Router hovers over half of project

[Rogue Booger]

Hello all. I'm banging my head on my desk over this sign, so I'm asking for some help. I created this sign from a JPG imported into VCarve Pro 6.5. I've attached pictures & files from the project. I can't figure out why the router does some of the carving but not all. Have a look at the pictures I've attached. The first is a copy of the tool path after the software calculates it. The second is the resulting carving on a test piece. Why isn't the unit carving everything? I've triple checked the XYZ zero before I start, but the router just cuts then hovers. Cuts then hovers.

I'm sure it's right in front of me, but after 8 hours trying to figure it out I'm asking the experts.

Thanks for your help

[FixitMike]

When the file is through running, is 0,0,0 still at the same place? If not, it means the zero has been lost.

Two possible reasons: First, is the gantry trying to move beyond its normal limits? This is accompanied by banging noises as it tries to move beyond its travel range. The second is that one or more of the set screws on the stepping motor couplings are not tight. The set screw has to also land on the flat on the shaft.

To check the Y axis set screws, loosen the 2 bolts that hold one of center table extrusions, and slide the extrusion away from the end with the motor. Unbolt the motor and slide the motor, screw, and gantry in the -Y direction so the coupling comes out and is accessible.

[fison]

You also might try posting the CRV and TAP files to see if there's a problem there.

[Eagle55]

The first of the two answers is what I would guess the problem to be. I had my gantry hardware mounted in the top three holes (highest position) that it could go in. After having almost identical results, I moved it down to the lowest position. I lost a little bit of hiegth range on the thickness of objects that could be carved but eliminated the problem of the "changing Z-Axis Zero" that was resulting from telling it to go past its Z limit thereby forcing a new zero for the machine that would not allow the machine to do its work. It was the only times that I felt I wasn't in tune with the machine and it drove me crazy until I realized what was going on.

Roger

[Rogue Booger]

Thank you, thank you for taking the time to reply. It's 0630 and I will check the gantry over carefully after some breakfast and ibuprofen.

The project is not going out side of the work area left & right or backwards, it just seems to have an error up & down. (It's too early for X.Y.Z for me) The router is definitely following the pattern, it's just not dropping down to carve.

I've attached the .crv & .tap files.

Many thanks again

P.S. - .tap file is not allowed here . . . dang. I also tried the file sharing section but I don't see a way to upload a .tap file. Any suggestions?

[Eagle55]

The CRV file looks good but from what I see, I believe the Z-axis travel is bottoming out when it gets over to the hair on the back of the man's head and changing your zero. One way you can confirm the problem of z-axis zero being changed is to run the file till the problems has obviously happened, then stop the program and hit the button to go to xyz 0. I bet you will be 1/8"-1/4" higher than you originally set it. To further test it, try to run the router bit a little ways down in the collet (out of the router) if you have enough travel to still hold the bit tightly and see if it is better. (may still not be correct though, but will do better) Solution is going to be to lower the gantry mounting at least one hole and better for 2 holes lower. I took mine all the way down, opting for the most stable and lowest position thinking it might make the gantry more firm, not having it up inn the air as much. You may give up an inch or so of working height but I'm not doing anything that thick anyway.

[Rogue Booger]

The CRV file looks good but from what I see, I believe the Z-axis travel is bottoming out when it gets over to the hair on the back of the man's head and changing your zero. One way you can confirm the problem of z-axis zero being changed is to run the file till the problems has obviously happened, then stop the program and hit the button to go to xyz 0. I bet you will be 1/8"-1/4" higher than you originally set it. To further test it, try to run the router bit a little ways down in the collet (out of the router) if you have enough travel to still hold the bit tightly and see if it is better. (may still not be correct though, but will do better) Solution is going to be to lower the gantry mounting at least one hole and better for 2 holes lower. I took mine all the way down, opting for the most stable and lowest position thinking it might make the gantry more firm, not having it up inn the air as much. You may give up an inch or so of working height but I'm not doing anything that thick anyway.

Thanks Eagle, I'll try that. If your theory is correct, if I edit the hair by hollowing it out so that it's just the outline of his hair, might that correct the problem?

[Eagle55]

No, thats not what I am saying at all. The whole point is that your router bit is not able to go down as low towards the bed as it needs to. The way to correct it is to lower the gantry in the mounting holes on each side to give the bit the Z-axis range to go into the wood as much as you have designed it to go. I guess theoretically you could modify your project and may be able to get it to work this time, but you are going to see this problem again, (in my opinion) on another project... possibly your very next one. To test my theory and demonstrate the need to lower the gantry, you can extend the bit out of the collet approx 1/4" if you have that much router bit shaft to still be able to hold it. If this makes the project cut better (even if its not right), I think you should lower the gantry via the mounting holes at least a couple of screw holes.

Roger

[jeb2cav]

The other thing you could try to see is set a blank piece of material underneath your current 'scrap' or 'test' piece, then clamp it down. You'd achieve the same thing as lowering the gantry. If that 'works' - and I agree with Roger that this is what is going on - then you can decide how you want to approach this.

In my case, I rarely need more than 3" clearance, and have mounted the gantry in the lowest possible position. I've also found that my v-carving is 'cleaner' or sharper in this position than it is in the 'higher' position. I'm on a ProPlus.