- November 20, 2015 at 2:43 pm #4294
I know this is like really far left field. but what about printing a mold of some of the parts and cast them with resin? The only problem is I am not sure what resin to use or if resin is even strong enough. Some google searching says yes resin can be used but Im hoping someone with more experience with resin can chime in on this. Why do this? To hopefully use stronger materials and stiffen up the machine.
note: Techinically if you already have a machine, couldnt you machine out a mold.November 21, 2015 at 10:25 am #4311
Yes, I have been researching this for months now.
Yesterday I was at tap plastic looking at there selection of resin for a test part. I talked with a Reynolds Rep 2 months ago for a long time about resin selection he gave me very good information and a ton of sample chips.
Now the down side. Most of my parts are too complicated to mold. The roller motor mounts are fine if you take out the solder-less part, and the roller locks are easy. All the rest are kind of a pain.
So, I could make Version 2 with injection molding in mind. This would cause it to use more hardware but could easily be mass produced. I’m not sure what to do. Places like lulzbot, the makers of the taz, Print all there parts. They have a nice print farm going and there product is very nice. A print farm allows for very fast part revisions. If You start making molds changes are difficult and expensive to make. So I will try to make a few parts mold-able or water jet cut but I am sure most will still have to be printed.
I have been working on the center gantry for version 2 a little bit depending on how that comes out I will make a decision on what to do.November 21, 2015 at 2:13 pm #4316
What kind of resin would you use if you were going this route?November 22, 2015 at 1:57 am #4320
I’m waiting on some more filament to finish printing mine so I don’t know how much more ridgid the parts could be. But this reminded you of an story on hack a day.
We could probably do something like this if needed.November 23, 2015 at 8:55 am #4324
vicious1KeymasterDecember 8, 2015 at 7:58 pm #4760
I have been tempted to try some more exotic filaments when printing the z axis/middle parts. Something like Taubmans range of nylon hybrid materials would be interesting to experiment with.
Ultimately something with similar mechanical properties PEET would be awesome. But at approximately 600euro per 100g it might be cheaper to have them milled out of high strength alloy lolDecember 15, 2015 at 12:05 am #4977
I would not use a polyester casting resin. Use a casting epoxy with 1/32″ – 1/16″ milled fiber or chopped strands. 5% to start would be a good guess.
The physicals of epoxy are far greater than polyesters. Another option would be a casting urethane. You could also add milled fibers or chopped strands to urethanes.
The milled fibers or chopped strands act like re-bar in concrete and add a massive amount of strength.
The hard part will be the molds. They need to be super smooth, and have enough draft so the finished part will come out easily. Matched metal molds would be a great option, but the cost of machining and polishing would probably not be justified.
ABS injection molded with 10% chopped strands would have great strength, but once again the metal injection mold price is very high.
If you have any more questions regarding epoxy, urethanes or casting resins just ask. I happen to be a certified composite technician..
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