Need Help With a Script

[RocketNut]

Hello

I need help writing a script to make a diffuser plate. I do not know how to explain the steps that are needed, so I made up a short video that shows and explains the steps along with the attached screenshots.

The video is too large to attach to this post so here is link:

https://www.dropbox.com/s/omq8sto5l1wzo27/Defusor Step Video.avi?dl=0

The package can be downloaded at

https://www.dropbox.com/s/hg62vxl0m...Feed Dome Defuser Disk V4 SP 40mm.AD_PKG?dl=0

Maybe I should mention all the parts (including the diffuser plate) are designed to be 3D printed in carbon fiber.

I wish you all a great day

 

[NateLiquidGravity]

Unfortunately none of the boolean features can be scripted yet. I believe this is an API limitation.

That said - it looks like your boolean tool is a revolve, so a revolve cut could be made and patterned around an axis.

 

[RocketNut]

Rats about the boolean features not being supported. Maybe at least the script should be able to draw the pilot holes. Then I can do the boolean function by hand. Is my thinking correct?

I need the boolean sub feature because the holes have to be in the shape as the boolean tool (please look at the defusor bool-tube pic in the previous post). I have attached the part. A revolve cut will be way to complex to model, not to mention the sheer number needed.

 

[idslk]

Hello RocketNut,
only 3 circles or more for the pattern? Do You build the rockets for real?
Regards
Stefan

 

[oldfox]

I don't really understand the actual construction of the "tool" nor the 5mm circle. Multi-part cutter? EDM profile?

Just my way of sketching it.

 

[oldfox]

only 3 circles or more for the pattern?

Just my way of sketching it.

No circles in the tool.

 

[oldfox]

Maybe I should mention all the parts (including the diffuser plate) are designed to be 3D printed in carbon fiber.

I don't see a problem with ADDITIVE fabrication. Physical cutter (SUBTRACTIVE fab) shouldn't be an issue either. (unless I'm totally
misunderstanding the issues)

 

[idslk]

Hi Chris,

No circles in the tool.

take a look a the video...

only 3 circles or more for the pattern?

is the question about the number and position of possible "holes" in the plate...(or will there be 20 circled patterns or so)

Just my way of sketching it.

Looks good.

Regards
Stefan

 

[RocketNut]

only 3 circles or more for the pattern? Do You build the rockets for real?

Yes, I do build rockets, but living in an apt I can only build small high powered rockets.
As for your question"3 circles or more for the pattern" I do not understand it.

I don't really understand the actual construction of the "tool" nor the 5mm circle. Multi-part cutter? EDM profile?

Just my way of sketching it.

I sketched so I can easily change the shape if needed. As for the 5mm circle, what one are you talking about?
Please explain what you meant by "Multi-part cutter? EDM profile?".

 

[idslk]

will you maybe (sometimes) have more than the shown number of "nozzles" in the video?
In the video you have 2 reference circles populated with nozzles and 2 "pilot holes" and a third reference circle with an additional hole, or did i misinterprate this?
Do you have a list of prefered measures? Diameters, thickness of plate, number of nozzles...or things like this?
Regards
Stefan

 

[RocketNut]

Yes, a lot more holes. I did the first 3 rings by hand to show what I need to do over the entire plate.

Think of this plate as a shower head. If you remove the showerhead, you get a stream of water hitting you in one spot with a lot of pressure. Then when you reinstalled the head you get water all over you. Because the stream is broken (diffused) into multi smaller streams inside the shower head. Thus covering a large area. In this application, if there was no diffuser then the fuel will not be spread equally across all the injectors. With the diffuser, the fuel spreads out the fuel overall injectors, so of them get equal pressure and flow rate. The attached screenshot shows a close up of the diffuser hole. As you can see the holes are not just a hole but contoured to cause a little back pressure to ensure the fuel is spread equally. Thus the design of the tool. On the bottom (exit side [tools Loft function]) the fuel coming out is sprayed over multi-injectors, ensuring all the injectors have equal pressure and flow rate.

What this all means I need as many holes I can get in the diffuser plate. I am hoping someone can help me write a script to draw the pilot holes. If my math holds up there are over 20 rings of pilot holes.

The pilot holes I use to place the diffusion holes, using the boolean subtraction function. With out the pilot holes, it would be impossible to place the tool accuracy.


I hope this explains what I need.

 

[idslk]

this is a first test...
(i've taken the single part from oldfox...)



as been said: no pattern in AlibreScript and no bool...
What i need is some of the dimensions and counts.
Are there rules like the first diameter has to be 10 times the height or the min distance between to nozzles has to be 20mm or so?

Regards
Stefan

 

[NateLiquidGravity]

@RocketNut
I believe this is like what you are doing: https://www.engineeringtoolbox.com/smaller-circles-in-larger-circle-d_1849.html

 

[idslk]

Hello RocketNut,

in the video you've used 104 counts for the circular pattern 2 with the second reference circle.
Which you've calculated with circumference 4178,318 divided by 40.
In the package you've used 106 for cp1, 99 for cp2 and 93 for cp3.
Which is a divider from 42,205232323232323232323232323232
Will you get this calculated automaticaly? Or will you enter the values by hand?

Regards
Stefan

 

[oldfox]

@RocketNut

As for the 5mm circle, what one are you talking about?

D11=6mm My bad. 5mm Deep.

Please explain what you meant by "Multi-part cutter? EDM profile?".

I was thinking of a milling center. Not 3D printing. Printing is brand new to me. Machining goes back many years. Again, my bad.

 

[idslk]

Hello Chris,

the needed product will be a diffusor disk like the following picture only with a lot more "holes"


"You're" Cool_Tool_No_Bool is the tool to boolean subtract the huge number of injectors...

@RocketNut : There will be max. 15 circles with a big diameter from 1450mm and an inner diameter of 230mm with a spacing of 40mm

Regards
Stefan

 

[oldfox]

"You're" Cool_Tool_No_Bool is the tool to boolean subtract the huge number of injectors...

Glad it was of some use to you. Should also be fairly easy for RocketNut to modify if necessary. I've never used CAD booleans. Only 0s and 1s.
Oh well.
Just make sure to return my tools when you are finished with them.

 

[idslk]

@RocketNut,

i've changed your disk (not the dimesions, i think so, only the cad work / sequence...)
The appended package is without the boolean subtract
TurboRockEngine 1.5meter Fuel Feed Dome Defuser Disk V4 SP 40mm _Base - injectors
The result file was round about 190 MB big...



so the last operations are up to you

may you have to rearange the closing rings (which is a new part instead of the included geometry before)

Take a deeper look on how the 994 tools are positioned. There are no circles and no pilot holes needed!
The counts for the different diameters and circular pattern are calculated with the table counts.zip (counts.xls -> no macros)

It could be done with a script, but doing it manual is simply to quick...

Regards
Stefan

 

[NateLiquidGravity]

FYI Assembly Boolean results are not parametric. If keeping it parametric matters to you I would suggest manually doing a Boolean Subtract feature at the part level using the Injectors tool. Or at least I think that should work.

 

[RocketNut]

[
idslk:

What can I say but WOW that's extremely simple. Except for one thing it forms a solid disk, meaning the fuel can not past through to the injectors. So I shelled the tool and got the attached screenshot. As you can see the exit cones are overlapped and not very functional. Not to mention the design forms packets that can trap fuel. All this means that the fuel will not flow properly to the injectors.

Now using the boolean subtract function I get nice an neat exit cone. That allows the fuel to form a curtain showering down on the injectors. Thus resulting in equal pressure for all injectors.

I am not up on database programing. What does the $F$2 of the count equation "INT(D4/$F$2)" does?