r/InjectionMolding • • Jan 04 '26

Cool Stuff Injection Moulding Machine built from LEGO, not yet finished

398 Upvotes

I'm a 3rd year apprentice, thought I'd built a machine just for fun, I like the result for now :)


r/InjectionMolding • • Mar 31 '24

Informational New Introduction Thread!

9 Upvotes

Hello everyone, please previous introduction thread was automatically archived as it has been 6 months, here's the new one.

Here is a link to the previous post: https://www.reddit.com/r/InjectionMolding/s/vmycWy4YDi

Suggested format below, please feel free to modify if you'd like, no links to websites.

Thank you and I hope everyone is enjoying their Easter or at least their Sunday if you don't celebrate it.

Name:

Company:

What does your company do?

What processes does your company engage in?

What do you do at your company?

Direct messages okay?


r/InjectionMolding • • 9h ago

Looking for Employment Molding certifications

3 Upvotes

Fellow process engineer/technician here (I’ve only recently gotten into the engineering side) I’m curious, when applying for these positions is there any certification that will clearly stand out and make it known that the individual is proficient/advanced in the field?

For context: I have 6 I believe, all from paulson.
Molding fundamentals
Technology of injection molding 1
Technology of injection molding 2
Technology of injection molding 3
Part problem and solutions
Pro-molder 1

All with a 90% or better passing grade.

I am having a really really hard time trying to find any solution to my immediate problem and am just looking for insight from the community. Are these not of sufficient accreditation? I know that plastics community is small…. Figured I’d ask idk.


r/InjectionMolding • • 1d ago

Question / Information Request Why is our injection-molded TPE warping more than thermoformed liners?

4 Upvotes

We’ve been running some long, thin-walled automotive interior parts in a TPE blend, and the post-mold warp is driving our QC team nuts. The shrinkage difference from the gate to the far edge keeps throwing the clip alignment features out of position.

I’ve noticed that a lot of larger footwell and cargo pieces seem to use heavy thermoforming instead of conventional injection molding. Is that mainly a tooling-cost choice for lower-volume runs, or does thermoforming do a better job of controlling internal stress and edge curl in semi-rigid flexible plastics?

We’ve adjusted the cooling lines and hold pressure, but the cycle time is getting hard to justify just to keep the edges flat. If anyone has worked on long, flat automotive trim parts, what tool design or material factors have made the biggest difference in keeping the edge height stable without adding a bunch of complicated ribbing?


r/InjectionMolding • • 2d ago

Ideas for Storing Clamps/Bolts not in use

2 Upvotes

Right now at my shop clamps and bolts get left at presses they were last used at... which ends up with clamps everywhere and a lot of time searching for a certian type for a certain tool/press combo. I understand a lot of it comes down to people and putting things back (5's) but we've tried in the past to consolidate how things are stored, whether it be one big toolbox, holding all the clamps in buckets/metal bins at each press, however none of them really worked: the buckets got dumped and used for material and the metal bins got bent and smashed...

Was wondering if you guys have had any lasting success with a certain storage set up and /or practice regarding this.


r/InjectionMolding • • 2d ago

Engel Victory clamp closing/ variable issue

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2 Upvotes

Hello all, share your wisdom, we have 2 Victory SPEX a 240 & 330ton. Recently lost a linear stroke transducer for Mold Position, got it replaced and recalibrated with little issue, problem is clamp is almost slamming shut and apparently has for a while. I know each machine is fine tuned during commissioning both machines have similar variables values in MoldClosing, but the highlighted lines are raising some questions.

Line 2 is way too fast, should probably be about 1-2"/sec

Line 3 would leave me to believe if you put an object smaller than 0.4" between the partingline the IMM could build tonnage so that should be near zero

Line 4should be closer to zero


r/InjectionMolding • • 2d ago

Dimensional stability of injection molding vs vacuum thermoforming for automotive footwell trays

1 Upvotes

I'm comparing injection molding and vacuum thermoforming for high wall automotive footwell trays, mainly using TPE-type materials.

From what I've seen, thermoforming obviously has a tooling cost advantage, but once you get into deeper draws, the material can thin out quite a bit around the vertical walls and tighter radii. I'm wondering how much that actually matters for long-term dimensional stability, especially after repeated hot/cold cycles inside a car.

Injection molding gives you more control over wall thickness, ribs, and local reinforcement, but the tooling cost gets pretty serious once the floor geometry becomes complicated.

For parts like this, how much of the warping resistance comes down to maintaining more consistent wall sections versus designing in ribs, radii, and proper stress relief?

I'm less interested in the cost side and more curious about what tends to keep the perimeter from slowly changing shape over time.


r/InjectionMolding • • 2d ago

Question / Information Request Advanced mold design training

6 Upvotes

I'm the lone mold designer at my mult. company corporation. They recently got into setting goals for engineering. I've got 15 years in mold design (small complex medical devices). They want me to go for more outside training/education to become the company wide SME.

I'm having trouble finding anything beyond basic entry level stuf or somewhat intermediate level.

Main topics:

Complex slides, angled side cores, and compound actions

Advanced lifter design and difficult undercuts

Complex parting lines, shut-offs, and insert design

Micro product molding

Complex overmolding

Complex core pin & Molding rod design

Unscrewing molds

Thank you for any leads!


r/InjectionMolding • • 2d ago

Inductive heating molds

2 Upvotes

Hello!
If anyone here has experience with molds using inductive heating (for cosmetic effects) please contact me!
Thank youu 🙂


r/InjectionMolding • • 3d ago

Custom injection molded housing with complex ribbing and tight tolerances — thoughts on the DFM?

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23 Upvotes

Just pulled this part off the press at our shop. It features some pretty complex internal ribbing and sealing grooves.

Always interested in how other engineers and manufacturers approach DFM for parts like this to avoid sink marks and warpage. How would you guys gate this one?


r/InjectionMolding • • 3d ago

Memes

39 Upvotes

r/InjectionMolding • • 3d ago

Machinery for cleaning mold cooling lines .

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2 Upvotes

Hi,

Anybody have experience with these machineries which will clean up the cooling lines from mold?

Bio-circle seems to be having some kind of machinery and Fidica also.

- Fidica seems to be having some kind of separate cleaning and protective media (neutralizer) tanks?

Not able to share links due rules.

Are these any good? I have small doubts little bit with that separate tank function and how does it work in real life.

What kind of chemicals you have used?

Fidica seems to be having some kind of cleaning agent available.


r/InjectionMolding • • 3d ago

Scoremaker-I Experience and Troubleshooting

2 Upvotes

So the company I work for has alot of old Van Dorn Injection Molding machines with Scoremaker-I, SCI Cards, and such controling these machines. I was wondering if there is more people out there with these machines and have a good amount of knowledge on how to troubleshoot them.

I was having trouble finding a good reddit area for this. Correct me if I'm in the wrong area.


r/InjectionMolding • • 5d ago

Why Did I Buy This? Part II

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22 Upvotes

A few days ago I posted a couple of pictures of an old injection molding machine I bought for 100 bucks. I put together a video showing everything in a bit more detail. Let me know if you think it's salvageable!


r/InjectionMolding • • 4d ago

Hwamda Experience

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5 Upvotes

Hi there. Has anyone worked with a Hwamda for general moulding? A client of mine has them and swears by them. They look decent considering their price.


r/InjectionMolding • • 4d ago

Straight-pull injection-molded snap fit for an irregular curved two-piece housing

1 Upvotes

I am designing a one-time-use injection-molded housing made from two irregular curved shell halves. The halves mate along the longitudinal seam shown in the image. I would prefer to avoid side actions and use a straight-pull mold.

Would a tongue-and-groove joint with discrete crush ribs or a segmented snap feature be appropriate? Is there a better snap-fit geometry for this type of curved housing? Adhesive bonding is also an option.

Material: Polycarbonate
wall thickness: 2mm
Assembly direction: Top clips into bottom part
Requirement: one-time assembly, no planned disassembly.


r/InjectionMolding • • 5d ago

Troubleshooting Help 1998 Arburg allrounder 320C problem with setting up a mold

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6 Upvotes

Hello guys, I have this 1998 320C and it was working absolutely fine until I took off the mold to change it. After I put the mold on and started closing the clamp the ejector came back as usual so I try to zero it but I can’t. What it says is that the clamp is too open while it’s not and I can’t change it. It was set at 280mm and after this happened it doesn’t allow me to do any movement because the measurements are wrong as it says. As you see it says 45-26mm and when I put 45 it says it’s over maximum but when I put 44.9 it’s under minimum. How can I solve it


r/InjectionMolding • • 5d ago

WTF?

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1 Upvotes

It’s not even an eyebolt. It’s just the eye welded to the cylinder mount.


r/InjectionMolding • • 7d ago

3D printable injection mold (for training)

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289 Upvotes

This one is on the final print and fitment stages, once I am happy with everything it will be on printables for free to download. I am going to make a basic blank mold with all plates and basic bolts as well. That one will have the STEP files released so people can make their own mold if they so please.

This one uses a sleeve style ejector which was fun to model and build. No cooling channels because of complexity of printing and no runner, mock parts will be available.

IT HAS BEEN POSTED!

https://www.printables.com/model/1883118-injection-mold-2-sleeve-ejectors

Took way longer to get posted than I wanted. Free time is something that apparently is a very very hot commodity. Please tell me all the good and bad of the design. It is hefty on filament. The face dimensions are 200mm x 200mm and well over that in thickness once assembled.


r/InjectionMolding • • 8d ago

Nice mirror finish!

136 Upvotes

r/InjectionMolding • • 9d ago

EDC

2 Upvotes

What is your edc as an injection molder/setup tech/process tech?


r/InjectionMolding • • 10d ago

Cool Stuff Why did I buy this?

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46 Upvotes

I bought this today for 100 bucks. I can't find any information about the company except a patent from the early 80's. I'm not sure if it's worth the effort to gut the old controls and get it up and running again.


r/InjectionMolding • • 10d ago

Question / Information Request Can someone explain decomp before metering

3 Upvotes

Ok so I know how decomp works. It's the screw that moves back without rotating and feeding melt. So I have seen a 5 mm decomp before metering on a machine and that made me think. If I have a cushion of 6 mm do I still get the 5 mm of decomp so the screw will be at 11mm before it starts to rotate.

Just wondering.


r/InjectionMolding • • 12d ago

Curl

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64 Upvotes

Makes your toes curl.


r/InjectionMolding • • 13d ago

Help Choosing IMM

5 Upvotes

Hi all. I need help choosing a brand of IMM moving forward. Our budget has always been tight since we are a smaller family owned company so we always bought older Nisseis and Demags to retrofit with PLCs and servodrives which served us well but the mismatch in brands and spare parts etc is starting to wear me down. We are steadily growing so looking to start purchasing one brand to stick with for the next few years. Every sales agent thinks their machines are the best so I need unbiased advice.

Our current options (these are brands that are all well represented in my country):

Demag (big stretch in budget)
Wintec (Engel is out of the budget)
Yizumi
Hatian
Milacron
Borche
DKM
Tederic

Our machines are all +350 tons

Our criteria:

Highest ROI
RELIABILITY
Spare parts
Energy Efficiency

Keep in mind that we mostly run recycled flexible PVC regrind for our in house products. We will start to pelletize the PVC but as of now it is purely regrind. We run virgin/recycled pellets for external client on their products.

We are new to the industry so would appreciate any guidance. Thanks in advance