3D Print Automotive center hubs, radio knobs and taillights and injection mold toolin

[ntonkin64]

I'm interested in your opinion on what printer can best support my applications.

1. I'm looking to 3D print center hubs. I believe the material that would work best for this is ABS due to the snap/click on features. As you can see from the link for the center hubs I will need to do some post processing. So I'm concerned about appearance if painted/chromed, etc. If anyone has post processed for painting or chroming I'd be interested in understanding your preparation, process, materials used and results.

https://www.google.com/search?q=cent...CTD4gQ_AUIBygC

2. I'm also looking to replace cracked tail lights for my airstream. I haven't been able to find translucent ABS that could be used for something like this. There is a digital ABS from Stratasys but I believe would be a specific printer. Polyjet? I have a budget of around 3-4K and would like to get as many of these items on my hit list covered in that budget.

https://www.google.com/search?q=airs...40T5oL3XGOM%3A

3. If I happen to run into a product that others are looking for I'd like to help them out and manufacture it for them. Depending on the demand, instead of printing it every time I would consider 3D printing injection mold tooling for small runs of injection molding (25-100 parts).

I might be better off starting with a printer that can handle #1 and #2 and then as things pick up purchase another printer specifically that can handle #3? I'd like to have access to some application support with the 3D printer for material selection etc. I'm leaning towards a Makerbot Replicator 2X since it seems like there is plenty of support behind this company. I think I could only cover #1 with this selection.

http://store.makerbot.com/replicator2x

Let me know your thoughts.

Thanks.

[LambdaFF]

PET can be bought quite clear and you can make it clearer with XTC smoothon http://www.smooth-on.com/Epoxy-Coati...429/index.html Taulman posted some interesting stuff on the effect of that on their T glase.

You can do rotocasting, which is the cheap version of injection moulding with a 3D printed mould. For more info, do a reasardch on products like the rotomaak.

You don't need more than 500$ for a rotocaster and 1500$ for a printer. You really don't. Don't go for a big manufacturer like 3D systems : no support, no added value there.

Pay attention to the build volume of your printer as moulds can be quite roomy. Try to pick up one with autolvelling, it's a good feature.

For ABS you need one that has a heated bed and is or can easily be enclosed. On the other hand, PET works just as well and is half as finicky.

I have a Printrbot metal plus, I'm really happy of its sturdyness and reliability. The support from PB is fine. Also they keep devising upgrades so that you can make it better without replacing it.

Others will tell you of lulzbot and flashforge copies.

[curious aardvark]

Also look for cheap desktop injection moulding machines. Couple on kickstarter and indiegogo at the moment.
One in an article here last week (could be the week before )

ABS probably isn't going to be your best friend. pet and polycarbonate would probably be better. And pla will be fine for a bunch of stuff.
They're all less hassle to print than abs.

Printer wise, look for wanhao duplicator i3. Cheap, decent build volume, easy to enclose if you must use abs and decent bit of kit. Also stupidly cheap so if you can't make the parts you want to - you haven't spent a lot of money.

[ntonkin64]

Thanks for the tip on Rotocasting. That is the first time I have heard about that. I'll have to read up on it more to understand the capabilities. What do you think about the Ultimaker? I think that I might need to print ABS for the mechanical properties of some of the parts needed for automotive applications. If I can find a way to injection mold or cast the parts to be faster and repeatable then 3D printing could only be the prototype. It looks like people are using the 3D print as a mold master and then producing the mold with some other material (I'm not familiar with this material either). This might be a good way to get around the temperature or pressure demands from injection molding. What is the material that can be used for rotocasting?

https://www.indiegogo.com/projects/g...ion-moulding#/

Also look for cheap desktop injection moulding machines. Couple on kickstarter and indiegogo at the moment.
One in an article here last week (could be the week before )

ABS probably isn't going to be your best friend. pet and polycarbonate would probably be better. And pla will be fine for a bunch of stuff.
They're all less hassle to print than abs.

Printer wise, look for wanhao duplicator i3. Cheap, decent build volume, easy to enclose if you must use abs and decent bit of kit. Also stupidly cheap so if you can't make the parts you want to - you haven't spent a lot of money.

[LambdaFF]

ABS is not a good option for rotocasting moulds : due to its high shrink rate, getting precise dimensions can be difficult and shrinkage induces warping.

Well for the material to be used in rotocasting, you can use resins. Start looking here to get an idea and look for a reseller closer to home. http://www.smooth-on.com/Prototyping...238/index.html

Ultimaker has a good reputation but their pricing is barely competitive in Europe so out of Europe I think it's worse. Where are you ?

[ntonkin64]

I live in Michigan, USA. Isn't rotocasting mainly for hollow parts or can you do solid?

ABS is not a good option for rotocasting moulds : due to its high shrink rate, getting precise dimensions can be difficult and shrinkage induces warping.

Well for the material to be used in rotocasting, you can use resins. Start looking here to get an idea and look for a reseller closer to home. http://www.smooth-on.com/Prototyping...238/index.html

Ultimaker has a good reputation but their pricing is barely competitive in Europe so out of Europe I think it's worse. Where are you ?

[awerby]

For solid parts you don't need to use rotocasting (although it can help if the mold is likely to catch air in its recesses). For short-run injection molds, you can use steel-filled epoxy. For molds you're simply pouring resin into, you can use silicone or urethane rubbers, which will flex to release undercuts.

Andrew Werby
Juxtamorph.com

[ntonkin64]

Won't the pressure from injection molding deform the mold if it is flexible enough to flex for the undercuts? Is there a psi limit for depending on the mold material used?

For solid parts you don't need to use rotocasting (although it can help if the mold is likely to catch air in its recesses). For short-run injection molds, you can use steel-filled epoxy. For molds you're simply pouring resin into, you can use silicone or urethane rubbers, which will flex to release undercuts.

Andrew Werby
Juxtamorph.com

[LambdaFF]

I live in Michigan, USA. Isn't rotocasting mainly for hollow parts or can you do solid?

If you live in the US, then look at US manufacturers : Wanhaousa, Printrbot, Lulzbot.


Rotocasting makes lighter parts as empty shell yes, but nothing stops you from filling it afterwards for increased weight and potentially increased strength (debatable as a failures propagate better in fully filled materials).

Won't the pressure from injection molding deform the mold if it is flexible enough to flex for the undercuts? Is there a psi limit for depending on the mold material used?

No, awerby is talking about simply pouring into a mould, not pressure injection I think. Pressure injection moulds are industrial settings that are expensive and made of machined steel. I don't think it makes sense to make one out of a thermoplastic.

[curious aardvark]

moulds are great things to 3d print.

using polyflex or a flexible tpu - you can easily make flexible moulds.

desktop injection moulders are around: http://www.injectionmolder.net/order_items.htm

Depends on the size and quantity of things you want to make.

Another approach would be to invest in a second hand nylon powder sls 3d printer.

But personally I'd grab a duplicator 13 and start designing and making stuff.