The Saltgator: A Desktop SoftGel Injection Molding Machine | Hacker News Reader

The Saltgator: A Desktop SoftGel Injection Molding Machine

core77.com

59 pointssurprisetalk21 comments

The kickstarter page seems to be more informative.

"From ultra-soft to firm - mold any feel"

"Multi-part bonding"

I see this as an add-on for those who already have a 3D printer (I don't), because you can print the mold for your softgel part.

https://www.kickstarter.com/projects/saltgator/saltgator-the...

It's a kickstarter, seems interesting but I'm going to pass until they can ship products and have reviews that don't read like sponsored content like this article.

The estimated shipping date is September 2025, so they must be ready to ship already, or they are scamming.

Looks like they are re-inventing the creepy crawler oven I had as a kid.

I had one too.

https://en.m.wikipedia.org/wiki/Thingmaker

Reminds me of the modified EZ-bake I had 30+ years ago [1]. I tried putting hooks in those to mixed success. One side was always flat though.

[1]: https://www.youtube.com/watch?v=PTFiJAH63xo

I've been watching Marling baits and he just shoots microwave oven heated plastisol into a mold for years.

I don't understand, does this just inject the plastic into the mold? Where do I get the mold from?

> You can use existing resin molds or 3D print your own.

I missed that, thanks.

You 3d print molds with a separate 3d printer.

It feels implied from the video and the pictures and the opening paragraph

> If you own a 3D printer, you've got hard plastics covered. . But what if you want to make something soft or squishy, like grip pads or a gadget enclosure?

Print in TPU? There is a limit to how soft one can get, and the finish is not so great (stringing). But fantastic for very tough semi-soft functional objects. Ninjaflex Cheetah and Armadillo are my favorites, but generic TPU also works. Direct drive extruder recommended, though I manage on my cheapo Bowden fed Ender 3.

Looks like a cross between a Rollie Egg Cooker and an Aeropress.

In fact, I think you could reproduce this invention using components of those two products.

Hmm, so basically it's a heated syringe? Is there a reason you couldn't just use a regular syringe and heat it up?

The Kickstarter video shows temperatures of 180°C, and polypropylene syringes don't support that. You can probably use a glass syringe but I suspect that would gum up quickly.

A lot of diy/custom lure makers are are already doing something very similar.

The process involves a plastic mix called Plastisol https://en.wikipedia.org/wiki/Plastisol which is initially liquid but after heating it for the first time and letting it cool it becomes rubbery.

In small scale setups the heating is typically done in a glass beaker and microwave or other heater. Injection is done using giant metal syringe (which are sold for exactly this purpose).

If you look up some videos of people doing it the process is quite messy. Search "making soft plastic lures" on youtube. Looks like this product just tries to streamline the process by integrating syringe, heater and mixer (typically you would mix in a dye and or glitter preferably without introducing a lot of air bubbles), while at the same time comparing their product to everything else except the direct competitors based on similar technology.

Considering the target audience (a lot of fishing lures) and information about their plastic/rubber - initially liquid, needs to be heated to ~180℃, becomes rubbery after cooling, recyclable seems likely that the rubber they are using is very similar to the plastisol stuff.

The recyclability claim is a bit weird. Yes you can remelt that stuff, which is not a problem if you heat it in a pot. Not sure how well it would work with their product which has the heater integrated and relies on the rubber initially being liquid at room temperature before the first heating so that you can suck it into syringe.

Using PLA molds also seems a bit of stretch. While their heater can be set to lower temperatures, the existing plastisol requires ~180℃ and screen in their own videos are showing similar temperature. PLA is melting temperature is ~210 and it becomes soft at 60. Might get away with PLA mold for some shapes once or twice. Maybe not so bad if it cools fast enough and actual melting temperature is lower than 180. In most of the lure making videos I have seen they are usually using aluminum molds.

Very informative!

How difficult is it to clean the syringe after the liquid passes through it? Does the leftover gum stick to metal and glass? Would it be possible to just pour the liquid into the mold (maybe through a a metal funnel), and use vibration on the mold to make sure all the creases are filled in? How important is the pressure?

Eh, seems kind of interesting, but can't you just use reagent cured soft plastics at room temperature without the cost of a machine?

I would hazard a guess you have to use their proprietary material to inject into your mold.

From their FAQ:

Can I use materials other than your SoftGel?

Yes. While we’ll offer our own optimized SoftGel formula, SALTGATOR is not locked to proprietary materials. You can experiment with other low-temperature thermoplastics that match our safety and flow specs.

No need to guess:

“This allows you to mold soft plastics (which you can buy from the company, also called Saltgator, or a hobby shop or fishing-lure supplier) and mold a piece up to 250mL (8.4 oz) in volume in about 15 minutes.”

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