3D printer

[Bitsyncmaster]

Did another test print this time using 1 mm thick walls on the cover. It is still very strong and does flex quite a bit with that thickness. I'm going to do some more testing in doing a complete cover for the Lambda relay I have now. I still can't use the current circuit boards because the cover would not let it clear the back of the OEM relay sockets. The lambda relay is very low current so heating will not be a problem.

I will need to buy some yellow resin after I make new circuit boards. With my formlabs printer you use a separate resin tray for each color resin. You don't empty and clean the tray. You just store them without tipping the tray that is full of resin.

The covers won't be removable. You would just break the cover and replace it if you needed to fix something inside.

[Bitsyncmaster]

Well I printed it flipped so the surface would not need any sanding. So I put supports on the bottom edge and inside supports to the top. That worked to keep the outside clean and smooth but the side walls bowed because they did not have the support of the top to keep them straight.

So it's back to the drawing board. The problem is that one electrical pin that is already very close to the edge. That limits the thickness of the wall on that side. The 3D printed material flexes a little but when you bend it to much it will shatter. Not like a PVC that will not shatter.

I wonder what it takes to 3D print a mold and use some type of injection molding.

[Jason]

Take a look at the Siraya Tech Tenacious and Blu resins. They're stronger and more flexible than the standard ones. I've done some printing with Tenacious and it's help up for me in some mechanical applications where the normal stuff would fail right away.

[jamesrguk]

Well I printed it flipped so the surface would not need any sanding. So I put supports on the bottom edge and inside supports to the top. That worked to keep the outside clean and smooth but the side walls bowed because they did not have the support of the top to keep them straight.

So it's back to the drawing board. The problem is that one electrical pin that is already very close to the edge. That limits the thickness of the wall on that side. The 3D printed material flexes a little but when you bend it to much it will shatter. Not like a PVC that will not shatter.

I wonder what it takes to 3D print a mold and use some type of injection molding.

Do you mind me asking what material you are printing with?

Just curious.

Edit...

Just taken a closer look, I'm guessing a resin of some kind.

J

Sent from my SM-G920F using Tapatalk

[Bitsyncmaster]

Do you mind me asking what material you are printing with?

Just curious.

Edit...

Just taken a closer look, I'm guessing a resin of some kind.

J

Sent from my SM-G920F using Tapatalk

https://sourcegraphics.com/supplies/...BoCCyQQAvD_BwE

[Bitsyncmaster]

I'm still thinking about relay covers. I looked into injection molded covers but would need to get real CAD software to send the design for a quote. Also looking at requirements for injection molding and there are a lot of design requirements to improve the design and reduce cost.

There is a home injection molding machine priced around $5000 but even if I went that way I don't think it would work my design. My design would require a higher pressure because the part has such thin walls.

So for now I sticking with potting of my relays. I did 3D print a simple tool to hold the circuit boards while I join them soldering the standoff jumpers.

[Bitsyncmaster]

Take a look at the Siraya Tech Tenacious and Blu resins. They're stronger and more flexible than the standard ones. I've done some printing with Tenacious and it's help up for me in some mechanical applications where the normal stuff would fail right away.

Formlabs has other resins that are more flexible and less brittle. I also see other vendors even have flexible resins for making gaskets or tires for your model cars etc. I look forward to trying other resins for some projects. So far my gear ball and the tool I made the standard hard resins are the best choice for those jobs.

[Bitsyncmaster]

Formlabs has a new resin that you can actually make some forms of springs in that you can bend it and it will return to original shape. I may buy this so I can play with it. I was reading up on the requirements for injection molded parts and it really gets complex making minor angles so the part ejects cleanly from the mold.

https://formlabs.com/store/form-2/ma...gh-1500-resin/

I also downloaded freeCAD and did some design work on it. It defiantly takes more time to learn than TinkerCAD but I like the idea of having "source" design files in my possession. And other cad packages can import the design. With TinkerCAD you can only save the .STL file to your devices.

[Bitsyncmaster]

Well I tried that new resin. It is flexible but my test print was not a good choice. It looks like you need a lot more support. The bottom of my print pull off the supports during the print and some of the layers got pulled apart but that may because of the support failed. Cleaning after the print is a lot harder to do. Seem like the alcohol does not absorb the remaining resin at all. The part is very soft until post curing.

I will probably pour the resin back into the jug and clean the tank until I think of a project to try it again.

[Bitsyncmaster]

I ran another test print with that new resin. I used larger supports but still lost a few during the print. So far I'm not happy using that new resin. I may try another resin someday.