Metal etching artwork questions

[Scottl]

I have drawn up all the parts now for several pillars for part of my Cisco Bridge project, but need some advice from those who have prepared etches before. 

How much supporting material is needed between the parts?  Should I plan to have supporting material around each piece, or can I put groups of pieces together, say over a 25mm (1") span, or even more?  I want to pack as many parts in the sheet as possible, but don't want to have problems with the parts falling off.

This is an early version of the artwork, to give you an idea of what I have done.



Thanks for your thoughts!

[Chris333]

This is something I had etched that came out fine:
https://picasaweb.google.com/ErieChris333/HopelessProjects#5641410580116524626
https://picasaweb.google.com/ErieChris333/HarlemStation#5650300009461612658

You could just draw a couple main boxes and have the small "ties" branch off to connect everything. If you sent it to PPD they may come back and ask you to put more ties on it if it looks light.

[Scottl]

Thanks, that helps a lot.

[TrainCat2]

I don't know much about this etching stuff, but I would think about . . .

• No less than .030" between parts or support structures
• Ties should be .020" half etched on top
• No less than three ties per major piece, four minimum if possible
• DO NOT exceed 4.0" without a tie to support the etched piece
• Create a support structure network of .030" minimum full thickness metal as the parts carrier.
• Try to group like sized parts together allowing for a better support network
• Surround your final layout with no less than .050" protective support

[Chris333]

I don't know much about this etching stuff, but
 

Yeah stick to what you know   

[Scottl]

Thanks again, very helpful.

Surround your final layout with a .050" protective support

Do you mean 0.50"?

 

[Chris333]

0.50" is 1/2" I highly doubt Bob meant that.

[TrainCat2]

Corrected for clarity . . . . .

[Scottl]

Great, thanks!

[Scottl]

How does this look?  Any obvious noobie mistakes?

[TrainCat2]

Sorry Scott, but yes.

Example #1:  Always try to attach the parts at the ends. Add support structures to keep the parts from flopping around. Here there is .030 clearance between parts and structure. Run a .030 full metal strip between parts to keep things together and structurally sound. You can see the .030 strips go both vertically and horizontally.


Example #2:  Group like parts together so it is easy to create organized support structures (both vertically and horizontally). Those structures are a frame that keep your items from moving around while hot acid is being sprayed onto the sheet with a good amount of pressure. Also, the sheet is moving through the machine. Without a good frame, parts are known to become detached, get hung-up in the machine and fall into the acid sump below. I know this first hand.


Just my $0.02 . . . . . . . .

Example #3:  Under fear of being called out on TRW . . .    . . . DON'T attach your pieces from the side. Use the Ends! Look at it this way. If you attach from the sides, you will have to clean-up the tie remnants from four locations instead of two. Since those pieces are long and skinny, there is a greatly increased chance of damaging the part while cleaning the remnants off of the sides. I know this first hand. Just not much to hold on to. From the ends, very little chance of damage. If the distance from the part to the frame is greater than .050, increase the tie with from .020 to .030 or .040. If you don't, the part can come loose and go plop, plop, fizz, fizz, bye, bye.

[Scottl]

OK, thanks!  This is my first crack at this so I welcome the constructive input.  I'll keep working at it and see if I can't solve these issues.

[Scottl]

How is this? 

[Scottl]

Just a follow up.  I arrived back in Canada and a nice package from PPD was in my mailbox.  Here are some quick phone shots- everything looks perfect up close.





Thanks for all the help.  Now I just need to put this together!

[Chris333]

Sweet!  Now you know the secret