Bobcad 24 Pocketing Tutorial

T

Tony Zinzola

AzB Silver Member
Silver Member
Since a lot of people seem to have problems using Bobcad 23 or 24 and are still stuck in the dark ages using 21 or lower, I figured I'd post a step by step tutorial on how to cut a pocket for a simple diamond. If there's any interest, I will post a similar tutorial on how to cut the parts later.
 
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In post #1, the second step of mirroring the points for your diamond, the selected plane should be Z-X. Your screen shot is correct, but text is not.

I'm sure this post is worth it's weight in gold to those who need the information. Thanks for taking the time.
 
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Tony,

What an incredibly generous gesture!! And you're elapsed time was 1hr and 9 minutes, pretty quick considering all the copy and paste of the screen shots, but also very generous for you to donate that time.

Thanks!!

Gary
 
Wow, bobcad has come a long way since I used V17 back in the day.
Good stuff, very well done tutorial!
 
One of the things that is useful in BobCad is the ability to enter formulas into the input boxes, rather than just absolute values. For example, a rule of thumb for calculating a finish pass side allowance is, finish tool diameter / 8. So, in the example above using a .0313 finish bit, you can enter .0313/8 in the side allowance box, hit tab, and BobCad will do the calculation for you. Works the same way if you have a rule of thumb for circular lead radius, depth of cut when multi-stepping, etc.

In a perfect world, BobCad would allow you to choose a different milling method (climb vs conventional) on the finish pass as opposed to the roughing pass in the same feature. This would allow you to climb mill roughing operations, which will keep the tool from deflecting into your boarder on the final roughing pass, and use conventional milling for the finish pass which will let's the bit's tendancy to grab into the material balance against the materials tendancy to resist penetration on a very fine cut. This can be accomplished using two different features instead of just one, or you can just conventionally mill the whole thing and use a larger roughing side allowance to compensate.
 
Mr Hoppe said:
One of the things that is useful in BobCad is the ability to enter formulas into the input boxes, rather than just absolute values. For example, a rule of thumb for calculating a finish pass side allowance is, finish tool diameter / 8. So, in the example above using a .0313 finish bit, you can enter .0313/8 in the side allowance box, hit tab, and BobCad will do the calculation for you. Works the same way if you have a rule of thumb for circular lead radius, depth of cut when multi-stepping, etc.
Click to expand...

I use this math function all the time. As an example if you want to scale, use the translate tool. In the scale box take the desired size that you want and divide by the current size of an object you have. For example if you have a line that is 1.5 inches long and you want it .75 then in the scale box type .75/1.5 and then tab. Your scale is now set to .5 or 50%.

Jim.
 
Question for Tony

First, let me say that your generosity in providing this tutorial is without measure!!!!!

Now for my question.

You stated that you make your roughing passes in steps and your finish pass at full depth. I tried that initially, but ran into problems when my design had a feature with an acute angle. I rough with a larger cutter and finish with a smaller diameter. At the root of the acute angle, my finish cutter would be in full cut because of the difference in the size of the cutter used for roughing. The result was that I broke a lot of small (i.e. - expensive) cutters. I could eliminate the problem by using the same diameter to rough and finish, but I like to use the less expensive cutters to hog out the majority of the pocket. I've since changed my finish passes to be in steps (like the roughing passes) and that solves the problem and the pocket wall is still smooth (no step marks), but I'd much rather do my finish pass at full depth. Just curious if you ran into similar problems and, if so, how you delt with them?
 
Good Post Tony,
I am sure this will help me, I'll have to get it on my other computer so to follow the direction.

Thanks
 
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