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Post by atgordon on Apr 4, 2019 17:08:33 GMT
I occasionally buy tooling from Helical, and so get emails allowing me to download their guide. I though it might be helpful to share the link with others. This link takes you to the FULL machining guide without having to register, you can just download the guide directly. Although the guide is entitled High Efficiency Milling, the advice sections which comprise the first half of the handbook, are very useful to anyone using a vertical mill, who wants to get the most out of their tooling. The speeds suggested are for production machining, where time is money, so use judgement and reduce spindle speeds to what you and your ears can tolerate. The feeds are less extreme, but once again, use common sense on what to ask from the tool (and use a FS calculator just to be sure ... this is a good free calculator)One useful nugget of info in the handbook is the suggestion that the full length of the cutter be used at all times- so maximum depth of cut that can be safely used is the starting point for material removal. The beginner is often tempted to use very small step down increments (sometimes as small as 1 or 2 mm) when roughing material, which overworks the cutting face of a milling cutter, and uses very little of the flutes ... if you buy a 12mm end mill, it will normally be 50-75mm long - a 30mm step down, with a very small step over (say 0.5mm) means that you are using 120mm of cutting edge on a 4 flute cutter, rather than over-working the 24mm of cutting edge on the face. If you paid for a 50mm end mill, then use as much as you can! If you don't you will quickly wear out the face cutting edges!
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Post by atgordon on Apr 5, 2019 0:04:49 GMT
Just added a direct download link ... got a heads up PM! I didn't realize that you had to go through a registration process (and having to share email address with Helical), and also didn't realize that the latest version doesn't include Guidance notes that I was twittering on about earlier ... sorry for the confusion.
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Post by Roger on Apr 5, 2019 8:11:07 GMT
Thanks for posting that, it's an interesting guide. The part about efficient machining is worth a look, but its scope is somewhat limited by the poor rigidity of most hobby machines.
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Post by 92220 on Apr 5, 2019 8:16:47 GMT
Hi.
Thanks for the link. Actually you don't need to register. I just clicked on your 'link' and the handbook came on screen with the option to save to disc or print. I thought 70 pages printing when I haven't looked at it yet, was a bit brave, so I saved it for reading, then printing later.
I didn't have to go through any registration of divulge my email address. Thanks for the link. Very useful. Even those of us who think we know enough about using our machine, can still learn more from others, so the handbook will come in very handy I am sure.
Bob.
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Midland
Elder Statesman
Posts: 1,870
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Post by Midland on Apr 5, 2019 9:16:01 GMT
Thanks for the link, worked fine for me. All good learning for us novices, some members excepted of course as they are experts!!!!!! D
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Post by Deleted on Apr 5, 2019 9:22:20 GMT
Link works for me too, PDF now downloaded and saved in my ME file... Cheers Pete
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Post by atgordon on Apr 7, 2019 5:37:53 GMT
Thanks for posting that, it's an interesting guide. The part about efficient machining is worth a look, but its scope is somewhat limited by the poor rigidity of most hobby machines. Roger, you are right ... production machines are built for heavy loads, and the machines used by hobbyist's are much lighter. The general principals do, thankfully, apply to all machines. And as someone with a wealth of machining experience (manual and CNC), you will know that for any new job (even in a production environment), you start with reduced spindle speeds and feeds. In my CNC work, with a new part, I tend to program a 50% spindle speed and 50% feed rate, and then increase spindle speeds using the pendent override until it sounds "right" and then up the feed until it doesn't sound quite as happy and then back off - I have used the same technique on my mill, which is quite light in production terms (it's a prototype mill, albeit weighing 3500lbs) and on a Haas FV-3 mill that I have access too for heavy stuff. I should add that software that I use (F360 now and Mastercam in the past) both supported constant chip load (which means the cutting force on the cutting tool never change during an operation), so I don't have the horrible tool change of direction "oh sh*t" moments any longer. On a manual mill, it's a balancing act ... with a high depth of cut (hard stuff x 3 dia), you are juggling spindle speed from a FS calculator (maybe start at 66%), and manual feeding the X until everything sound good before engaging the power feed (machines talk to you ... over time you learn when they are happy, as you will know).
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Post by Roger on Apr 7, 2019 7:59:44 GMT
Thanks for posting that, it's an interesting guide. The part about efficient machining is worth a look, but its scope is somewhat limited by the poor rigidity of most hobby machines. Roger, you are right ... production machines are built for heavy loads, and the machines used by hobbyist's are much lighter. The general principals do, thankfully, apply to all machines. And as someone with a wealth of machining experience (manual and CNC), you will know that for any new job (even in a production environment), you start with reduced spindle speeds and feeds. In my CNC work, with a new part, I tend to program a 50% spindle speed and 50% feed rate, and then increase spindle speeds using the pendent override until it sounds "right" and then up the feed until it doesn't sound quite as happy and then back off - I have used the same technique on my mill, which is quite light in production terms (it's a prototype mill, albeit weighing 3500lbs) and on a Haas FV-3 mill that I have access too for heavy stuff. I should add that software that I use (F360 now and Mastercam in the past) both supported constant chip load (which means the cutting force on the cutting tool never change during an operation), so I don't have the horrible tool change of direction "oh sh*t" moments any longer. On a manual mill, it's a balancing act ... with a high depth of cut (hard stuff x 3 dia), you are juggling spindle speed from a FS calculator (maybe start at 66%), and manual feeding the X until everything sound good before engaging the power feed (machines talk to you ... over time you learn when they are happy, as you will know). I'm hoping that Alibre CAM will introduce constant chip load tool paths at some point because that would make a big difference, particularly when using the smallest of cutters.
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