Author Topic: First Post, First Project, & Some Questions  (Read 20775 times)

Offline dh42

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Re: First Post, First Project, & Some Questions
« Reply #30 on: July 30, 2021, 01:10:26 am »
Quote
Yes, but I was probably mixing or misusing terminology. The parts under the machine tree to execute in the order they appear but the MOPs within them do not…….but as Gary mentions below…

In your files

CAMpart are: Mounting Holes, Plenum, Throttle Bores, Perimeter Profile

MOP are: Mtg Holes, Mtg Post Hole, Port Path, Guide Slots, Bore Pockets, Outside Spacer Profile

All are cut in the order in the list

MOP can contain multiple shapes (Primitives), ex: Bore Pockets contain shapes 125 to 132 (ID primitive property) and in this case the cut order is dependent of the Optimisation mode and the Start point defined for the mop ; if no start point designed, the cut begin at the closest shape and on the closest position from the last one (where the previous mop ends or if it is the first one, close to 0,0), then the next shape and start cut point is the closest shape into the mop for the other shape in the same mop. If none is selected for optimization, the shapes into a mop are cut in the same order they appears in the Primitive ID property of the mop (in the order they have been selected) and the start cut point is the 1st point of each polyline into the mop.

Quote
So I just assign a point list for circle and arc center locations and snap to those to reconstruct the circle or arc if needed

At least to reconstruct circles, maybe this plugin can be useful for you to distribute circles to a point list.

http://www.atelier-des-fougeres.fr/Cambam/Aide/Plugins/Copy2pointlist.html

++
David
« Last Edit: July 30, 2021, 01:13:38 am by dh42 »

Offline dave benson

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Re: First Post, First Project, & Some Questions
« Reply #31 on: July 30, 2021, 03:08:07 am »
Hi Kelly

I did this file last night so things have moved on a bit post wise, however this may still help.
I reverse engineered the file and metricated it, so it's an example more of how to set up the mops rather
than cut out an exact replica of your original file. (toolpaths to geometry can give anomalous results)
I'm assuming that you are still using Foam as the stock material and so have not included roughing and finishing
mops, which would be required for machining metal.

As a general rule what you have done by calculating the X,Y offset and using the lower left hand corner at the top of the stock
as XYZ = 0 is correct and the way most people would and should do this (you should do this first and if you run into
problems) when you have many pieces to cut out and they have different stock dimensions and they must be registered
then you can center the work piece’s around the origin of the drawing and indicate the center of the stock on the machine.

I'm not suggesting that you do this now for this job but this method is valid and can stop errors when the stock varies from the
size it should be. I've had some stock delivered that is mostly a little over but sometimes a little under
the dimensions that I've ordered.

The last pic is how I organise the tree structure, I separate the mop's into parts so that the parts and mops read from top to bottom in operation order and you don't have to change the optimisation mode, this also facilitates structuring more complex file's using different tool's from multiple tool libraries. 

Good luck with the gremlins.

Dave

Offline Tool-n-Around

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Re: First Post, First Project, & Some Questions
« Reply #32 on: July 30, 2021, 13:06:15 pm »
I did this file last night so things have moved on a bit post wise, however this may still help.

Thanks for that Dave. Much appreciated.

I'm assuming that you are still using Foam as the stock material and so have not included roughing and finishing mops, which would be required for machining metal.

I'm just using a 1" thick foam board for proofing. The actual part is only 3/8" thick and is a phenolic composite, which is a fair bit harder than most hardwoods. It's also a bit pricey thus the proofing. I'd rather not blow up a piece of phenolic stock if I can avoid it. I figured I could just change the stock thickness when I moved onto phenolic. On the actual piece, I was thinking I'd take Gary's suggestion and overstate the cutter diameter for roughing cuts and then follow with an identical MOP at full height cut on all machined features features. The other reason I was previously asking about order of cut were the features called "slide valve slots". They are cut at .3125 depth but in actuality it would only be .0625" depth of cut if the port was cut first.

As a general rule what you have done by calculating the X,Y offset and using the lower left hand corner at the top of the stock as XYZ = 0 is correct and the way most people would and should do this (you should do this first and if you run into problems) when you have many pieces to cut out and they have different stock dimensions and they must be registered then you can center the work piece’s around the origin of the drawing and indicate the center of the stock on the machine.

Since this part resides and is cut completely within an ample amount of stock, with all machining operations in one set up, I figure precision location of stock isn't that important and I can just draw the machine X&Y on my table/waste board and place the stock about the lines.

I have four more cb files mostly done. They cut the front and back side of two parts. They do need to be positioned precisely but I just incorporated some registration holes in the corners of the stock that locate on registration pegs mounted in the waste board and would be the same for all four files/two parts. Don't know if that is how it is usually done but more on that later.

The last pic is how I organise the tree structure, I separate the mop's into parts so that the parts and mops read from top to bottom in operation order and you don't have to change the optimisation mode, this also facilitates structuring more complex file's using different tool's from multiple tool libraries.


Got it, thanks for that Dave. Where did the solid view of the cut part come from? Can that be generated in CamBam or is it a screen capture from other software? Seems useful for me to discuss parts here on the forum.

Good luck with the gremlins.

EMI problem. I had to reroute a cable. Not sure if it is poor or compromised cable shielding, or weakness in stepper or driver, but for now, sorted....I hope. Had me chasing my tail for a while. Also some problems with soft limit settings. Dont want to turn them off and invite a crash....especially since I don't know what I'm doing....LoL!

Best,
Kelly

Offline Garyhlucas

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Re: First Post, First Project, & Some Questions
« Reply #33 on: July 30, 2021, 17:03:25 pm »
Kelly,
Another suggestion for you since you want to do both sides of a part and multiple tools. If your router tools won’t repeat on length when you take them in and out I suggest you program the table surface as Z zero and then the top of your stock will be the thickness of the material. Then the clearance plane value will need to be Greater than the thickness (VERY IMPORTANT!!).  All your cut depths will then be positive values measured from the table.

Two reasons you should do it this way. When you change a tool you always set them off the table which never changes. So switching to different height material the tools get set the same. If finished material thickness is important you can surface the top and material variations go away with no calculating or program changes. When you flip the part you good as well.
Gary H. Lucas

Have you read my blog?
 http://a-little-business.blogspot.com/

Offline BR52

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Re: First Post, First Project, & Some Questions
« Reply #34 on: July 30, 2021, 22:41:11 pm »
hello kelly,
Looking at your first poster photo, I see that the surface is uneven!

Attached is a mesh file, part of the car engine.

Do you have your part's STL mesh file?


   Armando

Offline dave benson

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Re: First Post, First Project, & Some Questions
« Reply #35 on: July 31, 2021, 01:32:19 am »
Hi Kelly

The pic is a screen shot of a Camotics screen, a free simulator.
There is a plugin here on the forum that enables you to call it from a CB Menu, It's very handy
for developing files, saving a lot of time and catching errors before the file hit's the mill.

I run Mach3 on the mill and lathe, Both have EMI filters, with GRBL and using USB
on my laser cutter and multi-axis grinder I  use these cables with a ferrite filter and
have no issues with interference (USB wise), so if you have problems with intermittent com's
failure between the controller and your Gcode sender then these may help.

Dave

Offline lloydsp

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Re: First Post, First Project, & Some Questions
« Reply #36 on: July 31, 2021, 11:24:14 am »
Dave,
That looks to be a pre-made cable with a 'molded-on' ferrite spike snubber.

For Kelly's situation, he should be made aware that those ferrites can also be purchased in a 'clip-on' form to fit existing cables.

Lloyd
"Pyro for Fun and Profit for More Than Fifty Years"

Offline Tool-n-Around

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Re: First Post, First Project, & Some Questions
« Reply #37 on: July 31, 2021, 21:43:46 pm »
hello kelly, Looking at your first poster photo, I see that the surface is uneven! Attached is a mesh file, part of the car engine. Do you have your part's STL mesh file? Armando

Uneven? I drew the part in CamBam and don't own any other CAD program so unless there is someway to do so with cb or CAMotics, no.

Best,
Kelly

Offline Tool-n-Around

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Re: First Post, First Project, & Some Questions
« Reply #38 on: July 31, 2021, 22:05:26 pm »
The pic is a screen shot of a Camotics screen, a free simulator. There is a plugin here on the forum that enables you to call it from a CB Menu, It's very handy for developing files, saving a lot of time and catching errors before the file hit's the mill.

I did download CAMotics after the earlier post in this thread, but when I run the simulation, I don’t get a nice smooth object like yours. I attached a couple screen shots and the gcode file which only differs from my previous file by me adding roughing clearance and finish cuts. It almost looks like the simulation used a smaller diameter cutter but I had loaded a .25” x 1.5” cylindrical tool with imperial settings. It was set to medium resolution and when I tried to change the setting to higher resolution it produced a blank, uncut piece of stock? On some simulation I saw run time and total cut length. Doesn’t appear to be available on CAMotics. Is it?

I run Mach3 on the mill and lathe, Both have EMI filters, with GRBL and using USB on my laser cutter and multi-axis grinder I use these cables with a ferrite filter and have no issues with interference (USB wise), so if you have problems with intermittent com's failure between the controller and your Gcode sender then these may help. Dave
Dave, That looks to be a pre-made cable with a 'molded-on' ferrite spike snubber. For Kelly's situation, he should be made aware that those ferrites can also be purchased in a 'clip-on' form to fit existing cables. Lloyd

I do have some clip-on ferrite beads. The problem appears to be associated with the USB cable between the computer and machine controller. If the USB cable touches a stepper cable or anything metallic the stepper cables touch, it produces intermittent coms failures.

Best,
Kelly

Offline Tool-n-Around

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Re: First Post, First Project, & Some Questions
« Reply #39 on: July 31, 2021, 22:12:14 pm »
Kelly,
Another suggestion for you since you want to do both sides of a part and multiple tools. If your router tools won’t repeat on length when you take them in and out I suggest you program the table surface as Z zero and then the top of your stock will be the thickness of the material. Then the clearance plane value will need to be Greater than the thickness (VERY IMPORTANT!!).  All your cut depths will then be positive values measured from the table.

Two reasons you should do it this way. When you change a tool you always set them off the table which never changes. So switching to different height material the tools get set the same. If finished material thickness is important you can surface the top and material variations go away with no calculating or program changes. When you flip the part you good as well.

I'll keep that in mind Gary. I have a zeroing touch plate for the router.

Best,
Kelly

Offline Tool-n-Around

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Re: First Post, First Project, & Some Questions
« Reply #40 on: July 31, 2021, 22:33:49 pm »
I did download CAMotics after the earlier post in this thread, but when I run the simulation, I don’t get a nice smooth object like yours.

Think I figured it out. I needed to either import the tool list (I need to read up on creating, saving, and exporting/importing tool libraries) or just make sure the tool numbers I add in the simulation match the tool numbers and characteristics of those in the CB generated gcode file.

Best,
Kelly
« Last Edit: July 31, 2021, 22:40:08 pm by Tool-n-Around »

Offline Tool-n-Around

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Re: First Post, First Project, & Some Questions
« Reply #41 on: July 31, 2021, 23:31:12 pm »
Much better with correct tools!!! See attached.

Best,
Kelly

Offline dave benson

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Re: First Post, First Project, & Some Questions
« Reply #42 on: August 01, 2021, 01:01:54 am »
HI Kelly

Quote
Think I figured it out. I needed to either import the tool list (I need to read up on creating, saving, and exporting/importing tool libraries) or just make sure the tool numbers
I add in the simulation match the tool numbers and characteristics of those in the CB generated gcode file.

Yes you’ve done well, It takes a little time to match the tools in the libraries, but once done things work well.

The usb cable should run as far away as possible from sources of EMI (steppers being one) VFD motor cables
being the other really bad source. If you have a plasma cutter in your shop, they can also cause a lot of interference.

It looks like your ready to do some cutting, and as I'm willing you on to a successful outcome
when you do machine it, It would be nice to see some pics.

Dave

Offline BR52

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Re: First Post, First Project, & Some Questions
« Reply #43 on: August 01, 2021, 01:23:00 am »
To do 3D modeling I recommend installing FreeCAD it's free.
View some tutorial videos on FreeCAD modeling.

See attached photo, is this the piece you want to do?
What is the model and brand of the piece, to do a Google search.

I Armando;  ::)  recommend building a probe for your CNC machine.
With Probe you scan the piece and make a 3D model.
My CamBam friends help you.

   Armando
« Last Edit: August 01, 2021, 01:47:18 am by BR52 »

Offline Tool-n-Around

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Re: First Post, First Project, & Some Questions
« Reply #44 on: August 01, 2021, 13:38:29 pm »
See attached photo, is this the piece you want to do? What is the model and brand of the piece, to do a Google search.

Yes, but you won't find that available anywhere because I'm the one that made that intake manifold and at the moment, it's the only one in existence. It was cast with the lost foam method and I hand built the pattern with rather crude methods as described here. There are imbedded YouTube videos but you may have to join the forum to see full size pictures:

http://forums.thehomefoundry.org/index.php?threads/automotive-intake-manifold-%E2%80%93-boss-302-independent-runner.1692/

When I mentioned I don't own a CAD program, it's not exactly true. I have access to Fusion 360, I'm just not at all proficient.....yet. If I had a good solid model, and could make this (see attached and portion pictured on the right) center section in two pieces (top and bottom) instead of the 56 pieces in the current method, the rest of the pattern pieces are straight forward and it would save a lot of time in constructing the pattern, as well as improving accuracy and quality of result.

I might even be able to cut it with CamBam but I don't think I could model/draw it with CB. I'll get there eventually.

Best,
Kelly
« Last Edit: August 01, 2021, 13:40:50 pm by Tool-n-Around »