[aldepoalo]

This video shows the work flow for setting up and open pocket in BobCAD CAM V26.

[SBC Cycle]

A simple and common use for an open pocket - a keyway on the end of a shaft.

I can reduce the stepover to about 15% of the cutter diameter but no less. Any ideas why?

I can't get the upload to work. Keyway is 0.875" wide x 4.000" long with one end "open" (end of the shaft)

Cutter Info:

( 0.3125 Dia. 0.0156 CRad. 4 Fl.0.7500 CL) (Eliminating the corner radius does not seem to have an effect)

It will do any stepover from ~15.666% to 50% but no less. This is an extremely hard shaft and 15% isn't going to do it. After snapping 2 endmills I realized it wasn't honoring my stepover.

I tried to workaround by using a 3 axis adaptive rough but it's worse. I can enter a stepover of 0.010" and I still get a stepover of about 0.070".

[jrmach]

Do you have V23 HSP ?

[rktman8888]

Same problem here. When I first down loaded the demo (build 1134) advanced rough would go to 1%. After buying V26 Pro and loading the current build. It only will generate path to about 20% step over. So frustrating,.. I have a pile of stainless I'm milling and I had to go back and use V23 with volumill. I hope this gets fixed , or I need to send this back. Its pretty much useless to me. All I do is cut full depth using HSM. Normally 4-7% is the area I work in. Al can you fix this for us?? Or How do I get the old 1134 build back? I need to get some work done!

[rktman8888]

Al, one more thing to note. It will allow you plug in any number value into the step over box. The tool path just does not reflect the actual value set. Translate some geometry around for quick measuring to see what I mean.

[aldepoalo]

I have an idea of whats causing this issue. I will verify tomorrow and post my findings.

[rktman8888]

That would be great! hope it's an easy fix.

Thanks

[SBC Cycle]

Do you have V23 HSP ?

Ahh, if only. Why tease me? lol, j/k

High Speed Machining IS what I'm looking for here. The tool is a Hanita Varimill and it will handle a higher RPM than most general purpose carbide endmills - but only if you nibble at it.

I ended up at 150 SFM, a 0.0008" chip load, and two passes at 0.245" deep and plunged straight down the middle and it survived 5 keys but it was painfully slow. I used advanced rough "offset" style to finish nibbling it out at 250SFM and 0.0014" chip load, full depth.

It seems as if everytime I try to use "adaptive" roughing on anything other than plastic I find a new limitation. The linking passes are always at cutting feed rate (slow), it will always leave more material than desired on inside corners, and now I find I can only use it if I intend to take more than 15% of the cutter diameter.

[SBC Cycle]

Same problem here. When I first down loaded the demo (build 1134) advanced rough would go to 1%. After buying V26 Pro and loading the current build. It only will generate path to about 20% step over. So frustrating,.. I have a pile of stainless I'm milling and I had to go back and use V23 with volumill. I hope this gets fixed , or I need to send this back. Its pretty much useless to me. All I do is cut full depth using HSM. Normally 4-7% is the area I work in. Al can you fix this for us?? Or How do I get the old 1134 build back? I need to get some work done!

I also always cut full depth and prefer to peel it out at high speed. 8% is my magic number in stainless with a 5/16" or larger cutter. With such a light load the feed rate is just high enough to make the linking paths tolerable.

I'm glad my memory is not failing. I also recall being able to do as low as 2% stepover without issue in V26.

[aldepoalo]

It does look like there is an issue with what we are passing in the back round. The issue has been reported and will be fixed for the next update.

[BurrMan]

Same problem here. When I first down loaded the demo (build 1134) advanced rough would go to 1%. After buying V26 Pro and loading the current build. It only will generate path to about 20% step over. So frustrating,.. I have a pile of stainless I'm milling and I had to go back and use V23 with volumill. I hope this gets fixed , or I need to send this back. Its pretty much useless to me. All I do is cut full depth using HSM. Normally 4-7% is the area I work in. Al can you fix this for us?? Or How do I get the old 1134 build back? I need to get some work done!

Are you using "one way" as a setting in the adaptive rough?

[BurrMan]

Does this file represent the step type in pocket being discussed?

pocket step percentage

Super small step.

[SBC Cycle]

That would be great! hope it's an easy fix.

Thanks

Something tickled my brain last night and I remembered a bug in a previous version (or build) that user mmoe found. In the 2-axis milling Pocketing feature, on the "Patterns" tab is the control for the cut direction. If you uncheck "Oneway" a new input box pops up. You can see the "conventional" stepover parameter is locked in at 25%. If you check the box next to it, you can change the conventional stepover. Reduce it to match your "Climb" stepover value. Then check the "Oneway" box again. It will now honor the "Climb" value (I think).

I haven't checked if it is actually the stepover I asked for but it looks a lot better. I don't believe this trick will work for 3-axis Adaptive Rough however.

[SBC Cycle]

Here is the file I tried to upload yesterday. I had to install Flash to get it to go

The end of the key has a full radius but it is basically the same as the examples I looked at.

Looking at Burr's example I see he has discovered the same. You must override the conventional setting whether you are using it or not.

[rktman8888]

Nice find SBC, seems to work ok using that method. In regards to linking speed. No doubt on a closed pocket the tool needs to blitz when not cutting. 50% of the movement is non cutting time in some cases. I noticed the open pockets do use G00 moves when cutting one direction so that's good. Maybe I'm just spoiled with the HSP plug in used in V23. The tool path engine was a volumill product. Poetry in motion in my mind, it's so reliable. No screw looking tool path, works every time. Problem I'm seeing with some of the 2D closed pocket Adaptive Rough, is with with islands. The tool path starts as a spiral then changing over to side milling arcs. In between strategies it leaves areas of uncut stock. When HSM'ing you can't have ANY areas of stock larger than the set tool engagement. The tool is already at the edge of max performance and these large uncut areas will break it and damage the part. It's pretty much useless at this point for those applications. Hope BC gets this stuff workout with the next Build number. As of now I still use the HSP in V23 in closed pockets. Things seems to be moving in the right direction. Im hanging in with BC for now,.. But the user beta testing thing is starting to get old when I have piles of work to get done.