Senior Member
John,
A very slick setup. You have a good range of lengths with that setup with minimal work to move.
How long have you had your indexer? What do you use your indexer for? How do you create files you cut on your indexer?
Good job, i enjoyed the link with the pics.
Senior Member
John,
Very nice job. It's nice to see more homebrewed documentation. Did you have to do any shimming to get it right? I plan on making a similar setup so I can do longer lengths. What are you using to create you files? I have been using Partwizard and then hacking the file so it travels the profile than rotates 1 degree and recuts the profile. I loop till I hit 370deg.
Senior Member
Jack,
I've had the indexer for a little over a year, but haven't begun to dig into it seriously until this past summer. Our indexer (and ShopBot) lives in a college theatrical scene shop, so it gets used for whatever anyone can think of. I envision lots of use when we are needing to build recreations of period furniture, but I also recognize that the sky's the limit. My early learning was exclusively done using the indexer tool [TI] command in the control software (and Part Wizard for the profiles). More recently, I've been experimenting with "unwrapping cylinders" in ArtCam Pro.
34988.jpg
This was a learning project that I did. It hasn't been used in a show, but I'm guessing that it will only be a matter of time...
More photos and detail are shown on my web site.
http://www.colby.edu/personal/j/jder...andleStand.htm
.
Senior Member
Todd,
I haven't found the need for shimming yet. Everything seems very parallel to the X-Rail. To keep the height parallel to the table, I've relied on the accuracy of the ShopBot to cut my mounting plates. I've been impressed with the accuracy of the Unistrut. That said, somewhere in the forum, I've seen a post where someone purchased a full-length piece of extruded aluminum tracking. This is an idea that I hope to persue some day.
See my previous post for how I've created my files so far (I've still got a lot of learning to do).
For the center-post of the candle stand (shown in the previous post), I drew the profile in Part Wizard and used the "Carve the blank to a shape using a PartWizard profile" option from the indexer tool command [TI] in the control software. That created a file that rotated the blank over 700,000 degrees and moved a 1/8" ball-nose bit .0125" along the X-axis each 360 degrees. Unfortunately, the control software has a max limit of roughly 530,000 degrees, so I had to create two different files. The result of this wasn't perfect and required "free-hand" corrections. I'm looking into using Excel to edit the cutting file so that any B-axis command over the limit could be reduced by a common variable, but haven't had the time to try it yet.
I've had problems cutting parallel to the length of the turning as you've described because any given distance from the center-line of the turning axis yields a unique amount of stepover resolution and my results have been less-than-desirable. For instance, 1° at 1/4" from the center-line is very different than 1° at 1". But, since I'm quite a newcomer to this, I do plan to explore everything much further.
As to longer lengths, it caused me great pains to cut down the Unistrut from their original 10' dimension. But I had to do so for the same reason forced me to buy a 48" x 48" table -- I didn't have enough room. Ideally, I would have kept the full length intact because while I could only cut around 48" at a time, longer turnings could still be achieved by tracking the indexer to different locations.
.
Senior Member
John,
I went to your link and got some real good info and was real impressed with the quality you got. What was the milling time for the center post?
Please explain what you mean by "The top-most ring in this view was "free-handed" with the ShopBot in keyboard mode."
I thought i understood that you could not move the axis' while the indexer is turning (if that is what you mean).
Did you have a rough cut/finish cut files? Was this all done with the one ballnose bit?
Very nice looking, you should be proud i'm impressed.
Senior Member
John,
"I've had problems cutting parallel to the length of the turning as you've described because any given distance from the center-line of the turning axis yields a unique amount of stepover resolution and my results have been less-than-desirable. For instance, 1° at 1/4" from the center-line is very different than 1° at 1". But, since I'm quite a newcomer to this, I do plan to explore everything much further. "
I am very new to this as well. I see your point about resolution. I am using this technique as a first pass. I found that I can take more off at one without as much tear out. I learned this technique from Christian Margo. He had it on a psot about newel post.
Senior Member
Jack,
I don't remember the turning time, because the work was done in phases (both roughing and finishing). My best guess is 1-2 hours but it could have been less.
My "free-handing" consisted of positioning the bit by eye (with the spindle running), using the keyboard command in step mode. Then I would close the keyboard and type [MB 360] or [MB 0], depending on its current position. I repeated that process several times until I had corrected the original cutting mistakes enough that I could finish the job by hand. The total length of the "free-handing" was about 1/2".
I don't recommend this method, but it's nice to know that it can be done in a pinch.
Senior Member
Todd,
Cutting each pass parallel to the indexer for a first pass makes sense to me and seems to be working well for you. How did you convert or "hack" the Part Wizard profile to the Z axis? And did you add the 1° turns to the file or run it multiple times; turning the blank inbetween each pass?
Senior Member
John,
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