table legs

Topics related to wrapped rotary machining in Aspire or VCarve Pro
mike1966
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table legs

Post by mike1966 »

Hi,
I am trying to make table legs using aspire, but they need to be square at the top 6in
I could just not machine the 6in by telling the software they are 22in instead of 28in but I wanted to see the preview of the legs before I cut them.Is that possible in aspire?

mike1966
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Re: table legs

Post by mike1966 »

this is a pic of one of the legs that I make so far I haven't been able to use aspire for these and have to use a lathe does anybody have any ideas on using a cnc for this?
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butcher block.jpg

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vfauto
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Re: table legs

Post by vfauto »

mike1966 wrote:this is a pic of one of the legs that I make so far I haven't been able to use aspire for these and have to use a lathe does anybody have any ideas on using a cnc for this?
What type of machine do you have?
Thank You
Frank

mike1966
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Re: table legs

Post by mike1966 »

I have a 5 x 10 homemade machine with a indexer, I am using aspire 3.5

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rscrawford
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Re: table legs

Post by rscrawford »

That would be very slow with an indexer, and you'd have a lot of sanding to make it smooth. Much faster if you bolted a regular lathe to your table, set a fairly high speed, and used your spindle as the tool, using only 2 axis (Z and X) and cutting slightly off centre to get a cleaner cut. Then sand it while the lathe is spinning. Then cut the mortises using the pin indexer on the regular lathe to index the 4 sides.
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Re: table legs

Post by tmerrill »

and you'd have a lot of sanding to make it smooth
I guess I don't understand this statement.

When done correctly, a 3D finish toolpath should produce a finish requiring little sanding - if any. At least those are the results I get.

It does not matter whether the material is flat or on an indexer.

Tim

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mezalick
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Re: table legs

Post by mezalick »

If I understand your question, you are asking about seeing the top square section... yes ?
If so, the answer is yes.
Here is a picture of a file I am working on.
This was done in Aspire
It's a bit tricky but making a square on the rotary can be done.
If you need help, drop me a line.
Michael
mezalic@nni.com
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rope leg 5 (2).jpg
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vfauto
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Re: table legs

Post by vfauto »

mezalick wrote:If I understand your question, you are asking about seeing the top square section... yes ?
If so, the answer is yes.
Here is a picture of a file I am working on.
This was done in Aspire
It's a bit tricky but making a square on the rotary can be done.
If you need help, drop me a line.
Michael
mezalic@nni.com
I have been trying to figure out how to draw a spindle in Aspire also. Michael can you give us the ten cent tour?
Thank You
Frank

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mezalick
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Re: table legs

Post by mezalick »

PM sent

vfauto wrote:
mezalick wrote:If I understand your question, you are asking about seeing the top square section... yes ?
If so, the answer is yes.
Here is a picture of a file I am working on.
This was done in Aspire
It's a bit tricky but making a square on the rotary can be done.
If you need help, drop me a line.
Michael
mezalic@nni.com
I have been trying to figure out how to draw a spindle in Aspire also. Michael can you give us the ten cent tour?
Michael Mezalick
https://www.youtube.com/user/mezalick
mm@mezalick.com

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Re: table legs

Post by dealguy11 »

Here is a rendering of a chair leg I made for a customer last week. The trick is to draw a square the size of the cross-section of the block, center it, rotate it 45 degrees, then use the Vector Unwrapper gadget to unwrap it. The resulting vector can be used in a 2-rail sweep to create the block section. As you noted, you don't actually carve it -- it's just for show.
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Back leg with modified center.PNG
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rscrawford
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Re: table legs

Post by rscrawford »

tmerrill wrote:
and you'd have a lot of sanding to make it smooth
I guess I don't understand this statement.

When done correctly, a 3D finish toolpath should produce a finish requiring little sanding - if any. At least those are the results I get.

It does not matter whether the material is flat or on an indexer.

Tim

You must not do much lathe work! Turnings are typically sanded and polished to a VERY smooth finish, and that is pretty much expected on any turning. My indexer doesn't come close to that kind of finish, even with a 5% stepover, and I am sure a home made indexer wouldn't give a better finish. While a job like that can be done on an indexer, it is better suited for a lathe. Sometimes when you have a hammer everything starts looking like a nail...

If I wanted to make all the pieces exactly the same and i was not confident in my lathe skills, I might rough it out on the indexer and finish it up on the lathe. My 4 jaw chuck will transfer back and forth. That way I could do the final sanding and finishing on the lathe.
Russell Crawford
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vfauto
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Re: table legs

Post by vfauto »

dealguy11 wrote:Here is a rendering of a chair leg I made for a customer last week. The trick is to draw a square the size of the cross-section of the block, center it, rotate it 45 degrees, then use the Vector Unwrapper gadget to unwrap it. The resulting vector can be used in a 2-rail sweep to create the block section. As you noted, you don't actually carve it -- it's just for show.
Steve I have a Artisian 72" and run Aspire 3.5 where can I get a video or some sort of training on how to draw that up in Aspire?

Frank
Thank You
Frank

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dealguy11
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Re: table legs

Post by dealguy11 »

Frank, I really don't know of any. I pretty much figured it out for myself based on other posts I've seen in the past and trial and error with the tools and gadgets in Aspire. Here are a few more tips:

1. the project needs to be set up on the wrapped job setup with the diameter set to the length of the diagonal, not to the sides of the square. In other words, if you're cutting a 2x2 column, then the diameter of the part needs to be set to 2.8284 inches.

2. I always increase the y-axis length in job setup after running the wrapped job setup. This means that the wrap actually goes a little more than 360 degrees, which addresses problems that can occur at the edges of the wrap otherwise. This doesn't affect the radius of the part, because that is controlled by the thickness.

2. You need to make sure the square you use for vector unwrapping is centered in the job before you try to unwrap it. You will get a very frustrating and uninformative error message if you don't. I wasted a lot of time figuring this out. Also, it has to be rotated 45 degrees with the start point on the bottom, or, again, you get an error message.

3. It is possible that you will get an error message anyway, if the height of the unwrapped vector rounds to a number that is greater than the radius of the part. It is unpredictable whether it will do this or not, and the error message doesn't really help you understand what's going on. If it does, make the square .01 or so smaller than it really should be (i.e., 1.99 inches to the side rather than 2.0 inches) - this won't really be noticeable in the rendering.

4. You will need to model the shoulder that goes on the end of the block. If you look at a lathe turning, you will notice that the shoulders are curved to some extent because of the intersection of the circle (from turning) with the square of the shoulder. They never go straight in (or almost never, except in some modern work), and going straight in doesn't look natural. I model this shoulder, and actually cut it using a small carving bit. You model this by setting up a slanted element with a 2-rail sweep that goes all the way to the end of the diagonal on the square. I'm probably not explaining this well. You can make the shoulder look natural in the rendering by overlapping the block and shoulder slightly and setting the combine mode to "Low".

If you need more help, leave me a PM and I can try to explain it better.
Steve Godding
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dealguy11
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Re: table legs

Post by dealguy11 »

Tim, my experience with finish on the indexer is the same as RSCrawford's. The quality of the cut doesn't even approach that of lathework, and I always take my turnings from the CNC to the lathe for sanding and even for some touchup with a gouge or a skew. I especially find that the shoulders of blocks (as described above) require work because of the steepness of the angle...the CNC gets it close, but the final work has be done by hand.

It's also very slow by comparison for some kinds of turnings. If it's commercial work and doesn't require something special, like spirals, carvings or asymmetrical shapes, then it's probably better just to do it on the lathe (if you have one).
Steve Godding
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mezalick
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Re: table legs

Post by mezalick »

This was cut from a 6" diameter piece of wood.
Square ends are possible to cut on the rotary.
Michael
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finished-rope-leg.jpg
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