PDA

View Full Version : Default(?) draft angle



Xblack
01-16-2013, 11:28 PM
I am cutting (1/2" thick) gears, etc. for a Skeleton clock with a straight 1/8" bit, and have noticed that there is a very small draft angle being cut into the parts even though the "draft angle" setting in designer is off. When I watch the machine cutting I see that this angle is being cut in intentionally. Is there any way to turn off this draft angle so that the gear teeth will be cut perpendicular to the gear face as they should be?

fwharris
01-17-2013, 12:13 AM
Welcome!

This is a new problem to the forum I believe! When you zoom/rotate you project in designer what do you see for the cut outs?

Xblack
01-17-2013, 01:00 AM
If you're asking if I can see the draft when the project is in Designer, no -not that I can see but it is a very small angle, perhaps less than 5 degrees. Perhaps this draft angle is programmed in because the default carving bit is 1/16" tapered?

fwharris
01-17-2013, 01:34 AM
If you're asking if I can see the draft when the project is in Designer, no -not that I can see but it is a very small angle, perhaps less than 5 degrees. Perhaps this draft angle is programmed in because the default carving bit is 1/16" tapered?

Correct the bit does have a 7* tapper..

bergerud
01-17-2013, 01:56 AM
Something must be wrong with your machine if it does not mill vertical edges with the 1/8 straight cutting bit. I really do not think it is the software. Do you have a QC? Maybe bit run out? Bad spindle bearings?

henry1
01-17-2013, 06:16 AM
Can you not put the pattern on here so we can see whats going on , that would help

DickB
01-17-2013, 07:28 AM
Yes, please post your mpc file.

Xblack
01-17-2013, 10:42 AM
Hi DickB
Do you also cut gears on your CW? Do you always get vertical edges?

Unfortunately I cannot presently post any mpc files because all my internet is done on Mac and everything else on PC for virus purposes.

fwharris
01-17-2013, 10:49 AM
I need to clarify a couple things. Are you carving (1/16" carving bit) and then cutting out the shapes with the 1/8" cutting bit?

eelamb
01-17-2013, 10:59 AM
Floyd has the right question. It sounds to me like you are either doing a cutout of a carving (raster) or you have a raster, and you are using the 1/8" cutting bit when it asks for the 1/16" carving bit.
Is the pattern a vector carve (vector lines) or a pattern of a gear (raster carve).

Xblack
01-17-2013, 11:35 AM
I'm just doing the whole thing with the 1/8" straight

fwharris
01-17-2013, 11:37 AM
Got any pictures??

Xblack
01-17-2013, 11:42 AM
They are high-resolution raster images converted from vector files. I wish I could bring dxfs into designer directly but I am having to convert them into bmps first to bring them in. Is that the problem? Does CW apply a slight draft to raster images? Is there any way to turn that off?

During setup the machine prompts to use 1/16" first and then promts to change to 1/8", so it knows it's using 1/8. I don't know why it prompts for 1/16" first -I just figure it's a foible.

Xblack
01-17-2013, 11:58 AM
I'll try to get some together

DickB
01-17-2013, 11:59 AM
Hi DickB
Do you also cut gears on your CW? Do you always get vertical edges?

Unfortunately I cannot presently post any mpc files because all my internet is done on Mac and everything else on PC for virus purposes.

Yes, I cut both 1/4" thick gears from Baltic birch and 7/16" thick gears from oak and hard maple using the 1/8" cutting bit. I actually have clock projects in the Pattern Depot. I do not get the angled cuts that you describe. Nor have any of the project customers commented on this.

DickB
01-17-2013, 12:05 PM
They are high-resolution raster images converted from vector files. I wish I could bring dxfs into designer directly but I am having to convert them into bmps first to bring them in. Is that the problem? Does CW apply a slight draft to raster images? Is there any way to turn that off?

During setup the machine prompts to use 1/16" first and then prompts to change to 1/8", so it knows it's using 1/8. I don't know why it prompts for 1/16" first -I just figure it's a foible.
I would guess that you are converting the bmps to patterns and creating an outline vector, then assigning a cutout, but it would be best if you described the whole process in detail. There is no draft applied to vector cuts or cutouts.

It's odd that you are getting the prompt for the 1/16" carving bit, unless you are selecting Jog To Position at the machine.

bergerud
01-17-2013, 12:06 PM
What bit is selected under the pattern bit in the board settings dialog box? 1/16 carving (default) or 1/8 cutting? Do you trace the bitmaps and the cut path the traced curves or are you doing something else?

Xblack
01-17-2013, 12:33 PM
Do your parts also come into designer as raster images? I'm thinking that may be causing the draft. My gear teeth are contoured helically so that's why the draft concerns me a little -involute teeth are a little redundant when they only make contact along their back edge. When I originally designed and built these clocks I cut them out of 3/16" and 1/4" steel plate on a CNC laser which cuts (in those thicknesses) with zero draft.

DickB
01-17-2013, 12:42 PM
I'm using the excellent tool that member JLT posted a while back: http://forum.carvewright.com/showthread.php?17794-Radial-Vector-Generator... but I've also cut stuff from images with no issue. If you're using the cutout tool there is no way to specify a draft or angled cut like you describe. Are you cutting the full 1/2" in one pass? What material? It's hard to know how to help without knowing your process in detail and posting an mpc.

Xblack
01-17-2013, 12:56 PM
I am new to CW so I may be missing a vital step in my process. My process is basically this: while the part is still a DXF I offset .15" to create an open area around the part (.2"around teeth) I saveas a high resolution TIF. In "paint" I flood the part and the background with black and leave the offset space white. At this point I also insert holding tabs because I found the ones in Designer to be not so great. I saveas a two color BMP and import into Designer. I uncheck "floored edges" and save. When I put the part on the board I zero feathering, set merging to subtractive, set bit optimization to "best" and set pattern bit to 1/8" ballnose, check pierced, set height to 999 and upload.

lawrence
01-17-2013, 01:00 PM
why not just import the DXF and use the cut out tool?

I'll see if I can get together another video

Lawrence

DickB
01-17-2013, 01:01 PM
In that case, you are carving, not cutting. You want to use a vector path to cut. You need to convert your pattern to a vector outline. Do not add tabs to your drawn gear. Put the part on the board, select Outline Pattern(s). Delete the original pattern. Select the outline that you created, click on the Cut Path tool, set up tabs the way you want them (I use 3/16" tabs, minimum number depends on gear size) and Flip Cutout.

BTW the 1/8" ballnose and 1/8" straight bits are different bits in CarveWrighTspeak and contributed to some confusion in comprehending.

Xblack
01-17-2013, 01:05 PM
I have not found a way to import DXFs directly into Designer -how do you do that?

DickB
01-17-2013, 01:07 PM
Spend more money: http://store.carvewright.com/product.php?productid=20566&cat=252&page=1

Xblack
01-17-2013, 01:08 PM
...and there's the Rub...

DickB
01-17-2013, 01:13 PM
You can use the method that I described at no additional cost. Please let us know how it goes, or ask if my directions were unclear. BTW skip the .2" offset, just import an image of the gear itself.

Xblack
01-17-2013, 01:15 PM
When I select "outline pattern" I'm just getting a square -how do I bring in an image without the square periphery?

lawrence
01-17-2013, 01:18 PM
one more option... send someone (me for instance) the DXF files and we can import them into a pattern and send them back.

PM me if interested

Lawrence

eelamb
01-17-2013, 01:28 PM
Back to the DXF comment. There is a DXF importer available. No conversion necessary using it.
Then the comment to DXF to BMP, and into designer. That concerns me. For that creates a pattern (raster carving using the 1/16" carving bit)
If you are outlining the pattern, and assigning the 1/8" bit to the outline, and deleting the pattern, you should not get any draft. If you are not deleting the pattern you outlines, then a feather may be left behind, and this is what you see in the cutout.
For a outlined cutout, with no pattern, you should not be asked for the 1/16" carving bit.

The square is because, you have not removed the backgound. Try lowering the slider when the pattern is shown in the importer, till the background is gone. Best to use DXF importer, or convert to AI and use the free ai2mpc converter.

As Lawrence said post the DXF someone will make the MPC for you. If you do not want it posted have them PM you.

Xblack
01-17-2013, 01:37 PM
Aah -that's it, the slider thingy. I did a trace and it worked -maybe this is the answer. I'll have to run it and see

Edit -but now how do I get the cut to move to the outside of the pattern instead of right down the middle?

fwharris
01-17-2013, 01:44 PM
Aah -that's it, the slider thingy. I did a trace and it worked -maybe this is the answer. I'll have to run it and see

Edit -but now how do I get the cut to move to the outside of the pattern instead of right down the middle?

The "flip cut" in the cutout settings tool window or the icon..

DickB
01-17-2013, 02:10 PM
Sounds like you assigned a bit to the vector outline, and did not use the Cut Out tool. If you assign a bit, it will follow "down the middle" and also leave no tabs. If you usde the Cut OUt tool, it will follow then inside, or noutside if you Flip Cut, and leave tabs. Use the Cut Out tooll

Xblack
01-17-2013, 07:41 PM
Yeah that's what I did alright -I'll try the cut out tool Thanks!

Xblack
01-18-2013, 10:23 AM
Hey! That did it! Honestly I did try the outline trace a long time ago, but gave up because I did not know what the slider thing in Importer was all about.

Thanks guys -that was a big help!

DickB
01-18-2013, 12:40 PM
Good! I would love to see some pictures of your finished clocks or even parts. I've posted a number of mine.

BTW some drawing software like paint.net also allows you to delete the background. When saved in .png format and imported the slider is not needed as the background is already gone.