[tubeguy]

I spent a good amount of time last night experimenting with different stratagies to mill this part in BC simm. It would seem the best plan would be to start with a big ball end mill and hog out as much as possible in the rough phase. (1.250). And then maybe a .250 to clean up in finish phase. I cant post all the different combinations I tried. But it seemed like no matter the stratagy I still wound up in the 5 hr range.

Does this seem right? I expect BC F/S to be on the conservative side, but it still seems a bit long.

I didnt get good results from advanced rough so I settled on

Z Level rough W 1.00 ball E mill
Slice planar finish (radial across groove) W .250 ball E Mill.

It was still in the 5 Hr range but the finish looked good (in simm)

This is in mild steel on a 7.5 HP bed mill 40 taper, tools are all HSS.

[Machineit]

You did not list or provide any of you feeds and speeds, but I would not rough with a ball endmill. Too much contact area and not good for heavy roughing.

I would use a good 1/2 inch or larger regular endmill and leave .010" or .020" for finish. Finish with a larger ball endmill to, the smaller the endmill the shorter your step over has to be for a good finish and your endmill is weaker. A 1/2 inch ball with a .005" step over would probably finish that nice. A 1" would be even nicer, you do have two inches of diameter there.

High Speed Steel does slow you down some too. Do you have flood coolant? Also remember that slow and steady wins the race unless you are doing mass production.

Mike

[txcncman]

This your part?

[tubeguy]

Yes, thats the part. I dont know why when I converted it to DWG it got those extra orintation lines. I posted it in that format as the files smaller and I dont have zip. TG

I used the BC "system F&S", yes on the flood coolant, I thought about using the big ball end mills as they are roughing ball end mills. (nice auction find) But am deffinley open to best suggestions....

[jrmach]

Carbide

[mcphill]

I posted it in that format as the files smaller and I dont have zip. TG

7zip is free: 7-Zip

[txcncman]

Yes, thats the part. I dont know why when I converted it to DWG it got those extra orintation lines. I posted it in that format as the files smaller and I dont have zip. TG

I used the BC "system F&S", yes on the flood coolant, I thought about using the big ball end mills as they are roughing ball end mills. (nice auction find) But am deffinley open to best suggestions....

Without surfaces or some type of indicating lines or dimensions, I can't tell what needs to be machined. Is it a mold for a tee?

[tubeguy]

Thanks for zip link. On the part, just the round cavity needs to be cut, the rest of the block is already to size.

The part is a half clamp for a tube bender, (2 in a set) the first bend is held on the straight section, second bend ( a 90 goes into the vertical cavity to be held for the second bending process.

We use these type of clamps to eliminate straight sections between bends for a more compact part. Sometimes we use a similar setup to put a ram end form right on the end of a tube next to the bend. You got nothing to hold on to except the radius bend itself.

Major hassel but what can you do.......

Anyway 5 hrs seems like alot, or maybe Im way off base.

[jrmach]

Can you zip a .bbcd file now.I am sure some of us can get that done in a 1/5 that time or better.Also don't know how accurate the timer is in simulation.But can check in Preditor Editor 2 for you.

[aldepoalo]

If you are using a 1" ball mill for the rough cut, Using the 1018 steel BobCAD is calculating:

SFM 78
Feed per tooth .0028
Plunge feed per tooth .0014
RPM 297.9381
Cutting feed rate of 3.33
Plunge feed 1.6

I used a DOC of .25 and a WOC of .125

Total Tool path length of 335"
Total rapid move length of 191"

I get run time est of 1h 47 m

I do feel my DOC and WOC would need to be adjusted if I was going to run any faster. In order to cut fast with a mild steel using a z level rough you would have a shallow DOC.

This is where the Advance Rough with Adaptive would allow you to run much faster. Using this high speed tool path you will have a more aggressive DOC and a shallow WOC. The tool path generated is smooth and cuts with arc motions that is using the flutes of the cutter more than the end of the cutter.

In this example I wouldn't use a Ball Mill to rough out the part but instead a 1/2" end mill or maybe a bull nose.

I used a DOC of .5 and a WOC of .06 ( just guessed at those )

Turn up my spindle speed to 3000
Cutting Feed rate at 33
plunge Feed rate at 16

Using these settings I get an est run time of 39m. Because I am taking a .06 step over I should be able to turn up the speeds and feeds even higher.

Depending on how your program this part I think 5+ hours to maybe 1:30 could be the range in run time. This will depend on tooling and speeds and feeds, coolant believe it or not and your machine. Some machines are setup for slow hogging, other machines are setup for fast light cutting.

Another thing to think about, all the time you've spending trying to figure out how to program the part to run fast, you could have been running the job and had it done. Running slow and steady does get the job done, but if you learn how to use the adaptive tool path yoiu can shave hours off your program run times : )


Here is a video of the Adaptive tool path cutting a 3D job: http://youtu.be/38IPVG75NGY

[txcncman]

Rough and finish with 1" HSS ball mill 4 flute - 4 hours 8 minutes running 133 RPM and 1.2 IPM 0.3 max depth on roughing.

[a1diesinker]

7.5 hp does it wind up or does it have batteries.

[Machineit]

7.5 hp does it wind up or does it have batteries.

Maybe solar panels from Solyndra!

I still would not rough steel with a ball, especially with only 7.5 hp, but go for it.

Mike

[SBC Cycle]

I was going to give this a shot but it's been so long since I've used HSS tooling I don't really know where to start.

With a good, solid carbide, variable helix square endmill I'd be running ~400 SFPM. I would personally use a 5/16" (0.0156 Corner Radius) with the horsepower you have available and IF you have the rpm, don't be shy with it. You're going to peel it off.

5/16" Endmill at ~400 SFPM = ~5000RPM

Full DOC: (1xD) = 0.3125
Stepover: 10% of D = 0.0313
Feed: 0.0009/Flute = 17.603 IPM

With the Advanced Roughing toolpath with 2 Intermediate steps I get 1h 12m

And you will reuse this endmill on 10 similar jobs before it's wore out.

I would also finish with a carbide ballnose, 0.500". Time would be based on how fast you are comfortable moving your table. You are more limited by feed than RPM here.

[SBC Cycle]

I still would not rough steel with a ball, especially with only 7.5 hp, but go for it.

Mike

Me neither.

[jrmach]

Me neither.Rough with Carbide .500 with .062 edge radius for 7.5 hp machine 4500 rpm .Carbide,Carbide,Carbide.With out Carbide,multiply your time by 4 or 5.If your machine is rigid enough,Climb Mill.Flood it well.If $ is an issue and your stuck with High Speed,use a corn cob,But at least buy a Cobalt one.You could take a deeper cut with that too,and the corners are radiused so they don't break as easy.But still I would do carbide as long as your machine is somewhat rigid.

[tubeguy]

OK OK wise guys, its 7.5 KW = 10 Hp, I know not a big manley machine like you'alls, cough cough.....

Well I got the zip thing figuered out, hopefully it'll show up below.....

[Big Chips]

oh OK so now we got to have a 30 hp mill?

sheet I got a 7.5 HP and it works JUST fine...

[tubeguy]

Thanks for the speed advice guys. Yes, it seems carbide is definitley the way to go.

Does anyone know if there is a plug in, MTB from BC, or other aftermarket tooling tables that can be imported to V25. Tables that would include ceramic, carbide, TDC coated etc.

Also thanks Al at BC for the long call explaining my solid model problems, the training vids dont cover the fine details. Its good they have a guy thats on top of this stuff.

[BurrMan]

OK OK wise guys, its 7.5 KW = 10 Hp, I know not a big manley machine like you'alls, cough cough..........

My brothers machine is a 1/4 HP. When I ask him to cut stuff for me, it's usually 13+ hours, because I'm always organic

He's taking delivery of a new manual lathe here soon. Not the Haas he wanted, but stepping up.