Toolpath Advise

[stevieboy]

Hello all

 

A D-2 die section 58-60 Rc appox. size 5.5 in.x 9x18 Tools (BEMs)Garr 350mx 1/2,1/4,1/8

Ok.. My qustion is what is a good toolpath to use on the cavity part of the die section, I need as smooth as finish as I can get.

Thanks for the help.

 

Ok... trying... to get the picture Here..

[Cuda84]

We use Scallop to finish our die's. Usually not hard yet.

[stevieboy]

[Jack Neelands™]

rule of thumb is 1% of dia for finishing for minimal polishing in tool and die

ie .500 dia ball is .005 stepover-for larger areas

.25 dia ball is .0025

.125 dia ball is .00125 stepover for fine corners

[stevieboy]

"Oh yea..

[htm01]

i'd try finish project/blend

[Cuda84]

Man the people in the shop would have a fit if I did that fine a stepover. We finish most tools with 1" ball at .03 stepover. If we use a smaller tool we shoot for the same cusp height.

[stevieboy]

"Oops..

Yea, my stepover is set at .005

Doc about .01-.02 Ipm 32 Rpms 4800

Really looking for,How you would cut the cavity.

(Toolpath type)

 

Thanks

[Jack Neelands™]

nobody polishes here ...it has to come off the machine finished and when you pulling 220 inches/min plus for finishing the boss loves it cause it comes off the machine in no time....

oh i should point out that we use miracle cutters for our hardened stuff...that lets us get away with it

[stevieboy]

htm01, that what I was thing also, that was the toolpath I used on the last draw section I did.

 

Cuda84,(shoot for the same cusp height) not sure what you mean.

1 in ball .03 stepover for finishing. what type of toolpath

Then leftover?

 

Thanks

 

[ 09-28-2006, 03:44 PM: Message edited by: stevieboy ]

[stevieboy]

miracle cutters ?

pulling 220 inches/min plus ?

 

"tell me more" "tell me more"

[Cuda84]

When I do leftover toolpaths I use a stepover for the smaller tools that produces the same cusp height as the .03 for the 1" tool.

 

I don't think our machines are very good. No matter how fine a stepover we always have to polish.

 

.03" stepover X 300 IPM = 9 - 12 hour finish program. At .01" stepover = 3 times as long. We can't tie up the machines that long for 1/2 of a mold.

[stevieboy]

html, blend toolpath 1/2 bem .005 stepover

18000 linear inches, not sure if tool will hold-up

(wear) 9 hrs. to finish blend

 

Cuda84, small parts are not to bad on the finish,

But large part where you have to use a Bem, and the breaks down, can be a major Pain.

1 in. Ball I'll keep that in mind.

Thank again

Gota go now.....

[Dan_AKA_ROY]

That 1% for the tool's diameter sounds right on. I've used .005 stepovers for a 1/2 bit and the finish is smooth as silk. Unfortunately, most molds I machine are far too big for that fine of a finish as time restraints kick in. For larger molds - I've used scallop toolpaths at .02 stepover with a 1/2 ball endmill and that looks fine. Some polishing, of course, but that does the trick.

 

Some toolpaths will produce a finer finish than others - using the same bit and stepover.

 

Scallop is a good one, it would machine the sides of your part well. Project/blend toolpaths are also excellent.

 

I would use the scallop toolpath - use as large a bit as possible [1/2 diameter ball endmill will do...I think. What's the radii on those surfs?] After scalloping, use finish leftover toolpaths using smaller bits incrementally. do the first finish leftover with a 1/4" ball, then use an 1/8" ball, etc. Be careful, if too much material is still left over - you might wanna do Surface Rough Restmill toolpaths to knock down those radii.

 

1. scallop finish [as small a stepover as time permits.

 

2. Restmill using a 1/4" ball

 

3. Finish leftover using a 1/4" ball.

 

4. Restmill using a 1/8" ball

 

5. Finish leftover using a 1/8" ball

 

^ Just a sample. Adjust according to your part's specs.

 

- The BEST surface finish can be achieved using Project/Blend, IMO. Good luck with your machine and I hope it turns out the way you want it.

[Chris Rizzo]

For that shape of part, project blend is fantastic. For your wire select the top two rails (or outline) of the cavity. Cut direction perpendicular to the "flow" of the part... xz and yz cutting.

[Dan_AKA_ROY]

Can you copy that yellow surf on another level and untrim it? Then machine that untrimed surf first? Then go back and machine the rest of your surf? Just a thought...

 

[not sure if that yellow surf was originally trimmed. If it was - untrimming it after copying it to another level is a nice trick to use]

[Jack Neelands™]

Mitubishi deals with these miracle cutters and they are outright nasty for hardened steel ie A2, D2, O1 ....but for soft stuff they cant keep up to a regular carbide cause you cant work it hard enough for some reason...

[Jack Neelands™]

I should have asked this and i dont know why i didnt before ..has the metal been hardened allready?

if not then cut your inside geometry to with .03 of a side and make sure you allow .01 for grinding on the outside of the block

send it for heat treat then hit it with hard machining cutters for the finish and mating face

depending on the tolerances of the part you may be able to cut to within .01 or even size as I cut forging dies to size on the inside geometry and left the outside with .01 for grinding and just polished the inside when it came back from heat treat..the customer allowed +/- .01 on their geometry

[stevieboy]

Good Morning all and tgif

 

Here's how I did it...

As I stated in my original post D-2 material 58-60 RC, I know that I can get 4 to 6 thous. linear inches from the garr 350mx bem (most of the time)

So I did 3 sf parallel on the top, 3 on the cavity,1 blend on the cavity corner using the 1/2 ball and 2 leftovers using 1/4 & 3/16 bem.

Time....17.5 hrs. run time

the part looks ok, but I will have to go back and blend one area that was a mismatch on the tool transistion.

Also I'd like to thank ya'll for the help and the tips,and I can't wait to try some of the other toolpaths,,,

 

From the dawn of man... TOOLMAKERS RULE!!

"And this is the Best Dam web site on the web"

and I know because, "I've been to the End"

Thanks again all

stevieboy