Perez Posted May 28, 2013 Report Share Posted May 28, 2013 Maybe a little of topic, but i know from a trusty source that Samuel aka Rockman put the pads on the microwave until they get the hardness he was searching for. Weird, but kinda workout, because the blue Rockpads are damn good! Quote Link to comment Share on other sites More sharing options...
FamilyBiker Posted May 28, 2013 Author Report Share Posted May 28, 2013 wouldnt that melt the pads? Quote Link to comment Share on other sites More sharing options...
bing Posted May 28, 2013 Report Share Posted May 28, 2013 No, because in small doses the heating up effect will cure the rubber. Its how we cure the glue roller at work, by heating it up in stages, 10 degrees at a time over a 12 hour period, then cool it down the same way Quote Link to comment Share on other sites More sharing options...
PaRtZ Posted May 28, 2013 Report Share Posted May 28, 2013 No, because in small doses the heating up effect will cure the rubber. Its how we cure the glue roller at work, by heating it up in stages, 10 degrees at a time over a 12 hour period, then cool it down the same way This is polymerisation or polymer cross-linking and it does as you say cure the plastic. But because Polyeurathene is a thermosetting plastic (it crosslinks) this curing is a one way process, if you go too far you cant break the bonds (i.e. melt it) Has anyone actually tried to melt a brake pad into a pool of liquid? Thermoplastic polyuerathane also exists apparently, but wouldnt have thought its pad material material With regards to thew liquid moulding approach, someone mentioned early on about the inclusion of plasticisizers into the compound. This COULD be worth looking into to improve performance but might end up being costly. You can also try and see if you can orientate polymer chains along the pad length to improve shear stresses? Quote Link to comment Share on other sites More sharing options...
FamilyBiker Posted May 28, 2013 Author Report Share Posted May 28, 2013 the filling material i´ll use is a fireproofing agent on the base of aluminium hydroxide,it hardens the pu up by 2 to 10 shore degrees,giving me the opportunity to get shore grades from 80a to 90a,and it reduces heat buildup in the pad. i´ll also get some red pigment,so the final colour will be like aubergine or so,the pigment is also hardening up by 2 degrees,so there are many mixtures to play with... Quote Link to comment Share on other sites More sharing options...
FamilyBiker Posted May 30, 2013 Author Report Share Posted May 30, 2013 (edited) bit of an update here,taken measurement of a viz pad i removed from the plastic backing with the oven method. if anyone needs the measurements: dont know if its worth the money,but to get the mould 3d-printed would cost me 60euros,very tempted... would be cool if someone could do a solidworks or freecad file for that,i´m too stupid for using that software lol edited for spelling correction Edited May 30, 2013 by FamilyBiker Quote Link to comment Share on other sites More sharing options...
FamilyBiker Posted May 31, 2013 Author Report Share Posted May 31, 2013 (edited) --- Edited June 2, 2013 by FamilyBiker Quote Link to comment Share on other sites More sharing options...
crilin202 Posted May 31, 2013 Report Share Posted May 31, 2013 would be cool if someone could do a solidworks or freecad file for that,i´m too stupid for using that software lol I'll help you out with the solidworks model when I have some time. I don't think it'll be this weekend though... Quote Link to comment Share on other sites More sharing options...
FamilyBiker Posted May 31, 2013 Author Report Share Posted May 31, 2013 (edited) very cool,thanks! would it be too much to ask for a negative of the shape,too? with that a 3d printer could print the mould.i´d like to make a mould that has holes in that shape with the funktion of that icecube maker things,to fill it up with resin. it wouldnt need the circle hole on the underside,just a straight 11mm wide distance like heatsink pads have would do the job... Edited May 31, 2013 by FamilyBiker Quote Link to comment Share on other sites More sharing options...
trials hoe Posted June 2, 2013 Report Share Posted June 2, 2013 snip have you measured all the recess area of the backing/pad? i'm looking into getting some of the 2 part mix stuff, making a mould but i measured my pads/backing at 7mm (internal with of recess of backing and external of the pad) then looked on tarty and they say 8mm. i don't have any other backings to measure for reference and don't want to make pads that'll only fit my backings, just unsure if i have odd pads and backings (unsure what they are got them from the f/s on here, will attach a pic if someone could identify them for definite that would be cool ) also i worked out the area:weight of my pad and the 250g (x2) mix i'm going to get about 70 pads from the lot with 10mm of material (by my maths*, so it'll probably be way off ) don't want to make X amount of pads the wrong size so if anyone can clear up the size (width) flap i've found my self in, that'd be cool...then i can crack on making a mould Quote Link to comment Share on other sites More sharing options...
FamilyBiker Posted June 2, 2013 Author Report Share Posted June 2, 2013 if we make them,say 48 x 8 x 4,7mm it´d fit any backing with sanding material off,always better than a pad thats too small lol the middle cutout is 11mm,if we make it 10 its cuttable to 11(power pad backings)and fitting to echo,tnn and so on. i played mindgames of getting some modelling clay and press the refill into it to make a negative,then bake it to harden it. the 3d printed version would be more pimped though... Quote Link to comment Share on other sites More sharing options...
trials hoe Posted June 2, 2013 Report Share Posted June 2, 2013 yeah, make them for the biggest fit backings, then cut them down for others sounds like the right approach i've measured everything up, i plan on making a negative out of wood, then make a mould from that with some of the 2 part mix stuff, then use that as the mould and will still have an original negative to make another from if i ruin it...which probably will haha not sure if i should go for a harder or softer compound mix than the pad material for the mould it's self yet though. Quote Link to comment Share on other sites More sharing options...
FamilyBiker Posted June 2, 2013 Author Report Share Posted June 2, 2013 (edited) i think harder is better,try epoxy resin for the mould.if its the same material the hardener will probably remelt the surface of your mould. other thing i thought of was tempering the finished pads for 4 hours at 80°C in an oven,big companies do that in cases where abrasion applies.(thats probably that microwave process mentioned earlier) if they shrink a few 10th of a mm during that its better they were too big before lol Edited June 2, 2013 by FamilyBiker Quote Link to comment Share on other sites More sharing options...
trials hoe Posted June 2, 2013 Report Share Posted June 2, 2013 might have access to a vacum forming machine (or whatever they're called) think that might be a better option. the e-crap listing for the mix i'm looking at says "30 min @ 70*C" and "60 min @ room temp" so 4 hours might be a bit too long haha unless it differs form each companies ingredients if your directions say different Quote Link to comment Share on other sites More sharing options...
FamilyBiker Posted June 2, 2013 Author Report Share Posted June 2, 2013 i think what you mean is the "pot"-time until it gets to hard to work with,what i mean is a heat treating after 3 days of hardening to get the pu polimerized. it stiffens up the material and adds abrasion resistance. with the heat filler i´ll use it´ll pretty much exactly 87 shore a when the pads are finished. thats hard enough for medium grinds but works until the grind has died imo for example smooth rim pads are 78-83 shore a,ground rim pads are like 90. Quote Link to comment Share on other sites More sharing options...
trials hoe Posted June 2, 2013 Report Share Posted June 2, 2013 yeah, closest i come to using mixed stuff is with glue so i'm assuming the 'demould time' is like saying touch dry with paint. looking to run on a smooth rim setup, not the biggest fan of grinds myself. just picked 70 as a 'that sounds about right' guide haha how many are having a go at this with what compounds so far? Quote Link to comment Share on other sites More sharing options...
FamilyBiker Posted June 2, 2013 Author Report Share Posted June 2, 2013 (edited) 70 will be like a pencil eraser,add filler to go to about 75a,then the wear time will be better,too. i think so far its me(waiting for materials) bing and mrstix. Edited June 2, 2013 by FamilyBiker Quote Link to comment Share on other sites More sharing options...
Blake Posted June 2, 2013 Report Share Posted June 2, 2013 yeah I still need money to order my compound :'( Quote Link to comment Share on other sites More sharing options...
FamilyBiker Posted June 3, 2013 Author Report Share Posted June 3, 2013 (edited) yeah I still need money to order my compound :'( that stuff is more expensive than i´ve thought,too. paid 37 euros for 500ml(when mixed) + 100g filler but its cool to have the possibility to change shore grade with fillers and tempering,having between 78-90a isnt a bad thing,lots of compounds edit:what glue is best to fit pads to backings? i really dont trust cyanoacrylates,from a technical view you wouldnt use something hard to glue something soft... maybe 2K-adhesives on epoxy-base? Edited June 3, 2013 by FamilyBiker Quote Link to comment Share on other sites More sharing options...
bing Posted June 3, 2013 Report Share Posted June 3, 2013 I'm going for ready made polyeruthane, from a rubber and plastic supplier my old fella uses through the print trade. Plus I'm back I'm back at work now, so I can see what they have knocking about in the stores, I may even be able to get a two piece ally mould made 1 Quote Link to comment Share on other sites More sharing options...
trials hoe Posted June 8, 2013 Report Share Posted June 8, 2013 (edited) how much further is everyone else? have got the pu mix stuff now after a trip to the sorting office (always grim)... also made a blank from plaster and found it was way to brittle to be used as a mould so that's now out of the window, was thinking of making it out of wood instead an giving it a coat of that funky laquor that nothing can stick too...if only i could remember what it was called, anyone else remember it's name and where i can get it or something similar? if it helps i saw it in a video where they coated a multitude of random objects with it then put green liquid on it, was a fascinating watch so someone must know what i'm on about Edited June 8, 2013 by trials hoe Quote Link to comment Share on other sites More sharing options...
shercofray Posted June 8, 2013 Report Share Posted June 8, 2013 how much further is everyone else? have got the pu mix stuff now after a trip to the sorting office (always grim)... also made a blank from plaster and found it was way to brittle to be used as a mould so that's now out of the window, was thinking of making it out of wood instead an giving it a coat of that funky laquor that nothing can stick too...if only i could remember what it was called, anyone else remember it's name and where i can get it or something similar? if it helps i saw it in a video where they coated a multitude of random objects with it then put green liquid on it, was a fascinating watch so someone must know what i'm on about YouTube ultra ever dry. But I've not researched whether it's available to the public/if they're still in the R&D process. It's an American company though. Quote Link to comment Share on other sites More sharing options...
FamilyBiker Posted June 8, 2013 Author Report Share Posted June 8, 2013 (edited) waiting for my resin,its from overseas... 3 weeks now,does come by ship as it seems lol edit:seen youve gone for 70a,thats really soft,thought about a filling agent ? you could just wax the wooden mould Edited June 8, 2013 by FamilyBiker Quote Link to comment Share on other sites More sharing options...
trials hoe Posted June 8, 2013 Report Share Posted June 8, 2013 YouTube ultra ever dry. But I've not researched whether it's available to the public/if they're still in the R&D process. It's an American company though. that's the stuff!, found it on amazon...damn expensive! looks like there are a few similar things about that behave like it too (super hydrophobic coatings), was looking to coat the mould with something that would act as a release agent at the same time as fixing the porous nature of a wooden mould i was planning of making...just not at that price haha reckon bee's wax would suffice? same as some use for fiberglass/carbon mould release agent, so i'm guessing it would work, don't want to have a mould with pads stuck in it i can't use haha Quote Link to comment Share on other sites More sharing options...
CurtisRider Posted June 8, 2013 Report Share Posted June 8, 2013 Beeswax would be fine, I use it loads for releasing vacuum forming moulds. Quote Link to comment Share on other sites More sharing options...
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