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Thanks for the reference @donald
For the upcoming week I’m going to research more in the process and see what can we learn from already used processes. Glass slumping, wood bending, plastic forming and all sort of different processes that might share some similarities in order to have a broader perspective of it.
I’ll keep updating!
So we want to make good quality products that uses easy to reproduce/ interesting processes to make the output apealing for the consumer eyes.
One of the processes that I’ve been digging in since quite a while it’s Bending since it uses one of the peculiarities of the material. You cannot bend metal or wood that easily. But a bending machine it’s expensive and quite especific to consider it accessible for people. What makes us think about another way of bending. The process it’s similar to thermoforming but instead of using vacuum to shape the piece we use a simple two-sided mould that presses the piece after being heated in a conventional oven.
*A little bit of an overkill for such a simple bent but honeslty the accessability makes it worth it.
In order to proof the concept we just described we desided to test a simple stool that implies bending in order to see how does it feel the end result.
– Is it strong enough?
– Does it look good?
– How easy is it to actually make it?
– What things went wrong?
– Can we use it in other materials than just PS?
We wanted to answer all this questions before deciding this is the direction we want to follow. And if we follow it what that actually implies. How much time would we need to refine the process, what is the scalability of this specific method…
Open source products is a hot topic and there is much to be discussed when it comes to how to make profit.
I believe that designers should earn something from each sell as they have made that possible in a way. However important it is this is not something we are referring here.
We shared this values in order to show what we stand for when designing for V4. Enable workspace to make profit is one of our clear focuses since we’ve seen people struggling with this, (long and slow processes, expensive collection system, not always the best output, lack of functionality…) This are problems that can be addressed from the designers point of view when a product has to be design. (Using the right amount of plastic, processes that are accessible yet gives a nice output, consistency through repetition and dividing production by stages to agilize the process…) This are all design considerations that will help enabling somebody who repeats the design make better profit on their products.
Having said that, this values are not ment to be a call for designers to give their designs for free. This is just to show what we stand for when designing products here in Eindhoven. If we ever make a platform such as open desk in which people can upload their designs, get tested and then accepted in our catalogues to produce wherever there is a PP machine then we can talk about designers rights. But that’s Butn the case now, maybe in the future. For now we are a bunch of designers contributing to V4 and that means that the same way we have engineers making a sheetpress we as a designers will make products as part of our contribution.
I hope this clarifies a bit what we ment by that even though I haven’t dig much into the open source topic. Thanks for sharing your comments.
Hey following here.
Last idea. Snap fit joinery with thick plates (or double plates). Maybe too heavy but definetely easy to make.
Let me know your thoughts about this and which is (from your perspective) the most accessible and interesting to reproduce.
Sorry this message is not following the Topic of profitability and open source philosophy that lately is being posted here but I have some designs I wanted to share with you.
Sorry I had no time to read all the coments and contribute in that manner but I’ll do and try to give my perspective too.
General path I’m following to design:
‘m focusing on a stool for now. Exploring different ways of making it. With sheets, with sheets + beams, only with beams… And also different ways of assembly it: screws, snap in fits or solvents (in the case of PS) After exploring several ideas I want to analize them and decide which technique will be the most accessible to reproduce by the comunity and the most profitable to invest in. Having selected that I will proceed with further iterations on the design but based on a selected range of techniques + tools and I will explore other typology options like chairs, tables or shelves.
Pic 1 – So my idea is to make a bending machine to use the properties of the material and make the structure lighter while still strong and stable. I briefly defined how many pieces will be needed and how will they be made to have an idea of how much accessible it is.
Pic 2 – Trying to reproduce same design with beams with an L shape. USing a big heated mould for the extruder and or cutting into the right shape for the legs. At this point I already decided that the stool seat should be two thick plates that helps the joinery.
Pic 3 – One idea is to weld PS plates with acetate or d-limonene to make the structure (up-left corner). But another idea that I explore (up-right corner) is to use the angle beams from @timslab to make the structre 😉
Today I did some scetches about one idea that we discussed the other day during the first brainstorming.
In the two first pictures the idea is to use beams as a corner piece / internal structure very simple, just solid triangles that could be done easily with a couple of cuts in a beam. The rest of the parts would be made with sheets following a pattern with the hand router and attached between each other with snaping joints.
In the third picture the pieces are bent in the corners so they don’t actually need any other attachment than screwing to the structural piece.
Quickly testing different settings on the Jigsaw
Objective: Exploring different velocities and modes on the Jigsaw
Material: HDPE, PP, PS
Tools: Jigsaw, T302H, T102D
I quickly wanted to try the pendulum mode since last time I didn’t use that into the test. I set the pendulum mode at the maximum level and rise up the velocity to the maximum. Then I proceed to cut on the three materials.
– For PS it’s the first time we cut 7mm plates without melting on the jigsaw. The downside is that on the top surface we have pretty brutal marks of chipping. even though the bottom is clean, and the cut as well.
– I tried also to cut thicker plates of PS (13mm) didn’t work out. Super hard. Difficult and completely melt again…
– For PP and HDPE turned out that I could cut much easier than before and that the control over the machine is much better. On the downside the cut surface gets few marks due to the fast feed I used. The best would be to find the balance between the feed and the pendulum modes.
Here you have an answer for the second part.
The single jack has 8ton pressing force But spreads the plastic over a longer period of time. Which requires less power. The cold press needs to spread the plastic fast since it is already cooling. This is especially important for HDPE which is still very viscous when molten. The hot press has a less consistent thickness output.
Here you go, hope I solved your questions!
The last plate I posted is made out of the cold press. Sorry for the mislead.
The cold press works with moulds of 1000x750mm with variable thickness.
The hot press on the other hand works with frames up to 1000x1000mm and the thickness of the plate comes from the thickness of the frame itself.
Hope that explains better what machine makes what. The question about the hydraulic jack I pass it to my college @markbertbach which will answer you with a more in depth answer.
Test 1: Make a sheet playing around with different size of pellets
Test 2: Make a sheet playing around with foils and pellets
Objective: Get interesting results with different size of pellets and also foils
Machine: Cold press
Material: (blue, white, transparent) HDPE bottles, (blue and transparent) HDPE foils and (red) Bottle caps
Tools: 1000 x 750 x 13mm Frame
In the process we shredded in three different ways in order to get three different types of pellets:
1. For small size pellets (10x10mm) we shredded twice the bottles in the dual axis shredder. That means you shred it once for making strips, and then you shred the result again to obtain finer pellets.
2. For the strips (30x10mm to 50x10mm) we shredded once the bottles and leave the result aside.
3. For the big pieces (30x30mm to 50x50mm) we just destroyed different bottle caps with a hammer.
* Tip for shredding foils. Since it generally gets stuck spinning in the shredder and doesn’t pass through it’s recommended to put in the hopper some solid plastic to help push the foils out of it. Could be a the strips that has to be shredded again or a full bottle. doesn’t matter.
– The amount of plastic we put in was not enough. Generally we put half a kg more in order to make sure it fills the whole. This time we put slightly less than that and the top surface didn’t look completely flat. Looks organic. Could be that the foils reduced its volume drastically, but we are not sure. Also we found few bubbles inside due to it.
– The mixture of pellets ended up having good-looking results. The small pellets make the whole consistent while the medium and big pieces of plastic contribute to the composition in interesting ways.
– Some foils ended up being burnt in the surface. Could be a problem of the mould being overused. Or maybe the foils are easier to burn since their thickness is ridiculous.
– While CNCing the plate later on, we found out that because of the foils it ended up being a little bit messy. It’s like lamination but at micro level. Didn’t affect the strength of the plate at first sight, but it’s inconvenient while milling because needs cleaning after. Or maybe passing again a second time.
– On the corners we found more flow marks than in the middle as it’s being usual with this types of plates.
@hanifkaruna, No worries, we’ll show all the details at the end of V4 in October. For now the process still under development and you can always follow the process on this following topics:
-Index (not complete)
-The machine development till now
@jpbarg, The only case I heard of is a Netherlands based company called New Marble. They don’t show much of the process but as far as I know this is the result of a research project done by Better future factory. We would like to know more about how to, but for now we are going to focus on HDPE, PP and PS.
@shhigg, actually you are right we are trying not to go above 205 or 210. But the oven heating distribution is not even so we always wear masks in order to prevent the toxic fumes.
Finding the best velocity (rpm) to cut with the table saw
Objective: Exploring different velocities with the plastic blade
Material: HDPE, PP, PS
Tools: Table saw, Plastic blade 222 from Oranje tools.
– First I used the original configuration 4500 rpm with the three materials. Trying first fast feeding against slow feeding speed to compare the results. With PP the results were bad in both slow and fast feeding. Same with PS. Pretty good results with HDPE.
– Then I changed the gears to a slower setting (3000 rpm) since there were pretty big melted areas. And made no sense to work at higher speed. The results were kinda impressive. PP worked the best with fast feeding. HDPE as well. And finally we got the cleanest cut of PS ever. All of them with pretty fast feeding which implies that you better clamp the piece to the table to make sure nothing moves during the cut. And also making sure the blade appears one finger above the plastic sheet.
– In general fast feed for all the materials works the best.
– 3000 rpm seems to be more suitable for plastics, especially for PP and PS.
– The blade works properly when placed slightly higher than normal. Around one finger above the top surface.
– The modified TCG blade with neg -3º cutting angle and 96 teeth works the best from all the testes made till now.
Okey, I have some results to share about cutting with the jigsaw. I found few interesting blades to work with that I’m sure will help somebody along the way.
– First I tried the T304H and got good results with HDPE and PP. Clean cut without melting and a sharp edge almost without scratches. But for PS got lots of melting again.
– Then I tried the T102BF and got similar results. To be honest I cannot tell you the differences between both cuts. Both really good for HDPE and PP and bad for PS.
– Finally I tested the T102D and got an interesting result. A little bit of scratches on the side but apart from that all good. Plus, is really fast, maybe good for fast jobs if the difference of quality is not that relevant. Still pretty clean cut. And I got a decent job with a 10mm PS plate. Clean cut without meltings but with quite a few scratches on the side of the cut. And on the top surface the blade is more likely to break some parts of the edge while cutting. So… not very sharp edge we could say. Then I tried with a 18mm plate and the result was totally different. Fully melted again and no way of achieving a clean cut. I wonder if with slower cutting speed would work out. But unfortunately ours doesn’t change that much the velocity from min to max.
Following the thread I’ve been testing with the hand-router to see how does it feels to use it for plastics. As always PP, HDPE and PS. And the results are kinda conclusive.
TEST A – First I tried regular router bits (ment for wood). The result on HDPE and PP are not that bad, sort of clean, very few melting spots detected. Not the perfect cut but reliable if there is nothing else around. Decent edges. But for PS seems that it just doesn’t work. Lots of melting made the process unstable and also unhealthy because of the fumes. (Very high cutting speed for the HDPE and PP around 30.000rpm)
TEST B – Then I tried a tool that would be generally used in the CNC to cut plastic and the results were much more precise. Worked very well for all the materials, including PS. No melting thanks to the polished surface that makes the chips fly away. (Medium cutting speed for HDPE and PP, around 21.500 to 25.000rpm) (Slow cutting speed for PS, 11.000rpm)
Hello @btmetz, that’s also an alternative to the table saw for straight cuts. Would you please be so kind to show me more or less which blade are you using and which are results you are getting so far?
I’ve been trying different blades this week and some works better than other but still haven’t achieved a clean clean cut. The blade “B” (mentioned few comments above) makes decent cuts for PP and HDPE but still needs to be polished after. Which I think its unavoidable even though we find the most suited blade for it.
PS it’s a little bit harder to cut and still don’t know what it’s the best way to approach it yet.
Let me know your thoughts. 🙂
hey @imuh, Good point, unfortunately hot wire, or hot knifes seems to give less than ideal cuts when cutting thick plates or at least that’s the theory. Would be really interesting to see it though. Indeed when cutting with circular saws it makes so much flakes but that could be fixed with a proper vacuuming system
Following the post I wrote the other day, I’ve been recommended that negative or 0º hook angles tend to work better. Also (for a given 25cm blade) configurations around 80 teeth seems to work best for thin plates up to 15mm. If the plate is around 20mm or superior the blade needs more space to retire the chips and that means less teeth, something around 60 teeth.
Talking about the family of blades, tungsten carbide chips blades are always recommended. But there are few types that seems to work best inside that family than others. Triple chip blades grind (TCG) are preffered (pic 1). But also I got recommended to try a variaton of that wich has two types of angled teeth (pic2).
Still have to find what is the difference between them and then try them out.
Soon I will update a final choose and the reasons behind it. Therefore I will jump into find the best blade for the jigsaw.
Hi, @btmetz. Thanks for the reply, Actually right now we are trying to find the best circular saw to cut plastic plates easy and clean. Definitely the mitter saw is not the best for cutting long straight cuts so we are going to focus only on the table saw.
Having said that, later I will post what we are doing and some results.
And yes definitely, a band saw seems to be a decent option to cut plastic as well. We’ll try to dig in as well, thanks for the comment.
Hello, @benj. Thanks for the suggestion, yes definitely water cutting is cool, but not very accessible and since we have limited options to try I’m afraid we are not going to be able to explore it much. And regarding the good parameters for the blades, from my short experience I would say that something between 50 to 70 teeth (for 200cm diammeter blade) seems to be a good number. And fast cutting speed works better for HDPE and PP while medium cutting speeds works better for PS.
Test: trying to apply a second layer out of foils
Objective: Trying to have a better understanding of how to add fine layers.
Tools: iron, PP foils, baking paper, pp plate
In order to add a layer in theory would be needed hot and pressure. So for a first test we used the iron to stick a fine layer of PP foils to a PP plate. The process is simple, ironing the foils on top of the surface using baking paper to prevent from sticking on the iron. The iron is somewhere in between 50º and 120º C having better and faster results the higher Temperatures.
– It worked pretty easilyThe aluminium shiny effect disappeared by applying heat.
– The effect could be interesting but somehow it seems easy to peel off.
– Few bubbles got trapped in the process.
– The outlook is not amazing.
– Maybe with colors would work more interestingly.
– Another improvement would be to put this foils on the plates while the sheet is still on the making. Will have to try that as well.
Test: Fine tooling of corners.
Objective: Finding the differences in the material while using router bits.
Material: PP, HDPE, PS
Tools: Manual milling machine, router bits
In order to finish the corners we wanted to try wood corner bits. The ideal way of working would be having a router table but since we don’t have it we can still try the method by using the manual milling machine. In order to have a good comparison we tried the same exercise in three different materials.
– PP worked the best
– HDPE still needs some polishing after
– PS is a bit complicated to work with, because the surface usually shines and when you cut it like this, then it became matt and it’s almost impossible to make it shine again.
– In general it works and it’s an interesting set of tools to work with.
– In general slower speeds work better than faster tooling speeds.
Test: Trying to make a T (90º) union
Objective: Test how to make a T union.
Tools: Caliper, clamps, jigsaw, chisel, hammer, drill, small circular saw, sander.
To make the T joint first I had to draw the desired shape. I had to invest a reasonable amount of time to have both parts properly done. The same problem happen again with the Jigsaw, the sides melted because of the friction. The ended result is really strong and could work very well to attach pieces in 90º.
– The amount of tools needed to make this type of union is high and the result is strong but not very good looking. Making the process slow. A CNC milling machine would solve this problem since it would be more precise and fast.
– The snapping is a really good technique since plastic works well with tolerances and keeps good pressure. Very tight.
Test: Trying to hammer an HDPE beam inside PP plates.
Objective: Test how strong is to join two parts joined by pression.
Material: PP & HDPE
Tools: vertical Drill, HDPE beam, hammer, clamps.
I tried to smash a piece of HDPE into two plates of PP in order to tight them together. The hole is slightly smaller than the piece so I made a cone out of the beam by polishing it carefully. Then I found a stable surface where I could start hammering it in. It worked out but I accidentally broke the second plate.
– HDPE is strong enough to resist the hits and fit inside the soft PP.
– Good base is required to hammer it.
– Having this type of union opens the possibility to melt the HDPE since it has a lower melting temperature than PP and therefore weld it into the surface.
– Kinda time consuming but the results can be interesting.
Test: Trying to use an HDPE joinery from the bazar
Objective: Learn how strong is the HDPE joinery from the bazar.
Material: PP & HDPE
Tools: Drill, HDPE joinery, marker, clamps.
Found this Joinery on the bazar and I wanted to give it a try. I predrilled a hole and then just used the joinery to attach them together. Unfortunately I broke the joinery while tighten up the parts. Still really strong since it has a big contact surface.
– PP is kinda Soft and makes it perfect to work with bolts because it keeps the pressure really well.
– The HDPE union can brake if not used properly.
– The HDPE union works really well keeping both parts tighten because of his big contact surface.
Test: Trying to screw in PP sheets
Objective: Find how the material behaves when screw in.
Tools: measuring tape, hammer, marker, screwdriver + drilling tool
In order to attach two plates I wanted to test the crews as it is a basic joinery technique. I tried three different distances from the edge (12mm, 8mm and 5mm). Just by screwing directly into the material, the 8mm and the 5mm test are not recomendable. But for the 12mm worked well. In order to avoid cracks I did a second test with preholes on it. This time it worked much better. 12mm – ok, 8mm – ok, 5mm – cracked a bit.
– Screwing on PP (which is kinda soft) is relatively easy.
– And then you have the marks in the inside hole.
– Screwing directly near the corners is not recommended.
– Prehole first is recommended.
– The union is really strong.
Test: Trying to achieve a transparent PS sheet
Objective: Trying to make a transparent sheet
Machine: Hot press
Tools: 800 x 500 x 10mm Frame
We tried to put shredded CD cases in the hot press to see the result, unfortunately it went not fully transparent because most of the plate inner structure ended up being amorf. I don’t know exactly the good parameters to make it. We put 220º on the press for one hour, and when the temperature was more or less there we put inside the frame and we fill it with flakes. We distributed the plastic evenly and left one mountain in the middle and 4 small ones near by the corners. After 1 more hour of compression we turned off the machine. and at the following day we had the result. We noticed that maybe it was too much time with the heating on since few yellow spots due to burning plastic appeared. see pics below.
– Not fully transparent, still need iteration in terms of Tº, timing and pressure (maybe?)
– Less than one hour needed since it was slightly burnt.
– Still some wrinkles characteristic from the hot press (teflon sheets).
– The frame deformed a little bit in the middle because of the pressure the ended result is not a perfect rectangle but a little bit rounded sides.
@shhigg Yes indeed, making the machines easy to make and replicable is one of the objectives. But also getting good quality products from it is a must. We are aware of the problems that come along making the actual machines and we are also working on that.
But take in mind that for the next generation of machines we want to prioritize quality since it’s been demanded from the community in order to be able to produce valuable products. And for that a more engineering background is going to be needed. So if people don’t have it would be a matter of finding the right partners to work with. Also considering that good quality products are going to be achievable a bigger investment is justified.
Anyway thank you very much for your comment, let me know your thoughts.
HEllo @maltiti, here you can find the post where Mark explains his full process while mking that machine. And during the upcoming months he is going to work improving that machine in different topics. 🙂
Test: Trying to cut circles out of PP and HDPE
Objective: Apply wood hole saw to plastic
Material: PP & HDPE
Tools: Hole saw, drilling machine
In order to do holes I tried a regular wood hole saw, and it was relatively easy to cut on both but unfortunately It leaves marks on the sides due to the tool. While cutting, the machine gets really messy. Also the tool gets hot really easy and little deformations could appear, some flakes got welded to the surface. And that took a while to clean afterwards.
– The tool is not the correct one, too many imperfections on the process.
– Will have to find a bettter one.
– HDPE worked better than PP (I think because it’s stronger)
Test: Trying to cut PS with the Jigsaw
Objective: Trying to find the best cutting method.
Tools: Pencil, Jigsaw, Handsaw,
PS is very interesting because it could be transparent and it’s very rigid. What makes it different from PP and HDPE. However it’s tougher to cut, and very fragile. The process itself it’s been straight forward, mark where to cut, and start cutting. Seems easy, but the reality is that was hard as F to go from one side to the other and unfortunately nothing happened. The blade melted both sides of the plate so they got welded immediately after. I used a wood blade that’s why.
– When you try to cut with the Jigsaw the plastic melts by friction and the cut is imprecise.
– Too much friction on the walls of the cut ended up welding the parts together again.
– When trying to use the hammer to detach both parts PS brakes.
– Best blade or machine or technique has to be found to cut PS.
Test: Trying to cut multiple sheets at once.
Objective: Speed up the cutting process
Tools: Caliper, pencil, clamps, Jigsaw, sanding machine, chisel and hammer.
In order to speed the process we wanted to try to make an inner cut over four sheets of PP at once. First we clamp them all together. Then we sand the sides in order to have them all equal. After that we clamp it to the table. Then we made 4 cuts with the jigsaw. And finished the cut with a chisel and a hammer.
– When you try to cut it with the Jigsaw the plastic melts by friction and the cut is imprecise.
– After cutting the 4 pieces just became a block and we had to separate them.
– The chisel is useful but pretty fragile when working with PP.
– After the second piece the cut is not in the right place anymore.
– Bad idea in general to cut with the jigsaw 4 plates at once. Table saw would be more ideal.
Test: Trying to cut PP with the Mitter saw
Objective: Cut one sheet into small beams
Tools: Caliper, pencil, clamps, mitter saw, sanding machine.
This is a very straight forward test of how does the Jigsaw work with PP. For this test we are going to use a regular wood saw. The first thing I noticed is that you can easily tell by the side of the samples that the end result is too rough and needs to be polished. Through iteration I discovered that the smoother you make the cuts the cleaner it gets the result. But still needs to be polished because of the saw.
The saw will need to be cleaned after few cuts since it gets super dirty after every cut.The jigsaw is not the best for long cuts. That’s not the purpose of this machine.The smoother you make the cut the cleaner it gets. Preferably by one cut.