Toolpaths for indexer

[denver]

I'm in the middle of setting up an indexer, so I'm also investigating methods of generating the necessary toolpaths. I've had good luck so far making cylindrical things using Vectric's Cut3D and carving two sides. That works as long as the object is properly symmetrical, but I've recently gotten some requests for things that can't easily be done that way. I've included an example of one below.

I've noticed that if I use similar settings for the indexer as I used for Cut3D, the resulting indexer files sometimes take a lot longer to cut than the two sided ones. For example, the two sided version for the finial takes a little over an hour for each side. Using code produced by DeskProto, it takes nearly 5 hours.

On the other hand, the bead and reel molding that I've made in the past takes about the same time either way.

Is there a different relationship between the bit diameter and the stepover when using an indexer? For relatively small or detailed objects, I generally use a 1/8" ball nose. If I want a very smooth finish, I use a stepover of .01". If it doesn't need to be real smooth I'll go up to .015". Seldom as high as .02".

Thanks,

Denver


35621.jpg

[denver]

I should add that the finial is about 14" tall. The bead & reel molding I've made in the past was about 1" in diameter and 24" long.

Thanks,

Denver

[myxpykalix]

It would seem to me that you could use a more liberal stepover because most of it is symetrical and you could simply sand out any rough marks by spinning it and using sandpaper or putting it on your lathe to do that (if you have one).
As far as your reeding goes, i have been trying to make a toolpath using a simple profile of the reeded part to use a side reeding bit follow the path, move back, rotate (X) degrees then do the next, without much luck.
This would not work with a reeding bit keeping your part as a whole like you show, but would have to make it in 2 pieces like i illustrate here.
To make it like you illustrate i would think you would need a tall roundover bit and even then i can't see how you would make this as one piece, but if you can i'd like to know how also.

35629.jpg

[myxpykalix]

also, If you need any spiral toolpaths to try on your indexer or help setting it up, let me know.

[cmagro]

Denver,

What's the diameter at the base?

[denver]

Thanks Jack. Your approach is interesting, but the radius of the flutes, or reeds, gets smaller as they get closer to the center. It would be difficult to duplicate that with a fixed radius roundover bit.

I'll keep the offer for spiral toolpaths in mind. I enjoyed reading about your adventures along those lines and seeing your photos.

Christian, the base is about 4" in diameter in this model. I don't have exact dimensions of the originals yet. I just made that model guessing from a long distance photograph. I'll be making these as part of a restoration project, if it gets approved.

Thanks,

Denver

[cmagro]

Thanks for the info Denver....I'm a little ahead of schedule with stuff and wouldn't mind taking some time to make a couple of finials. I'll post step by step if I do get a chance.

Christian

[denver]

Hi Christian, that sounds good. Do you want a copy of the model?


Thanks,

Denver

[cmagro]

Already modeled it but go ahead and send what you've got.

[cutitout]

how many reads are on the turning? can you program one or two reeds then rotate/index a division of deg to reeds. if 36 reeds index 10deg