New indexer user question

[bruce_taylor]

I finally got my indexer together and I've cut a couple test columns out of glued together particleboard with good success. I would like to cut a 3d corbel now and have a question on how. The part is not centered in the axis. If you set the axis in the long part of the piece and install the blank in the indexer off center and facing up and toolpath the part in aspire will this work. Or does anybody know a better way to machine parts that the center of the axis isn't the longest of the part.

[myxpykalix]

Can you take a picture of what you have in the indexer? Maybe a picture of the file you are trying to cut on the indexer. Usually you need to have things centered in the indexer if the pattern is symetrical and you would need to have it set in the indexer similar to how you set it up within whatever pgm you create it in.
Plus i'm not real clear on your explanation or question maybe a couple pics would help the confusion.:confused:

[bruce_taylor]

This is a similar piece to what I would like to do. Any help would be appreciated.

[Brady Watson]

Bruce,
It is possible to cut a corbel on the indexer, but there are drawbacks to it - especially if you are using an SG series stepper to drive it. It will have too much backlash to keep the big flat parts stable while cutting, and quality and accuracy will suffer.

In theory, the indexer seems ideal for the task of indexing a 3-sided part, turning 90 deg + or -. But...in reality, the best way to machine would be to do the 2 sides, then set the corbel down in the table with the leading edge pointed up and then machine the relief on the front. You will have to make yourself a 'drop table' or find a way to fixture the part to the 3X5 crossmember and get creative. You would toolpath it just like any other 3D strategy.

If you are bent on using the indexer to do this, then set the part between centers, rotate 180 between the 2 'cheek' sides, zeroing on top of the block like any other 3D toolpath. When done, you can rotate the part -90 to get the front/leading edge and machine that. All the indexer is doing is flipping the part...nothing else. No special toolpaths etc. Just do an MB,180 to flip to side 2 and then an MB, 90 to point the leading edge up. If you don't have the Z room, you'll have to come up with your own little trick for holding the part and getting down deep enough.

(cross posted with your pics...)

You can either leave extra material on the ends and restrict the toolpath so that it doesn't cut off your 'on center axis bridges' or just make the material larger and flip on the table.

-B

[bruce_taylor]

Brady,
Thanks once again for a good lesson. I didn't really think about setting it up as you described. Just seemed like the indexer would be good at the 3 sided part,
but will play around with your suggestion. I just have my mind wrapped around
learning the indexer and didn't put down the hammer when I needed the saw.

[myxpykalix]

I think Brady is on the right path. I would make a jig to hold it flat on the table and 3d carve one side, flip it and carve the other.

Then for the narrow side, and following his advice on making a jig to hold the narrow side up i would make the jig at an angle so that the design on the front was as flat to the router bit as possible and create the toolpath on your model that way.
I'd cut away as much waste material on the face of that side to a flat surface and confine your toolpath to that carving. And set your model in your material to that depth so that it carves it appropriately to the curves on the front.

I hope i've explained it plain enough, and maybe Brady could jump in if it's not correct:confused:

Where you will get the most pleasure out of creating with your indexer is with symetrical carvings where you are doing a round carving or something like regular or hollow spirals or designs that wrap around a column. Let me know if you need any help in that pursuit.

[bruce_taylor]

Jack ,
I have read your tutorial on the hollow spiral with great interest and can't wait to try some of that real soon, Really neat stuff!! Some of the 3d stuff really seems to stand off the part so I thought the indexer would be ideal but with Brady's and your insight you guys have saved me hours of fruitless pursuit for sure. It is certainly nice to bounce ideas off such a knowledgeable base of people, This indexer is a whole new animal and I'm learning how to walk once again.

[kevin]

Bruce also the corbel is the most over used elment in kitchens

There cheap to buy they range 100 to 300

Look in the indexing page that helped me when I got my indexing head last year

[bruce_taylor]

Thanks Kevin,
Not really planning on making a bunch of corbels, just trying to polish my skills and learn to utilize the full capabilities of the machine and my brain. Maybe do some one of a kind stuff for myself. I owe myself a really cool mantel for my fireplace so working on the skill set to accomplish that. I have read the tutorials and everything else I can get ahold of and gone through the aspire tutorials on wrapping and I think I know just enough to be dangerous...LOL

[Brady Watson]

This indexer is a whole new animal and I'm learning how to walk once again.

Well...in many ways it is...and in many ways it is the same as you've been doing.

The indexer can be used in many different configurations, and here are a few distinct examples:

1) As an automated part flipper. Turn indexer 90 or 180 degrees for 4 sided or 2 sided part, respectively.

2) As a 'twist synchronizer' where movement of carriage is synchronized with turning of the indexer. This could be used to make threads, barley twists, and even 'fish mouth' tubing notches in PVC pipe or AL, although that is more like #3 below.

3) As an 'unwrapper' - flat 2D and 3D designs can be unwrapped by lying to the indexer by locking your unused axis, and replacing the B axis in degrees with let's say the Y axis, which is in inches. This will 'roll' a 2D or 3D symmetrical design around the indexer, provided that your material setup in CAD/CAM is the exact same dimension as the diameter of your workpiece times pi.

4) As a means to machine a continuous symmetrical 3D 'relief in the round', using strategies such as those in Aspire where the process of unwrapping is handled in the software rather than jumping through hoops as in #3. The leaning tower of Pisa lithopane is an example.

5) As a means to machine a continuous non-symmetrical 3D relief or 3D part that is non-symmetrical and difficult to unwrap using conventional software, such as a French cabriole leg, statue or similar model that does not possess any appendages sticking way out from the center axis, such as the Statue of Liberty.

This list is by no means comprehensive...and I know some parts may be confusing. You see the indexer can be used in SO MANY different ways that many people get so confused because they may think it can only be used in one way...

Don't be afraid to blaze your own trail and do your own experiments. Get the blue/pink foam back out and chuck it up. Play & learn. When you feel comfortable, move up to MDF...then poplar...then the harder stuff. Each material has it's own 'twang' when it is in between centers.

-B

[myxpykalix]

here is a indexer tutorial put together by Randall Newcomb that i think will give you some background and help you:
http://www.humblesticks.com/cnc-rotary-tutorial.html

[bruce_taylor]

I have read these tutorials and it was really good info, thanks to all that contributed to it.

[donclifton]

Glad to see you got it up and running. Get Deskproto and all the problem will go away. You can download a full working demo for 30 days and it has a post for shopbot.
Don Clifton