By Yosiu
Updated by: August 22, 2017, 9:03 am
Shoulder length and tool stickout [SOLVED]
Hi, I'm still testing your software and I really like it. However, tool deflection can;t cope with some of my tasks. I tend to do a lot of work in welded parts, using tools with long stick out. For example - 32 mm indexed endmill with 80mm shoulder length mounted on long Weldon 32 shank with A=230mm and diameter of 78mm. To describe this tool I would need flute length(for the length of carbide insert), shoulder length for the length of the tool before Weldon shank, and shank diameter and tool stick out for this Weldon shank. First thing - tool visualization counts shank diameter as only upper diameter and supposes that lower diameter is the diameter of the tool - this makes shank a cone rather than a cylinder which isn't correct in my case. Would you consider adding lower and upper shank diameter? Second, it doesn't count shoulder length into tool deflection calculations which give unreliable feeds and speeds for those kinds of long stickout applications. Other than that, for regular stickouts, I think your software is very good. Especially tool management is much better than in G-competitor I have also trialed ;)
Eldar Gerfanov (Admin)
Hi, thanks for complementing Calculator and the Tool Database. I was actually considering making the database a standalone product, but decided to make it a part of HSMAdvisor instead of spending a lot of tome and resources into it. Can you attach a a sketch of your tool here or a picture, so I can suggest how to better enter its parameters? In general it is VERY rare that I could not accurately enter the info that mattered In to the calc. By the way. You are right. Shoulder length does nothing right now. I entered it for better Mastercam integration. Regards.
Yosiu
Thanks for the fast response, I've attached a screenshot from Fusion360 with additional comment. As you see tool is pretty long with varying geometry. I'm looking forward to see how to parametrize that kind of tool in your software. Kind regards, Jan Oko?
Eldar Gerfanov (Admin)
Ah I see what's the problem! You are trying to enter the tool holder geometry into the calc. This is not possible in case of simple end mills. Not only it is not possible, it is not sensible to do so either. You should enter the meaningful info. The best way to figure out which info to enter is this: Think which part if the setup will break off should you take too deep of a cut? It is obvious that it is the straight portion of the endmill just below the tool's shank. So it only makes sense to enter just the tool diameter, its flute, stickout would be your shoulder length. Even entering proper shank diameter would not change the picture. The holder and the shank (in this case) are too strong in relation to the tiny endmill. Sure they will bend, but this bending will not cause either to fail and thus should not he included into the calculation. Yes, the overall setup will be a lot more flimsy with long-reach holders, but I do not want to enter the holder calculation into the mix because the involving complexity. Right now you can adjust for flimsy setups by moving the Performance Slider to any value below x1 In your case I would set it at x0.75 In general whenever you are getting something maxed out, or deflection too high, it is better to adjust the Performance Slider until the problem goes away. I hope I could answer your question and offer a satisfactory way of dealing with unavoidable software limitation. Best regards.:ernaehrung004:
Yosiu
Thanks for answering. It's new tool and toolholder for me so I have no experience how this will work out in the long run. In this setup I had to use pretty slow feeds, I'll try this tool in the regular toolholder probably during this week so I'll see how much of additional flimsiness comes from this long toolholder and what comes from the tool itself. I'll drop by and give feedback after the tests. Kind Regards, Jan Okon
Yosiu
On the other hand, even now, if you check in your calculator: Same tool(32 mm indexed end mill 90deg angle) with shank diameter 32mm and stickout of 88mm (tool geometry only ) would have twice less tool deflection than tool with shank diameter 78 and 230mm tool stickout (using shank geometry only). This means that tool is probably more rigid than the toolholder. Using only tool geometry would, in fact, give less significant information than only shank geometry as feeds and speeds suggested for shank geometry are more conservative than those for tool geometry. In reality tool deflection would be (in the best case, I guess) additive, so with those kinds of long reach application, it might not be enough even to use 0.5 performance slider if you restrain only to tool geometry. I guess I'll have to dig some information about tool deflection to better predict the impact of the long toolholder.
Eldar Gerfanov (Admin)
Besides the endmill (the only thing my program concerns about) there is as, you said, Tool Holder but also the whole spindle, column and helluvalot other things bending in the machine. IE: if you take an "unbendable" 12.5mm dia 12.5mm long endmill and take a 6mm slot in some tool steel. You will still get measurable deflection of the actual tool path from programmed one. Machine Deflection. I would get at least 0.003" doing that. It is VERY hard to predict what and how much will be happening beyond the actual cutter. Any way try to take your tests and let's see if there is any room for improvement on my side :) I am always looking for ways to improve. Cheers!