and noticed the Y was a bit stiffer than I like it. Moving it back and forth I was actually able to lock it up. The non keypad side was fine but the motor side looked like I may have set the motor assy too low. In other words I think the outer shaft of the gear was rubbing the bottom of the U channel on the frame. Had to be. So anyway it's carving. So far so good.

Remember a worn thin Y gearbox shaft will let the big gear lean toward the center of the machine even with new bearings. I would find something to mark on the flat side of the big plastic gear. If the gear is white a black marker would work but if black harder to find something to mark the surface. You want something that will rub OFF when the plastic rubs against the U shaped channel. Use it as an indicator for troubleshooting. I like to install the Y flat to the surface of the U channel.

Also a frozen Y Bearing will sometimes slide in one direction and not in another and a dirty Y Rail can let it slide easy in a clean area and slide hard in a dirty area... I keep a tooth brush size brass wire brush near my machine and scrub the rails from time to time. Mark the bearings with a black marker to watch for sliding.

At least you are carving... Good Job !!!

AL

unitedcases
09-20-2014, 11:15 AM
Remember a worn thin Y gearbox shaft will let the big gear lean toward the center of the machine even with new bearings. I would find something to mark on the flat side of the big plastic gear. If the gear is white a black marker would work but if black harder to find something to mark the surface. You want something that will rub OFF when the plastic rubs against the U shaped channel. Use it as an indicator for troubleshooting. I like to install the Y flat to the surface of the U channel.

Also a frozen Y Bearing will sometimes slide in one direction and not in another and a dirty Y Rail can let it slide easy in a clean area and slide hard in a dirty area... I keep a tooth brush size brass wire brush near my machine and scrub the rails from time to time. Mark the bearings with a black marker to watch for sliding.

At least you are carving... Good Job !!!

AL
All bearings are good. I did double check that and when I adjusted I put the Y assy flat with the rail. No rubbing.

unitedcases
09-20-2014, 03:51 PM
That was it al. Remember the original post, the Y belt being stripped. It's cause it was hung up. Definitely feeling better about it now. 1 and 3 have been running all day with 11 hour carved while that one is on its 3rd carve of the day. Going to call it good for now.

Digitalwoodshop
09-20-2014, 04:25 PM
That was it al. Remember the original post, the Y belt being stripped. It's cause it was hung up. Definitely feeling better about it now. 1 and 3 have been running all day with 11 hour carved while that one is on its 3rd carve of the day. Going to call it good for now.

Good JOB.... Here is my project for today... Cutting the Red EARS off the boards to start installing the wood handles...:oops::shock::oops:

AL

PSQRD
09-23-2014, 08:17 PM
I know it's off topic but how do you like that saw Al? I've seen them at the stores but wasn't sure what to think - if it'd be worth the purchase or just a gimmick?