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Turning only part of a drawing
« on: April 11, 2012, 09:52:18 PM »
I've drawn a 3/4 diameter 2.24 in. long clock pillar in the baluster style and want to use LazyTurn and Mach3 Turn to finish it. I'll form the 1/4 OD end parts that fit into the 1/8 in. clock plates first as I need to drill and tap them. I'm not up to doing that with a Sherline lathe under CNC so have not shown them on the drawing. I assume I must show the spigots, as these parts are called, on the drawing but how do I tell the two programs to machine only the center part? My knowledge of the relationship of machine, program and part coordinates is a bit hazy. The machining appears to be between the end of the billet and the chuck. I'll probably use a 4 jaw chuck and a tailstock center for holding and both a right and left hand bit.

Another related matter is the example of a 35 degree diamond tool in LazyTurn. I haven't seen such a shape in the 1/4 in holder size. I've got a set of Warner's holders and 80 degree HSS inserts but they don't appear to have 35? Any idea of where to get 35 degree inserts and holders, carbide or HSS? The 80 diamond's do not get fully into the corners of the baluster but a 35 should do better.
Need to remove only center portion of drawing
« Reply #1 on: April 12, 2012, 10:04:35 AM »
The system is timing out using Reply

Here are some images to further explain some problems. The DXF is a redrawn pillar with the “spigots” added. The major diameter is ¾ or radius of .375, the minor radius is .172 leaving a radius to cut off of .203. Assume .05 per cut so it should make 4 rough passes. Correct?

Tif 1 is a screen shot of the righthand tool setup. The left and center tools have similar specifics. Tif 2 shows LazyTurn before the rough pass is created. Note the depth per pass is .05. Tif 3 shows the first rough pass.

I’d really like Mach3 to skip any machining at the spigots as shown by the paths at these locations. How do I set up the drawing or LazyTurn just to machine in the center of the rod?

Why is the amount removed only .118 or what exactly is the .118? I didn’t find this in the manual. Why do the passes leave so much left on the minor diameter section? The second rough profile with the lefthand tool (not shown) is similar to the first but takes only .001 off. Tif 4 is the finish profile (not shown, only 4 attachments allowed) and it apparently has to take a lot off. The number of passes should be 3 but there have to be many more.

Any suggestions?
Need to turn only middle section of drawing
« Reply #2 on: April 12, 2012, 10:08:12 AM »
The system is timing out using Reply just for images. Here are 2.
Re: Turning only part of a drawing
« Reply #3 on: April 12, 2012, 12:04:38 PM »
  I assume I must show the spigots, as these parts are called, on the drawing  ...................

You can jimmy the start point but not the end point.
Might be best off to do another dwg including ONLY the portion that you want to machine as you do not have to show the spiggots.
I'd just reference the the face of the spiggot seat as Z0 when you set up the part.
Re: Turning only part of a drawing
« Reply #4 on: April 21, 2012, 09:23:23 PM »
Both LazyCam's SIM and LazyTurn insist on facing off the stock all the way to the center regardless of whether the spigots are shown or not. Unfortunately, there's going to be a live center there. Setting the start point to -.25, for example, doesn't seem to help. It looks like these sections of the G code will have to be manually deleted.

Offline RICH

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Re: Turning only part of a drawing
« Reply #5 on: April 22, 2012, 01:23:44 PM »
Quote
35 degree diamond tool in LazyTurn. I haven't seen such a shape in the 1/4 in holder size

Can't be of much help on that statement other than grind your owne or check vendor sites to see what's available.
Even a 35 degree will not get into the very tight corners and you need a point tool with a radius on one or both sides such that it won't gouge the work. One should take into consideration the type of tooling to be used when designing a profile.

You can't select sections of a profile and the only way around that restriction is to use different dxf's files. Higher end programs will let you select the start and end points along a profile. Lt never went that far in development and thus it is what it is for the price.

I can't comment on some of your questions as i need to see some pic's.
I would suggest you play with the rough and fine pass settings to get a handle on the pathing. The manual covers pathing.

Quote
Both LazyCam's SIM and LazyTurn insist on facing off the stock
No comment on LazyCam Lathe and strongly suggest you use LazyTurn.

Quote
LazyTurn insist on facing off the stock all the way to the center regardless of whether the spigots are shown or
not.
Note the attached pic and first few lines of the code below as it does not face it off to the center and starts on the outside of the profile with the spigots removed.

N15   G40G90   
N25  (Change to Tool: 35 DIAM 379 FLANK L                                                           -R0.0020-IC0.3790    Angle:00)
N35  T0000
N45  S402 F1.00 M3
N55  G0Z0.0130
N65  G0X4.8651
N75  G1 F1.0000  X2.8611  
N85   X0.8311  
N95   F1.0000  Z-2.2533  
N105  G0  X2.8311  
N115   Z0.0130  
N125  G1 F1.0000  X0.8311  
N135   X0.8011  
N145   F1.0000  Z-2.2533  
N155  G0  X2.8011  
N165   Z0.0130  
N175  G1 F1.0000  X0.8011  
N185   X0.7711  
N195   F1.0000  Z-2.2533  
N205  G0  X2.7711  
N215   Z0.0130  
N225  G1 F1.0000  X0.7711  
N235   F1.0000  Z-0.1147  
N245   F1.0000  X0.7411  
N255   F1.0000  Z-1.6765  
N265  G0  X2.7411  
N275   Z-0.1147



 

« Last Edit: April 22, 2012, 01:26:21 PM by RICH »
Re: Turning only part of a drawing
« Reply #6 on: April 23, 2012, 04:43:53 PM »
Thanks for the reply.

If the Rev: 8 Lazyturn manual is ever updated, the following could be added to the appropriate sections.

In 6.2.1 Ruler Pentagons
Note: if the graphics shows a path for facing the stock and this is not your intention, set both green and yellow icons to 0.

The Z start offset (yellow) section could use further explanation: what is it used for?


In 7.2 DXF Drawing
Note: do not show on the drawing sections of the part that are not to be machined such as spigots or additional length of the part to allow for turning centers.

Offline RICH

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Re: Turning only part of a drawing
« Reply #7 on: April 23, 2012, 06:14:14 PM »
Thanks for the comments, and so noted here for future updating of the manual.

Quote
The Z start offset (yellow) section could use further explanation: what is it used for?
See attached file.

WYSIWYG :D

RICH
Re: Turning only part of a drawing
« Reply #8 on: April 24, 2012, 07:21:07 AM »
Very good, thank you very much. I'll have to play around some more.

Next question. The tool code, for example "R0.0100-IC0.3750"

Is there a source that explains these codes? The ISO is a hint.

If there is ever a reason to update the LazyTurn manual, I'm available to assist.
Re: Turning only part of a drawing
« Reply #9 on: April 24, 2012, 09:44:47 AM »
Forget what I wrote about setting the yellow pentagon to 0 to stop facing off the stock – it doesn’t work all the time. I’ve duplicated your images (thank you again) except your very first one. LC insists on machining the spigot and facing off the face of the pillar using a left 35 degree diamond doing a fine pass. The rough pass does not do this. I’d like to overcome the quirks in LC as any alternative CAM is at least $400 and I’ve just retired. Please don’t take these comments as a criticism of Mach3 software. Mach3 Mill and even LazyCam are a great resource, a pleasure to use and I actually get things produced.