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Inside Shell Finishing
Hi,
I have this part that needs to have a very good finish on the inside. Was just curious as to if I am using the best strategies to achieve this. My first thoughts was to use a ramp tool path to finish the inside radius followed by a parallel strategy to finish the floor and top radius. Will I be better off with a parallel path to finish all of the inside like the last toolpath in the file? Would this get me a better consistent finish across the part or is my initial paths a better option?
Thanks in advance
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I would not recommend using a Parallel toolpath to finish the entire part, it's not going to be efficient or produce an ideal finish. I would use a mix of toolpaths to accomplish this, such as Scallop and Flow:

Seth Madore
Customer Advocacy Manager - Manufacturing
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Geodesic also makes a really nice toolpath, and it's almost 25% the code size of Scallop:

Seth Madore
Customer Advocacy Manager - Manufacturing
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Thanks for the help. How are you getting much smaller code using geodesic? my code is much larger with the same smoothing and stepover figures in the scallop.
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Actually, the Smoothing in Geodesic doesn't reduce code size in many cases, it creates an "even point distribution". Turn off Smoothing and watch your code size plummet

Seth Madore
Customer Advocacy Manager - Manufacturing
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Thank you soo much for the help. Code size was heavily reduced and have produced a half decent part! Last question, is there a way to smooth out the code even more? Have a very nice finish in the "x axis" but y not great with a fait amount of "gouging". Have played around with the tolerance but doesn't seem to make a huge difference.
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Well, that's less than desired. What is your machine and controller?
Another option would be to use a Blend toolpath for the bottom face, that toolpath produces just a bit more code than the Geodesic toolpath and virtually no points in the cutting motion:

Seth Madore
Customer Advocacy Manager - Manufacturing
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Sorry to pick this up again. I have a few variants of these to do and looking to get the right strategy to allow minimal polishing.
I seem to be getting the best results using a parallel path but comes out looking like multiple lines making up the arc and not a smooth arc, as per pictures. Could it be the model is made up of multiple lines and not a true radius? Drawing states a R405.8. If this is the case is there any way to "smooth" the model?
Thanks for all the help so far.
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Without seeing the file with that parallel toolpath it's hard to guess but if your tolerance value is too large you will see faceting like that.
0.01 is standard and should provide good results, you can try going to 0.005mm but another trick i like to try out is to right click on the toolpath and select compare and edit.
then find the value for "Surface triangulation tolerance"
Change that form "tolerance*0.5" to "tolerance*0.05"
might help
Also make sure you have smoothing turned on in the post properties, this will activate CYCLE 32 in the controller which will make it run better than with it off.
I wouldn't use the 0.1 value though on the standard Heidenhain post, I have modified mine to output different values depending on the operation tolerance and whether its roughing or not.
Heidenhain recommend 1.3*tolerance for the optimum values for CYCLE 32 (that's the tolerance value in the operation)
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Thank you for the help. I have posted the file. I had my tolerance set to 0.06, will try dropping to 0.005 on next run. Would you also use smoothing tolerance on this? Having looked at the Surface triangulation tolerance it was set at 0.03mm. what affects this figure or is it a manual change? My cycle32 was set at .1mm and "finishing", could it be that the tolerance was set too high on this causing issues as well?
Appreciate all the help.
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Yea 0.06mm is too high for a finishing path and is likely what is causing the faceting.
The surface triangulation tolerance is by default tolerance*0.5 which is why it was at 0.03.
I would start by reducing the tolerance to 0.01 and see how you get on, it should be much better.
Your cycle 32 tolerance should be 1.3*0.01=0.013
Fusion