Messages

1

CamBam help (General usage) / 3D Profile Zeros and Stock surfaces.

« on: November 25, 2018, 19:50:04 pm »

Hi,

Finally getting around to 3D Milling some parts again, kinda as a practice session for more projects upcoming.
In particular I'm trying to 3D mill the 'grinds' in a knife blade, along with some precision 2.5D milling. (The part is basically a 2.5D part, with one region on each side done in 3D. It's mirrored across the middle Z of the part) 

In my model the 3D Z zero is in the middle of the blade, that is the blade is extruded up and down from zero. When imported into cambam, this holds true. I've got some cb code hacked out that seems to mill the front and back side parts, however it isn't 100% clear to me where my stock surface should be placed.

In order to get any backside 3D tool paths that are reasonable, it seems that my machine zero needs to bet set to the middle of my part and stock (As it is in the drawing). Otherwise backside machining operations generate weird tool paths.

Are there any recommended procedures for setting up a Z zero for a 3D model when doing front and backside machining in cambam? Any other 3D recommendations or conventions I should be following in general?

I'll attach the part. (Cambam .cb file to follow later if requested...)

Thanks,
Dan

2

Post Processors (*.cbpp) / Re: Spindle Speed manual change.

« on: October 16, 2018, 03:34:17 am »

Loyd and David,

Both of these examples look very visual basic...   ...something I can actually code in. So this is a very awesome start for me! Based on what I'm seeing here, maybe the best thing is to just post process any {$s} commands into the "M00" codes, and delete duplicates as they're encountered...

Quick questions: So, where do I find some more info on the object model to actually write these sorts of scripts for CB? And what vb versions/editors are you guys using? I do A LOT of VB (DSP, FFT, DFT, data analysis, etc.),  but it's VB5/6 and VBA. No VBS code at all, yet...

Thanks!
Dan

3

Post Processors (*.cbpp) / Spindle Speed manual change.

« on: October 16, 2018, 01:07:58 am »

Hi,

So, I run a Chinese auxiliary spindle on my mill. I'm setting up a second post process for use with this spindle. The speed settings are done manually via a potentiometer.

Now, my mill has a M00 code, which displays a message to the user, pausing until the dialog box accepted. This is very useful for cases where manual intervention is required.

Now, I'd like to use this M00 code to throw a message telling me to change the spindle speed. Currently I have it set up int the start of the MOP portion of the post, using {$s} command do display the spindle speed. However the issue here is if there are many MOPS with the same spindle speed, the M00 message is displayed for every mop. I'd like that onlty to display for MOP's where the spindle speed actually needs to change.

So, any suggestions on where or how I can trap this situation and send the message when speed changes are required???

I'm thinking maybe some conditionals with variables in the MOP header that makes G code which will catch this???  I haven't even begun to figure that out yet...


Thanks!
Dan

4

Related Softwares / G Wizard

« on: October 12, 2018, 02:20:37 am »

Hi All,

Anyone else using this?

I've had it for quite a few years now. The latest editions (Your forced to upgrade via Adobe AIM platform, which it's written on) are giving me some way too fast feed and speeds. I've broken a few cutters. Lots of bugs in the interface, etc.

It used to work well, but lately with the small cutters I'm running there are way too many things that don't give good results. I've basically gotten to the point where I don't trust it anymore. When I attempt to address the issues, I always seem to get blown off by the author when trying to get answers.

For example, choosing 440C as a material defaults to 412 SFM, where Harvey tool recommends 150 SFM. Of course the 413 is waaaayyy too fast. It tried to tell me to slot at full width with a 1/8" carbide .750 inches deep in 440C earlier tonight!!!

Deflection calculation was nice, but it's all screwed up now. Every version changes things and add bugs.

Anyone else using it, if so anyone seeing similar issues?

Thanks,
Dan
 

5

Feature Requests / Re: 3D machining profile, Boundary Taper negative value.

« on: December 25, 2017, 22:33:59 pm »

At the risk of offending, did you read the whole sentence? 

I can't make it do what isn't there, but an alternative might be to use several 3D waterline finish MOPs starting with a large roughing clearance and eventually finish with zero roughing clearance. 

Yes, I did read the whole thing. And I will play with this option also. My concern is DOC may be harder to control than what the automatic code in the Waterline Rough does. Visualizing what's actually being cut with a ball end mill is a bit difficult without a simulator, so checking for a DOC too deep would be hard to do manually.

As you said, it'll will take more time to get a working solution than just letting it cut air. Of course, at this point it has become an academic exercise. The tool has been made, heat treated, tempered, and used to finish the job already!

I will also play with Eddy's plugin. (Which is very cool, BTW). I haven't played with it enough to realize the limitation existed in code.

If the boundary taper could be made to work both positive and negative, it would be a neat solution. I just never figured it would only grow the toolpath in +Z.

Thanks, and Merry Christmas. Hopefully Santa brought you lots of goodies to make chips with!

Dan

6

Feature Requests / Re: 3D machining profile, Boundary Taper negative value.

« on: December 24, 2017, 04:13:33 am »

Ok, First, please do not take offence. None is intended here. Sorry if I did so.

Bob, you have offered help many times in the past, so I do appreciate your input. Very much. However, your comment about not making it do something that isn't there seemed a bit sharp. Sorry if I snapped back.

I agree letting it cut air is faster for a one off. However the engineer in me always wonders if there's a better way. So, when I spotted the boundary and boundary taper options, and I absolutely knew they would do what I needed. Placed the boundary circle, and set the taper...   ...then set the taper negative. Both made it larger. Hmmm, that's weird, time for feature request.

Usually when I post there's a clever way to do something I haven't thought of yet. Maybe defining the stock with a 3D object, or some other neat little trick. Dunno, you guys are darned good at this.

Sorry to drag you into this problem.

Thanks,
Dan

7

Feature Requests / Re: 3D machining profile, Boundary Taper negative value.

« on: December 23, 2017, 15:37:30 pm »

I can't make it do what isn't there, but an alternative might be to use several 3D waterline finish MOPs starting with a large roughing clearance and eventually finish with zero roughing clearance.  

Well, that's why it's in the feature request feedback forum. Taking out an abs(BoundaryTaper) in the code may all it takes... 

Usually when I post, I learn there's some other trick that I missed. I have some ideas for similar projects again, so I was being hopefull for future projects  

I do have a lot of AlTiN coated stuff, and it's great stuff. However, there aren't any AlTiN coated ball end mills in the home shop right now. So, trying to save on carbide that's here.  Once the feeds and speeds dialed in you can cut all day with one cutter. I run a lot of 440C and CPM154 stainless, and a bit of S7. It seems to hold up really well for that.

There's also a place in Canada that CVD coats carbide. Worked great on some big G10 fiberglass. That stuff eats regular carbide fast, and the coated stuff did the job with one cutter... 
http://www.cvddiamond.com/products

Merry Christmas!

Dan

8

Feature Requests / Re: 3D machining profile, Boundary Taper negative value.

« on: December 23, 2017, 01:03:57 am »

Hi Bob,

OK, maybe I'm not being clear. See image. I want to turn the object on the left into the object on the right, but not waste time cutting a lot of air.  I did not use boundary taper for my actual rough, because it didn't work like I wanted it to. I wanted to use it to save cycle time, where A LOT of air was being cut. Make sense?

The part is relatively hard 1050 steel, I didn't want to burn cutter life on a small carbide ball end mill. So I removed extra material in the lathe.  Maybe 40% of the waste volume was removed with a lathe in about 60 seconds...

So, I started with a bar with a tapered end (Left image), then 3D milled the final shape into it (Right image). Because a bunch of the steel had been removed previously, it cut a lot of air. However, roughing still needed to be done as a lot of material remained.

I thought the boundary taper could be used to taper the shape moving up from the boundary. It can do that, very well. The only problem is that it can only taper outwards, not inwards. (Many cambam settings work +/-, if a negative sign is used in the setting, roughing clearance for example...)

Try the cambam file I posted. Set both a positive and negative value for boundary taper. If the roughing boundary taper could have been be set to tip inwards, it would have achieved exactly what I wanted.

The part cut well with both MOP's. However about 50% of the machining time in the 16 minute long roughing operation was cutting air. (But, at least it wasn't cutting waste metal burning carbide life! )

Hopefully this make sense now.

Dan

9

Feature Requests / Re: 3D machining profile, Boundary Taper negative value.

« on: December 22, 2017, 22:28:36 pm »

Hi Bob,

OK, maybe there is a technique i'm missing, so if you have time to show me, by all means... 

Anyway this is the object I'm trying to create. I start with a bar, and turn some of the rough stock off, leaving what's in red (transparent so you can see the target design underneath...)

Then I use a 3D rough profile to hog out the rest of the metal, and then follow with a finish pass.

You can see there is a boundary profile object (circle, 14), that sets the boundary with a boundary margin to force cutting out to the edge of the boundary. However since I have a tapered stock to start with, I don't want to mill air where metal is already removed. Setting the boundary taper setting of both positive and negative both swell the tool paths larger at the top. (CB screen shot). One would expect negative to shrink it and positive expanded it, or vise versa (As with many other settings in cambam).

See attached images, and .cb file...

Merry Christmas!

Dan

10

Feature Requests / 3D machining profile, Boundary Taper negative value.

« on: December 22, 2017, 01:18:07 am »

Hi,

So, it seems that using a boundary shape ID allows one to trim a 3D machining operation to a boundary shape. The boundary taper seem to work well also, however taper gives positive results only (Making the boundary taper wider at the top.

I have an application where I'd like a negative boundary taper. That is, Narrower at the top than the bottom, for an outside machining operation. It would be nice if the boundary taper allowed both negative and positive values to tip the boundary in or out as needed.

The application is 3D profile on the end of a round bar. I've removed most of the extra stock with the lathe, and would like to tip the boundary to be smaller at the top. This would allow much less cutting of 'air'.

Thanks,
Dan

11

CamBam help (General usage) / Re: Pocket and Profile, Corner slowdown.

« on: June 15, 2017, 02:01:42 am »

Hi Bob,

Long time no see! OK on the explanation.

I thought that's what would happen, although I hadn't considered the ramp up/down rates at the stop points. Yeah, my mill can be cranked up there for feedrate and accel, but normally I run it with lower speeds and accelerations as it jumps around too hard when running 'full out'. I'll have to try ES a try on the next project.


Hi Gary,

I hadn't drawn in material removed in the example, but yes I do understand your point about material to be removed in corners. Normally my cuts are pretty mild to begin with. My concern is more with finishing passes on close to tool radius corners, and getting the best surface finish out of the machine while keeping tool deflection down. Normally try to leave enough material that the cutter is actually cutting on the finish pass, but not too much. For example, a single finishing pass on ~.100" to .125" thick high alloy martensitic stainless with .070" radius corners with 1/8" carbide. The .070r corners can be a bit 'grabby' with the cutter. I'm just looking for way to improve the process.

As for young engineers, Yeah, a little thought during design can go a long way when actually making a part. Just the other week, I saw a square corner drawn into a pocket in a part! I think that every mechanical engineer should run a mill for a while. It's easy to CAD up a fancy part, but not always simple to build it!  (My excuse is that I'm an electrical! )


Anyway, "Corner slowdown" would be a nice to have a feature to have. I guess it's just not there yet (hint, hint! )

Thanks,
Dan

12

CamBam help (General usage) / Re: Pocket and Profile, Corner slowdown.

« on: June 14, 2017, 18:05:38 pm »

Hi,

I'll play with it some more, but it didn't seem to affect what I was looking for with a quick test...

Anyway, just to be sure I'm being clear about my concern, here's a little diagram. The problem arises when trying to mill around a corner, where the radius of the tool is close to the radius of the cut. Looking at the diagram, the green lines are the tool path, and the cut edge is black, the tool diameter is shown for reference also. As the tool progresses along straight lines, the cutting speed is the same as the tool center line feed rate. However if the tool turns a tight radius, the cutting edge speed gets multiplied by the ratio of the radii. This effectively increases the feed rate and tool loading going around inside corners. This is because the tool path feed rate remains the same, even through the cut edge is longer. Make sense?

The is also true, when going around outside corners. That is, the tool path effectively slows down the actual cut feed rate (although, this isn't as big of a problem when it happens).

Maybe the settings you suggested are correct. Again. I still need to play with it more...

Thanks,
Dan

13

CamBam help (General usage) / Pocket and Profile, Corner slowdown.

« on: June 14, 2017, 02:15:17 am »

Hi All,

I glanced through the settings, and I'm wondering if CamBam has any methods to slow down the cutter then entering or traversing a small through tool radius corner.

That is, if I'm cutting a corner or curve that's close to the diameter of the tool, the cutter should slow down in the corner to maintain the feed rate at the tool cutting edge. Is there a way to set cambam to generate code that will slow down the feed rate in corners to prevent over feeding material into the cutter?

Thanks,
Dan

14

CamBam help (General usage) / Re: Fast Plunge not working...

« on: June 06, 2017, 22:00:38 pm »

Hi,

G30 moves to a reference point. In this case P2 and P3 are reference points defined in the mill. P2 is defined as the Machine zero Plus .2 inches of offset into the machine envelope on each axis. P3 is defined as the program coordinate system Zero.

The "G30 P2 Z0" moves only the Z axis. That puts the to a Z height of -.2000 inches. (This is basically retracts the Z axis fully.)

The "G30 P3 X0 Y0" moves the only the X and Y to the Program Zero, leaving the Z axis at the previous -.2000 inches.

All this does is retract the z axis (almost) fully and park the machine over the program zero point. It's a good spot for tool change, and gets the cutter out of the way for part changes without going all the way to the machine zero.

Dan

15

CamBam help (General usage) / Re: Fast Plunge not working...

« on: June 06, 2017, 01:37:38 am »

So, Setting all values to NaN is still seems to work.
The code currently generated is:
G17
M3 S8350
G00 Z0.25000
X-0.027472 Y0.077792
Z0.12500
G01 Z0.00000 F8.00000
G02 X0.08250 Y0.00000 Z-0.022149 I0.027472 J-0.077792 F2.00000

There's some weirdness in this example caused by the settings for Clearance Plane and fast Plunge height. But the code seems to make sense, even given the somewhat strange setup.

Thanks!
Dan