Machsupport Forum
G-Code, CAD, and CAM => LazyCam (Beta) => Topic started by: Sage on October 09, 2008, 08:57:54 AM
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LazyCam reverses the machining order of entities and I can't figure a way to put them back in the order I want them.
Attached is a simple dxf file of a cam lobe.
I Load the file into LazyCam - Mill.
Clean it, and optimize it works fine. You get a simple cam with minimum of 4 entities and the order of their machining in the chain is clockwise just how I want it.
I need to apply an offset so it can be machined with a 1/4" in mill so I select the chain and apply an outside offset with clockwise order. LazyCam creates this properly and the entities in the new offset chain are in the correct clockwise order.
For some reason it adds some extra very short entities but I can ignore that for now.
I no longer need the original chain so I delete it. No problem.
The problem starts here.
I don't like the way the start of the machining is right at the tip of the cam lobe. (this appears to move around depending on if you clean and optimize or even do the whole thing over but this is mostly where it starts machining for me).
So without any information I assumed I can drag the start point to somewhere else, maybe along the left side and I also drag the origin to the left a bit so the tool approaches from the left on more of a tangent to the flat rising side of the cam lobe. When I do that, the order of the entities making up the chain become reversed and I can't see a way to get them back in the correct clockwise machining order.
Does anyone know how to re-order entities.
Sage
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double click your direction arrow,and a dialoge box will open,set it to auto.
bill
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Where is this "Direction Arrow" ?
If your talking about the dot at the end of the rapid line (or the lead-in line) double clicking that opens up the lead-in line diag box. In there is a setting for auto as you mention but it does'nt do anything to re-order the entities.
A real basic manual simply outlining the basic functionality of LazyCam would be in order here. Yes I'm aware of the videos.
Sage
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Sage,
We'd all LOVE a manual, but alas, they don't have time to write one, I guess. I had heard that someone was supposed to have written one (in German maybe?) and it was going to be translated for us. Well that was a while ago and I recently posted a question about this to Brian Barker and he said he would ask that person who was going to translate it but it pretty much got swept under the rug....again.
As for putting the entities and chains in the order you'd like it to cut, you have to drag them into that order. Yes, I know you saw the videos but they show exactly how to do this.
Let us know how you make out, ok?
Dave
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Dragging only works to put CHAINS in the order you want them to be acted on. ENTITIES are the basic pieces inside the chains. It doesn't appear you can do much with them. Hence the question.
I stand corrected if you saw someting in the videos about dragging ENTITIES.
If so let me know. I'll apologize and take another look.
Sage
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My apologies to YOU, as I simply thought you mean the chains overall. I also do not think you can change order of entities but mine always seem to be "in order". In other words, lets say I have the letter "S" to cut. Obviously the whole chain is the complete letter S and if I click the little "plus" next to that chain, it expands and shows every single entity in that chain. Now if I click on the first entity and hit the down arrow on my keyboard, it goes right through each entity in order from one point of the "S" all the way around itself and right back to it.
Now if I apply an offset to the "S" and delete the original, and then relocate the cutting start point, I'm still not having the problem you're having. Try this, when you're offsetting, try zooming in as close as you can as Art has in the past, said this makes a difference. Worth a shot, right?
Dave
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Sage
is this what you are after,attached is a lcam file.the offset is done with a .250 tool clockwise.your original layer is still there but has been set disabled.when i imported your dxf my connection line tolerance is set to
.001 -- i am using lcam ver 3.00.2
bill
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Docltf:
Yes, Your file seems to be ok. Why is the question? What did you do different from the process I described in the first post. MY connection tolerance is fine (also .001). This is evidenced by the original import of the DXF file which is clean and has only 4 simple arcs the way it was drawn in Acad. It's only when you move the rapid point that it screws up.
Did you try moving the rapid line and start point??
Budman68: You are correct there is something fishy connected with zooming in. When I zoomed in on the point at the end of the rapid as I moved it the entities did remain in the correct order A COUPLE OF TIMES. Then I guess I didn't zoom in the magic "enough" and moved the point and the entities re-ordered themselves and were then screwed.
THIS IS CRAP !!
Docltf:
I'm using what is reported in help\about as version 2.61 but I'm pretty sure I downloaded the version posted by Ron Gingery in a message here recently (January??). I also understand the version numbers are all screwed up so who know what I'm running.
Maybe you can point me to the version you have. As I understand it the latest version on the MACH website is not the newest one. The one posted here is apparently newer.
It's all very confusing an pretty hoakey. If it wasn't for the fact that it sort-of-works and I have no immediate alternative I'd ask for my license fee back.
Having said that. I'll will stick with it because I have faith in the author. When we finally get to the bottom of this it will be another chapter in the manual.
Sage
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Ok. It looks like V3.00.2 from the Mach website corrects this "out of order entities" problem. Still not sure if this is the latest since I thought the one posted by Ron was supposed to be newer but I trust that the website should have the latest and greatest. I'll see what happens. I can't recall what the posted one was supposed to fix.
SO another question:
How do you get rid of all the tiny entities created when you do an offset.
Docltf:
You will notice your file has a bunch of extities not in the original dxf (originally only 4 simple arcs in the file).
Sage
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That's the exact version I'm using as well. As for the entities, mine creates 8 total (0-7) but they are indeed in order and would cut in one smooth path. Is 8 an issue?
Dave
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Hi All,
Just on the side trying to learn something about those "entities" which may apply to the turn part of lazcam.
So nothing to add in here, but, may ask a question while you guys are active. Hope you don't mind.
RICH
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No 8 isn't a problem. It's just a curosity why it needs to create them. If I use Autocad to create an offset in the origial dxf file it still imports into LazyCam as only 4 arcs.
The extra entities are very small but I've had other files with them in and they create a very small pause and leave a small mark on the part. Luckily in this case they don't (not sure why) but it's a good thing because I don't really want bumps in the cam.
Sage
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Sage
some of us started working with lcam from the first ver until now.it has always been a beta program.there is no instruction manual that has any real value.but for the price it has power.
after some user time it will get smoother for you.lcam is just a raw tool.you will also find that how you use your cad will change.
EXTRA ENTITIES: this is a cad thing.lcam sees the junction point that your cad created.if you did the same drawing longhand with g-code,the junction points would be perfect,and lcam
will act accordingly.when you do a offset lcam adds a entity to go around that trashy junction.the next drawing you do ,try a greater scale say 4 to 1, then scale to size with lcam.small arcs
generated with a cad can sometimes be trouble with lcam.
bill
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Sage
i forgot to add this.when a tool goes around a junction point doing a outside offset it has to hold the cutting edge to that point.the center of the tool has to have it's own arc path to
do this.lcam will add a entity for this.
bill
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SAGE
i looked deeper at your drawing .i zoomed in on the junction points without using clean and optimize first.when lcam joins these points you will be left with bumps in the road.you have to figure out
if the cad is doing this or you are.
bill
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It's interesting that the disconnects show up in lazyCam because they are not showing in AutoCad. I am aware of this problem and corrected some disconnects using the extend line and trim line functions in autocad and they look clean. At least for all reasonable zooms in Autocad. So perhaps there is something amis in the mathematics of the DXF conversion that LazyCam has a difference of opinion on. Apparently this is an issue else LazyCam wouldn't have the conection resolution variable.
Presumably clean and optimize are supposed to remove these problems from the file and it appears to do so, evidenced by the fact that after cleaning it is translated properly as 4 arcs for the whole cam. It's only when you offset it with lazyCam that the extra entities (presumably due to disconnects) show up again. As mentioned - if I do the offset in AutoCad before sending it to LazyCam it imports into LazyCam properly as 4 arcs.
BTW after offsetting and moving the rapid point, I've seen extra entities added right in the middle of what was a perfectly good arc. So something isn't right.
Still. I agree with you. It is a powerful tool that I can't do without. It's all a matter of understanding the limitations and all of the work arounds and this thread will help in that regard. At least LazyCam generates the geometry - something my math limited brain appreciates. The rest of the code can be cleaned up and optimized by hand.
Sage
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Rich:
I see you patiently waiting.
You had a question ???
Sage
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Sage,
Not yet, just continue hacking away your doing great and educating me.
RICH
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So something isn't right.
I could not have said it any better - ;)
Dave