How to machine this on Indexer

[khalid]

I want to make the following part on indexer...Neither I want to machine the part through lathe nor i want to make 3D model and unwrape it and make tedious 3D toolpath indexing.....I have a stock diameter of 3" and the part maximum diameter is 2.5"...

Question is:
1- Is there any simple way (2D or 2.5D) to make this part?
2- After making this part i want to do some barley twist..is it possible??How can I make this part?..
3- How will you make this part...


38329.jpg

[myxpykalix]

To carve the profile, use the virtual tool "carve the blank using a partwizard profile"
to carve your profile.

Now the problem is you can't put a spiral or a barley twist on a curved surface. The section you would want to spiral has to be 90 degrees to the surface of the bit.

Now if you want to spiral a straight section of the part Christian Magro has shown how he spiraled on a taper however I believe it was done with some utility he made up or something other than shopbot software. In any event it was a straight taper.

In leiu of having what he has, my thought was to first carve a taper using the virtual tools then my thought was to make some type of jig that would raise that taper so it was parallel to the bit then you could spiral it.
This is just in my head haven't tried it so i don't know if that would work.
The better solution would be a software solution but i don't know of any.

[jseiler]

depending on how you have your indexer set up, you can program this directly or at the keyboard. If your bit will take that in one pass and your indexer is set up in distance instead of angle (swapped indexer for y axis).

Say your indexer is on y and if you tell it 4", it goes around 1 revolution. if you were at x=0 and had z=0 at the center and you wanted a nice smooth finish so you wanted 1" x moved for every 20 rotations, you'd

plunge z down (call it .5 in)
cut the first inch of that slope using spiral
(20 rev * 4 circumferance * 1 in) for y.
change direction for y?
cut the next increment
continue until done

mz .5
m3 1,80,.6
m3 2,0,.7
m3 3,80,.8

when you do a curve, space your points closer together. If you are good with excel, this would be very easy to code as a macro.

if you work in xzAngle mode, changes would have to be made but the method should work.

[khalid]

Hmmm... Still working on from yesterday to get the easy solution
Thanks jack and John, for enlightening

[bill.young]

If you're using the "turn a profile" option in the Indexer Virtual Tool to create your original shape, I've just uploaded a "Profile Twister" program to ShopBot Labs that will create a spiral toolpath that follows the contour of the shaped blank.

http://www.shopbottools.com/ShopBot_labs.htm

You know the drill...everything in ShopBot Labs should be considered experimental. Don't be surprised if it doesn't work the way you expect, or doesn't work at all. If you have issues or suggestions please email me and let me know...

Bill

[myxpykalix]

Bill,
This is why we like you, aside from your good looks and charming personality you got brains!
This is something i've been trying to do for a while. Let me ask a few questions though so i understand.

Number of revolutions to turn for twist (in degrees)- you have 360 input. Can I assume that means 1 revolution?

If so, then the diameter of your bit will have a bearing on how many revolutions (or part revolutions) you input correct?
As an example, I have a 6" long piece and a 2" diameter rope spiraling bit so the number i would input in that box would be 1080 (or equal to 3)?

Cutting depth (below the face of the already shaped profile)- Am I right in assuming that you are Zzeroing to the surface of the material at the beginning of the profile or Zzeroing to the middle of the stock?

Start point of twist-(must be the same as original profile)-If you have different diameter bits you couldn't have the same start and end points as original profile or you would cut into your start or end points right?

Bit diameter that was used in creating original toolpath-I would be using a rope spiraling or barley twist bit that would be different from the bit used to create the profile, why is this box needed, to correlate the pattern between the different size bits?

How is the contoured toolpath made with no place to input the shape of the profile?

As i am rereading all of this some of my assumptions are based the drawing above and your description "will create a spiral toolpath that follows the contour of the shaped blank". Should I go back and assume this works with a straight taper and NOT a curved taper as depicted above?

Maybe i am overanalyzing and not seeing the forest for the trees, but I'm a bit confused. Thanks for your work on things like this I appreciate the time and effort Bill.

[bill.young]

Jack,

You would use this after you turn your blank to the profile using the Profile option in the Indexer Virtual Tool. It follows that profile but rotates as it moves along the blank. So when it's moved halfway down the blank, it's done half the number of degrees that you specified.

The only reason that it needs to know what size bit you used to create the original profile toolpath is because of the offset for the ballnose that's in the file..it needs to be compensated for.

You zero from the surface of the blank for this program because you've already accurately sized and shaped your blank when you profiled.

When you click the "create my file" button it will ask for the name of the new output file it will create, and then the name of the toolpath that you used to create the profile...that's how it knows the shape.

And yes it should work for any profile that you can turn using the Profile option of the Indexer Tool, like the curved one above.

Bill

[myxpykalix]

I had not gone as far as clicking on create file so that accounts for some of the confusion.

I'm still a bit confused about starting points. If you look at my example (disregard the angle of the curve and my shaky handed picture) how or where, because i have the shoulder on the left that i don't want to hit would i position the larger bit?

38339.jpg

[khalid]

Bill Many Thanks for your contributions...Both for the program and the explaination...

The bad part is that I am not the shopbot user
I am using Artcam.... So I don't Know about the Part Wizard and its 'Virtual Tool' to profile the shape...

Also the problem is that i can't use the output file in Mach3 for my Machine..
..You See Lots of Problems ;)...

Now, can I ask some question and advices


1- If I pre-turn the part on the lathe to the same countour/Profile, then use Feature Machining operation in Artcam by making the relief first and then make some vectors and Toolpath it through Feature Machining.... Is that possible?? If it is possible then we can make complex shapes in very short time... We can engrave names and slopy surfaces..etc..

2- The second way is To make the 3D relief in Artcam and then unwrape it and generate the toolpath... My Machine will cut the above Profile in multipassess... Then I use Feature machining option..

3- I can make 3D relief of the whole part including barley twist, and machine it... This will take much longer time because lot of short moves to make ropes...


I think the first option is right to save the time..I will go through it and experiment it and will show you the results in this week end.. I don't have barley twist tool but will make simle spiral flute on the above mentioned profile shape..

Thanks for reading my fractured english and bearing with me that long..

P.S: Jack ask many questions as you can.. You are a shopbotter and BILL is kind enough to help us in resolving this matter...