Could someone help me machine this part

[Frank]

Hi all: I've uploaded a part to the ftp site in the MC8 folders and labeled it "waterpump impellor" . I don't really do a lot of 3d work and this job seems pretty straight forward. But for some reason the boss must have seen this job run somewhere, and wants me to think about how I'm going to machine it, and I think there will be a test......lol. I have put another job here and just a couple of toolpaths, that some great programmers here put on it, taught me a lot. Like using a bull mill to quickly remove most of the stock. I'll be running it first on the lathe, and finishing the O.D. and I.D. and back. Then locating on the center hole to hold it down for the 3d toolpath. Any heads up or toolpaths would be greatly appreciated.

 

Thanks

Frank

 

[ 08-12-2003, 07:08 AM: Message edited by: Frank ]

[Jean-Simon]

Good morning Frank, I had a look at the part and can send you something for you to have an idea how to machine it but if you want a bullet proof program ( to run it ) then it's another thing because there's time involved. There's many ways to machine this part, in 3D it always depends how much time you want to put on optimizing the program (if you have 1 part to do or 500). I'll upload the part back today with simon extension but as I said it'll only be a way to do things.

 

HTH!

 

Simon

[Frank]

Thanks....I don't need a bulletproof program but just some idea on how to get started, or how others would do it. Would it make sense to create a stl file of the rough stock, so I don't cut much air? And what path would work best ? Thanks for such a quick reply.

 

Frank

[Frank]

Also time isn't as much an issue as the finish. The boss is a perfectionist.

[Jean-Simon]

Hi Frank, I've uploaded the file with some paths and made a transform (instead of programing 6 time the same thing). In V9, you'd have a lot less work to do (extend/trim surfaces) and some more toolpaths options. I didn't finish it all because I would have had to remodelise some regions of the part but you have a good idea.HTH.

 

 

Simon

[John Summers]

Hi Frank, First, move whole part to top view, on center.

Create a clean hub by CREATE-CURVE-PROJECT, projecting a straight line thru the origin on the surface. The cross section is a line and an arc. Extend the line .5 in. on the OD, and CREATE-SPLINE-CURVES with the line and arc to get a spline. Create a revolved surface with this line. Now you have a clean hub.

The blades are 2 arcs, .090 apart. If you make new arcs, it will be easier to extend them.

I think you can use a .250 cutter with a .0625 radius. Offset the arcs .125, and make a flat surface between them. If you do it right, it can be machined flowline. Then project the flowline toolpath to the hub TOOLPATH-NEXT MENU-PROJECT. This will put the toolpath right on the hub without moving anything in the top view.

The fillets against the walls will blend into the hub, but I would leave them alone.

If you machine one way towards the center, the cutter will cut cleaner, since it's moving upwards. Same method for roughing with a larger cutter.

The little scrap of a fillet looks like it shouldn't be there. The left curve of the cavity needs to wrap around the tip of the blade a little bit before you create the flowline surface.

[crazy^millman]

Looked at your part are you worried about relieving of material once you take all that material off what it might do the the diameters you already have finished. May not hurt a thing but might want to leave some material on it for finishing if it fights tight into a impeller housing like i have seem some fit in the past.

I also like the surface/rough/pocket to get some of the materail out of there bull are greta but an inserted ball will give the flexiablity of semi roughing all the ribs withoutleaving alot of extra stock and then you might g ogo to a finish pass form there. Just something to think about dont know the Material or the machine.

 

Good luck looks like a fun part.

 

Crazy Millman

[John Summers]

Hi Frank, I blew the last part of my reply -- TOOLPATH-PROJECT is a legacy (old) function, and really doesn't fit this problem. Use the c-hook FLOOR5AX. Make the 2d toolpath, then project it to the floor (hub) using FLOOR5AX. There's a peculiar bug in it. Select the OPERATION (OK the toolpath), select COMP SURFACES (the hub), select APPROACH/RETRACT (use the 3rd option, ...normals and vectors, THEN select AXIS LIMITS and OK - this fixes the bug, where axis limits aren't initialized unless you select it.

On my second try, the blade thickness was .087.

[Frank]

Thanks all who replied, It ended up working great, with the help of some on this board. I've just talked the boss into Version 9......so I'll be hanging out here, and picking some brains.

 

Now if I could just think of a good quote here !

 

Thanks again,

Frank