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A couple questions about cutting shapes

Posté : sam. févr. 09, 2008 4:17 am
par SteveC68
I want to use Jedicut to cut shapes out of foam and I have a few questions. My plan is to cut oval shapes but I want to cut the ovals similar to the way you would cut a wing. One oval would be similar to the root of a wing and the other oval would be like the tip. My first question is how do I align the ovals?

Thanks,
Steve

Re: A couple questions about cutting shapes

Posté : sam. févr. 09, 2008 2:37 pm
par Jerome
Hi,

If I understand what you want to do, you just have to move the hot wire using the Jedicut manual control, and when it's done, you start your cut.

Re: A couple questions about cutting shapes

Posté : ven. févr. 15, 2008 3:33 am
par Jerome
I have been using a Hobby CNC board and Jedicut 2.1.7, so far it is working. The only problem I have experienced with the software does not seem to set the template spacing via the cutting wizard. If I cut 2 different airfoils for root and tip the cut does not come out as expected, it does not seem to matter if the distance in cutting wizard is set as it seems the cut is the same no matter. Is it my perception or is it not working correctly? I work with CNC router machinery so I have a little knowledge of those types and this is my first wire cut. Thanks in advance.

Eric

Re: A couple questions about cutting shapes

Posté : lun. févr. 18, 2008 1:14 pm
par Jerome
Hello,

The cutting wizard works well. Do you enable it by clicking on a checkbox in your cut window called "Enable cutting wizard" or something like that ?

Re: A couple questions about cutting shapes

Posté : mar. févr. 19, 2008 4:08 am
par Jerome
Hi Jerome,

Yes I have checked the box on the wing cut dialogue and still it does not read the different shapes correctly or so it seems. The test was with a triangle and square with equal number of segments in both dat files, the triangle side came out more square in shape. I like the ease of setup and handling the machine but I suppose it is a little much to ask for fuselage shapes that are drawn in CAD and not in the native program.

Eric

Re: A couple questions about cutting shapes

Posté : mar. févr. 19, 2008 6:15 am
par SteveC68
Jerome,

Here is a picture of what I am talking about. I plan to cut these shapes out of 1/2" thick foam. The ovals will vary in size from only a couple of inches to maybe 8 inches in height. The difference in size of the ovals will be much smaller and the distance between my towers will be around 24 inches. I need to make sure that the ovals are aligned as they are in this simple sketch. How is that done in Jedicut?

Thanks,
Steve

http://img521.imageshack.us/img521/5728/ovalskp3.jpg

Re: A couple questions about cutting shapes

Posté : mar. févr. 19, 2008 6:54 am
par SteveC68
Also I'm not trying to cut out a ring this will be a solid oval. Think of it like a tapered wing with a very short (1/2 inch) wingspan.

Steve

Re: A couple questions about cutting shapes

Posté : ven. févr. 22, 2008 2:34 am
par Jerome
Hello,

I am experiencing the same issues. I have spent countless hours running tests to see where the problem lies. From what I can tell, the "Cutting Wizard" does not correctly compensate for the foam placement.

If I use the software to make straight cuts (not requiring Cut Wizard) the software works perfectly. But if I need to make complex parts, such as, fuselage parts that all need to be exact in order to fit together - this is where the Cut Wizards fails. I have some great CAD designs for foam aircraft, but cannot use JC to cut them as the pieces just dont come out as expected. I know the designs are correct as they do work fine in GMFC.

I am a very experienced CAD and CNC engineer. I have raised these issues in the past but will re-iterate my finding. I am persisting with the JC software as I am very impressed with the software and believe it has a lot of potential --- Jerome has done a great job in writing it. Jerome, if you need assistance in the software development, I have many friends that are software developers.

Let me show an example ...

Lets say that I have a square shape at one end, and a circle shape at the other end.

** My machine cutting axis are spaced at 600mm apart
** The foam block is 240mm wide
-> Therefore: Left Offset = 180mm & Right Offset = 180mm
-> I then configure the "Cut Wizard" to 180, 240, 180

After the cut is run these are the following results:

* The actual foam cut is shorter than that configured in the JC chord field
* The cut shape is distorted -- for example the circle is distorted by the square and vise-versa.

I notice that the greater the value in the offset fields, the worse the error in the actual cut.

Cheers,
Luke

Re: A couple questions about cutting shapes

Posté : mer. févr. 27, 2008 1:26 pm
par Jerome
Hi all,

I think I understand your problems using wizard cut and if you knom mathematical algorithm to calculate the points of the shape you want to cut, please contact me ;)

The wizard cut works like I design it. I explain. You have to shap to cut, a circle and a square. If you use the wizard, Jedicut increase or decrease the size of your shapes. But if you use different shapes on the both side, Jedicut will calculate 2 news shapes (not a circle nor a square in my example). If you know how to do that, contact me.

Now I work on dynamical wire heating control for MM2001 and compatible board. After that, I will take a look at the wizard cut.

Luke, than you for your support ;)

Re: A couple questions about cutting shapes

Posté : mar. mai 20, 2008 9:11 pm
par SteveC68
Jerome,

Any news on the cut wizard? Have you finished working on the heat control for the MM2001 board?

Steve