[MFchief]

Hi All,

Hoping to get a sanity check on something I need to cut, it's 4140 steel, I believe it's annealed, but checking on that now.

I need to cut a radiused bottom (about 0.5" radius) slot, 0.08" deep and about 0.7" wide. I plan to use a 1/2: HSS ball endmill.

Gwizard tells me to cut it at 1390 rpm and says I can go up to 105 ipm. Does that sound right to everyone?

Terry

[MFchief]

Interesting thing just happened, I uploaded a newer version of Gwizard and it changed the feed to 5 ipm. Don't know it that was because of the new version, or just because I closed and restarted the program?

Terry

[WOTDesigns]

105 definitely wasn't even in the right Galaxy even with carbide high performance insert ball mill.

One BIG thing to consider is your depth. If your only going 0.08" DOC then it may be confusing the wizard little. 5ipm sounds good, but since you only have 0.25" (guessing) actually engaged in the material that rpm seems a little low. That sounds like a 0.5" tool speed... Your not using 0.5" if only 0.25" is engaged you would need to double the theoretical rpm vs actually using 0.5" engagement. That said... Ball Mills are tricky and require more testing and "feel" and inspection than standard Mills because at some point you are cutting with a 0.03" diameter in addition to the widest part since it let lower than the wider part. I'd try 1500 or 2000 and 5ipm then speed up the feed from there.

Brian
WOT Designs

[MFchief]

Thanks Brian, I get what you're saying about not really cutting with a .5" cutter when it's a ball mill and only cutting .08".

Unfortunately, this piece belongs to a friend and I only get one shot at it. That's why I wanted to ask around before trying the cut.

Terry

[WOTDesigns]

Then slow and low is the way to go. Take a few passes at 1500 & 5ipm. Pause and peak at the first pass. Check for chatter. If chatter bump the feed 1-2 ipm. Keep in mind the cut load increases with each identical depth step with a ball

Brian
WOT Designs

[SCzEngrgGroup]

Gwizard tells me to cut it at 1390 rpm and says I can go up to 105 ipm. Does that sound right to everyone?

That kind of nonsense is one of many reasons why I MUCH prefer HSMAdvisor to GWizard. The several times I tried to use GWizard, I found it not uncommon for it to get into a state where it comes up with completely insane numbers, like yours, and it has to be shutdown and re-started to get it working right again. Other times, you could change cut parameters all over the place, and the calculated RPM and feed would never change. That's never once happened with HSMAdvisor, and I've found I can take the HSMAdvisor numbers and just run with them with very few problems. Only when I'm really pushing to the limit of the machine is it necessary to back off a bit from the calculated values and do some test cuts to make sure I'm not pushing it too hard.

Regards,
Ray L.

[MFchief]

Ray,

I've experienced a few weird things like you mentioned, especially changing parameters and not seeing a RPM/feed rate change. Usually attributed it to my only occasional use of the program, so...... maybe not!

I've found out since my original post that the 4140 is hardened to 28-32 Rockwell, which seems to be pretty common. I also found a short piece of it on eBay for just a couple of bucks, so I ordered that and now I can experiment as Brian suggested.
Thanks Guys

Terry

[MichaelHenry]

I've also had the issues with GWizard that Ray raised. Unfortunately the user interface for GWizard makes more sense to me than does the one for HSMAdvisor so I mostly use GW now (with common sense applied) but am trying to gradually change over if only because GWizard wants to update almost every time I use it and that often prompts an update to Adobe AIR as well. It also won't work with my Android phone and never will according to the developer.

Mike

[WOTDesigns]

I've also had the issues with GWizard that Ray raised. Unfortunately the user interface for GWizard makes more sense to me than does the one for HSMAdvisor so I mostly use GW now (with common sense applied) but am trying to gradually change over if only because GWizard wants to update almost every time I use it and that often prompts an update to Adobe AIR as well. It also won't work with my Android phone and never will according to the developer.

Mike

+1 on the annoying almost weekly updates...

Brian
WOT Designs

[SCzEngrgGroup]

I've also had the issues with GWizard that Ray raised. Unfortunately the user interface for GWizard makes more sense to me than does the one for HSMAdvisor so I mostly use GW now (with common sense applied) but am trying to gradually change over if only because GWizard wants to update almost every time I use it and that often prompts an update to Adobe AIR as well. It also won't work with my Android phone and never will according to the developer.

Mike

Mike,

The perpetual updates were the one thing, more than anything else, that made me give up on GWizard. It seemed like every time I'd want to run it, I had to first spend 10 minutes downloading and installing updates, and the Adobe Air updates, often as not, did not install properly. I've no such problems with HSMAdvisor. It just works. The UI works well, once you wrap your head around why it is like it is. But I agree it can take some getting used to. Most important, it always gives the right answers, and has helped me reduce my machining times by an average of 30-50%.

Regards,
Ray L.

[Hirudin]

I recently installed Windows 8.1 on a new drive on my computer so I've been reinstalling the software that I use. I haven't got to G-Wizard yet because I ****ing hate Adobe Air. In fact, I hate Adobe everything; I'm surprised those idiots [edit]at Adobe[/edit] know how to tie their shoes based on just how ****ty ALL their software seems to be. And why can't G-Wizard be installed on other OSes? Isn't that the ****ing point of Air?

Ugh... I don't mind software updates, if they're somewhat seamless. I hate having to load a web page, find the link, download the file, close the program, and run the file (I forget if unzipping is part of the process as well). Then, I guess since it runs through Air, I have to re-pin the link to my task bar. Doing that, seemingly, every time I launch the program is getting a little old. I have good luck with G-Wizard and I like the interface and the numbers it produces. I like the little tips it gives too. I just don't know if I can bring myself to install Adobe Garbage v15.729.92 in order to run it. It's probably time to give HSMAdvisor another try.

[pickled]

FYI I have machined annealed 4140 with a cheap, HSS 4 FL stub length ball end mill before. Looking back at my notes I got good results running conventional milling at 750 RPM, 3.5 IPM and a DOC of 0.09. Sorry, but I didn't record the plunge...probably somewhere around .6-.9 IPM. If I remember correctly the tool stick out was minimal. Hope that this helps you with a starting point.

[Concepts_Design]

I'm glad it's not just me having these problems with G-wizard. I've read so many good things about it, but yet I have these same issues. Tried emailing them a couple times and no response, it's like they know the issues with the software but don't fix them. and every new update has it's own issues

[kstrauss]

With G-wizard the only certain (?) way to get cutting guesses updated seems to be to change the fine-rough slider. And, yes, the incessant updates are really annoying. Particularly those that require an uninstall and re-install. At least you don't have to reboot!

[MFchief]

Pickled,

Thanks for checking through your notes for me. That sounds like a good starting point for the annealed 4140. I will play around with my "sample stock" when it arrives.

Terry

[MichaelHenry]

The UI works well, once you wrap your head around why it is like it is. But I agree it can take some getting used to. Most important, it always gives the right answers, and has helped me reduce my machining times by an average of 30-50%.

I'm assuming that I just need to get used to Eldar's UI and that a week or so of intermittent immersion in it will do the trick. Getting the right answers is right up there on the priority list and I've had to massage code that used faulty GW's F&S recommendations more than once.

Mike

[quapman]

Annealed 4140 will cut very much like CRS, but "real" 4140, as stated before, will be around 32 Rc and will cut with 2-3 times the difficulty. This type of steel is awesome for building things due to its strength and toughness, but it can be a bear to machine. It has molybdenum and chrome which is why it's sometimes called "chrome-moly".

Coated carbide will be your friend. Uncoated will work ok for a few passes, but will wear rapidly. 4140 is tough and abrasive. Side cutting will yield better results than end cutting, but I think you said you're pocketing, so you don't have much choice. Be careful not to feed TOO slowly, because then you'll rub rather than cut and workharden the material.

Lots of coolant and chip evacuation will help also.

[MichaelHenry]

I'm assuming that I just need to get used to Eldar's UI and that a week or so of intermittent immersion in it will do the trick. Getting the right answers is right up there on the priority list and I've had to massage code that used faulty GW's F&S recommendations more than once.

Mike

Ah, one more bugaboo - Norton decided that Eldar's program is a virus and promptly removed it from my system.

[MFchief]

Hi All,

Just wanted to update my progress.

I rec'vd my sample 4140 and did a test cut.

I ran it conservatively at 950 rpm, 1.5 ipm and .020 DOC.

I think the finish is fairly good and more than adequate for the project so I didn't do any further experimenting.
Attachment 270458

Please ignore the flat area on the left, that's just from putting a flat on the bar to do the test cut and eyeballing X&Y zero.

Thanks to all for your suggestions and also the discussion about GW, glad to know I'm not the only one who has had odd results.

Terry

[MichaelHenry]

I'm glad it's not just me having these problems with G-wizard. I've read so many good things about it, but yet I have these same issues. Tried emailing them a couple times and no response, it's like they know the issues with the software but don't fix them. and every new update has it's own issues

I will say that the author (Bob Warfield) has been pretty responsive to my tech support questions. I generally get a response within a few hours of emailing him. He used to have a members forum for Q&A stuff, but changed that recently to something else. There should be mention of it on the G-Wizard or CNC Cookbook web sites.

Mike