DLP Resin voltage breakdown ??

[GailInNM]

Does anyone have any data on the the breakdown voltage of any of the common DLP resins, or links to any data?
I have spent several hours searching the internet for information, but all I have found is one special ceramic filled resin with a specification. And at a price of over $300+/500ml I am not that interested. Probably could not print it with my little MARS printer anyway.
I am playing with a distributor design and would like to print some prototype parts. They could be machined, but not easily. I could also print a pattern and make a silicon transfer mold and mold them out of glass filled epoxy with known breakdown properties but that would also be time consuming.
I could also build up a simple HIPOT tester and measure the breakdown properties of some of the resins I have on hand. I did HIPOT testing quite a bit about 45 years ago so I am confident that I could get values that are resonably accurate by calibrating with some known materials. But this would also take a week of time that I would rather spend playing with toys.
Gail

 

[ddmckee54]

Gail:

Was this the article you found?
Dielectric Properties and 3D Printing Fesibility of UV Curable Polymer Composites

I haven't read it yet and I'm not going to if it's the same one that you found. From the abstract, it sounds like they added other materials to existing resins to print their samples.

Don

 

[GailInNM]

Don,
Thanks for the reply and link.
The article you linked to appears to have about the same information that I already have. I checked the shed and I think I have almost everything to build up the simple HIPOT tester so it will go on the to-do list. I have several other projects ahead of it so if I find some information before then I will be ahead of the game.
Thanks again,
Gail

 

[ddmckee54]

Gail:

You know any friendly industrial electricians? A six-pack of their favorite beverage and a few minutes minutes of their time would probably get the job done. Unless you REALLY want to have a home-built HIPOT tester sitting around, in which case go for it.

Don

 

[bluejets]

Lookup scotchcast resin

 

[74Sprint]

Here are a couple of articles that might help you, mostly the first one.

Ray

 

[GailInNM]

Thanks for the responses.
The Scotch Cast resins have great properties but none of the series are able to be processed with DLP printers.
Ray -- The first PDF you attached has a LOT of great and useful information. It gives me all the baseline information that I was looking for. The sample processing was with SLA and bit DLP, but I do not think that will matter at all. Some quick bacvk of the envelope calculations show that I can still have a safety factor of about 3 when fitting into the available space I had allocated on my preliminary design sketches. So I feel confident that I will not have too many problems if I continue with it.
You were right that the second PDF was not too useful as it delt mostly fith filled resins.
Thanks for the assistance.
Gail

 

[Peter Twissell]

Hi Gail,

I went through an exercise similar to yours when deciding on material and manufacturing process for my radial engine distributor cap.
Among the things I found was another important factor - hygroscopic properties.
Some resins appear suitable, but will absorb atmospheric water and their dielectric properties will degrade significantly over time.
In the end, I made a mould and cast my cap, first in clear polyester resin so I can see what's going on inside (errant arcing), then later in polyurethane.

 

[bluejets]

I'll bite...what's a dlp printer?
Wasn't this about resin dielectric strength..?

 

[GailInNM]

Pete,
Thanks for your comments and observations. Since I have lived in the high desert for the last 60 years I tend to forget that there are places in this world were there is moisture in the air. Here our problem is that many plastics dry out and become brittle. Standard practice for the radio control aircraft flyeeres is to boil nylon propellers in water evcery couple of months to reduce breakage. Home owners often store the lines for string tirmmers used in lawn care in airtight containers with water in the bottom. Extends the useful life by about 4 times.
My plan is to print several different sets of functional parts and then print patterns for a simple transfer mold for the one I like the best. The final part would then be molded out of epoxy filled with milled glass fiber as it will have better mechanical and electriccal properties than the 3d printer parts.
Thanks to you and Ray I feel confident tat this is a reasonable plan.
Gail

 

[GailInNM]

Bluejets,
DLP stands for "digital light processing". The process prints a part in 3D by exposing a resin that hardens when exposed to ultra violet light one layer at a time. The problem was that the number of resins available that can be hardened with the UV light are limited and the manufactures of these resins dont give any electrical specifications, only mechanical specs.
Gail

 

[awake]

To add to Gail's description, DLP is one way of achieving the UV exposure in the basic resin printer. Others include MSLA (essentially, an LCD panel that masks the UV light in the required pattern) and laser - though I'm not aware of any hobby level machines with the latter!