Re: Setting Rapid Feed and Maximum Cutting Feedrate when Z rapid is different than X
I use a slip guage (More accurate than jrmach piece of paper although that works fine as well).
I take it another step further by subtracting the paper thickness too :)
If I need perfection on an EM,I start her up and put on my bionic goggles and touch off the surface that I marked with marking pen.:)
Using an edge finder to precision,is a skill all of its own,,,
Yes,start a new thread with your solid attached,,,I am sure we can get you so confused you will wanna quit,,,:)
Kidding,the collective knowledge on this forum will surpass anything you will need to know.
Re: Setting Rapid Feed and Maximum Cutting Feedrate when Z rapid is different than X
I drew the part for the design to make sure it would all fit the real application. I have to machine from that. I don't plan on using the CAD in bobCAD, it is not as good as mine. I can do a lot more including assemblies and all that stuff...
This is all starting to make sense. I guess what I should do is go ahead and try to generate the tool paths and just use the generic tools in there that match what I plan to use.
I am curious about this:
"When doing a shape like you have I would always draw it with the centre of the job at X and Y zero, that way it is very easy to machine the shape from your stock slightly deeper than the thickness of the part.
That can be done as an advanced pocket operation for both the outside shape and the inner shape.
Then after you have done the desired shape machine out some soft jaws in the vise and machine off the excess material from the back of the part, if you are going to run a small chamfer to the part for de-burr/cosmetics then that is why you would do the soft jaws, if you are finishing it off by hand de-burr then the machined soft jaws are not required."
This does not make complete sense to me. Not sure why it would have to be in the middle of X and Y rather than the whole thing being positive X and Y (how I drew it in my CAD). How does that keep you from milling deeper than the part (3/8" by the way). My material is the thickness I need. There will be no face milling or cleaning.
Re: Setting Rapid Feed and Maximum Cutting Feedrate when Z rapid is different than X
You still need to learn some CAD in BoB or you are handicapping yourself.
It will become clear to you once you start getting some experience.
What CAD do you have?
Start a new thread and upload your solid,,,I and others can walk you thru the whole process.
As far as you not understanding what Rob said,,,,,well,it's a little different way than you are thinking.It's faster than what you are thinking of doing.
It will become obvious as we CAM your part.
Re: Setting Rapid Feed and Maximum Cutting Feedrate when Z rapid is different than X
Doesn`t keep you from milling deeper, keeps the part in the exact position if it needs to be turned over for example other operations that may need to be machined from side two.
Looking at your part there is no need in this particular instance but IMHO it is a good habit to get into right from the start.
If your material is the same thickness as the part then I assume you will be leaving a small amount and then knocking out the part, either that or doing the holes and bolting it to a sacrificial plate :D
It will all come with time, I have various vises that I have set keys into the bases so that it will always be in the same location on the machine bed every time I put it on, along with some pre-set end stops I have no need to position the vise or the workpiece, a simple bit of math will tell me where material centre or corner is every time :D :D
Regards
Rob
:rainfro: :rainfro: :rainfro:
Re: Setting Rapid Feed and Maximum Cutting Feedrate when Z rapid is different than X
Quote:
Originally Posted by
jrmach
You still need to learn some CAD in BoB or you are handicapping yourself.
It will become clear to you once you start getting some experience.
What CAD do you have?
Start a new thread and upload your solid,,,I and others can walk you thru the whole process.
As far as you not understanding what Rob said,,,,,well,it's a little different way than you are thinking.It's faster than what you are thinking of doing.
It will become obvious as we CAM your part.
I have Geomagic Design, formely Alibre (similar to solidworks).
I can muddle through some stuff with BobCAD.
You want the solid as an IGS or as a BobCAD file?
Re: Setting Rapid Feed and Maximum Cutting Feedrate when Z rapid is different than X
I do need to figure out how I am going to hold this thing. I did draw it with a nice chamfer on both sides.....just to make it harder I guess.
I have heard another person say something about drilling a set of the holes in a jig plate or something to bolt this to.
Anyway, I will start a new thread now :)
Re: Setting Rapid Feed and Maximum Cutting Feedrate when Z rapid is different than X
I posted some pics of one of my soft jaw setups in your other thread. But wanted to show you a example of using a very simple jig plate here, since you mentioned it. And seeing your part in this thread, a jig plate would be a better setup for this part. You could also use dowel pins in some of the holes to locate it.
This was a very simple jig with some holes drilled through some bar stock. I set my zero for the fixture to the back left corner, top of the jig plate. This required drawing my jig plate in a separate layer from my part in bobcad, so I could set my part origin in relation to the jig plate. This is where you will want to learn some of the basic cad functions in bobad,
https://lh5.googleusercontent.com/-F...344573_HDR.jpg
Re: Setting Rapid Feed and Maximum Cutting Feedrate when Z rapid is different than X
And seeing your part in this thread, a jig plate would be a better setup for this part. You could also use dowel pins in some of the holes to locate it.
that's adding a lot more time and a higher level of difficulty for the OP.
Also another operation is added assuming you want both sides machined on the face.
Re: Setting Rapid Feed and Maximum Cutting Feedrate when Z rapid is different than X
He did mention that he wanted to chamfer both sides.
Re: Setting Rapid Feed and Maximum Cutting Feedrate when Z rapid is different than X
no biggie,but you have to face both sides before you put it in the fixture.Once in the fixture you chamfer 2nd side.3 ops plus make fixture.
If doing lots of part,then yes do it with a fixture.
I am trying to keep it as simple as possible while he is so new to all this.
Re: Setting Rapid Feed and Maximum Cutting Feedrate when Z rapid is different than X
Quote:
Originally Posted by
jevs
My machine has a different rapid traverse rate on the Z axis than the X and Y. How do I accommodate this in BobCAD-CAM v27?
You don't. If the rapid speed is causing a problem for your machine then just change the rapid speed in your machine setup. CAM software only sets the cutting feed rate, not the rapid speed. Does the speed scare you? It can if the cutter is close to your part. LOL.
Re: Setting Rapid Feed and Maximum Cutting Feedrate when Z rapid is different than X
What if I just forget about the chamfer on both sides and use my 3/8 plate I already have and just knock the sharp edges off the back side with my 1" bench belt sander. Basically, just drill and chamfer the holes on one side and cut/chamfer the outer profile. I can chamfer the other side of the holes and edge manually.
How would this get set up and cut? Can I do this easier without a bunch of special stuff or flipping it to machine from the other side?
Re: Setting Rapid Feed and Maximum Cutting Feedrate when Z rapid is different than X
Quote:
Originally Posted by
Bob La Londe
You don't. If the rapid speed is causing a problem for your machine then just change the rapid speed in your machine setup. CAM software only sets the cutting feed rate, not the rapid speed. Does the speed scare you? It can if the cutter is close to your part. LOL.
I did this already. I set the X and Y to 250 IPM and the Z to 150 IPM in Mach3 so the rapids will just move at that speed.
Re: Setting Rapid Feed and Maximum Cutting Feedrate when Z rapid is different than X
Sure you can,,but the learning curve is steeper.It will also take longer.You will also need a sacrificial plate to make the fixture out of.You will also need dowel pins.
If I were to do this project,I got to produce perfect and pretty parts.I also charge by the hour.I do not fiddlefart around.Wasting an 1/8 of material by machiingng it off is "cheap".
This is the way I would make it,the way I have explained last night.
It is also faster and the rigidiyt of the set-up in way better.
Always a lot of ways to do the same thing.
I believe Rob is also on the same page here and he does this for a living too and has been for a very long time
I am not trying to be a dck to MIKE,,it is just with all things considered,especially you experience,just go for the best way.
Re: Setting Rapid Feed and Maximum Cutting Feedrate when Z rapid is different than X
Quote:
Originally Posted by
jevs
My head is spinning on setting up tools. I am starting some coffee, so maybe I will get focused soon. I feel like it is taking way too long just to getting to cut a part...
Quite often I can make a part faster just by doing it manually. I have a couple small mill drills I'll probably never get rid of for exactly that reason. Although, I have gotten familiar enough with the g-codes that I often will "manually" cut a part on one of the CNC mills by using the midi mode and just typing in the instructions. A pendant doesn't hurt either.
Re: Setting Rapid Feed and Maximum Cutting Feedrate when Z rapid is different than X
Quote:
Originally Posted by
jevs
I did this already. I set the X and Y to 250 IPM and the Z to 150 IPM in Mach3 so the rapids will just move at that speed.
Yep. Rapids are the fastest your machine can move consistently (with zero faults) when it is not under cutting load. I like to set "safe Z" for things like "goto to zero" etc, so I don't slam the cutter into a part or a vise, but yep. The rapid speed is the speed your machine moves when it is in between tool paths. If the rapid is a diagonal move it will actually be even faster than that as each axis will be moving at its max speed. A^2+B^2=C^2 Remember that from your geometry class?
Re: Setting Rapid Feed and Maximum Cutting Feedrate when Z rapid is different than X
Ok, I will stick to plan A and just make the thing beautiful :) I already ordered some soft jaws last night and they shipped today. I will still pick up some 1/2" material tonight. I will also practice more with BobCAD tonight. I got through making the tool paths last night, but screwed some things up. I want to compare mine to the sample that was given to me and see where I went wrong.
I do like that simulation. You would laugh if you saw what my initial attempts did so far :)
Re: Setting Rapid Feed and Maximum Cutting Feedrate when Z rapid is different than X
For things like bolt and pin holes I chamfer before I drill. Atleast on the front side. I spot drill A little deeper than the radius of the drill size, then I drill. For other stuff I only chamfer if its necessary. For safety I usually de-burr manually so somebody doesn't cut themselves on a part edge. For the back side of bolt and pin holes I usually do it with an air drill and a deburring bit on the work bench while the CNC mill is cutting its next part. I also rarely tap on the mill. Sometimes I will thread mill, but regular tapping is usually faster and easier on the drill press with a tapping head (for what I do), and a lot less stress on me.
Re: Setting Rapid Feed and Maximum Cutting Feedrate when Z rapid is different than X
Quote:
Originally Posted by
jevs
Ok, I will stick to plan A and just make the thing beautiful :) I already ordered some soft jaws last night and they shipped today. I will still pick up some 1/2" material tonight. I will also practice more with BobCAD tonight. I got through making the tool paths last night, but screwed some things up. I want to compare mine to the sample that was given to me and see where I went wrong.
I do like that simulation. You would laugh if you saw what my initial attempts did so far :)
I just use scrap pieces of aluminum I screwed up from other projects for soft jaws. I machine bolt holes in them, slap them on the vises, and then machine them square in place, and then just amount necessary to hold the part.