# Moulding Toolpaths



## tuffduck (Jun 24, 2021)

Hello,
Does anybody have any experience making mouldings and trim longer than your machine using the Vectric moulding toolpath function? I have made a few test runs and I always wind up with a step where the two parts overlap. What am I doing wrong? I have made sure the material is consistent, the table has been surfaced and the jigging has been machined to ensure it is parallel with the axis. Thanks in advance for any help.


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## old55 (Aug 11, 2013)

Welcome to the forum.


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## Jacky (Jun 21, 2021)

Maybe we can further discuss


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## tuffduck (Jun 24, 2021)

Thanks for the welcome. Any help would be great.


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## TimPa (Jan 4, 2011)

can you show a picture of it? how big/deep is the step? is it consistent or repeatable? are you using the same toolpath for both cuts, bit direction? have you checked for play in the x and y axis movement? things may need tightened up... my guess is that the wood is moving, either at the end of the first cut or beginning of the next... 

you may consider using lead-ins and lead-outs to smooth them out. or, if the step is repeatable, compensate for it by offsetting the wood by the step amount in the other direction.


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## tuffduck (Jun 24, 2021)

It doesn't seem to be repeatable. The same tool path was used for both cuts. There is no play in any of the axis. The wood didn't move the ends were clamped and the centre glued to the spoilboard.


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## TimPa (Jan 4, 2011)

tuff, how are you registering the wood for the second cut, or follow on cut? the wood which has been machined, appears to have rough edges. and it is fairly important to have some way to register or align the wood in order for the second cut to be accurate. typically it is done with pins in the table, a laser, or a cleat screwed to the table, something like that. you could probably even draw a (very accurate) line on the table to align an edge to...


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## tuffduck (Jun 24, 2021)

The reference edge of the board was planed on a jointer. The stick was much longer and I ran tests on both sides, that is why the edges are messed up. A 30" long cleat was fasten to the spoilboard and the I routed along that edge on the cnc to ensure it was parallel to the axis.


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## 4DThinker (Feb 16, 2014)

What bit did you use? I'd suspect a loose collet. I've seen collets get jammed with sawdust and prevent a bit from being clamped in tight. Upcut or downcut spiral bits can be moved, particularly in hardwoods. The move in the collet can be a small amount over time, which means when you restart a job cut depth can be different between the jobs, showing up as a step between them in your situation. The only other situation where I've seen that happen was when the wood bowed up after material was removed and as such the following cut left a a step between them. 
4D


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## tuffduck (Jun 24, 2021)

4DThinker said:


> What bit did you use? I'd suspect a loose collet. I've seen collets get jammed with sawdust and prevent a bit from being clamped in tight. Upcut or downcut spiral bits can be moved, particularly in hardwoods. The move in the collet can be a small amount over time, which means when you restart a job cut depth can be different between the jobs, showing up as a step between them in your situation. The only other situation where I've seen that happen was when the wood bowed up after material was removed and as such the following cut left a a step between them.
> 4D


Hello, I used a 1/4" ballnose bit. The collets are cleaned with a brush between each tool change and replaced after I see signs of wear or slippage. The wood was glued the spoilboard with 
3M Super 77 Multi Purpose Spray where I can clamp and screwed down where I can.


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## 4DThinker (Feb 16, 2014)

If your spoilboard is MDF and the project board is hardwood then the hardwood may have warped the MDF if it was fully held down to it. I've had this very same happen a few times with hardwood on my MDF spoil board with t-tracks every 4". I finally gave up on MDF and now use BB plywood t-shaped bridges that span my CNC frame rails to clamp projects to: 








CNC Frame Bridges as an Alternative to T-Track rows or Vacuum Beds.


I previously made a couple of frame bridges to support an assembled student project for some CNC joinery cuts. Lately I've been using the br...




4dfurniture.blogspot.com


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## tuffduck (Jun 24, 2021)

That is an interesting concept, I will give it a try. Thanks for the tip.


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## gwilki (Nov 12, 2012)

I do a lot of "tiled" toolpaths using Vectric and any screw ups have been a misalignment in either X or Y .From the pics, it looks like Z0 has changed from one cut to another. Am I seeing this right?


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## tuffduck (Jun 24, 2021)

Yes, you are seeing it right.


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## DsKnees (Mar 4, 2021)

tuffduck said:


> Hello,
> Does anybody have any experience making mouldings and trim longer than your machine using the Vectric moulding toolpath function? I have made a few test runs and I always wind up with a step where the two parts overlap. What am I doing wrong? I have made sure the material is consistent, the table has been surfaced and the jigging has been machined to ensure it is parallel with the axis. Thanks in advance for any help.


That is a curious problem. Can you upload a picture of you setup? 

From your description it sounds like you thought of everything, but from the photo it is clear that something is moving. One photo is off in the X(?) axis, and the other is off in the Z axis. (I assume the material is oriented along the Y axis.)

From this first description, I assumed the step you found was a few thousandths. But in the photo it seems to be nearly the diameter of the cutter, which I believe you said is 1/4". That's a lot! 

It seems to me that there's something about what you're doing that is different that what we are expecting. What you are doing should work without any issue, so there must be some variable in the works that we aren't expecting. The photo of the problem seems to contradict what you are explaining, so I'm a little confused. 

But a photo that shows the big picture, the router, the fixture, and the stock, that will likely go a long way toward getting an answer to what is going on.


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## tuffduck (Jun 24, 2021)

I went over all of the bearing blocks, ball screws, guide bearings, etc. Everything is tight. 
The part is machined out of the centre. The piece is oversized.


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## DsKnees (Mar 4, 2021)

tuffduck said:


> I went over all of the bearing blocks, ball screws, guide bearings, etc. Everything is tight.
> The part is machined out of the centre. The piece is oversized.


It sounded like you knew what you were talking about, and it sure looks like you know what you're doing. And I'm sure there isn't a mechanical issue at play that could explain the issue...so it must be something in the software.

Is VCarve trying to cut your desired profile in 2 passes? Maybe an oddball thought, but....if you repositioned the work piece inbetween the first and second passes, that would explain the photos you posted. It seems unlikely, but I suppose it could happen.

I don't have all that much experience with VCarve, but I have seen it default to multiple shallow passes when a single pass is perfectly adequate.. Like I was cutting out some 1/2" plywood, and VCarve's default setting was like 5 passes. I manually changed it to a single pass. The multiple passes was probably due to a setting in the tool setup.

Beyond that, maybe I could set up a similar project and see what VCarve does? I'm curious, because this kind of operation should just work.


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## 4DThinker (Feb 16, 2014)

In a tiling job with varying results sometimes changing your typical strategy is required. For example I don't know where you zeroed the job, or if each tile you reset Z before starting it. The seam between tiles is where I'd zero each half. Reset Z at seam at the beginning of each tile job. Then at least that point should have a clean transition with no unexpected step. It sounds like you've checked all the other possible variables. 
4D


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## tuffduck (Jun 24, 2021)

Here is program I used.








File on MEGA







mega.nz


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## DsKnees (Mar 4, 2021)

tuffduck said:


> Here is program I used.
> 
> 
> 
> ...


Are you using Aspire? My VCarve Pro (10.5) doesn't recognize the *.crv3d file. I tried changing the extension to *.crv, and got the warning "this program can't open Aspire files." Rhino doesn't recognize it either.

Have you tried to repeat the program a couple times without advancing the work piece? That is a troubleshooting step to isolate variables. If a second and third pass just touches the work piece, then the program is running correctly. But if there is a problem with the program itself, I expect you'll see it right away.


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## tuffduck (Jun 24, 2021)

Try this one. I saved it as a Vcarve file. Yes, I use Aspire.








33.5 KB file on MEGA







mega.nz





I haven't tried running the the program without advancing the piece yet to see if it changes.


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## tuffduck (Jun 24, 2021)

Here is the first try after I install a new control board.


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## dovetail_65 (Jan 22, 2008)

Have you tested the profile using MDF or plastic to ensure its not the wood itself I never test stuff like this using wood.


The file opens perfectly for me and actually cuts perfectly so you have some type of alignment issue as you are resetting the material.


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## tuffduck (Jun 24, 2021)

Thanks for testing it for me. I will check my alignment and try some MDF or acrylic.


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## dovetail_65 (Jan 22, 2008)

tuffduck said:


> Thanks for testing it for me. I will check my alignment and try some MDF or acrylic.


You might want to zero off the spoil board, I used the material top and generally do because I do pockets in a lot of my work. I used MDF for your test and I find it to be very consistent in its thickness so using the top worked fine.

It seems to me if you are using hardwood and you didn't plane this wood yourself and are using material top as a reference that may cause the Z part of the error I think I am seeing in your piece. When tiling and if one end is different in thickness even a little bit and referencing off the top the molding profile may not match at the tiling seam.

Even when I plane my own wood especially in summer sometimes the thickness can vary by several thousandths or more within a only a few hours even. Check the thickness in many areas with a caliper in any case.


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## tuffduck (Jun 24, 2021)

Okay, thanks.


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## DsKnees (Mar 4, 2021)

tuffduck said:


> Here is the first try after I install a new control board.


I also tried it, and it worked fine for me. In the photos below, I used MDF, and I'm using the vacuum table on my machine. The ligher color piece is standard chip board, and I cut a straight edge in it for the test. And it's also just held by vacuum since it is a quick test.











Close up of the overlap. Texture is slightly different, but the program is repeating ok.










Here is my first try. I just clamped a pine 2x4 to the machine. It was definitely twisted and not at all flat. The nail holes just add character. 

I think this looks more similar to what you ended up with? In your last image, the mis-alignment between passes isn't consistent across the profile, so the twisted lumber suggestion seems plausible. 











An an unrelated note, is you machine capable of running faster speeds? The program was set to run 80ipm, and it kind of looks like there are burn marks where the passes overlap. I ran my test at 300ipm. 

It looks like you have a pretty stout machine. It looks like a ShopSabre, right? And it has a spindle...in the photo it looks a bit bigger than my machine. So I am assuming you can cut faster than 80ipm. I don't want to give bad advice, but just something to think about.


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## tuffduck (Jun 24, 2021)

Thanks for running tests for me. My machine is similar to a ShopSabre and I can run it at a faster feed rate. It has a 48" x 40" workspace.


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## wyzarddoc (Dec 31, 2006)

It might be the Vectrics generated G-code file. I have had problems with Cut-3D not registering correctly when my work piece was rotated 90 degrees to cut the next side, eventhough I put the correct diminsions in the work setup screen. Are you running the same G-code file and just manually indexing the work piece and restarting the G-code or are you running tiled G-code files with stops / pauses inserted? Also are you re-zeroing the axis after each section is completed? Check your G-code file and see if any of the statements have changed value from one pass to another. If not then you may be experiencing stepper missed steps due to speed or bit loading. In addition you might have a cumulative missed step error. I am considering setting up a fixed tool zero position on my table and rewriting my post processor so that zero will be checked multiple times during a run. I have Vcarve Pro 10 and things seem more stable than previous versions. You might also use a permanent marker and place a mark on the tool shaft to see if the bit is moving up in the collet. Place a small dot on one side of the shaft before beginning the cut and then a 2nd dot after the 1st pass. Take the bit out and both marks should be the same. I am running Mach3 cam with a Ethernet smooth stepper so it maybe the cause of my misalignment./ missed steps. I have had problems with multiple piece runs when I restart the G-code file from the "finished" home position without re-zeroing the axis.
hope this helps


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## tuffduck (Jun 24, 2021)

Thanks for the tips.


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## ger21 (Feb 10, 2019)

The simple answer is that what you want to do is very difficult to pull off.
Your best bet would be to drill some registration dowel holes in the back side for alignment. But how do you drill the alignment holes in perfect alignment? No simple answer.


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## tuffduck (Jun 24, 2021)

Well, I got it.


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## wyzarddoc (Dec 31, 2006)

I like it!!! Low ceilings or tall light switch?


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## tuffduck (Jun 24, 2021)

Thanks. It is part of a basement reno. Transition piece between the drywall and the brick.


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