Precious Plastic USA - extrusion-workspaces

Does anyone have a workspace with 5+ extruders?

Why ?

Curious to see how they are setup. I'm working on starting my workspace and plan on running at least 7 in a partnership with a rural county in my state in order to absorb the majority of their plastic. (solved my supply problem)

Mh, I know only a small scale PVC producer/recycler. They have lots fume extraction pipes coming from the ceiling, as well power supply cables. Not sure about regulations in the US - but here we have inspectors stamping their final say for the insurance. (edited)

I'm drowning in regulations...but I'm also taking on way more than I originally intended.

Right, I see. From a technical point of view, I'd approach this as like that : 1. Put monitoring in place, count the consumption, current/flow. I have done this a few times for higher grade VFDs (Omron) via Modbus but also current meters as the SMD320. 2. Same for the PIDs (Omron) - got some ready to go stuff here too - enables you to detect burnouts, and alarms. There are also cheaper multi-channel PIDs on Alibaba - not sure about the quality but seems promising. 3. Make the extruder accessible from all sides - Having a good floor plan for long term reduces a lot re-wiring and material handling. 4. Wire up all to a central hub - so monitoring and profiling becomes more easy. There's a bunch of IoT (internet of shit) tools you can use here. You just need to map modbus to MQTT messages. I can explain this more in detail. 5. The mentioned fume extraction might be crucial but possibly you can place extraction at the hopper and also contain the nozzle/dryer area. 6. Heatbands, depending on the thermal tolerances, you might also need fans .... I hope I didn't miss anything. If it's any interesting - let me know - I can guide you through the existing tools/sources

(edited)

9:13 PM

Interesting case btw. eager to see it up and running

(edited)

Thanks! Plenty for me to work through for right now. I plan to modify the extruder for degassing and port it to the hopper, then test to see if another fume extraction point at the end (could pipe all 3 together and house them within the insulated barrel shroud). As far as automation/IOT.....speak nerdy to me!

My 1st degree was Information Systems Management, the programming side of things is easier for me than welding. I plan on using a few sensors to help streamline production, monitoring the hopper (alert/light before it runs dry), automatic mold switching (dedicated lines with multiple molds -I have concerns the process may not take long enough to effectively cool them in the carousel, if sucessful I can attempt to automate the process of removing the finished product from the mold), and master control for monitoring/secondary emergency stop. Automation is planned later on down the line since I'm going to be required to hire local employees as part of my agreements with the city/county.

Sounds amazing what you're doing there! Unfortunately it's bed time here for me. For now, here's some ready to go boilerplate for Omron VFD/PIDs : https://github.com/plastic-hub/pp-next/tree/master/projects/Printhead/firmware/firmware (beta, that was for a 3D print head on a ABB robot arm). Basically Modbus485 devices proxied over custom ModbusTCP - which you can control from any Modbus phone app

Let's go on via direct message, I am stoked already

(edited)

@Def1ant1 - Hi again, I've got some more footage from a client who extended the extruder for professional needs. However, I am merging his addons into a new extruder version - providing all the monitoring and controls - all Modbus-TCP eventually some other protocols as well. Not cheap though, the electrics incl. heatbands and fans adds about 3k - labour excluded. For the automation part I am curious too. A carousel sounds great! Possibly with extra cooling, yup.

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3:32 PM

Here the cabinet, PLC & Remote i/o boards not included

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3:33 PM

Looks like we may upgrade to 45mm diameter screws. v4 is ok - but apparently folks need more juice

Has anyone ordered their screw from https://m.robotdigg.com/product/1753/30mm-diameter-extrusion-screw-for-Precious-Plastic-project# ?

30mm diameter extrusion screw for Precious Plastic project - RobotDigg

Screw and Barrel for Plastic Recycling RobotDigg are glad to work with worldwide Plastic Recycling projects which can help to reduce, repair, reuse, and recycle the Plastics. This extrusion screw is d...

1:51 PM

I am just curious which which option they went with, quality, ship time etc. I am thinking about getting the 825mm screw @ $145 and the RobotDigg designed barrel @ $105. I think they correspond but could be wrong his drawings aren't so clear and I'm not an engineer! (edited)

these are quite ok - using this since long

@itsgeorge - in addition, Robodigg ships really fast. One out of 30 screws is scrap but they replace it in no time without any discussion. There is an custom tax charge at the door. Quality is ok as said but they do have weird/rubbish things in their videos from time to time : https://youtu.be/O3Jroy6gAA4?t=188 (this guy is fired, my little sister can do better

RobotDigg Shanghai

What is the process on the injection or extrusion screw after Nitried?

-- osr-support --

@itsgeorge - in addition, Robodigg ships really fast. One out of 30 screws is scrap but they replace it in no time without any discussion. There is an custom tax charge at the door. Quality is ok as said but they do have weird/rubbish things in their videos from time to time : https://youtu.be/O3Jroy6gAA4?t=188 (this guy is fired, my little sister can do better

Just ordered thanks for confirming

Hello friends, I understand this channel is for machines but I would like to showcase what I got from a large PS compactor (auger extruder... It over ran and turned this styrofoam into a uncut plastic diamond

@TEglen I see you updated the PP USA Part list with your extruder parts. Thank you! Just want to confirm that 3hp and a 5:1 gearbox is the way to go. I just picked up a 3 hp 1 Phase from from a junkyard that is practically new for $80 and hoping I can use it. How far along are you on your build?

@itsgeorge Sorry for the delay. I'm still in shopping/ordering now (waiting on grant funding to come through) so the motor/gearbox combo and screw/barrel (from robotdigg) should be arriving in the next week. I'll come back and update once I have more! (I can say the shredder is up and crushing, I'll share videos on the other channel soon)

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Awesome to hear you both are making and using machines! I am exploring getting something setup in Kansas!

TEglen

@itsgeorge Sorry for the delay. I'm still in shopping/ordering now (waiting on grant funding to come through) so the motor/gearbox combo and screw/barrel (from robotdigg) should be arriving in the next week. I'll come back and update once I have more! (I can say the shredder is up and crushing, I'll share videos on the other channel soon)

Nice can't wait to see what you built. But the 5:1 ratio on the gear box sounds like the screw will still be running fast no? I just checked whats posted on the PP website and Pro version says 263 rpm and basic is 40-140 rpm. @1750 rpm for a normal motor 5:1 puts you at 350 rpm. I've only started building this stuff a little while ago so I'm not sure if it will be a problem, looking to purchase components too!

Yes, 5:1 is a little to fast and needs actually extra care on the mold side, at least to get a nice surface finish for beams. We usually deploy those systems with 1:10. A VFD gives you playroom of 50% speed variation. More expensive VFDs (500$+) can deal with more.

Btw, interestingly, motors here in the EU come with 1450 RPM as default - so you might better off with 1:10 - depending on material and desired quality but also mold overhead. I guess we should collect more data ... (edited)

That´s more like it, https://www.youtube.com/watch?v=5zNhneCMbOI&ab_channel=BussAG nice takeaways

modular screw system, able to deal with lots of different materials, that gives lot´s more control over processes - I am trying to get more infos how to get this done -
the barrel can opened and everything easier to clean - I noticed a few times that user need more guidance regarding purge and longer storage. the kneading elements are also great idea
precise and metered feed
second hopper

Great input for the OpenSource plastic recycling project getting closer to quality and more flexibility

Buss AG

BUSS Kneader Technology

itsgeorge

Nice can't wait to see what you built. But the 5:1 ratio on the gear box sounds like the screw will still be running fast no? I just checked whats posted on the PP website and Pro version says 263 rpm and basic is 40-140 rpm. @1750 rpm for a normal motor 5:1 puts you at 350 rpm. I've only started building this stuff a little while ago so I'm not sure if it will be a problem, looking to purchase components too!

Your calculations are correct - this will be on the fast side. We'll be dialing it back with the VFD, but I wanted to be sure I could reach the recommended top speeds(320 rpm) as well. With the 3hp motor the torque output(924 in lbs) at full speed is still right at the upper torque recommendations(120Nm, 1062 in lbs) they have listed. I'll report back once we have it up and running. (edited)

Extruding polymers is quite an exact thing, speeds and temperatures are based on material, screw and as said, desired quality, etc.. Till today, I have haven't seen any tables which map this 'recommended' speeds to certain products, the material or the setup. The beams they extruded were all far below average quality (way too fast) and what's left are the bricks with a apparently similar odd configuration. But there is a thumb of rule to it, the lower the speed the better the outcome, which also applies for v3 extrusion which was running good for beams in the 30 - 50 RPM range - using same pitch of 22+ mm. Then doing granulate/pellets for the injection also wants quite a different speed, somewhere in the 100RPM range. Just saying, I'd really investigate what results you want to archive, ask around for settings and then build the machine. As last resort, mould heating helps in most cases.

copy that - I appreciate the insight. seems like a big spreadsheet of all the tube diameters, screw speeds, temps and resin types is needed. Unless one of those already exists?

okey, let's do that. Let me hammer this into a GSheet over the weekend. I will ask around for more data. There are also a number of new materials to be added, PVC, PE and some other industrial sorts. See you in a bit. According to industrial extruder vendors ( Leistritz ), the data can be scaled. I'd just add a few more columns as : Barrel-Heat-Insulation, Barrel - Wall-Thickness, Screw length, Mold Type/Details.

Sounds like a plan - I'll follow your lead and help source more info to add to the sheet. Post your link here when ready

@-- osr-support -- @TEglen Exciting stuff, not anywhere close to extrusion but getting together material and very interested in the results. I only have 1 phase at my house and I have a 3hp 1 phase motor I am hoping to use for extrusion machine, but could I use a VFD in this instance since speed control seems so essential? After doing some reading probably not and I should probably look into getting a 3phase motor. Or is there a VFD (Or some other component) I could use to control speeds for my 1 Phase motor?

could you send a picture of the motor plate?

Single phase VFDs exist so you should be able to find something. Probably will need to be 220VAC though. Single to 3 phase VFDs and 3 phase motors generally are inexpensive and readily compatible for Single phase mains input as well.

Single phase motors have it a lot harder to catch up with the line, even though there should be a run capacitator which compensates a little for the missing coils - yet, for running extrusion it's rather unsuited - especially when you extrude flakes instead of pellets (which come out a lot more consistently). I know from pro users that every detail matters. We had to remake even a v4 barrel because the opening was too big and caused flex (4x2cm) and another time because the screw shaft extension wasn't running true (0.05mm off). For the interested reader, here some papers and books: https://github.com/plastic-hub/pp-next/tree/master/resources/incoming/rureq and https://github.com/plastic-hub/pp-next/tree/master/resources/papers. there will be online file browser sometime. (edited)

Here the sheet, https://docs.google.com/spreadsheets/d/1l_yVBWFibwhoFrZVc-O0NgKxFU9uTkHVER2Z-bNIRnM/edit?usp=sharing

feel free to add options to the preset columns (1. right click on column, 2. adjust "Data Validation")
feel free to alter the table to whatever you like
might take some time to get data from our users
no idea where this goes but definitely good to have results, machines, specs and contacts linked/mapped somewhere
if you have multiple results to add, keep them in one block
failed configs are interesting as well

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TEglen

could you send a picture of the motor plate?

Ended up just getting a 3 phase motor

Btw. I've seen this a few times recently, don't make the hopper openings too wide if you can't hold against the increased flex on the barrel properly - even though - it's adding debts. For v3 & v4 with an average barrel wall thickness of 5mm, 4x2cm is a good size for the opening (recommended/remarked by industrial users). If you're not sure, holding a level indicator on the nozzle gives good feedback about how smooth your extruder runs (of course without belt/supports = not that easy to make btw.). It's not just about consistent streams but also preventing wear out of the barrel. Btw, there is an OS addon for v3/v4/ ... in progress which enables an one stage pellet system - using a face die cutter with multiple output holes. We've got told that pellets are increasingly replacing filament. Should be there before the summer

(edited)

10:08 PM

was wondering to go for feed control (auger) at the hopper btw... suggestions are welcome

Anyone know if 1200in pounds....or roughly 100ft lbs output from gearbox will be enough to make plastic beams 2x2in x 8ft?..kinda like in daves video from 2017?

Hi folks! Got an extrusion machine question. Our frame attaches to the motor (far left of the picture), and the barrel (bracket underneath the hopper), and when it runs it tends to bow slightly, pushing the gearbox up away from the frame and the nozzle down towards the frame. So we're looking to redesign our frame.

1:35 PM

I'd like to make a rectangular frame between the gearbox and the hopper, with the barrel's shaft running through the middle. Frame would mount to all four corners of the gearbox. Here's a picture of the gearbox mounting holes. (edited)

1:35 PM

I'd also like to do as little welding as possible.

1:38 PM

T-slot framing seems like a good option for us, but I'm unsure how to mount the gearbox to t-slot? Anyone know how one might accomplish that?

@adamj537 your frame does look a little light weight so might explain the bowing. But it's also important to put a thrust bearing on the screw to prevent pressure being transferred down to the gear box. If you have a good thrust bearing near the barrel, it will limit the bending effect.

3:05 PM

Be careful though as we broke a few gearboxes in our early days by not adding a bearing.

3:05 PM

Due to the pressure.

Oh! That makes sense. Thanks!

Rory

@adamj537 your frame does look a little light weight so might explain the bowing. But it's also important to put a thrust bearing on the screw to prevent pressure being transferred down to the gear box. If you have a good thrust bearing near the barrel, it will limit the bending effect.

Since the barrel doesn't have a flange, any idea of the best way to mount a thrust bearing? The barrel and screw we have is the design from precious plastic (https://www.robotdigg.com/product/1719/Precious-Plastic-design-single-screw-and-barrel-for-extrusion-machine).

7:18 PM

Is a tapered roller bearing a good choice? https://www.mcmaster.com/thrust-bearings/tapered-roller-bearings/

Oh, this guy looks like he has a decent structure in his build (2:05 - 3:50): https://youtu.be/1A05nDBKzVc?t=205

adamj537

Since the barrel doesn't have a flange, any idea of the best way to mount a thrust bearing? The barrel and screw we have is the design from precious plastic (https://www.robotdigg.com/product/1719/Precious-Plastic-design-single-screw-and-barrel-for-extrusion-machine).

Look for a flanged bearing, probably angular contact.

adamj537

I'd like to make a rectangular frame between the gearbox and the hopper, with the barrel's shaft running through the middle. Frame would mount to all four corners of the gearbox. Here's a picture of the gearbox mounting holes. (edited)

I would just get a thick steel plate, drill five holes in it (4 mounting holes, and a center shaft hole with plenty of clearance), and weld 45° support arms down to your existing frame.

12:49 AM

It's also entirely possible to do this weld-free if you drill and tap holes strategically

Hey everyone in the process of building the extruder and following the part list that @TEglen put together. He was kind enough to steer me over to this build walkthrough https://wikifab.org/wiki/PP_Extruder_Pro.

I have a question about the bearings. What kind of bearings are these? Are they thrust bearings? Links? I am not an engineer but what about the back pressure on the screw from the plastic being pushed forward (Axial/thrust load). Don't you need a taper bearing? (edited)

@itsgeorge There are more parts in the flange assembly that use stops to contain and support the back pressure. The stack is backed by spacers that retain the central rings on the bearing shaft, and a bolted flange that keeps everything tight in the flange chamber. We're about a year into this design and so far no fails to speak of, people producing beams and large molds on it repeatedly.

Anyone have experience with pultrusion? I've been cutting my teeth on Josh N Bee's Recreator 3D pulstruder (http://www.recreator3d.com/) to make PET 3D printer filament. Roman Neskashev in Russia has a more robust pulstruder, including a version designed from the ground up for educational use and maker spaces: https://drive.google.com/file/d/18HshocHEcGSNwkM0rHCQx5DCvaXbuzAl/view?usp=sharing Importing 10 of these kits into the US would cost around $350 per kit. Shipping around the US would be $20 to $30 more. If there's enough interest, I could be the middle person. How many want one?

The ReCreator 3D

The ReCreator3D - A variant of the PET-PULL Concept, Created with the XViCO X3S 3D Printer as a Base unit. Convert Soda Bottle PET into 3D Filament!

lv_0_20220202121435.mp4

Sweet! Never seen this one before and affordable

I made this wiring diagram to help me during building, just want to send it out there incase I made any mistakes. V4 has their wiring diagram but its in 3 Phase (5 wires). The diagram is 1 Phase with relay and using the 240V Band Heaters found on the PPUSA Part List (https://tinyurl.com/bdhcnu5p) Couple Questions: 1. Is it okay to run PID Controllers on 120v? I didn't see why you would have to run them at 240V and they seem to work fine on the lower 120 voltage. 2. As seen on the PPUSA part list there are 6 band heaters (3 pairs of 2). Each heat band powered at 240V run at 1.67A / Pair runs at 3.36. When They are all on together the band heaters are pulling 10.07A. Ten guage wire should be more than fine to handle this. Just wanted to see if anyone used different band heaters in their set up and how the loads were. (edited)

PP USA part list

Shredder How to add this sheet! 1. Add a new row for each item. [right click on the column index and click "insert one below"] 2. Add your name to the first column [and CA or US in brackets to denote your location], followed by the product Id and any other pertinant specifications. 3. Provide l...

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IIRC you want to switch both hot legs not just one.

9:38 PM

But not sure that required just best practice as I understand it.

switch both hot legs where?

So you are switching both hot legs going to the VFD but going to the band heaters you are not.

9:42 PM

Do you have an external disconnect going into the machine that breaks both legs?

ah ok you are right

https://www.amazon.com/SIEMENS-LF211N-240-Volt-General-Indoor/dp/B000HOV8FU/ something like this

SIEMENS LF211N 30 Amp, 2 Pole, 240-Volt, PLUG Fused, General Duty, ...

SIEMENS general duty safety switches have a compact size, are horsepower rated, and have a quick make-quick break mechanism. All switches are provided with highly visible "ON" and "OFF" indicators and padlocking provisions on the handle and door. All switches are UL listed and are suitable for co...

Hey everyone we are having a terrible time keeping our extruder to maintain temp. We are seeing drops of 70c or greater. Does anyone have any ideas on how to fix this?

Under what conditions is the temperature dropping?

With all the hype coming to Pultrusion Methods... I'd like to show my build. Got an Ender 3 or access to a used or returned unit for cheap? Check out my Free DIY build, The Recreator3D : PET#1 Plastic Bottle to 3D Filament Pultrusion Unit: https://youtu.be/PLiHF8iA8iA

JRT3D

The Recreator 3D - MK5Kit : Ender3 - DIY Build Notes - PET#1 Filam...

1

6:56 PM

Maybe a pultrusion-workspace would expand the community a little

2

Is anyone using a UV additive? We are experiencing a drastic slow down in our extrusion process and wondering if it is caused by our UV additive (possibly affected by humidity)

@GoUpcycled we are using the additive and saw no real change in time on the process

Anyone have an optimal speed drive/temp for extrusion? Having a hard time getting steady flow

What kind of workspaces are you guys working out of? We are currently in a garage but need a bigger space to scale up

Hi folks! I'm wondering if there's a way to build the barrel holder for the PP extrusion machine (the welded structure in this picture) out of T-slotted framing (https://www.mcmaster.com/T-Slotted-Framing). Has anyone done that by chance?

1:19 PM

I'd also like to ask this question in the main PP discord to get the perspective of folks outside the US, but am unsure which channel to post in. Can someone point me in the right direction? (edited)

adamj537

I'd also like to ask this question in the main PP discord to get the perspective of folks outside the US, but am unsure which channel to post in. Can someone point me in the right direction? (edited)

I suggest the #machines channel -- if you don't have access to it yet, go to #pp-start-here and select a role, it'll unlock that and other channels.

Graveheist

I suggest the #machines channel -- if you don't have access to it yet, go to #pp-start-here and select a role, it'll unlock that and other channels.

Thanks!

Any time!

adamj537

I'd also like to ask this question in the main PP discord to get the perspective of folks outside the US, but am unsure which channel to post in. Can someone point me in the right direction? (edited)

How to Reddy the exclusion machine

adamj537

Hi folks! I'm wondering if there's a way to build the barrel holder for the PP extrusion machine (the welded structure in this picture) out of T-slotted framing (https://www.mcmaster.com/T-Slotted-Framing). Has anyone done that by chance?

The extruder in the workspace I use is made out of the aluminum extrusions like that. It frequently needs adjustment, the pressure from the screw pushes the vertical blue plates forward, and has started stripping the aluminum threads in the t-slot. One of these days I'm going to take it apart and weld it so it's solid steel....I don't recommend aluminum for mounting the actual extrusion screw. It's fine for a base/table, but not for the features which are under force. (edited)

8:59 PM

Oh, I see! Thanks!

9:04 PM

Out of curiosity, what's the small black fan for?

Hahaha, just to circulate air in the room, it gets pretty hot!

9:31 PM

It really should be mounted on the wall, or have a table of its own, that's not a great spot for it.

Erik72

The extruder in the workspace I use is made out of the aluminum extrusions like that. It frequently needs adjustment, the pressure from the screw pushes the vertical blue plates forward, and has started stripping the aluminum threads in the t-slot. One of these days I'm going to take it apart and weld it so it's solid steel....I don't recommend aluminum for mounting the actual extrusion screw. It's fine for a base/table, but not for the features which are under force. (edited)

I remember this one, it was initially damaged because that team ran F value at C numbers and never replaced the beams.

Arrakis

I remember this one, it was initially damaged because that team ran F value at C numbers and never replaced the beams.

I've worked on this machine personally, a lot. I'm aware of the initial damage, but I reversed the extruded pieces and it still re-stripped the threads. It's just not a great place to use aluminum IMHO... I recommend welded steel

Erik72

I've worked on this machine personally, a lot. I'm aware of the initial damage, but I reversed the extruded pieces and it still re-stripped the threads. It's just not a great place to use aluminum IMHO... I recommend welded steel

We made this machine and we've only seen this type of problem on this particular machine. I remember sending new plates to repair it. If you simply reversed the beams then you didn't fix the threads, so they'll just move on the back end and keep your problem going. We use the same design on much more powerful extruders and have a working practice on dozens of various extruders for years now. I wouldn't confuse your working practice with a machine that still needs some love with the design in general.

CitSciWorkshop

We made this machine and we've only seen this type of problem on this particular machine. I remember sending new plates to repair it. If you simply reversed the beams then you didn't fix the threads, so they'll just move on the back end and keep your problem going. We use the same design on much more powerful extruders and have a working practice on dozens of various extruders for years now. I wouldn't confuse your working practice with a machine that still needs some love with the design in general.

I understand what you're saying, and agree with most of what you say. But I feel like the design is marginal, has zero room for any type of error, and if I was going to build an extruder for myself I would weld those parts from steel. Yes, the machine functions, and we've extruded a lot of plastic through it......but it requires constant maintenance. I'm not saying it is bad, per se, just that it is not a very robust design. Adam asked if anyone had experience, I am just sharing mine.

I can agree with that. We've developed our Basic design alot since 2020.

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10:10 PM

Plus no one said this was easy..

10:12 PM

@Erik72 If you'd like the thicker plates we added in late 2020 and new beams, even as a band-aid just let me know.

CitSciWorkshop

@Erik72 If you'd like the thicker plates we added in late 2020 and new beams, even as a band-aid just let me know.

Someday when I get around to it, I'm planning on welding some plate like so:

You could just drill holes for bolts and do an adjustable coupling.

10:22 PM

But I guess you're trying to avoid the need to periodically adjust anything?

It's hard to say if that would help without addressing the damage from user error. Those plates will probably just move in unison. Generally things get set and locked in and don't move unless you want them to.

Steel that is welded at both ends will absorb a lot more operator error than aluminum threads.

adamj537

You could just drill holes for bolts and do an adjustable coupling.

Yeah, I thought about drilling holes and running threaded rods front to back, but at the end of the day welding would be both stronger and easier

But it's still held on by aluminum threads. You're just welding two pieces together and not repairing the threads.

10:57 PM

It'll be super stable if you do both.

CitSciWorkshop

But it's still held on by aluminum threads. You're just welding two pieces together and not repairing the threads.

No, the force on the bolts will be at a 90° to the bolt instead of pushing against threads

10:57 PM

If I weld that plate on there, I don't need threads

11:04 PM

The four 90° brackets at the bottom of the assembly provide adjustment, & like I mentioned earlier, it's a lateral force to the bolts instead of pulling against threads. And there are four bolts versus two.

Is there a particular type of metal that is best for beam molds? The PP video didn't specify and I wanted to see what folks use. Thanks!

Joblin#9607

Is there a particular type of metal that is best for beam molds? The PP video didn't specify and I wanted to see what folks use. Thanks!

We use regular mild steel tubes with welded flanges.

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Does anyone have any mould / mold files they would be willing to share? I was looking for carabiner and a bottle cap opener or anything really. I am having a heck of a time modifying / createing my own. I have downloaded some from PP but guess I dont know what I am doing. LOL. The rar files for the carabiner look like laser cutter files so they aare not correct for 3dprinting....

are you trying to 3D print a mold?

yes, I have been researching and I would sandwhich an 3d printed ABS shape (carbiner, etc) between 2 aluminum layers and use the injection machine to fill. Have you tried that?

Caustic

yes, I have been researching and I would sandwhich an 3d printed ABS shape (carbiner, etc) between 2 aluminum layers and use the injection machine to fill. Have you tried that?

Curious how would you create an aluminum layer that fits the curves of the mold without folds?

so this is still a trial and and let me clairfy a bit what I am thinking. One type of mold has 3 layes, all flat. The top and bottom could be aluminum and the middle layer that typically has the shape would be 3d printed from ABS. Like this https://bazar.preciousplastic.com/moulds/injection-moulds/stainless-injection-moulds/

Stainless Injection Moulds

1:31 AM

Other types of molds are for more complex shapes and I will try to print the entire mold from ABS an example is this: https://www.thingiverse.com/thing:17507

Chocolate Bunny Mold by rweaving

This is a mold that you can use to make chocolate bunnies. With this mold I will be able to make my nieces vegan bunnies for Easter, something that can be hard to find. If you want just an ear make http://www.thingiverse.com/thing:17391

1:32 AM

from what I researched, ABS has a higher melting point that HDPE so some articles suggest that ABS may work for a mold and I want to try it out..... any ideas?

I spent months trying to make two part "complex" molds from alternative materials: plastic, epoxy, wood, concrete, plaster, custom made ceramics, and others im forgetting. Plastic is so sticky I could never get it to release from any of these materials.

Cmjstealth

I spent months trying to make two part "complex" molds from alternative materials: plastic, epoxy, wood, concrete, plaster, custom made ceramics, and others im forgetting. Plastic is so sticky I could never get it to release from any of these materials.

https://all3dp.com/1/3d-printing-injection-molds-the-ultimate-guide/

3D Printing Injection Molds – The Ultimate Guide

Discover the cost, speed, and design benefits of 3D printing molds and rapid tooling for injection molding, vacuum forming, and other molding processes.

1:37 AM

I have not yet tried IRL since I am fiddling with the mold still but hope to try it soon. I hvae been messing with homemade molds and sheet press from HDPE with some success (edited)

If you are fdm printing I fear the layer lines are going to make things even worse

yes, the above article mentioned that the lines interfere with a nice finish but also suggests its possible. Again, will try soon and can let you know.

1:39 AM

Resin may be better but I will try FMD since that is all I have right now. But, my local community college has resin printers avaiblae for use if FMD soes not work. (edited)

I was milling my molds. By the time I bought a 3d priter I had given up on molds using alternative materials and started using a cnc to mill molds out of foam which I would then use for lost foam casting into solid aluminum.

What item are you trying to make a mold for?

1:41 AM

Hmm, that sounds interesting, I also have a small 3018 CNC that I will experiment with too.

1:42 AM

Does your CNC mill the aluminum well? Is it a hobby CNC or larger?

For my testing I was using a part designed for a hydroponics system.

1:44 AM

I had trouble milling aluminum directly. my CNC machine is really intended more for engraving although it does have ball screws

I have a carbiner svg but cannot seem to learn Blender well enuf to extrude it to 6-8mm thickness then print out with ABS. (edited)

Milling foam is really easy, no cooling required and crazy high feed rates work fine

1

I milled a 3mm aluminum but dont think I have the right end bit tip - it works OK but... not great (edited)

I taught myself solidworks, ezpwnsive but this was years ago before free 3d cad programs were a thing. Solidworks has functionality specifically designed for creating 3d molds for the plastic injection industry.

ok I may have to check it out if I dont get traction with Blender

1:48 AM

Thanks.

My understanding is blender is more for mesh models for animation, gaming, etc. Haven't heard of people using it for industrial design

1:51 AM

Is that a thing now?

1:53 AM

You tried freecad or fusion 360?

I thought it would be OK for any 3d but maybe that is part of my problem... LOL. Blender can import dwg and dxf files so maybe trying to enter that niche too. (edited)

1:53 AM

I like FREE so will try out the free cad software too. Thanks

It will take time to learn any of them, they mostly work in a similar way, but there are lots of guides on YouTube to get you started.

Great, thanks for the info and discussion. Good luck

(edited)

FreeCad is to solidworks as gimp is to photoshop as far as I can tell.

1:58 AM

The full version of solidworks is over a thousand dollars I think. Kinda designed for professionals. FreeCad is sort of an open source knockoff

2:00 AM

Not sure if freecad does mold design but you could always design a mold manually as a part.

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Thank you

Cmjstealth

I was milling my molds. By the time I bought a 3d priter I had given up on molds using alternative materials and started using a cnc to mill molds out of foam which I would then use for lost foam casting into solid aluminum.

Lost foam casting sounds very intriguing...how did you do it? I wonder if other materials could be used with aluminum cast around a positive original, such as clay or polymer clay

JohnNephew

Lost foam casting sounds very intriguing...how did you do it? I wonder if other materials could be used with aluminum cast around a positive original, such as clay or polymer clay

Essentially you make a positive of your part out of foam and hot glue a chunk of foam to the top to act as the sprue. Bury it in sand and pour molten aluminum into it. The hot metal burns away the foam and replaces it as a metal replica. I get best results if I coat the foam with drywall topping compound before burying in the sand. Essentially I just buy a bag of it at home depot water some of it down in a bucket so it is more of a "gravy" consistency. I then dip the foam in the bucket and hang until dry. I repeat twice for two layers. I have since learned that this is actually very similar to processes that many factories use for lost foam casting.

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1:06 AM

I'm bad at remembering to take pictures when I make stuff. I haven't looked but I bet there are a bunch of videos on youtube of people that have done it. I'm sure I'm not the first.

Couple examples of molds I made using lost foam casting. None of them perfect. The mold for the controller control knob didn't work well due to release issues - too hard to get the cooled plastic out without breaking it or deforming it somehow (edited)

There are lots of youtube videos on how to melt and cast aluminum. The advice I'd add is if you are going to be doing a bunch of pours don't waste your time with steel crucibles made out of tin cans or surplus empty fire extinguishers that have been cut in half. they only work a couple times at best, make a mess, contaminate your molten metal, etc. I bought a couple proper mullite crucibles from a local pottery supply shop for maybe $15 each. Still working great after countless uses. (edited)

1

Cmjstealth

Essentially you make a positive of your part out of foam and hot glue a chunk of foam to the top to act as the sprue. Bury it in sand and pour molten aluminum into it. The hot metal burns away the foam and replaces it as a metal replica. I get best results if I coat the foam with drywall topping compound before burying in the sand. Essentially I just buy a bag of it at home depot water some of it down in a bucket so it is more of a "gravy" consistency. I then dip the foam in the bucket and hang until dry. I repeat twice for two layers. I have since learned that this is actually very similar to processes that many factories use for lost foam casting.

Also... I should clarify that when I said drywall topping compound I mean that specifically. It is sold wet. It is different than joint compound which is sold dry and a very different product that is designed to undergo a chemical reaction when water is added to set up. It is not heat stable and will break down and offgass when exposed to hot things

1

There are a couple parametric modeling tools being made for blender. CAD-Sketcher comes to mind. That said, even as a blender user, I have chosen to learn the RealThunder branch of FreeCAD rather than any of those, it seems like a more stable project that will continue to be developed for a long time, whereas blender add-ons come and go without warning.

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1:40 AM

And trying to keep old add-ons running in old versions of blender is just such a workflow headache.

I like CAD-Sketcher because I use Blender for some of my video game models and I don’t like to work in multiple programs

It does look like it works just fine. Not knocking it as a choice. Just not my first choice.

If I was only doing 3D printing and stuff for the “real world” I would definitely use FreeCAD as my main program.

Cmjstealth

I'm bad at remembering to take pictures when I make stuff. I haven't looked but I bet there are a bunch of videos on youtube of people that have done it. I'm sure I'm not the first.

Ah...so the foam positive is the shape of the mold for plastic, as opposed to the item that the mold itself will be making. Sounds like aluminum casting is something I will need to try. I'm also interested in ideas of how to translate a physical original (say, a sculpted object) to an injection mold, without 3D modeling/scanning/CNC.

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JohnNephew

Ah...so the foam positive is the shape of the mold for plastic, as opposed to the item that the mold itself will be making. Sounds like aluminum casting is something I will need to try. I'm also interested in ideas of how to translate a physical original (say, a sculpted object) to an injection mold, without 3D modeling/scanning/CNC.

I'm sure it would be possible. If the part has sufficient draft, for example, maybe cut it in half and form a block of clay (or casting resin) around each? That would give you two positives of each half of a two part mold. Then you could use standard silicone mold techniques to make molds for the... molds. With this you could make a foam positive of the injection mold using expanding foam or wax to do an aluminum lost foam or lost wax casting. (edited)

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1:43 PM

I haven't tried it yet myself but there are alternatively now also 3d photogrammetry tools that allow you to create very accurate 3d models from a bunch of overlapping photographs. If you have a cnc mill or 3d printer this might also allow you digitize a physical object and design a mold for it. You can now buy foaming 3d filament that lets you print foam objects. I've also seen videos of people doing lost PLA castings although that sounds like a lot of burning plastic to me. (edited)

Basic question here: on the Bazar why is the difference between the extruder pro and the V4? Are they the same thing? Can we buy the V4/pro in parts, or is that the more basic v1.2 only? Also, can these machines make a 6ft beam? Any tips for what to look for would be appreciated!

Hi. I am trying to figure out why my mini extruder isn’t heating up. I followed the wiring diagram exactly as it shows but the SSR doesn’t turn on.

@MBrady is that one of ours? Sustainable Design Studio?

11:37 AM

Note that some PIDs that we supply have the + and - flipped (4&5) if this is the case you need to also flip them.

HI, I had just had a similar issue and can take some pix if needed but here in the USA...... I have PID ITC-100VH so 2 strand thermocoupler on PID slots 3 (blue) and 4 (red), slot 6 to SSR 4, PID slot 8 to SSR3 and slot 9 and 10 to power/switch. EU or other PID's might be differnt and yours should have a connection diagram. Heat bands will connect to power and SSR2. Let me know if you need any clarification. (edited)

Caustic

HI, I had just had a similar issue and can take some pix if needed but here in the USA...... I have PID ITC-100VH so 2 strand thermocoupler on PID slots 3 (blue) and 4 (red), slot 6 to SSR 4, PID slot 8 to SSR3 and slot 9 and 10 to power/switch. EU or other PID's might be differnt and yours should have a connection diagram. Heat bands will connect to power and SSR2. Let me know if you need any clarification. (edited)

Thanks @Caustic !

MBrady

Thanks @Caustic !

Here are a few pix to start mid assembly. What PID do you have? (edited)

8:51 PM

OH, and just to clarify - this is an injector but the concepts and connections are the same minus a motor I think (edited)

Rory

Note that some PIDs that we supply have the + and - flipped (4&5) if this is the case you need to also flip them.

Right, my Ink Bird ITC-100VH was differnt than above pix

8:57 PM

One more pix of the side of the PID for the diagram

Thanks!

9:32 PM

I ended up replacing the PID and that did the trick

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MBrady

I ended up replacing the PID and that did the trick

✅

My extruder is running well but when I attach the molds, the plastic never reaches the extents of the molds. I get the plastic oozing out first to ensure it’s a good viscosity. The extruder is hand cranked so maybe I just need to use a drill a push it through faster? I sprayed it with mold release.

10:24 PM

*hand cranked right now

Warm moulds really help

10:51 PM

Should be too hot to touch with bare hands

Thanks Rory. I tried that too. Could the inlet be too small?

Hi, I have a question about the motor specifications of the extruder. I don’t have one yet but I’m gathering materials and just curious if a motor that I have will work. It’s an old garage door motor that is a 1/2 HP motor. The wattage in research says 1,100 to 1,400 starting watts, and 550 to 725 running watts so that fits under the maximum power output. I’m not finding anything for motor output on them (Chamberlain model if anyone is better at digging this stuff up). Their site says they’re capable of 1725 rpms but I don’t think that they run that fast attached to a garage door and I know it’s probably capable of being wired to run slower. Any advice?

Hey machine builders! Can you show me the nozzles of your extrusion machines? I'm currently mentoring a college senior design team that is making an extruder, and am looking for a design that allows molds and nozzles to be attached easily. Bonus points if welding is not required. (Sorry for the cross-post. Wasn't sure if it was better to post this question here or in #machine-shops)