Are there any resin casting experts that could help me find the best product for my project?

[G+_James Hughes]

Are there any resin casting experts that could help me find the best product for my project?

I'm want to cast some small bumpers for a project I'm making. I 3d printed some out of ABS and they work really good. But after a few times taking them off and on they start to get a little bit of layer delamination. It would need to be a bit flexible as it has to flex to be put on. But not too flexible as it needs to capture a sheet of acrylic.

[G+_Jason Perry]

I am not an expert with 3d printing but is there not some post print processing you can do to strengthen the print?

[G+_Mark Jurisch]

Do a search for "urethane casting resin", you should find plenty of different types, usually being sold in a gallon kit for around $50. You will still need to 3D print a mold. You will also want a mold release agent to help get the parts out of the mold.

[G+_James Hughes]

Mark Jurisch I did a little research and found that I need something with a durometer of around A70 which should be similar to the rubber tread on an automobile tire. The resin, pigment, and silicone mold material is going to set me back about $120. So I'm going to have to think about it for a day or two.

[G+_James Hughes]

Jason Perry I'm printing abs at 258c which should give me good layer adhesion. Might need to redesign the part to beef it up a bit. Don't want to go too far and lose the flexibility needed to put it on and take it off. Plus I think casting would be quicker.

[G+_Shooter_FPV (Shooter_FP]

Would NinjaFlex work if the infill was high enough? On the F1 car I just built I used NinjaFlex for the tires at about a 20% infill, and they do flex with a really good squeeze, but not as rubbery as you'd think...

[G+_Mark Jurisch]

What about casting it into a 3D printed mold versus a silicone mold? Printing it in ABS and then vapor smoothing it to decrease the layer lines may provide decent results.

 

Another option is to work with a place that does this stuff on a regular basis, if the part is really small and you don't need that many (under 20) they can likely do it from a single small mold that could be economical. I've personally used five-star-plastics.com - Plastics Product Development - Five Star Plastics for several projects. They've gone way above and beyond to help me out. Might be worth a shot.

[G+_James Hughes]

Ken Jancef ninja flex wouldn't be rigid enough for the weight it needs to hold.

[G+_Shooter_FPV (Shooter_FP]

James Hughes Ahh... ok.. curious to see how this turns out though...

[G+_James Hughes]

Ken Jancef I bought the materials to do the casting approach. Now to get the model sanded and formed perfectly.

[G+_Michael Young]

Trying different filament may produce better results, there are higher quality filaments meant for high-quality parts.

[G+_James Hughes]

Just a quick update. I think I found the right mix. I used a resin with a hardness of A60 in a silicone mold from the 3d printed part. I need to put more pigment in if it's going to come out black but I'm super happy with the results. photos.google.com - New photo by James Hughes

[G+_James Hughes]

Mark Jurisch thanks for the lead on five start plastics. If this goes into production I may be talking to them. As for the print, I haven't tried vapor smoothing but I am going to use some filler primer and some sand paper as I've had great results with that combination.

[G+_Mark Jurisch]

My experience with them is you can generally get 20-30 parts off each silicone mold. They also do 3D printing of nylon parts at pretty reasonable prices for low volume production, although that probably won't have the flex you are looking for.

[G+_James Hughes]

Did some more casting yesterday. Going to make another mold from the parts cast so I can make four parts at a time instead of one. Had a few fails but did get four good parts.

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[G+_Mark Jurisch]

Awesome! I'm glad it worked out.

[G+_James Hughes]

The next casting project is going to be a (relatively) large flat piece. Going to be a two piece mold.