Making Plastic Injection Molded Parts

[@abatter]

Great video. Thanks for putting it out there. Plastic injection is fascinating and it's great to see it in a benchtop application.

[@samellowery]

I appreciate you talking about how you used a taig cnc to do your early work shows how this can be done on the cheap.

[@jonnyhifi]

I love your videos John - I’ve learnt so much from you - thank you for sharing your experiences.

[@nickp4793]

Nice job on organization and still having all the molds 10 years later:)

[@JohnSL]

All of the molds I've made, and there are quite a few, fit into a single drawer. They're small.

[@ruimilanesejunior2619]

@@JohnSL you manufacture to order?

[@shanegonzales]

Absolutely love trimming new parts from the tree.

[@DragonflyEngineering]

that's cool that you did some model railroad stuff. One day I hope to do the same. Nice video

[@JohnSL]

I didn't know you had an interest in that too! I'm happy to collaborate on a project if you're interested, as your machines are all larger than my largest machine.

[@DragonflyEngineering]

@@JohnSL Hi John, yes a collaboration sounds fun. I'm thinking about using a HO train as a parts conveyor between work cells. Maybe we can come up with a hopper car that I can move molded parts on a track. 50 cars should be a good start. we can sell them too

[@copperkerf3846]

I appreciate your attention to detail and best practices. Nice work.

[@pierrebouteillon]

Very intersting to see you working in real time!

[@bruno_lewin]

Nice to see an injection molding video again

[@JohnSL]

Thanks Bruno. I have more coming. I have been making molds, but unfortunately have not been able to show them.

[@eugene4154]

Good practice is to leave the last office sample with the tool in its bag,as reference to what it is , then on a post it paper record your settings and last run qty add the material used to the list

[@lonnalachner7344]

Thanks Jon for another informative video. Keep up the Solidwork

[@jimmyhuesandthehouserocker1069]

I'm looking to get started in doing what you're doing, if I can find out more in detail such as where to buy supplies. I want to make replacement playfield inserts to restore old pinball machines. If you're not familiar with pinball machines, they have plastic inserts, generally about an inch in diameter, lighted underneath with numbers, letters or arrows printed on top. The old ones become dished down, and the ball gets caught in them

[@JohnSL]

It sounds like that's a good fit for desktop machines. LNS and other companies sell small batches of plastic. So getting started feels intimidating, but it's actually not that bad as long as you're using simple desktop machines.

[@pedro09pm]

Awesome video!

[@wizrom3046]

For a basic machine you have modded that and refined it to have a very respectable throughput. 🥇👍

[@AngelMorales-do1el]

Good day... excellent video, I loved your injector. I would love to know if you have a machine like the one in the video, the AB-150, for sale. I would love to quote the cost and if they ship to Mexico and how much the total cost would be with everything and shipping. sorry if something is written wrong

[@clypeum5063]

Great looking parts, youve got a nice Setup there. I think that injection molding is slowly starting to make its way into the Diy and 3d printing industry. Im really looking Forward to make molds with SLA printers.

[@JohnSL]

I've been thinking about doing a video on SLA inserts for injection molding, but haven't gotten around to it. If you have SLA printer and have something in mind, shoot me an email and we can collaborate.

[@clypeum5063]

@@JohnSL yeah, ive got a printer and have even Made some 'pallets' Out of Aluminium to hold a smaller SLA Insert. The only Problem i found is that cooling is an issue. Once i Figure It Out and get Something Worth watching i send you an e-mail. Greetings

[@MrRustydawg]

Pretty cool . I enjoyed that video. Good work.

[@antonkukoba3378]

Could you explain in one of your videos how the maximum molded part size is calculated. I.e. from this video it seems like this machine is only capable of making really small parts. But if for example I want to injection mold the parts that are like 60 mm wide but 30 mm tall. What will be the limiting factor in this case? Is it the mold which I wouldn't be able to use with this kind of the machine? Is it the plastic that is not going to fill in the whole mold due to it gets solid too quickly? Or maybe it's the insufficient pressure that wouldn't allow this machine to inject enough plastic to fill in the mold?

[@germancarfan]

Yes the pressure would be too low

[@dass1333]

It would be interesting to see a catalog of part \ models you have worked on. Do you have a train? Or two? With your talents any thing is makable.

[@JohnSL]

I could do a video about that. I've probably made 30 or more molds in the past 10 years. What in particular are you interested in seeing/learning? As to trains, I picked up the hobby because I was stressed at work (I'm not anymore) and needed something to get my mind off it. Fairly quickly I discovered I loved to design and create projects, and along the way decided I really wanted to be able to make my own injection molded products. So no, I don't have a train layout.

[@dass1333]

@@JohnSL I don't have any particular interest in model trains, I do think they are interesting and have tried some other people's set ups. I even built a bridge for one just to test myself. Was just thinking it could shine some light on the hobby. If you have your table full of projects keep with them. I find every video you make is interesting even if it is out of my field of interest. Methods and creativity!

[@ruimilanesejunior2619]

@@JohnSL Veryy goodd

[@tukbuk2353]

I’m here after listening to within tolerance 140. Good content.

[@JohnSL]

Thanks!

[@bigbird2100]

Great video 👍 When adjusting air pressure will the moisture content of the material make forming and cavity filling any different.

[@JohnSL]

There are many different factors that contribute the pressure, temperature, clamping force, etc. What I should do is keep track of the parameters I've used for each mold. I don't. I dial it in again each time, which means I "account for" all of those factors by trial and error.

[@bigbird2100]

@@JohnSL a description of every sort of process type of job that requires a human to adjust by experience 👍

[@juanp.5364]

Dawn, I want to make custom toys. Amazing videos.

[@Emanuelmartins69]

I want to do a project and make miniatures of characters for gaming (like for dnd and warhammer) using HIPS. I wonder why the molds only last about a hundred castings. What should I know to get a really good precise mold for detailed miniatures?

[@JohnSL]

When you say the molds only last a hundred castings, are these 3D printed molds? I have another video on that topic. I'm not sure what you're asking about precise molds. Generally it requires a good 3D model and then someone who can machine the molds--assuming you don't have any undercuts.

[@Emanuelmartins69]

​@@JohnSL From what I understood from the start your video, is that aluminum molds can make parts around the hundreds, so I wondered how many pieces a mold could make.. So an aluminium mold could go on indefintely? Im not really interested in 3D printed molds, ive seen that they just cant wisthand any production... Regarding precision, I met with a friend, who has a CNC that was used to make aluminum molds for shoe soles, and I wonder what I should look for in a CNC to be able to machine molds for injection of high impact polystyrene for detailed figures character kits, and start a business creating these plastic model figures. I'm trying to find out how to have figures of similar quality to what Gamesworkshop manages to do, so i question myself how precise must the machine be to achieve this result. I have seen quite a few of your videos and they added much knowledge to me already, thanks a lot! Got curious about what injector machine I should get to start this business, now that I know that there is the possibility of machines that eject the parts automatically.

[@JohnSL]

Aluminum molds can often produce 10K to 100K parts before they start to wear. In my case, the parts I wanted to make didn't have much demand--on the order of hundreds of parts. So it was about demand, rather than the life of the mold. For miniatures, there is low-temperature injection molding process that uses rubber molds: www.siocast.com/siocast-for-miniatures/. While their machines are expensive, there are some companies who own their machines and will make molds and parts for other companies. Here is one company I've heard of that offers this as a service: zealotminiatures.com/injection-moulding/. One advantage of this technology is that it allows for some undercut. Additionally, you don't need to design a mold with a very complicated parting line, as would be required for a metal mold for miniatures. If you don't absolutely have to use HIPS, this is a much lower-cost way to get started.

[@Emanuelmartins69]

@@JohnSL the whole proprietary plastic/resin from siocast, and the fact that the material doesn’t work with tipical plastic glue is a big turn down strategically for my vision of business. I’d rather use other materials such as pewter or even highgrade 3D printing than their solution. The undercut limitation doesn’t imideately bothers me. The costs for starting the business is something that I’ll have to account for, and the most important cost that I just can’t find is how much the metal molds would cost…

[@kevinbarbour7649]

Hi john, Have you ever tried making a three mold part, for like a cup for example?

[@rhokdatroll]

Great video 😎

[@Supramonk]

Did you build the machine? I am super curious we’re to get one

[@rayblankenship432]

Thanks for posting this video!!

[@billknighton4181]

I’m trying to understand how the injection molding machine works. It looks like a pneumatic piston presses down into a cylinder that is on a sliding axis. Is the force of the piston acting through the plastic the only force that makes the injector press against the mold? Is it a ratio of the piston diameter to the diameter of the injector orifice that causes a tight seal? The force pressing the injector against the mold doesn’t seem like it would be anywhere near the force that is holding the mold halves together presumably it does not leak. What is the spring function? Is it to ensure the injector lifts off from the mold when the pneumatic piston is removed?

[@JohnSL]

Hope this answers all your questions: kzbin.info/www/bejne/qXWxq3mBdtBqb8k

[@larrykent196]

Very interesting, thanks for the video. Cheer!

[@danielseman9324]

To keep that pin in the back of the mold. Take a larger ball bearing than the hole diameter. Put it on the back side of the mold and hit it with a hammer. This will swage the hole around the backside and push material in. The pin can then be press fit into the hole from the inside. That will capture it and keep you from having to worry about it.

[@JohnSL]

Thanks. I'm using removable Loctite these days to keep my pins in place. I've also switch to 1/4" pins, with a smaller hole drilled all the way through the back. That way if I need to, I can remove the pins and then do any required machining. So far I haven't needed to do that, but it takes very little extra time.

[@robertmartin2936]

Great series

[@MrLolnovak]

How did you polish your moulds?

[@JohnSL]

I don't. A mold maker for model train kits gave me a suggestion a long time ago--let the machine do the work. So I use small step-overs with small end mills. The tool marks therefore don't show up in the part.

[@greisofaulim7471]

Show seu trabalho!!!

[@dancollins1012]

For a given mold, is the right pressure (no flashing) constant over time? If so, the why not measure the ideal pressure and write it on the mold?

[@JohnSL]

It's not for several reasons. One is the temperature of the mold. Another is the amount of plastic in the cylinder. As it increases in temperature, you need less pressure. But yes, keeping records would be a good idea for molds that I planned to run again. These molds have now been retired and I actually used a different machine previously to run these molds. So the settings would have been slightly different.

[@plasticman3952]

For future reference. It's always good practice to record and retain all cycle parameters that produce acceptable parts.

[@JurassicLures]

The cylinder that presses the mold, how many kilograms does the clamp hold?

[@JohnSL]

I believe it's 2 tons (imperial).

[@JurassicLures]

@@JohnSL can you tell me what model it is?

[@pablorambo123]

What kind of price is the ab150? Thanks

[@jimstamper7062]

can i suggest a little adhesive to hold the pin in place? something that can be undone like Loctite or ca glue?

[@plasticman3952]

Always vent the mold's cavities. Trapped air and Volatile gases in molten plastics need to be vented out ahead of melt flow. Plunger machines lack the necessary fill rate controls, so vents are advised.

[@JohnSL]

I often add vents, but have found they're not always needed. I've been told that the surface roughness of the milled halves provides some venting.

[@plasticman3952]

@@JohnSL Slower injection fill rates will control burning and shorting problems. And since that's not possible with a plunger machine. Parting line vents are advised. Place them where at last section is filled. Rough surfaces foul quick and require constant cleaning. Venting gases can arc and damage cavity walls.

[@burningdieselproduction5498]

Interesting little injection machine. Is this a diy or purchased unit? Thanks for a nice video!

[@JohnSL]

Details are in the video description as well. Here's a link: www.abplasticinjectors.com/ab-150

[@ruimilanesejunior2619]

@@JohnSL Out of curiosity, what price did you pay?

[@littlewingpsc27]

So did you design your own parts in a CAD tool then make your own molds? Are there companies that make molds for hobby use / small scale production, or is it something you need to do on your own to be cost competative?

[@JohnSL]

Yes, I did all the work: CAD, CAM, machining, and injection molding. Most of these were parts I wanted to make and were not profitable, as the volumes were very low. But they were fun to make. Doing this for yourself isn't really cost effective unless you sell at least several hundred and can charge enough.

[@ruimilanesejunior2619]

@@JohnSL You can send your e-mail?

[@David_11111]

You say sometimes it sticks in both half's What is the plan to stop this happening on future Moulds ?

[@JohnSL]

For molds like these, it really isn't that much of a problem, so I don't worry about it. Where it will matter is when I get to automatic molds. And in those cases, there are tricks you can use to get it to stick more to one side.

[@bitsurfer0101]

Where do you buy your pellets?

[@JohnSL]

It depends on the material. The polystyrene pellets I purchased from Tichy Train Group. He doesn't advertise that, so I'm not sure if he's still doing that. Generally it's hard to buy less than about 55 pounds of pellets of a single type and color. So I buy 3D printer filament and then use a chopper from an earlier video to chop the filament into pellets. Yes, that might be a little more expensive. But not that much, and I can get a lot more variety of pellets that way. This works as long as the plastic you want is available in a filament roll.

[@Runnerbeandaz]

Hi John what type of plastic did use for this job?

[@JohnSL]

Polystyrene, which is the standard for most model kits as it's easy to glue and you don't need something like ABS.

[@tomluque]

Would you provide quotes to make these small molds and/or do the printing of parts for me? I'm in the state of Washington.

[@JohnSL]

Yes, I do make molds for other people as well as parts. You can contact me by click on the About section of my KZbin page and then there is a button that will show my email address. I'm located on the East side (Seattle area).

[@tomluque]

I could not find the "About section" on your KZbin page

[@JohnSL]

kzbin.infoabout

[@astroclone]

Nice shout out to within tolerance. That's how i found you.

[@JohnSL]

I love that podcast. And thanks for coming over.

[@911TM-h4q]

Great ! As usual 🙌🏻

[@JohnSL]

Thanks again!

[@PascalScheffers]

Do the moulds get hot at all?

[@JohnJones-oy3md]

I was thinking the same thing. Wondering if the metal soaking up the heat necessitates continual tweaking of parameters.

[@VagabondTE]

From what I heard molds get warm, but that's a good thing. Molds work better when they're warmed up so you only need to do it at first and then they stay that way once you have a rhythm.

[@JohnSL]

Eventually. The more plastic being injected into a mold, the faster it heats up. These molds have so little plastic that it would take a very long time (probably hours) before they got too warm to hold. But yes, as molds heat up, the plastic flows more freely, and therefore requires less injection pressure. It's actually a good idea to heat molds that have lots of details, but the aluminum dissipates the heat very quickly, so pre-heating the molds doesn't actually help that much.

[@dnjmachine]

Love the injection videos.

[@JohnSL]

Glad you like them!

[@gustavoa4607]

Exelente video

[@TheRobsterUK]

Interesting, thanks :)

[@tomluque]

I'm concerned about who I can find to make a mold for me before looking at Injection molding as a Hobby. I use 3D CAD that produces STL files for my FMD printers. I'm looking to make 100 pieces per year with the mold.

[@David_11111]

yay

[@hamidelmouden2048]

Great 👍

[@OscarGonzalez-qm9qw]

niceee

[@truckimthanh3280]

Hello cho hỏi máy này giá bao nhiêu

[@JohnSL]

I don't know, as I purchased mine used. You'll need to contact A.B. Machinery: www.abplasticinjectors.com/ab-150

[@kallyanolekar5061]

Hi sir

[@bobweiram6321]

$3K for that tiny, feckless TAIG mill probably made out of stock cutoffs in somebody's garage? That's a down payment on a nice used Haas. LOL!