Carving past edge of the mpc

[easybuilt]

This is the second sign I've carved a sign this size this weekend and I keep getting clean "Y" rails. I know it is because the bit is going beyond the carved area. As you can see from the notches it does it irregular and goes for a while correctly. I have a dc attached and have been been blowing the cw out. The board is a all one width and even. Any ideas what I need to adjust to stop this from happening. This is the bottom half of two signs.
Thanks for your help.

[AskBud]

Did you use an actual board wider than the design? You need to provide a top rail for the rollers to ride on. When you get to the option about scaling, select NO, and center on board. This will give you a rail that you may remove after the carve completes.

This is my first impression.
AskBud

[easybuilt]

Did you use an actual board wider than the design? You need to provide a top rail for the rollers to ride on. When you get to the option about scaling, select NO, and center on board. This will give you a rail that you may remove after the carve completes.

This is my first impression.
AskBud
The board is 14 5/8" and yes there is a rail on the keyboard side.

[AskBud]

1) Does the actual carve leave a rail on the keyboard side?
2) Did you select Center?
3) If #1 is no and #2 is yes, you may just need to rotate your text, and force/add a top rail to your design by moving the carve area away from the top
4) Since I now know the your error was the "Y" axis, depending upon the answers to #'s 1 & 2, you may just have something impeding that travel.
Page 51 of the TSG may point you to what is holding the Y-axis hostage (sawdust in the track, frozen bearings, wire out of place on non-keyboard side).
http://www.carvewright.com/2010CWweb/service/Maintenence/Troubleshooting_Guide.pdf
AskBud

[easybuilt]

1) Does the actual carve leave a rail on the keyboard side?
2) Did you select Center?
3) If #1 is no and #2 is yes, you may just need to rotate your text, and force/add a top rail to your design by moving the carve area away from the top
4) Since I now know the your error was the "Y" axis, depending upon the answers to #'s 1 & 2, you may just have something impeding that travel.
Page 51 of the TSG may point you to what is holding the Y-axis hostage (sawdust in the track, frozen bearings, wire out of place on non-keyboard side).
http://www.carvewright.com/2010CWweb/service/Maintenence/Troubleshooting_Guide.pdf
AskBud
Thank you!
1. yes
2. yes
I looks like the bit is going too far which is causing the stall.
I will check the line of travel tomorrow.
Here is a picture of part of the top board and the wide side is by the keyboard.
Thanks again for your help.

[Digitalwoodshop]

I am a bit confused looking at your latest Picture..... Looks like error in the Y left to right AND X board Length....

I think the main problem is the pressure to hold the board down on the brass roller..... I think you bit off a little more than you can chew.... And the board does not have a good enough left and right in the X or board length area to keep enough pressure down on the board letting it lift off the Brass Roller.....

And before I would have started this very ambitious project, I would have inspected the Y inner Gear Box Bearings..... A Worn Bearing with this much of a Work Load can be causing the Y to loose Steps... And since you did not say you got a Y Stall until the End I would guess then the Bearings would be the most likely cause.... Because the Encoder Was HAPPY.... The Belt will NEVER Slip with the big teeth..... But with the Big Plastic Gear bent over you may hear clicking especially when the head is at the Bit Flag....

I think the Weight of the Board is a small factor.... I saw you did a .25 deep Carve Region.... I would do something less.... When it is painted you still see the shadow Lines....

Another Thought is to use the 1/16 inch carving bit in a vector mode or assign a 1/16 bull nose bit... And Outline all the letters on the main board. Then make a 2nd project and Cut Out the letters with a Trace and Cut Path.... Keeping the Grain the same.... Then Attaching the letters to the sign board.... CRACKING of the cut out letters will be an issue as the main board expands and contracts..... IF this is going to be all painted.... PVC Board might be an option.... For a 18 foot long x 11.25 wide, 3/4 thick will set you back a Hundred Bucks... But you could cut out the PVC Letters and attach them....

A Sign like you are doing could be sand blasted... Apply the Sand Blast Resist Film and outline the letters and weed the carve region areas..... Hitting it with Crushed Walnuts would work....

WOW... It must be the Fumes.... This is a Off the Wall Post.... Well, it is almost 2 AM... Just finished...

I would say to try it with 5/4 Stock or real 1 inch thick... But the Weight.... I would inspect the belts for a Roll Under too.... And like I said the Y Gear Box too....

Good Luck,

AL

[liquidguitars]

You need to provide a top rail for the rollers to ride on.




yes I agree , I think you need more even roller contact on the board... according to your MPC your 14" wide so if you use a 14.5" you only have 1/2 to work with, better to have 1/2 on eace side if you can....

I also concur with Al on the plastic y and x gear rebuild and dirt in the race like Bud said.

as a side note, if you run the 3/16" mill bit you will cut the carving time down from (7:39:17) to (3:47:22) that a huge saving!

50105

[bergerud]

I agree that no front roller support is not good, but, I cannot see how it could have anything to do with the problem of the y overshooting the edge. It looks to me like something responsible for holding the bit is loose. (not a bad QC is it?) Check the truck for slop. Maybe one of the bearing eccentrics is rotating.

[AskBud]

Let's all remember that Tom's first post said "Carving past edge of the mpc
This is the second sign I've carved a sign this size this weekend and I keep getting clean "Y" rails."

This would indicate that the machine senses a problem with the truck travel.
AskBud

[easybuilt]

Thank you everyone one for you suggestions and advise! I am going to check and clean the Y motor bearings and encoder. I have spare bearings on hand from Al's suggestion. I am going to try a test board at 14.5" as Askbub thought with a 1" rail on both sides too. The bit was not loose because I checked that and I have the rock.
I will let you know what I find out.

[Digitalwoodshop]

A frozen Y Rail Bearing can cause this too......

AL