Can someone take a look at this part

[Frank]

Hi all: I put a part in the MC9 files of cadcam's FTP site labeled "case cover right new" I'm not brand new to 3d machining, but am definatly still at the learning stage. first off , on this part it was ok'd to use a .375 cutter to finish the inside of this pocket, so that's why I'm using that tool. I don't understand why my surface contour is starting about an inch down in the part, and could someone tell me if this is the way they would machine it.

I know all the experts are here, and if I want to do it the best possible way, this is the place to get the answer.

 

Thanks for all your help

Frank

[crazy^millman]

Well I will give you this tip. I would use the Surface Rough Pocket with that same tool with that same step down. I would turn off roughing and that should do what you are looking for very well. The only problem with this tool path in using it this way is if there are undercuts and they are grabbed as machined surface and you do not have a boundary to keep it from undercutting it will. Been there done that the hard way.

 

I might also look at flowline for a toolpath here. Contour is good but soemtimes I have seen this very thing and find doing something off the wall like the surface rough pocket does just the trick and if in a hurry all you need to do is copy change tool, change stock to leave to 0, turn off roughing, regen and done.

[Frank]

Thanks for the quick response Millman. How do you shut off the rough operation on the surface rough toolpath ? And I just tried flowline and there was a conflict and it couldn't create the toolpath. Or are you saying to use flowline to finish the inside radius's.

 

Thanks again

[crazy^millman]

Two part answer.

 

1) to turn off rough on any pocket operation not just here you just uncheck the rough at the top left hand corner and that will do it.

 

 

2) When using flowline use the meaning of the word as your guide. Think about drving a car if you ca ndrive in a straight line then your flow is always good to be straight. If going in curves then you would want ot keep your curves all curves. I might to the wall as one flowline operation making it step fro mthe top down. I would then do another flowling to the radius from the top down. You change change it from scallop to step over and that becomes your step down amount if you want .05 than that becomes your step over. I hope that was a clear enough explaintion if not I can do the part but it wil have to be later today sorry but very very busy. Just cruching toolpaths right now and that is why I can help the little I have.

[TREV]

frank,

i just looked real quick at your file . i will look in depth more later. to answerr your question about the cut starting about a inch down if you swithch your containment from inside to center that will fix that problem.

more later .

trevor

[TREV]

frank,

rons idea of flowline will not work with the 3/8 ball on this part without doing some modeling first.or being real cretive in your gap settings.your part has 3 mm rads in it so to do a flowline path it would be best to use something smaller than a 6 mm cutter to preventthe tool from going straight into the corner.a flowline path with follow true surface curvature end to end .(this can also be adjusted in gap settings to extend or shorten)

trevor

[TREV]

frank,

 

quote:

__________________________________________________

and could someone tell me if this is the way they would machine it.

__________________________________________________

 

NO

you are probly going to break a few cutters with your agressiveness .1 step downs are going to be hard on tooling that is sticking out over 3 inches even if this part is alluminum.you are also roughing ,semi finishing,and finishing with same tool.

 

nuff of that, now your strategy is not all that of the wall just your follow thru

i would probly delete that parrallel path and instead use a shallow in that case right after a countour.

hth, lunch is down ill check back later,

trevor

[TREV]

frank,

are you still there?

trevor

[Frank]

Hi sorry I took so long to reply, thanks for all the suggustions ! I tried to run this part on Sat. , besides having a very hard to handle CEO (know it all) who says why should it be a problem " all you do is tell Mastercam the size of the cutter and the feedrate, and it knows how to cut it ! Anyway after I got the first deep pocket roughed out...he said from a company standpoint we would be better off having the pocket EDM'd ! I asked him to let the tools run before making his desision, and was told no just finish the front 3d toolpath and the outside of the part and he will send the rest out. So that's what I did, and guess what, he saw how the flowline toolpath worked and said why can't we do that to the rest of the part (duhhhhhhhhh). So here I am Monday morn. rewriting the toolpath ( I deleted it all when he was going to get it EDM'd.) What I truly am having problems with now is the filets in the corners, is there a way to be able to run a .236 ball right along those? I tried flowline for the radius's and it keeps kicking it out.

 

Thanks for letting me vent.

 

And again thanks for the responses

[crazy^millman]

Vent on.

 

 

Then you feel so much better. I would say you may need to apporach that isdei radius as possible a 3d contour if you have a majority of it roughed out. Draw a curve using the indside surface edge as the control. Then just do a contour using that as your chain. I would recommend doing those lines on a seperate level. I would also recommend maybe doing depth of cuts also just to make sure you get all the material out of the way. You can give it a feed plane of .05 and do .01 depth of cuts. I hope that helps and good luck been and had 2 days off becuase of promised and not hard work so I feel your pain.

[TREV]

frank,

are all your surface normals pointed in same direction? are you triing to flowline multiple surfs at once?

like ron said in an earlier reply flowline the verticle rads first then do the bottom edge. the verticle ones will all have to be seperate ops since they do not touch edges.

hth,

trevor