Grippy flex material?
I need to make some bumpers to line jaws that will hold pieces of wood, like say in a 'Longworth Chuck' as shown, used for woodturning.
I tried Fiberlogy Fiberflex 40D but the surface friction coefficient is a tad low. I need to apply quite some force to get good grip, and that is not consistent with the plastic construction designy. I make do with adhesive rubber tape now: superb friction but it looks shitty and comes off all the time.
Obviously filament material must be smooth in order to pass the extruder, but do you people have any recommendations for printable tmaterials for grippers?
RE: Grippy flex material?
You can try using colorFabb Varioshore TPU or Recreus FilaFlex Foamy. They’re both foamy TPU. More heat causes it to foam more.
There is a tradeoff between printability and flexibility. The softer/grippier the filament the harder it is to print - if you have some idea of the shore hardness required we might be able to give specific advice.
Your other option is to design a negative shape and print it as a mould with which you can cast flexible setting resins or even silicone/latex grout.
Cheerio,
RE: Grippy flex material?
You can try using colorFabb Varioshore TPU or Recreus FilaFlex Foamy. They’re both foamy TPU. More heat causes it to foam more.
Thanks. I have been looking at these but since they are also TPU I was not sure whether they have a higher surface coefficient of friction.
Also I understand the degree of foaming depends on exposure time as well as on nozzle temperature, which would make it difficult to reach a consistent hardness through the object. Reports I had told me these varioshore filaments work well, both at full-foam and at no-foam, but are difficult to control in the range between these two extremes.
This is one of those cases where it would be great to be able to buy a 10m/€5 sample rather than having to buy a full 250m/€50 spool, the remains of which may sit on my shelf for the rest of its usable life.
RE:
There is a tradeoff between printability and flexibility. The softer/grippier the filament the harder it is to print - if you have some idea of the shore hardness required we might be able to give specific advice.
Your other option is to design a negative shape and print it as a mould with which you can cast flexible setting resins or even silicone/latex grout.
Cheerio,
Thank you for your reply.
The actual shore hardness is not so important. The quest is for a high surface coefficient of friction. And, yes, the filament needs to be low-friction to pass well through the tubes and feeder. (Wild idea of coated filament or cored filament comes to mind).
Indeed the safest way forward I think is to print a negative mould with whatever filament and use silicone rubber to cast the buffers.
RE: Grippy flex material?
Hi,
By any luck have you found what you were looking for? I'm also looking for some grippy/rubbery filament to use, but don't seem to find any source on this matter.
RE: Grippy flex material?
No, not yet. The two things that are important for gripping (elastic so there's good contact area and high surface friction coefficient) simply do not go together well with feeding filament through a tube.
I tried coating the surface with a thin layer of silicone filler. It was a moderate success. Silicone filler is soft so it tends to be pressed aside when compressed on the surface. This results in a peeling force just outside the contact area, causing the bond, ever problematic with silicones, to fail. This leads to blistering and progressive failure.
Looking now at primers and other types of silicone, like silicone-NO, that claim to have better adhesion to other materials.
I looked at two-component silicone but I was advised it has very bad adhesion properties also, and many 3D print filaments contain substances that inhibit curing.
So, still looking.
RE: Grippy flex material?
NeedItMakeIt tried making a machine belt with TPU. His conclusion is that TPU as a material simply isn't grippy enough, but he didn't do that of an extensive test.
RE: Grippy flex material?
I can't speak to the original question, but regarding the above comment I'd TPU as a belt... I've purchased extruded TPU in the appropriate diameter to make a custom length belt for a set of cycling rollers years ago. I cut and spliced it using a hot blade to join the ends. I didn't put it to an intense test (it was briefly used by my son for a small road bike), but at least in that one application, there was adequate material friction. Of course that wasn't 3d printed material, but it presumably was fairly similar in characteristics.
-J
RE: Grippy flex material?
Hi,
I've just gotten a spool of ColorFabb varioshore to try to have something grippy, I thought I would share my experiance. It's easier to print than an other TPU I have used in the past and the finish is not grippy but some what of a soft touch instead of the very hard touch of the last TPU I tried. From my understanding this wouldn't suite your needs as you want something very grippy.
RE: Grippy flex material?
Thank you for responding. You are right about the Varioshore. I have tried it. It is great stuff but it is not grippy.
Very soft rubbers are hard to print. Better to print a mould in PLA and cast a suitable latex.
Cheeri,
RE: Grippy flex material?
Yes, exploring that route now.
I have been looking at 2-component silicones: they have perfect high CoF, but I was told that the type of silicone that cures to higher hardness will not cure in contact with filament material. It thus would leave a sticky surface that leaves traces of silicones on the other surface, which will affect later finish. The cast will need to have some thickness to fill and so I need rubber with high Shore number to ensure the firmness of the grip. I could print the positive shape, cast that in plaster and then cast the silicone in the plaster mould. I'm not that desparate yet. It also does not help the stuff is not inexpensive and available only in large cans while I need it for pieces less than 1 cm3 in size.
Anyway, thanks for the advice. I will soldier on.
First find a suitable material - also explore meltables and grouts - then work backwards from that to suitable mould materials and decide what you need to print. For example; I have cast lead in sacrificial, single use, plaster moulds that were themselves cast in printed PLA mould moulds.
Cheerio,
RE: Grippy flex material?
Might be a stupid question, but have you tried to modify the final result after the print? Like by puting some alcohol on it or some other chemical that might degrade the finish? Or have you tried to use the "fuzzy skin" finish with a TPU to make if somewhat more grippy?
I thought about this because I've used the Varioshure TPU for a mechanical keyboard case (as a layer of foam here and there to make it more silent) and I've also used it for some knobs. At first I tried with PETG, but the result was too slippery to use with one finger. So I tried with the Varioshure, which also was to slippery at first, but adding the "fuzzy skin" in PrusaSlicer made just "grippy" enough for me. Let's be honnest, it's not grippy like rubber or anything, but just a tad more that makes it usable.