Messages

1

CamBam help (General usage) / Re: Ball Mill Advice

« on: December 17, 2025, 21:49:35 pm »

Progress: the attached photo shows the latest effort straight off the square-cut tool.

Some light work with files and cutting paper will provide a perfectly acceptable wheel.
Then mount on axle and shape the tread.

Stock 100 mm x 18 mm cast iron, 4 mm solid carbide end mill at 3000 RPM, 150 mm/min, 0.1 mm steps, 0.2 stepover etc.
About 4 hrs.

MOPs:
- drill Dia 12 mm centre of each pocket,
- profile pocket with 5 mm carbide end mill,
- rough spokes down to profile (hand code circles).
- waterline finish to half thickness.
- invert wheel to other side, repeat as appropriate.

Not a ball end-mill in sight !

Now to see if I can reduce the 4 hrs.


John

2

CamBam help (General usage) / Re: Errors in stl File - Mesh Correction Tool

« on: October 19, 2025, 10:05:55 am »

I am continuing the machining of the wheels, and getting numerous "open poly" messages.

Is it possible open polys are produced in CamBam when a tool path ( slice ?) passes through a poly in the stl mesh ?
And cuts one of the edges in a mesh triangular element ?

Just trying to understand if my source stl mesh actually has errors.

John.

3

CamBam help (General usage) / Re: Ball Mill Advice

« on: October 07, 2025, 21:47:49 pm »

Thanks Dave for those images and the CB file.

The way you added multiple polylines to guide multiple MOPs is just what I was heading towards.
Your example shows that this approach will work.

I am intrigued with the polylines following contour paths.
A ball-end mill following these polylines may give a perfectly acceptable result.
I will get some time soon to try some MOPs on cast iron test pieces.

How did you produce these contour polylines ?

John.

4

CamBam help (General usage) / Re: Ball Mill Advice

« on: October 06, 2025, 06:36:41 am »

I duplicated Dave's example, but with my tapered oval spoke, and a 5 mm ball-end tool.
Result was the excess "hip" in the machined curves,

Re-did with a 4 mm square end-mill, 0.1 depth step, and got a good approximation to the desired surface.
I think filing/emery paper will provide the correct shape.

Unfortunately, I have come to the same conclusion as Kelly, the Waterline Finish MOP with a ball-end mill has issues.
The Forum history has numerous discussions on problems with ball-end and Waterline Finish.

My understanding of the Documentation description of the ball-end algorithm almost guarantees incorrect machined surface for tapers like mine.

But, there is always another way !
I am exploring a mix of MOPs as suggested.
Drilling for chip evacuation, pocketing to get close, ball-end WLFinish to get all the fillets, and a final square end mill on just the linear part of the spokes.
The fillets only have to "look" nice,

I use LinuxCNC for the machining, and I have tested its co-ordinate rotation responses to be comfortable with its operation.
So that is simply a MOP subroutine called 8 times, the number of spokes, at 45 degree increments.

As a side note, if you search for a more general discussion of ball-end algorithms, you discover wide-ranging discussion for all the major machine and cam products.
CamBam is normal for the problem.

 John.

5

CamBam help (General usage) / Re: Ball Mill Advice

« on: October 02, 2025, 04:33:19 am »

Kelly, thanks for the comments.
I had seen some of your contributions and I was considering the possible use of Scanlines.
 
I am spending time reading documentation and searching old threads.

The problem undoubtedly is one of misapplication, so I am sure it will be solved.
There are so many variables and ways of approaching the problem, I just need to learn more.

Dave, thank you for the work you have done, it is a great example.

But, there is a fundamental difference to my job, the wheel spokes are tapered for both width and height.
I will duplicate your example with one tapered spoke as a test.

Don't worry, FreecAd and I are old friends (protagonists?) dealing with fillets.
And MeshLab and I are starting a great relationship, with Blender commenting from the side.

Thanks for showing the Camotics simulation with a ball-end cutter.
It prompted me to review the tool table in Camotics so that my future simulations will show the correct tip.

John.

6

CamBam help (General usage) / Re: Ball Mill Advice

« on: September 30, 2025, 22:04:09 pm »

Two tests:

1. Existing Spoke:
Spoke previously cut with 5 mm end mill Waterline Finish and Roughing Clearance 0.1 mm that gave a good profile.

Run with 5 mm Ball-end mill with Roughing Clearance = 0 mm.
The Ball-end mill barely touched the surface.
So, possibility is that the previous incorrect Roughing Clearance caused some errors.

2. New Spoke:
New stock with 6 mm end mill Waterline Rough, then 5 mm Ball-end mill Waterline Finish.
Roughing Clearance = 0.5 mm for WR and 0 mm for WF.

Same result, spoke comes out with the previously reported "bulge".

My set-ups are repeatable, just wrong.

I have a friend who is an experienced CNC operator visiting in a couple of days.
We will review everything then.

At the moment, the best result is with a square end mill.

John.

7

CamBam help (General usage) / Re: Ball Mill Advice

« on: September 30, 2025, 05:01:13 am »

Thanks for the comments.

The Roughing Clearance could be the problem.

Desired: White,
Actual cut: Green.

Definitely " Ball Nose".

The square end mill gives the correct profile.

Just setting up to redo the 5 Ball Nose, with Roughing Clearance 0.
I will leave Resolution at 0.2 so that only one thing is changed.

John

8

CamBam help (General usage) / Re: Ball Mill Advice

« on: September 30, 2025, 02:49:34 am »

I previously posted an image of the wheel model on 03Jul25.

Attached is an image providing a rough idea of my observation.
I think my problem is incorrect set-up of CamBam and/or milling machine.
I have started reading the French Documentation, hoping to get some guidance.

I have mounted a test-piece on the machine and trialling cuts on a single spoke.
Most of the two adjacent pockets is present so the tool engages the spoke correctly.
Keeps development and job times bearable.

(A) Waterline Roughing cut was made with 6 mm end mill with 0.5 depth of cut.

(B) Waterline Finish with 5 mm ball-end mill.
I selected "Ball Nose" for the tool and 4 flutes, but left all other tool entries at 0.
Nominated:
 - Depth Increment 0.2,
 - Max Crossover Distance 0.2,
 - Resolution 0.2,
 - Roughing clearance 0.1,
 - Stepover 0.2.

Results in the bulge depicted in the image.

(C) Waterline Finish with 5 mm square end mill.
Nominated:
 - Depth Increment 0.2,
 - Max Crossover Distance 0.2,
 - Resolution 0.2,
 - Roughing clearance 0.1,
 - Stepover 0.2.
 
 Result after (C) is a good representation of the tapered oval shape.
 The end mill cleaned out the bulge left by (B).

Are my CB selections in (B) reasonable ?

John.

9

CamBam help (General usage) / Ball Mill Advice

« on: September 29, 2025, 22:47:03 pm »

I am 3D Profiling tapered oval spokes in Cast Iron wheels for a 5 inch gauge locomotive.

5 mm end mill, 0.5 mm clearance, followed by 5 mm ball mill, 0 mm clearance.

The spoke oval profile produced is wrong, correct overall size but the side curvature is too sharp.

A 5 mm end mill, 0 mm clearance, is the correct size and profile, but shows the depth steps.

Just looking for advice and suggestions on where to look for hints on how to mix and match end mills and ball mills.

John.

10

CamBam help (General usage) / Re: Waterline Finish with Bull Nose - Radius Allowance

« on: September 18, 2025, 07:35:48 am »

CamBam.CAD : 1.0.7233.21741

Thanks David.
I redid the code, changing bull to ball, with an identical result, both in line count and Camotics time estimate.

I "thought" I saw the division number in one of the reports, path generation or gcode generation.
Could not find it in the reports for ball.
Does it report ?

I will do a simple test case to see what differences there may be.

Running the job anyway as I have other issues to investigate.
John.

11

CamBam help (General usage) / Waterline Finish with Bull Nose - Radius Allowance

« on: September 18, 2025, 00:13:32 am »

Using CB for 3D Profiling with 5 mm bull nose cutter.
Looks good.
I can report MeshLab is very useful.

While playing around (learning ?), I believe I saw CB report the cutter path calculations allowed multiple cut radii.
That is, the actual cutting point was divided up into, say 6, points along the mill curvature.

But currently, I am not seeing this reported.

Could someone enlighten me as to the conditions for reporting the multiple step - or was I dreaming ?

John.

12

CamBam help (General usage) / Re: Errors in stl File - Mesh Correction Tool

« on: July 08, 2025, 07:30:55 am »

The cube in the centre is, I think, a left-over from Blender.
A quick search shows that the cube is the default when opening Blender, but can be deleted.
I will watch this in future.

Downloaded MeshLab and opened the errant STL file with the option to integrate vertices cleared.
Looks impressive, very crisp rendering and responsive 3D scrolling.
Showed 121,078 Faces and 363,234 Vertices.

Selected Filters in the Menu, Cleaning and Repairing, Remove Duplicate Vertices - no change to count.
Then Merge Close Vertices - count dropped to 120,732 Faces and 60,352 Vertices.
It appears to be operating in mm, with a Merge Distance of 0.0096 mm?.

When Exported back to file, size dropped from 6.1 MB to 6 MB.
Opened the changed file in CamBam - looks the same.
But, will generate code to see if problem persists.

Thanks pixelmaker for suggesting MeshLab, it looks very capable.

Did a wheel pocket last night, 35 minutes, result nearly good enough.
Need to improve Boundaries.
This makes a wheel side more than 4 hours, probably a bit much.
I will also try a test using the Region suggested by EddyCurrent.

It is all the little things that make improvements, thanks to all.
I will be missing for a week or so.
John.

13

CamBam help (General usage) / Re: Errors in stl File - Mesh Correction Tool

« on: July 06, 2025, 09:50:16 am »

Thanks for the effort.

Your MOP differs from mine in a few areas.
I am away from my workshop at the moment, could be 18 h before I get back to check your version.
My workshop desktop is a Linux 64 bit Lubuntu system of moderate performance.

The StepOver was coded as 0.2, not -0.2;  another poor choice of language.

My installation does not allow selection of tool profile in the drop-down dialog.
Tried many times.

John.

14

CamBam help (General usage) / Re: Errors in stl File - Mesh Correction Tool

« on: July 06, 2025, 05:22:19 am »

Tried file straight from zip:
Noted that Tool #99 not in the Tool Library.
Also Profile listed as "Ball Nose" - how does one enter this ?

Report: 'Stepover must be positive and non-zero"
Calculation for 6 seconds, to give nil result.

Added StepOver - 0.2.

Report: 5 ball steps
Calculate paths: Duration: 11:30
Warnings for open poly:
at -3.9 offset 2x 1.7992, 2x 2.1992.
at -4.9 offset 3.3992, 3.7992, 4.1992.
At -5.0 offset 5x 3.7992.
Tool Library "Default-mm' not found.
Tool index (99) not found.
Computer abandoned for 90 minutes.
A 52 MB file generated that Camotics could not open, reporting errors.
CamBam opened the file, looks impressive.
1,000,033 lines of Gcode ! The largest I have ever dealt with.
Though, obviously at the limit or graphic responsiveness on my computer.

Now to sort out the crossover and tool table problems.
Then MOPs to a depth of 1 mm to get comfortable with calculation times versus finish.
With errors in the stl file still to be investigated.

Thanks to all for your assistance, especially EddyCurrent for pointing me to Regions.
John.

15

CamBam help (General usage) / Re: Errors in stl File - Mesh Correction Tool

« on: July 05, 2025, 05:23:37 am »

Prior to milling, the bore is reamed on the lathe and the tread/flange roughed out.
Considering roughing out the full cross-section in addition.

Final tread/flange will be done once the wheels are mounted onto axles.

This a hobby machine, so long duration code generation is not really a problem

Included is a link to the STL file.
Hope this works as it is my first effort.

https://files.catbox.moe/z0dowy.zip

For those that might be interested, here is the FreeCad file:

https://files.catbox.moe/d3fb2p.FCStd

John

Added:
My MOPs are on the back of the wheel, flange uppermost.
The first pocket is at the top, then CCW for the 2nd and 3rd.
The 3rd one fails for a Waterline Finish with the boundary shown.